Chest Pain / Angina Pectoris: Difference between revisions

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In 1772 doctor William Heberden first described angina pectoris, he wrote: ''“They who are afflicted with it are seized, while they are walking (more especially if it be up hill), with a painful and most disagreeable sensation in the breast, which seems as if it would extinguish life if it were to increase or to continue, but the moment the patient stands still all this uneasiness vanishes”''.<cite>Davies</cite>
[[File:Heart_coronary_artery.jpg|thumb|400px|An epicardial coronary artery with a atherosclerotic narrowing]]
Stable angina (pectoris) is a clinical syndrome characterized by discomfort in the chest, jaw, shoulder, back, or arms, typically elicited by exertion or emotional stress and relieved
by rest or nitroglycerin. It can be attributed to myocardial ischemia which is most commonly caused by atherosclerotic coronary artery disease or aortic valve stenosis.  


Three major coronary arteries provide the heart with oxygenated blood, the right coronary artery (RCA), the left coronary artery (LCA) and the circumflex artery (Cx). When the coronary arteries are affected by atherosclerosis and the lumen of the coronary arteries narrows, the heart receives less oxygenated blood and becomes hypoxic, which results in angina pectoris.  
Three major coronary arteries supply the heart with oxygenated blood, the right coronary artery (RCA), the left anterior descending coronary artery (LAD) and the left circumflex artery (LCx). When the coronary arteries are affected by atherosclerosis and the lumen of the coronary arteries progressively narrow, a dysbalance between myocardial oxygen supply and myocardial oxygen consumption may occur, causing myocardial ischemia.
In stable angina this imbalance mainly occurs when oxygen demand increases due to exercise, increased heart rate, contractility or wall stress.


Complete history and physical examination are essential to determine angina pectoris as diagnosis and to exclude other causes of chest pain, such as aorta dissection, arrhythmias, pulmonary embolism, pneumonia, heartburn, hyperventilation or musculoskeletal problems.<cite>Sampson</cite>
A complete history and physical examination are essential to support the diagnosis (stable) angina pectoris and to exclude other (acute) causes of chest pain such as an acute coronary syndrome, aortic dissection, arrhythmias, pulmonary embolism, (tension) pneumothorax or pneumonia, gastroesophageal reflux or spams, hyperventilation or musculoskeletal pain. <Cite>REFNAME2</Cite> In addition, laboratory tests and specific cardiac investigations are often necessary.


===History===
==History==
Patients often experience angina pectoris as if a elephant stands on their chest. Because the heart itself has very few nerves the pain can be sensible elsewhere in the upper body, mainly arms, jaw and/or back.<cite>Foreman</cite> Some patients only complain about stomach ache so the presentation can be very a specific.<cite>Canto</cite>,<cite>Pope</cite>
[[File:Chest_pain_areas.svg|thumb|Typical chest pain is retrosternal. Pain may radiate to the arms, jaw, and / or back.]]
Patients often describe angina pectoris as pressure, tightness, or heaviness located centrally in the chest, and sometimes as strangling, constricting, or burning. The pain often radiates elsewhere in the upper body, mainly arms, jaw and/or back. <Cite>REFNAME3</Cite> Some patients only complain about abdominal pain so the presentation can be aspecific. <Cite>REFNAME4</Cite>, <Cite>REFNAME5</Cite>


Angina pectoris however has some characteristics that can help to differentiate between other causes of (chest) pain. Angina pectoris is gradual in onset and offset, with the intensity increasing and decreasing over several minutes. The pain is constant and does not change with respiration or position. If patients had angina pectoris before they will recognize the pain immediately.<cite>Constant</cite>
Angina pectoris however has some characteristics that can help to differentiate between other causes of (chest) pain. Angina pectoris is usually is brief and gradual in onset and offset, with the intensity increasing and decreasing over several minutes. The pain does not change with respiration or position. If patients had angina pectoris previously they are often able to recognize the pain immediately.  <Cite>REFNAME6</Cite>
Angina pectoris is a manifestation of arterial insufficiency and usually occurs with increasing oxygen demand such as during exercise. As soon as the demand is decreased (by stopping the exercise for example) complaints usually disappears within a few minutes.
Another way to relieve pain is by administration of nitro-glycerine. Nitro-glycerine spray is a vasodilator which reduces venous return to the heart and therefore decreases the workload and therefore oxygen demand. It also dilates the coronary arteries and increases coronary blood flow. <Cite>REFNAME7</Cite> The response to nitro-glycerine is however not specific for angina pectoris, a similar response may be seen with oesophageal spasm or other gastrointestinal problems because nitro-glycerine relaxes smooth muscle tissue. <Cite>REFNAME8</Cite>


Angina pectoris usually occurs during exercise when the demand for oxygenated blood increases. Coronary arteries with a narrowed lumen can not meet the demand of oxygenated blood during exercise. As soon as the exercise is aborted angina pectoris decreases. This is called stable angina pectoris.
Depending on the characteristics, chest pain can be identified as typical angina, atypical angina or non-cardiac chest pain, see Table 1.


Unstable angina pectoris means angina pectoris at rest which consists less than two months. Over time the angina pectoris develops to more often, severe and prolonged, so that symptoms are to occur at less and less effort than before.<cite>Anderson</cite>
{| class="wikitable" border="1" width="600px"
|-
Stable angina pectoris responds to nitro-glycerine spray, unstable angina pectoris does not.
! align="center" colspan="2" | Table 1. Clinical classification of chest pain <Cite>REFNAME17</Cite>
Nitro-glycerine spray is a venodilator which reduces venous return to the heart and therefore decreases the workload and therefore oxygen demand. It also vasodilates the coronary arteries and increases coronary blood flow.<cite>Abrams</cite>
|-
|valign="top" align="left"|Typical angina (definite)
|Meets three of the following characteristics:
*Substernal chest discomfort of characteristic quality and duration
*Provoked by exertion or emotional stress
*Relieved by rest and/or nitroglycerine
|-
| valign="top"|Atypical angina (probable)
|Meets two of these characteristics
|-
| valign="top"|Non-cardiac chest pain
|Meets one or none of the characteristics
|}


Nitro-glycerine is however not specific for angina pectoris, a similar response may be seen with oesophageal spasm or other gastrointestinal problems because nitro-glycerine also relaxes smooth muscle.<cite>Henrikson</cite>
The classification of chest pain in combination with age and sex is helpful in estimating the pretest likelihood of angiographically significant coronary artery disease, see Table 2.  


During angina pectoris so called vegetative symptoms can occur, this includes sweating, nausea, paleface, anxiety and agitation. The idea is that the vegetative nerve system is more active in a reaction to stress.<cite>Antman</cite>
{| class="wikitable" border="1" width="600px"
|-
! align="left" colspan = "7" | Table 2. Clinical pre-test probabilities <sup>a</sup> in patients with stable chest pain symptoms. <Cite>REFNAME20</Cite>
|-
| align="center"|
| align="center" colspan="2" bgcolor="#FFFFFF" | <b>Typical angina</b>
| align="center" colspan="2" bgcolor="#FFFFFF" | <b>Atypical angina</b>
| align="center" colspan="2" bgcolor="#FFFFFF" | <b>Non-anginal pain</b>
|-
! Age
! Men
! Women
! Men
! Women
! Men
! Women
|-
! 30-39
| align="center" bgcolor="#F0F8FF" | 59
| align="center" bgcolor="#F0F8FF" | 28
| align="center" bgcolor="#F0F8FF" | 29
| align="center" bgcolor="#FFFFFF" | 10
| align="center" bgcolor="#F0F8FF" | 18
| align="center" bgcolor="#FFFFFF" | 5
|-
! 40-49
| align="center" bgcolor="#FFCCCC" | 69
| align="center" bgcolor="#F0F8FF" | 37
| align="center" bgcolor="#F0F8FF" | 38
| align="center" bgcolor="#FFFFFF" | 14
| align="center" bgcolor="#F0F8FF" | 25
| align="center" bgcolor="#FFFFFF" | 8
|-
! 50-59
| align="center" bgcolor="#FFCCCC" | 77
| align="center" bgcolor="#F0F8FF" | 47
| align="center" bgcolor="#F0F8FF" | 49
| align="center" bgcolor="#F0F8FF" | 20
| align="center" bgcolor="#F0F8FF" | 34
| align="center" bgcolor="#FFFFFF" | 12
|-
! 60-69
| align="center" bgcolor="#FFCCCC" | 84
| align="center" bgcolor="#F0F8FF" | 58
| align="center" bgcolor="#F0F8FF" | 59
| align="center" bgcolor="#F0F8FF" | 28
| align="center" bgcolor="#F0F8FF" | 44
| align="center" bgcolor="#F0F8FF" | 17
|-
! 70-79
| align="center" bgcolor="#FF69B4" | 89
| align="center" bgcolor="#FFCCCC" | 68
| align="center" bgcolor="#FFCCCC" | 69
| align="center" bgcolor="#F0F8FF" | 37
| align="center" bgcolor="#F0F8FF" | 54
| align="center" bgcolor="#F0F8FF" | 24
|-
! >80
| align="center" bgcolor="#FF69B4" | 93
| align="center" bgcolor="#FFCCCC" | 76
| align="center" bgcolor="#FFCCCC" | 78
| align="center" bgcolor="#F0F8FF" | 47
| align="center" bgcolor="#F0F8FF" | 65
| align="center" bgcolor="#F0F8FF" | 32
|-
| colspan = "7" bgcolor="#FFFFFF"|
|-
! colspan = "7" | ECG = electrocardiogram; PTP = pre-test probability; SCAD = stable coronary artery disease.
|-
| colspan = "7" bgcolor="#FFFFFF" | <b><sup>a</sup></b> Probabilities of obstructive coronary disease shown reflect the estimates for patients aged 35, 45, 55, 65, 75 and 85 years.
*Groups in <i>white boxes</i> have a PTP <15% and hence can be managed without further testing.
*Groups in <i>blue boxes</i> have a PTP of 15–65%. They could have an exercise ECG if feasible as the initial test. However, if local expertise and availability permit a non-invasive imaging based test for ischaemia this would be preferable given the superior diagnostic capabilities of such tests. In young patients radiation issues should be considered.
*Groups in <i>light pink boxes</i> have PTPs between 66–85% and hence should have a non-invasive imaging functional test for making a diagnosis of SCAD.
*In groups in <i>dark pink boxes</i> the PTP is >85% and one can assume that SCAD is present. They need risk stratification only.
|}


===Physical Examination===
The severity of complaints can be classified according to the Canadian Cardiovascular Society as shown in Table 3
Oxygen deficiency of the heart leads to ischemia, ischemia and the discomfort the patient experiences lead to sympathetic activation of the nervous system. This is detectable during physical examination by an increase in heart rate and elevation in blood pressure.
Ischemia can also cause a temporarily impairment in myocardial function, on auscultation you could hear a paradoxically split second heart sound, a third or fourth heart sound and a mitral regurgitation murmur. All these findings however disappear with resolution of the ischemia. Up to date: Pathophysiology and clinical presentation of ischemic chest pain, geen bronvermelding.


===ECG===
{| class="wikitable" border="1" width="600px"
[[File:TBC00003.jpg|200px|thumb|right|]]
|-
! colspan="2" | Table 3. Classification of angina severity according to the Canadian Cardiovascular Society
|-
! width="100"| ''Class''
| ''Level of Symptoms''
|-
! valign="top"| Class I
| 'Ordinary activity does not cause angina'
Angina with strenuous or rapid or prolonged exertion only
|-
! valign="top"| Class II
| 'Slight limitation of ordinary activity'
Angina on walking or climbing stairs rapidly, walking uphill or exertion after meals, in cold weather, when under emotional stress, or only during the first few hours after awakening
|-
! valign="top"| Class III
| 'Marked limitation of ordinary physical activity'
Angina on walking one or two blocks on the level or one flight of stairs at a normal pace under normal conditions
|-
! valign="top"| Class IV
| 'Inability to carry out physical activity without discomfort' or 'angina at rest'
|}


The electrocardiogram (ECG) is an easy and important tool to differentiate between myocardial ischemia and infarction. Patients with unstable angina pectoris will show abnormalities on the ECG at rest, in particular ST depression.
During angina pectoris ‘vegetative’ symptoms can occur, including sweating, nausea, paleface, anxiety and agitation. This is probably caused by the autonomic nerve system in reaction to stress. <Cite>REFNAME9</Cite>
Patients with stable angina pectoris are likely to have a completely normal ECG at rest, exercise ECG testing will be necessary to show any abnormalities.<cite>Ref1</cite> During exercise ECG testing an ECG is made during cycling on a home trainer or walking on a treadmill. While exercising the oxygen demand of the heart increases, if the narrowed coronary arteries are unable to supply enough oxygenated blood, the patient develops pain on the chest and the ECG will show abnormalities.<cite>Fox</cite>


===Additional Research===
Finally, it is important to differentiate unstable angina (indicating an acute coronary syndrome or even myocardial infarction requiring urgent treatment) from stable angina. Unstable angina typically is severe, occurs without typical provocation and does not disappear with rest, and has a longer duration than stable angina. It is important to initiate prompt treatment in these patients, as described in the acute coronary syndromes chapter.
If the ECG made during exercise testing does not show any abnormalities angina pectoris becomes very unlikely. If the ECG does show abnormalities during exercise testing additional research needs to be done.<cite>Fox</cite> Depending on the hospital one of the below standing research will be done.
# Exercise echocardiography means that an echocardiography is made directly after exercise. The poorly perfused parts of the heart will show less activity.<cite>Amanullah</cite>
# Myocardium Perfusion Scintigraphy (MPS) is able to show the perfusion of the heart during exercise and at rest.<cite>Brown</cite>
# MRI can be done with vasodilatory dobutamine or stimulating adenosine to assess how the heart behaves during exercise.<cite>Kwong</cite>
The findings on stress testing can be used to determine the choice between medical therapy and revascularization in patients with stable angina. Coronary angiography is recommended based upon symptoms, left ventricular function, and estimated risk by stress testing.<cite>Fraker</cite>


'''Table 1'''
==Physical Examination==
There are no specific signs in angina pectoris. Physical examination of a patient with (suspected) angina pectoris is important to assess the presence of hypertension,
valvular heart disease (in particular aortic valve stenosis) or hypertrophic obstructive cardiomyopathy. It should include the body-mass index, evidence of non-coronary vascular disease which may be asymptomatic and other signs of co-morbid conditions. E.g.: absence of palpable pulsations in the dorsal foot artery is associated with an 8 fold increase in the likelihood of coronary artery disease.


==Coronary Angiography==
==Electrocardiogram (ECG)==
In patients with unstable angina pectoris early coronary angiography possibly followed by revascularization is usually performed within 4 to 24 hours of admission in the hospital. In most clinical trials this strategy has shown a reduction in the incidence of death or nonfatal myocardial infraction.<cite>Anderson</cite>
The electrocardiogram (ECG) is an important tool to differentiate between unstable angina (acute coronary syndrome) and stable angina in addition to the patient’s history. Patients with unstable angina pectoris are likely to show abnormalities on the ECG at rest, in particular ST-segment deviations.  
Although a resting ECG may show signs of coronary artery disease such as pathological Q-waves indicating a previous MI or other abnormalities, many patients with stable angina pectoris have a normal ECG at rest. Therefore exercise ECG testing may be necessary to show signs of myocardial ischemia. <Cite>REFNAME10</Cite>


A CAG is an X ray examination of the coronary arteries, a catheter is inserted into the femoral artery or into the radial artery. The tip of the catheter is positioned at the beginning of the coronary arteries and contrast fluid is injected. Contrast is visible by X ray and the images that are obtained are called angiograms.
'''Exercise ECG testing''' is performed with gradually increasing intensity on a treadmill or a bicycle ergo-meter. Exercise increases the oxygen demand of the heart, potentially revealing myocardial ischemia by the occurrence of ST-segment depression on the ECG. <Cite>REFNAME11</Cite>


On an angiogram stenoses will be visible, if the stenosis is significant coronary intervention will take place. Ideally this happens immediately following the CAG but not all hospitals that are entitled to carry out CAG are qualified to perform percutaneous coronary intervention (PCI).  
==Laboratory Testing==
Laboratory testing in the setting of angina pectoris can be useful to differentiate between different causes of the pain, including an acute coronary syndrome in which there will be elevation of the marker of myocardial necrosis. Anaemia should be ruled out as a cause of ischemia. Renal function is important for pharmacological therapy. Moreover, it might assist in establishing a cardiovascular risk profile.


==Treatment==
==Stress Testing in Combination with Imaging==
===Medication===
Some patients are unable to perform physical exercise. Furthermore, in patients with resting ECG abnormalities the exercise ECG is associated with low sensitivity and specificity.  
In patients with stable angina pectoris percutaneous coronary intervention does not offer any benefit in terms of death, myocardial infarction, or the need for subsequent revascularization compared with conservative medical treatment.<cite>Katritsis</cite>


Initial treatment of stable angina pectoris therefore focuses on medication to keep the workload of the heart as low as possible. β blockers lower heart rate and blood pressure, this decreases the oxygen demand of the heart.<cite>Garcia</cite> Nitrates dilatate the coronary arteries so the heart receives more oxygenated blood.<cite>Abrams</cite> Anticoagulants (aspirin) to reduce the risk of development of a thrombus in the coronary arteries.<cite>Hennekens</cite>
{| class="wikitable" border="1" width="600px"
 
|-
Apart from starting medication the patient needs to minimize any present risk factors like smoking, overweight and drinking alcohol. ''See chronic coronary diseases''.
|colspan = "7" | <b>Table 4. Characteristics of tests commonly used to diagnose the presence of coronary artery disease. <Cite>REFNAME20</Cite></b>
 
===Percutaneous Coronary Intervention===
The procedure of PCI is similar to a CAG, except this time a catheter with an inflatable balloon will be brought at the site of the stenosis. Inflation of the balloon within the coronary artery will crush the atherosclerosis and eliminate the stenosis. To prevent that the effect of the balloon is only temporarily a stent is often positioned at the site of the stenosis.
 
===Coronary Artery Bypass Graft===
There are circumstances in which CABG should be performed.
CABG does not eliminate the stenosis like PCI does. Using the internal thoracic arteries or the saphenous veins from the legs a bypass is made around the stenosis. The bypass originates from the aorta and terminates directly after the stenosis. Thereby restoring the blood supply to the ramifications.
 
=Myocardial Infarction=
 
In 2006 425.425 people died from a heart attack, 1.255.000 new and recurrent coronary attacks took place, about 34% died, 17.600.000 victims of angina, heart attack and other forms of coronary heart disease are still living.
 
These numbers only account for the United States.
 
===Pathofysiology===
A heart attack or myocardial infarction (MI) is an acute presentation of a process that has been going on much longer. The process responsible is atherosclerosis. Atherosclerosis is a chronic disease of the arteries in which artery walls thicken by deposition of fatty materials such as cholesterol. The result over decades are plaques, which can narrow the lumen of the arteries significantly and progressively causing symptoms as angina pectoris. Plaques can also suddenly rupture, trigger a cascade which results in a thrombus and thereby cause myocardial infarction.<cite>Davies3</cite>
 
===History===
Classic presentation of a myocardial infarction is acute chest pain which lasts longer than a few minutes.<cite>Swap</cite> The pain does not decrease at rest and is only temporarily relieved with nitroglycerin. Common accompanying symptoms are radiating pain to shoulder, arm, back and/or jaw.<cite>Foreman</cite> Shortness of breath can occur, as well as sweating, fainting, nausea and vomiting, so called vegetative symptoms. Some patients not really complain about chest pain but more about abdominal pain so as with angina pectoris the presentation can be very a specific.<cite>Canto</cite>,<cite>Pope</cite>
 
It is important to complete the history with information about past history (prior history of ischemic events or vascular disease), risk factors for cardiovascular disease (o.a. smoking, hypertension, hyperlipidemia, obesity) and family history (direct family with myocardial infarction and/or sudden cardiac death).
 
Signs of heart failure such as orthopnea (not able to sleep without a pillow), progressive dyspnoea and oedematous ankles are indicative for the extent of the problem.<cite>Antman</cite>
 
A suspected myocardial infarction should be rapidly evaluated to initiate appropriate therapy.
 
===Physical Examination===
On physical examination evidence of systemic hypoperfusion can be found such as hypotension, tachycardia, impaired cognition, pale and ashen skin.<cite>Antman</cite>
 
If during auscultation pulmonary crackles are heard and pitting oedema of the ankles is seen heart failure is complicating the myocardial infarction.
 
History and physical examination are helpful to determine myocardial infarction as diagnosis and to exclude other causes of chest pain, such as angina pectoris, aorta dissection, arrhythmias, pulmonary embolism, pneumonia, heartburn, hyperventilation or musculoskeletal problems.<cite>Antman</cite>
 
===Electrocardiogram===
An electrocardiogram (ECG) should be made within 10 minutes of arrival in every patient with suspected myocardial infarction.<cite>Antman</cite>
An ECG is important to differentiate between myocardial ischemia and infarction:
* ST elevation in myocardial infarction
* ST depression in myocardial ischemia
 
And to differentiate between STEMI and NSTEMI:
* STEMI stands for ST elevated (>20 min) Myocardial Infarction
* NSTEMI stand for Non ST elevated Myocardial Infarction
 
It can however take 90 minutes after the onset of the symptoms to see abnormalities on the ECG. Therefore it is important to make a serial ECG, certainly if a patient has ongoing symptoms.<cite>Antman</cite>
 
An ECG is also helpful in localising the ischemia:
Anterior wall ischemia - One or more of leads V1-V6
Anteroseptal ischemia - Leads V1 to V3
Apical or lateral ischemia - Leads aVL and I, and leads V4 to V6
Inferior wall ischemia - Leads II, III, and aVF
 
===Cardiac Markers===
Cardiac markers are essential for confirming the diagnosis of infarction. Elevated CK MB and Troponin I indicate damage of the myocardium. Cardiac Troponin I concentration begins to rise two to three hours after myocardial ischemia.<cite>Macrae</cite>
It can take 4-6 hours before the CK MB concentration is elevated. The advise is to repeat the measurements after 4-6 hours.<cite>Puleo</cite>
A pitfall concerning elevated Troponin I can be patients with renal failure or pulmonary embolism.<cite>Thygesen</cite> Although cardiac markers are helpful for confirming the diagnosis reperfusion should not always wait till the cardiac markers are known.  
 
==ST elevated Myocardial Infarct==
 
Initial treatment of STEMI is relief of ischemic pain, stabilize the hemodynamic status and reduce the ischemia as quickly as possible by fibrinolysis or primary percutaneous coronary intervention (PCI). Meanwhile other measures as continuous cardiac monitoring, oxygen and intravenous access are necessary to guarantee the safety of the patient.<cite>Antman</cite>
 
Rapid revascularisation is essential to minimize the impact of the myocardial infarction and thereby reduce mortality. In the first hours after symptom onset the amount of salvageable myocardium by reperfusion is greatest. <cite>Anderson2</cite>, <cite>Bassand</cite>
Revascularisation can be achieved by fibrinolysis or PCI.
 
PCI is, if available, the preferred revascularisation method for patients with STEMI.
But not all hospitals are qualified to perform PCI and therefore fibrinolysis is still used. There are however some circumstances in which transfer to a PCI qualified hospital is essential:
 
* Patients with contraindications for fibrinolysis as active bleedings, recent dental surgery, past history of intracranial bleeding.<cite>Grzybowski</cite>
* Patients with cardiogenic shock, severe heart failure and/or pulmonary oedema complicating the myocardial infarction.<cite>Thune</cite>, <cite>Kent</cite>
 
Or when PCI has a better outcome:
* Patients who present three hours to four hours after the onset of the symptoms.<cite>VandeWerf</cite>
* Patients with a non diagnostic ECG or a atypical history a coronary angiography with the ability to perform a PCI is preferred.<cite>VandeWerf</cite>
 
===Fibrinolysis===
Fibrinolytics like streptokinase stimulate the conversion of plasminogen to plasmin. Plasmin demolishes fibrin which is an important constituent of the thrombus. Fibrinolytics are most effective the first hours after the onset of symptoms, after twelve hours the outcome will not improve.<cite>Bassand</cite>
Because re occlusion after fibrinolysis is possible patients should be transferred to a PCI qualified hospital once fibrinolysis is done.<cite>Silber</cite>
 
===Percutaneous Coronary Intervention (PCI)===
'''Table 3 Considerations for selecting primary percutaneous coronary intervention (PCI) for reperfusion therapy in patients with ST elevation myocardial infarction (STEMI)'''
 
The procedure of PCI starts off as a coronary angiography (see CAG). When the stenosis is visualized a catheter with an inflatable balloon will be brought at the site of the stenosis. Inflation of the balloon within the coronary artery will crush the atherosclerosis and eliminate the stenosis. To prevent that the effect of the balloon is only temporarily a stent is positioned at the site of the stenosis. To reduce the risk of coronary artery stent thrombosis antiplatelet therapy should be given.
 
===CORONARY ARTERY BYPASS GRAFT===
There are circumstances in which CABG should be performed.
 
{| class="wikitable" border="1" style="width: 700px"
|-  
|-  
! style="background: #34abff; color: white; " | Class of recommendations
| bgcolor="#FFFFFF" rowspan="2"|
! style="background: #34abff; color: white" | ACC / AHA 2004 Guideline on CABG in STEMI patients <cite>AHACABG</cite>
|align="center" colspan="2" bgcolor="#FFFFFF" | <b>Diagnosis of CAD</b>
|-
| align="center" bgcolor="#FFFFFF" | <b>Sensitivity (%)</b>
| align="center" bgcolor="#FFFFFF" | <b>Specificity (%)</b>
|-
| <b>Exercise ECG <sup>a, 91, 94, 95</sup></b>
!45–50
!85–90
|-
| <b>Exercise stress echocardiography <sup>96</sup></b>
!80–85
!80–88
|-
| <b>Exercise stress SPECT <sup>96-99</sup></b>
!73–92
!63–87
|-
| <b>Dobutamine stress echocardiography <sup>96</sup></b>
!79–83
!82–86
|-
| <b>Dobutamine stress MRI <sup>b,100</sup></b>
!79–88
!81–91
|-
| <b>Vasodilator stress echocardiography <sup>96</sup></b>
!72–79
!92–95
|-
|-
| style="background: #74fb3f; vertical-align:top;" | '''Class I'''
| <b>Vasodilator stress SPECT <sup>96, 99</sup></b>
| style="background: white" | There is evidence and/or general agreement that CABG should be performed in patients with STEMI in the following settings:
!90–91
#Failed percutaneous coronary intervention (PCI) with persistent pain or hemodynamic instability if coronary anatomy is suitable for surgery.
!75–84
#Persistent or recurrent ischemia refractory to medical therapy if coronary anatomy is suitable for surgery, a significant area of myocardium is at risk, and the patient is not a candidate for PCI.
#At the time of surgical repair of postinfarction ventricular septal rupture or mitral regurgitation.
#Cardiogenic shock in patients less than 75 years of age who develop shock within 36 hours of MI and are suitable and appropriate candidates for revascularization that can be performed within 18 hours of shock.
#Life-threatening ventricular arrhythmias in the presence of at least 50 percent left main stenosis and/or triple-vessel disease.
If possible, an internal mammary artery graft should be used to bypass a significantly stenosed left anterior descending artery.
|-
|-
| style="background: #fdaa02; vertical-align:top;" | '''Class IIa'''
| <b>Vasodilator stress MRI <sup>b,98, 100-102</sup></b>
| style="background: white" | The weight of evidence or opinion is in favor of benefit from CABG in patients with STEMI in the following settings:
!67–94
#For primary reperfusion in patients who have suitable anatomy, are not candidates for or have failed fibrinolysis/PCI, and are in the first 6 to 12 hours of an evolving STEMI.
!61–85
#Since CABG mortality is elevated for the first 3 to 7 days after infarction, the benefit of revascularization must be balanced against this risk. Patients who are stable (no ongoing ischemia, hemodynamic compromise, or life-threatening arrhythmia) and who have incurred a significant fall in left ventricular function should have their surgery delayed to allow myocardial recovery to occur. If critical anatomy exists, revascularization should be performed during the index hospitalization.
|-
|-
| style="background: #fdaa02; vertical-align:top;" | '''Class IIb'''
| <b>Coronary CTA <sup>c,103-105</sup></b>
| style="background: white" |
!95–99
!64–83
|-
|-
| style="background: #fd3535; vertical-align:top;" | '''Class III'''
| <b>Vasodilator stress PET <sup>97, 99, 106</sup></b>
| style="background: white" |
!81–97
There is evidence and/or general agreement that emergency CABG should not be performed in patients with STEMI in the following settings:
!74–91
#Persistent angina and a small area of myocardium at risk in hemodynamically stable patients.
#Successful epicardial reperfusion in the absence of successful microvascular reperfusion.
|-
|-
| colspan="2" |  
| colspan="3" bgcolor="#FFFFFF"| <b>CAD</b> = coronary artery disease; <b>CTA</b> = computed tomography angiography; <b>ECG</b> = electrocardiogram; <b>MRI</b> = magnetic resonance imaging; <b>PET</b> = positron emission tomography; <b>SPECT</b> = single photon emission computed tomography.
<small>''Class I:'' Evidence and/or general agreement that a given treatment or procedure is beneficial, useful, effective. ''Class II:''
|-
Conflicting evidence and/or a divergence of opinion about the usefulness/efficacy of the given treatment or procedure. ''IIa:'' Weight of evidence/opinion is in favour of usefulness/efficacy. ''IIb:'' Usefulness/efficacy is less well established by evidence/opinion. ''Class III'': Evidence or general agreement that the given treatment or procedure is not usefull effective, and in some cases may be harmful.</small>
| colspan="3"|<b><sup>a</sup></b> Results without/with minimal referral bias.
|}


CABG does not eliminate the stenosis like PCI does. Using the internal thoracic arteries or the saphenous veins from the legs a bypass is made around the stenosis. The bypass originates from the aorta and terminates directly after the stenosis. Thereby restoring the blood supply to the ramifications. A bypass can be single or multiple, multiple meaning that there are several coronary arteries bypassed using the same bypass.
<b><sup>b</sup></b> Results obtained in populations with medium-to-high prevalence of disease without compensation for referral bias.


Major surgery is not preferable in patients with STEMI, but CABG is inevitable when fibrinolysis and/or PCI failed or when the patient develops cardiogenic shock, life threatening ventricular arrhymthmias or three vessel disease.<cite>Antman2</cite>
<b><sup>c</sup></b> Results obtained in populations with low-to-medium prevalence of disease.
|}


MEDICATION TO START AFTER MI<cite>Antman3</cite>
[[File:Algorithm_for_the_initial_evaluation_of_patients_with_clinical_symptoms_of_angina.svg|thumb|right|500px|Figure 1. Algorithm for the initial evaluation of patients with clinical symptoms of angina]]
β blockers lower heart rate and blood pressure, this decreases the oxygen demand of the heart.  
Nitrates dilatate the coronary arteries so the heart receives more oxygenated blood. Anticoagulants reduce the risk of development of a thrombus in the coronary arteries.
Statins to lower cholesterol.


Apart from starting medication the patient needs to minimize any present risk factors like smoking, overweight and drinking alcohol.
If the ECG made during exercise testing does not show any abnormalities myocardial ischemia becomes unlikely as cause of the complaints. If the diagnosis is still in doubt, the following additional tests may be performed.
#Exercise echocardiography means that an echocardiography is made before and during different stages up to peak exercise in order to identify wall motion abnormalities. <Cite>REFNAME12</Cite> An alternative is pharmacological stress testing using dobutamine.
#Myocardium Perfusion Scintigraphy (MPS) is able to show the perfusion of the heart during exercise and at rest based on radiopharmaceutical tracer uptake . <Cite>REFNAME13</Cite>
#Magnetic Resonance Imaging can be done with vasodilatory adenosine or stimulating dobutamine to detect wall motion abnormalities induced by ischemia during pharmacological stress. <Cite>REFNAME14</Cite>


=Non ST elevated Myocardial Infarct=
The findings on stress testing can be used to determine the choice between medical therapy only or medical therapy and invasive assessment of the coronary anatomy in patients with stable angina. Coronary angiography is recommended based upon the severity of symptoms, likelihood of ischemic disease, and risk of the patient for subsequent complications including mortality based on risk scores. <Cite>REFNAME15</Cite> For the algorithm for the initial evaluation of patients with clinical symptoms of angina see Figure 1.
Initial treatment in NSTEMI is to reduce ischemia, stabilize the hemodynamic status, make serial ECG and to repeat measurements of the cardiac markers. Depending on the early risk stratification a choice has to be made between early invasive therapy or conservative therapy with medicines.<cite>Antman</cite>


Early risk stratification is helpful to identify patients at high risk who need a more aggressive therapeutic approach to prevent further ischemic events.<cite>Antman4</cite>
==Coronoary Angiography==
* Age ≥65 years
Coronary angiography (CAG) can assist in the diagnosis and the selection of treatment options for stable angina pectoris. During CAG, the coronary anatomy is visualized including the presence of coronary luminal stenoses.  A catheter is inserted into the femoral artery or into the radial artery. The tip of the catheter is positioned at the beginning of the coronary arteries and contrast fluid is injected. The contrast is made visible by X ray and the images that are obtained are called angiograms.
* Presence of at least three risk factors for coronary heart disease (hypertension, diabetes, dyslipidemia, smoking, or positive family history of early MI)
If stenoses are visible, the operator will judge whether this stenosis is significant and eligible for percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG).  
* Prior coronary stenosis of ≥50 percent
* Presence of ST segment deviation on admission ECG
* At least two anginal episodes in prior 24 hours
* Elevated serum cardiac biomarkers
* Use of aspirin in the prior seven days
Patients with a score of 0 to 1 are at low risk, score 2 to 3 are at intermediate risk, score 4 to 6 are at high risk.


===Conservative Therapy===
==Treatment==
The main objective of in hospital conservative therapy is to relieve ischemic pain by intensifying medical therapy with aspirin and clopidogrel orally and nitro-glycerine, heparin and a beta blocker intravenously. If the patients becomes asymptomatic on these medication and is still asymptomatic when the medication is stopped, rest and stress imaging testing will be performed. The advantage of conservative therapy is reduction of the number of unnecessary revascularizations. The disadvantage is a prolonged stay in the hospital.
Stable angina pectoris is always treated with medical therapy aimed at reducing risk and at alleviating symptoms. Current guidelines recommend revascularization in patients with persistent symptoms despite optimal medical therapy. <Cite>REFNAME16</Cite> Furthermore, revascularization is indicated in case of large areas of myocardial ischemia (such as a left main stem stenosis, a proximal LAD stenosis or significant three vessel disease) and in the presence of high-risk features such as ventricular arrhythmia, heart failure, widening of QRS during ischemia, axis deviation during ischemia or hypotension during ischemia. The choice between PCI and CABG depends on the coronary anatomy and clinical characteristics and the choice should be made in a team including (interventional) cardiologists and thoracic surgeons.  
Up to date: Trials of conservative versus early invasive therapy in unstable angina and non-ST elevation myocardial infarction, geen specifiekere bronvermelding.  


===Rest and Stress Imaging Tests===
==Medical Therapy==
Rest and stress testing is indicated in patients with:<cite>Klocke</cite>
Initial treatment of stable angina pectoris focuses on medication reducing the oxygen demand of the heart. ß blockers lower heart rate and blood pressure. <Cite>REFNAME17</Cite> Nitrates dilatate the coronary arteries and reduce venous return if used to abort an episode of pain. <Cite>REFNAME18</Cite> Antiplatelet therapy (aspirin) reduces the risk of development of a thrombus and thus acute (coronary) ischemic events. <Cite>REFNAME19</Cite>
# Angina pectoris with ECG abnormalities during exercise ECG testing
Risk factors like smoking, overweight, hypertension, dyslipidemia and diabetes need to be treated in order to prevent disease progression and future events. See chronic coronary diseases.
# Asymptomatic NSTEMI after in hospital conservative therapy


Exercise echocardiography means that an echocardiography is made directly after exercise. The poorly perfused parts of the heart will show less activity.<cite>Amanullah</cite>
==PCI==
Myocardium Perfusion Scintigraphy (MPS) is able to show the perfusion of the heart during exercise and at rest.<cite>Brown</cite>
The procedure of PCI is similar to a CAG, except this time a catheter with an inflatable balloon will be brought to the site of the stenosis. Inflation of the balloon within the coronary artery will crush the atherosclerosis and eliminate the stenosis. To prevent collapse of the arteric wall and restenosis, a stent is often positioned at the site of the stenosis.  
MRI can be done with vasodilatory dobutamine or stimulating adenosine to assess how the heart behaves during exercise.<cite>Kwong</cite>


===Invasive Therapy===
==CABG==
High risk patients, patients with persistent symptoms despite medication or a positive stress test need invasive therapy. Depending on what is seen during coronary angiography PCI or a CABG is indicated. (see PCI/CABG)
With CABG, a bypass is placed around the stenosis using the internal thoracic arteries or the saphenous veins from the legs. The bypass originates proximal from the stenosis and terminates distally from the stenosis. The operation usually requires the use of cardiopulmonary bypass and cardiac arrest, however in certain cases the grafts can be placed on the beating heart (“off-pump” surgery)
Fibrinolytic therapy is not used in NSTEMI.<cite>Ref2</cite>
 
== References ==
==Chronic Coronary Disease==
Even though chronic coronary disease mortality rates have declined since 1970 it is still the leading cause of death in many western countries and in an increasing number of non western countries.<cite>Lloyd-Jones</cite>
 
The cause of the reduction in mortality rates is mainly due to rapid recognition at special cardiac care units and the possibility of early intervention.<cite>Capewell</cite>, <cite>Heidenreich</cite>
 
But because survivors of a myocardial infarction still face a substantial risk of further cardiovascular events recognizing and reducing of risk factors is very important.  
 
The following risk factors for chronic coronary disease are modifiable and should be tackled.<cite>Yusuf</cite>
 
'''Cigarette smoking''' damages the endothelium of the blood vessels making it easy for the cholesterol to adhere. Smoking is therefore a leading preventable cause of coronary disease.  All patients who smoke should be counselled to give up smoking. Nicotine replacement therapy and behavioural therapy can help.
 
'''Hypertension''' is like smoking disadvantageous for the endothelium of the blood vessels and so hypertension contributes to the progression of atherosclerosis. Hypertension is defined as a systolic pressure >140 mmHg and/or diastolic pressure >90 mmHg. Patients with hypertension should be first treated with non pharmacologic therapies, including salt restriction, weight reduction in overweight/obese patients, and avoidance of excess alcohol intake. Antihypertensive drugs are indicated in patients with persistent hypertension despite non pharmacologic therapy. Most patients will require multiple antihypertensive drug therapies.
'''Cholesterol''' is the felon in the atherosclerosis tale and therefore cholesterol levels in the blood should be optimal, meaning low LDL levels and high HDL levels. This can be achieved by using statins.
'''Exercise''' lowers morbidity and mortality from coronary disease.
'''Obesity''' increases several risk factors for coronary heart disease, including hypertension, high cholesterol and insulin resistance as well as diabetes. Data show a linear relationship of higher body weight with morbidity and mortality from coronary disease. All patients who are willing, ready and able to lose weight should receive information about behaviour modification, diet, and increased physical activity.
'''A healthy diet''' results in a significantly lower risk of coronary disease. A healthy diet consists of high intake of fruit and vegetables, high fiber intake, a low glycemic index and load, unsaturated fat rather than saturated fat, a limited intake of red or processed meat and intake of omega 3 fatty acids.
Several studies have shown that people who have a high intake of fruit and vegetables have a reduce risk coronary disease. It is possible that this is due to specific compounds in vegetables and fruits, or because people who eat more vegetables and fruits tend to eat less meat and saturated fat.
 
'''In diabetes mellitus''' tight glycemic control is important to protect against many vascular complications, including coronary disease.
A small amount of '''alcohol''' results in a lower risk of morbidity and mortality from coronary disease.
 
===Screening===
Because extensive coronary disease can exist with minimal or no symptoms screening for coronary disease has been suggested. Although screening results in indentifying patients at increased risk there is lack of evidence that screening actually improves outcome.<cite>Gibbons</cite>
 
=References=
<biblio>
<biblio>
#Davies pmid=11756201
#REFNAME1 pmid=11756201
#Sampson pmid=4997794
#REFNAME2 pmid=4997794
#Foreman pmid=10099685
#REFNAME3 pmid=10099685
#Canto pmid=10866870
#REFNAME4 pmid=10866870
#Pope pmid=10751787
#REFNAME5 pmid=10751787
#Constant pmid=6831781
#REFNAME6 pmid=6831781
#Anderson pmid=17692738
#REFNAME7 pmid=3925741
#Anderson2 pmid=8712096
#REFNAME8 pmid=14678917
#Abrams pmid=3925741
#REFNAME9 pmid=15289388
#Henrikson pmid=14678917
#REFNAME10 pmid=8375424
#Antman pmid=15289388
#REFNAME11 pmid=17162834
#Fox pmid=17162834
#REFNAME12 pmid=1352191
#Amanullah pmid=1352191
#REFNAME13 pmid=2007701
#Brown pmid=2007701
#REFNAME14 pmid=12566362
#Kwong pmid=12566362
#REFNAME15 pmid=18061078
#Fraker pmid=18061078
#REFNAME16 pmid=20802248
#Katritsis pmid=15927966
#REFNAME17 pmid=16735367
#Garcia pmid=16735367
#REFNAME18 pmid=3925741
#Hennekens pmid=9355934
#REFNAME19 pmid=9355934
#Davies3 pmid=11084798
#REFNAME20 pmid=23996286
#Swap pmid=16304077
#Macrae pmid=16556688
#Thygesen pmid=17951284
#Puleo pmid=7702648
#Bassand pmid=16311237
#Grzybowski pmid=14532318
#Thune pmid=16186438
#Kent pmid=12472924
#VandeWerf pmid=12559937
#Silber pmid=f15769784
#Antman2 pmid=18191746
#Antman3 pmid=15339869
#Antman4 pmid=10938172
#Klocke pmid=12975245
#Lloyd-Jones pmid=20177011
#Gibbons pmid=12392846
#Capewell pmid=11004141
#Heidenreich pmid=11182101
#Yusuf pmid=15364185
#Ref1 pmid=8375424
#Ref2 pmid=8149520
#AHACABG pmid=15466654
</biblio>
</biblio>

Latest revision as of 12:50, 16 September 2013

An epicardial coronary artery with a atherosclerotic narrowing

Stable angina (pectoris) is a clinical syndrome characterized by discomfort in the chest, jaw, shoulder, back, or arms, typically elicited by exertion or emotional stress and relieved by rest or nitroglycerin. It can be attributed to myocardial ischemia which is most commonly caused by atherosclerotic coronary artery disease or aortic valve stenosis.

Three major coronary arteries supply the heart with oxygenated blood, the right coronary artery (RCA), the left anterior descending coronary artery (LAD) and the left circumflex artery (LCx). When the coronary arteries are affected by atherosclerosis and the lumen of the coronary arteries progressively narrow, a dysbalance between myocardial oxygen supply and myocardial oxygen consumption may occur, causing myocardial ischemia. In stable angina this imbalance mainly occurs when oxygen demand increases due to exercise, increased heart rate, contractility or wall stress.

A complete history and physical examination are essential to support the diagnosis (stable) angina pectoris and to exclude other (acute) causes of chest pain such as an acute coronary syndrome, aortic dissection, arrhythmias, pulmonary embolism, (tension) pneumothorax or pneumonia, gastroesophageal reflux or spams, hyperventilation or musculoskeletal pain. [1] In addition, laboratory tests and specific cardiac investigations are often necessary.

History

Typical chest pain is retrosternal. Pain may radiate to the arms, jaw, and / or back.

Patients often describe angina pectoris as pressure, tightness, or heaviness located centrally in the chest, and sometimes as strangling, constricting, or burning. The pain often radiates elsewhere in the upper body, mainly arms, jaw and/or back. [2] Some patients only complain about abdominal pain so the presentation can be aspecific. [3], [4]

Angina pectoris however has some characteristics that can help to differentiate between other causes of (chest) pain. Angina pectoris is usually is brief and gradual in onset and offset, with the intensity increasing and decreasing over several minutes. The pain does not change with respiration or position. If patients had angina pectoris previously they are often able to recognize the pain immediately. [5] Angina pectoris is a manifestation of arterial insufficiency and usually occurs with increasing oxygen demand such as during exercise. As soon as the demand is decreased (by stopping the exercise for example) complaints usually disappears within a few minutes. Another way to relieve pain is by administration of nitro-glycerine. Nitro-glycerine spray is a vasodilator which reduces venous return to the heart and therefore decreases the workload and therefore oxygen demand. It also dilates the coronary arteries and increases coronary blood flow. [6] The response to nitro-glycerine is however not specific for angina pectoris, a similar response may be seen with oesophageal spasm or other gastrointestinal problems because nitro-glycerine relaxes smooth muscle tissue. [7]

Depending on the characteristics, chest pain can be identified as typical angina, atypical angina or non-cardiac chest pain, see Table 1.

Table 1. Clinical classification of chest pain [8]
Typical angina (definite) Meets three of the following characteristics:
  • Substernal chest discomfort of characteristic quality and duration
  • Provoked by exertion or emotional stress
  • Relieved by rest and/or nitroglycerine
Atypical angina (probable) Meets two of these characteristics
Non-cardiac chest pain Meets one or none of the characteristics

The classification of chest pain in combination with age and sex is helpful in estimating the pretest likelihood of angiographically significant coronary artery disease, see Table 2.

Table 2. Clinical pre-test probabilities a in patients with stable chest pain symptoms. [9]
Typical angina Atypical angina Non-anginal pain
Age Men Women Men Women Men Women
30-39 59 28 29 10 18 5
40-49 69 37 38 14 25 8
50-59 77 47 49 20 34 12
60-69 84 58 59 28 44 17
70-79 89 68 69 37 54 24
>80 93 76 78 47 65 32
ECG = electrocardiogram; PTP = pre-test probability; SCAD = stable coronary artery disease.
a Probabilities of obstructive coronary disease shown reflect the estimates for patients aged 35, 45, 55, 65, 75 and 85 years.
  • Groups in white boxes have a PTP <15% and hence can be managed without further testing.
  • Groups in blue boxes have a PTP of 15–65%. They could have an exercise ECG if feasible as the initial test. However, if local expertise and availability permit a non-invasive imaging based test for ischaemia this would be preferable given the superior diagnostic capabilities of such tests. In young patients radiation issues should be considered.
  • Groups in light pink boxes have PTPs between 66–85% and hence should have a non-invasive imaging functional test for making a diagnosis of SCAD.
  • In groups in dark pink boxes the PTP is >85% and one can assume that SCAD is present. They need risk stratification only.

The severity of complaints can be classified according to the Canadian Cardiovascular Society as shown in Table 3

Table 3. Classification of angina severity according to the Canadian Cardiovascular Society
Class Level of Symptoms
Class I 'Ordinary activity does not cause angina'

Angina with strenuous or rapid or prolonged exertion only

Class II 'Slight limitation of ordinary activity'

Angina on walking or climbing stairs rapidly, walking uphill or exertion after meals, in cold weather, when under emotional stress, or only during the first few hours after awakening

Class III 'Marked limitation of ordinary physical activity'

Angina on walking one or two blocks on the level or one flight of stairs at a normal pace under normal conditions

Class IV 'Inability to carry out physical activity without discomfort' or 'angina at rest'

During angina pectoris ‘vegetative’ symptoms can occur, including sweating, nausea, paleface, anxiety and agitation. This is probably caused by the autonomic nerve system in reaction to stress. [10]

Finally, it is important to differentiate unstable angina (indicating an acute coronary syndrome or even myocardial infarction requiring urgent treatment) from stable angina. Unstable angina typically is severe, occurs without typical provocation and does not disappear with rest, and has a longer duration than stable angina. It is important to initiate prompt treatment in these patients, as described in the acute coronary syndromes chapter.

Physical Examination

There are no specific signs in angina pectoris. Physical examination of a patient with (suspected) angina pectoris is important to assess the presence of hypertension, valvular heart disease (in particular aortic valve stenosis) or hypertrophic obstructive cardiomyopathy. It should include the body-mass index, evidence of non-coronary vascular disease which may be asymptomatic and other signs of co-morbid conditions. E.g.: absence of palpable pulsations in the dorsal foot artery is associated with an 8 fold increase in the likelihood of coronary artery disease.

Electrocardiogram (ECG)

The electrocardiogram (ECG) is an important tool to differentiate between unstable angina (acute coronary syndrome) and stable angina in addition to the patient’s history. Patients with unstable angina pectoris are likely to show abnormalities on the ECG at rest, in particular ST-segment deviations. Although a resting ECG may show signs of coronary artery disease such as pathological Q-waves indicating a previous MI or other abnormalities, many patients with stable angina pectoris have a normal ECG at rest. Therefore exercise ECG testing may be necessary to show signs of myocardial ischemia. [11]

Exercise ECG testing is performed with gradually increasing intensity on a treadmill or a bicycle ergo-meter. Exercise increases the oxygen demand of the heart, potentially revealing myocardial ischemia by the occurrence of ST-segment depression on the ECG. [12]

Laboratory Testing

Laboratory testing in the setting of angina pectoris can be useful to differentiate between different causes of the pain, including an acute coronary syndrome in which there will be elevation of the marker of myocardial necrosis. Anaemia should be ruled out as a cause of ischemia. Renal function is important for pharmacological therapy. Moreover, it might assist in establishing a cardiovascular risk profile.

Stress Testing in Combination with Imaging

Some patients are unable to perform physical exercise. Furthermore, in patients with resting ECG abnormalities the exercise ECG is associated with low sensitivity and specificity.

Table 4. Characteristics of tests commonly used to diagnose the presence of coronary artery disease. [9]
Diagnosis of CAD
Sensitivity (%) Specificity (%)
Exercise ECG a, 91, 94, 95 45–50 85–90
Exercise stress echocardiography 96 80–85 80–88
Exercise stress SPECT 96-99 73–92 63–87
Dobutamine stress echocardiography 96 79–83 82–86
Dobutamine stress MRI b,100 79–88 81–91
Vasodilator stress echocardiography 96 72–79 92–95
Vasodilator stress SPECT 96, 99 90–91 75–84
Vasodilator stress MRI b,98, 100-102 67–94 61–85
Coronary CTA c,103-105 95–99 64–83
Vasodilator stress PET 97, 99, 106 81–97 74–91
CAD = coronary artery disease; CTA = computed tomography angiography; ECG = electrocardiogram; MRI = magnetic resonance imaging; PET = positron emission tomography; SPECT = single photon emission computed tomography.
a Results without/with minimal referral bias.

b Results obtained in populations with medium-to-high prevalence of disease without compensation for referral bias.

c Results obtained in populations with low-to-medium prevalence of disease.

Figure 1. Algorithm for the initial evaluation of patients with clinical symptoms of angina

If the ECG made during exercise testing does not show any abnormalities myocardial ischemia becomes unlikely as cause of the complaints. If the diagnosis is still in doubt, the following additional tests may be performed.

  1. Exercise echocardiography means that an echocardiography is made before and during different stages up to peak exercise in order to identify wall motion abnormalities. [13] An alternative is pharmacological stress testing using dobutamine.
  2. Myocardium Perfusion Scintigraphy (MPS) is able to show the perfusion of the heart during exercise and at rest based on radiopharmaceutical tracer uptake . [14]
  3. Magnetic Resonance Imaging can be done with vasodilatory adenosine or stimulating dobutamine to detect wall motion abnormalities induced by ischemia during pharmacological stress. [15]

The findings on stress testing can be used to determine the choice between medical therapy only or medical therapy and invasive assessment of the coronary anatomy in patients with stable angina. Coronary angiography is recommended based upon the severity of symptoms, likelihood of ischemic disease, and risk of the patient for subsequent complications including mortality based on risk scores. [16] For the algorithm for the initial evaluation of patients with clinical symptoms of angina see Figure 1.

Coronoary Angiography

Coronary angiography (CAG) can assist in the diagnosis and the selection of treatment options for stable angina pectoris. During CAG, the coronary anatomy is visualized including the presence of coronary luminal stenoses. A catheter is inserted into the femoral artery or into the radial artery. The tip of the catheter is positioned at the beginning of the coronary arteries and contrast fluid is injected. The contrast is made visible by X ray and the images that are obtained are called angiograms. If stenoses are visible, the operator will judge whether this stenosis is significant and eligible for percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG).

Treatment

Stable angina pectoris is always treated with medical therapy aimed at reducing risk and at alleviating symptoms. Current guidelines recommend revascularization in patients with persistent symptoms despite optimal medical therapy. [17] Furthermore, revascularization is indicated in case of large areas of myocardial ischemia (such as a left main stem stenosis, a proximal LAD stenosis or significant three vessel disease) and in the presence of high-risk features such as ventricular arrhythmia, heart failure, widening of QRS during ischemia, axis deviation during ischemia or hypotension during ischemia. The choice between PCI and CABG depends on the coronary anatomy and clinical characteristics and the choice should be made in a team including (interventional) cardiologists and thoracic surgeons.

Medical Therapy

Initial treatment of stable angina pectoris focuses on medication reducing the oxygen demand of the heart. ß blockers lower heart rate and blood pressure. [8] Nitrates dilatate the coronary arteries and reduce venous return if used to abort an episode of pain. [18] Antiplatelet therapy (aspirin) reduces the risk of development of a thrombus and thus acute (coronary) ischemic events. [19] Risk factors like smoking, overweight, hypertension, dyslipidemia and diabetes need to be treated in order to prevent disease progression and future events. See chronic coronary diseases.

PCI

The procedure of PCI is similar to a CAG, except this time a catheter with an inflatable balloon will be brought to the site of the stenosis. Inflation of the balloon within the coronary artery will crush the atherosclerosis and eliminate the stenosis. To prevent collapse of the arteric wall and restenosis, a stent is often positioned at the site of the stenosis.

CABG

With CABG, a bypass is placed around the stenosis using the internal thoracic arteries or the saphenous veins from the legs. The bypass originates proximal from the stenosis and terminates distally from the stenosis. The operation usually requires the use of cardiopulmonary bypass and cardiac arrest, however in certain cases the grafts can be placed on the beating heart (“off-pump” surgery)

References

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  2. Foreman RD. Mechanisms of cardiac pain. Annu Rev Physiol. 1999;61:143-67. DOI:10.1146/annurev.physiol.61.1.143 | PubMed ID:10099685 | HubMed [REFNAME3]
  3. Canto JG, Shlipak MG, Rogers WJ, Malmgren JA, Frederick PD, Lambrew CT, Ornato JP, Barron HV, and Kiefe CI. Prevalence, clinical characteristics, and mortality among patients with myocardial infarction presenting without chest pain. JAMA. 2000 Jun 28;283(24):3223-9. DOI:10.1001/jama.283.24.3223 | PubMed ID:10866870 | HubMed [REFNAME4]
  4. Pope JH, Ruthazer R, Beshansky JR, Griffith JL, and Selker HP. Clinical Features of Emergency Department Patients Presenting with Symptoms Suggestive of Acute Cardiac Ischemia: A Multicenter Study. J Thromb Thrombolysis. 1998 Jul;6(1):63-74. DOI:10.1023/A:1008876322599 | PubMed ID:10751787 | HubMed [REFNAME5]
  5. Constant J. The clinical diagnosis of nonanginal chest pain: the differentiation of angina from nonanginal chest pain by history. Clin Cardiol. 1983 Jan;6(1):11-6. DOI:10.1002/clc.4960060102 | PubMed ID:6831781 | HubMed [REFNAME6]
  6. Abrams J. Hemodynamic effects of nitroglycerin and long-acting nitrates. Am Heart J. 1985 Jul;110(1 Pt 2):216-24. PubMed ID:3925741 | HubMed [REFNAME7]
  7. Henrikson CA, Howell EE, Bush DE, Miles JS, Meininger GR, Friedlander T, Bushnell AC, and Chandra-Strobos N. Chest pain relief by nitroglycerin does not predict active coronary artery disease. Ann Intern Med. 2003 Dec 16;139(12):979-86. DOI:10.7326/0003-4819-139-12-200312160-00007 | PubMed ID:14678917 | HubMed [REFNAME8]
  8. Fox K, Garcia MA, Ardissino D, Buszman P, Camici PG, Crea F, Daly C, De Backer G, Hjemdahl P, Lopez-Sendon J, Marco J, Morais J, Pepper J, Sechtem U, Simoons M, Thygesen K, Priori SG, Blanc JJ, Budaj A, Camm J, Dean V, Deckers J, Dickstein K, Lekakis J, McGregor K, Metra M, Morais J, Osterspey A, Tamargo J, Zamorano JL, Task Force on the Management of Stable Angina Pectoris of the European Society of Cardiology, and ESC Committee for Practice Guidelines (CPG). Guidelines on the management of stable angina pectoris: executive summary: The Task Force on the Management of Stable Angina Pectoris of the European Society of Cardiology. Eur Heart J. 2006 Jun;27(11):1341-81. DOI:10.1093/eurheartj/ehl001 | PubMed ID:16735367 | HubMed [REFNAME17]
  9. Task Force Members, Montalescot G, Sechtem U, Achenbach S, Andreotti F, Arden C, Budaj A, Bugiardini R, Crea F, Cuisset T, Di Mario C, Ferreira JR, Gersh BJ, Gitt AK, Hulot JS, Marx N, Opie LH, Pfisterer M, Prescott E, Ruschitzka F, Sabaté M, Senior R, Taggart DP, van der Wall EE, Vrints CJ, ESC Committee for Practice Guidelines, Zamorano JL, Achenbach S, Baumgartner H, Bax JJ, Bueno H, Dean V, Deaton C, Erol C, Fagard R, Ferrari R, Hasdai D, Hoes AW, Kirchhof P, Knuuti J, Kolh P, Lancellotti P, Linhart A, Nihoyannopoulos P, Piepoli MF, Ponikowski P, Sirnes PA, Tamargo JL, Tendera M, Torbicki A, Wijns W, Windecker S, Document Reviewers, Knuuti J, Valgimigli M, Bueno H, Claeys MJ, Donner-Banzhoff N, Erol C, Frank H, Funck-Brentano C, Gaemperli O, Gonzalez-Juanatey JR, Hamilos M, Hasdai D, Husted S, James SK, Kervinen K, Kolh P, Kristensen SD, Lancellotti P, Maggioni AP, Piepoli MF, Pries AR, Romeo F, Rydén L, Simoons ML, Sirnes PA, Steg PG, Timmis A, Wijns W, Windecker S, Yildirir A, and Zamorano JL. 2013 ESC guidelines on the management of stable coronary artery disease: the Task Force on the management of stable coronary artery disease of the European Society of Cardiology. Eur Heart J. 2013 Oct;34(38):2949-3003. DOI:10.1093/eurheartj/eht296 | PubMed ID:23996286 | HubMed [REFNAME20]
  10. Antman EM, Anbe DT, Armstrong PW, Bates ER, Green LA, Hand M, Hochman JS, Krumholz HM, Kushner FG, Lamas GA, Mullany CJ, Ornato JP, Pearle DL, Sloan MA, Smith SC Jr, Alpert JS, Anderson JL, Faxon DP, Fuster V, Gibbons RJ, Gregoratos G, Halperin JL, Hiratzka LF, Hunt SA, Jacobs AK, and American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 1999 Guidelines for the Management of Patients With Acute Myocardial Infarction). ACC/AHA guidelines for the management of patients with ST-elevation myocardial infarction--executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 1999 Guidelines for the Management of Patients With Acute Myocardial Infarction). Circulation. 2004 Aug 3;110(5):588-636. DOI:10.1161/01.CIR.0000134791.68010.FA | PubMed ID:15289388 | HubMed [REFNAME9]
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  12. Fox K, García MA, Ardissino D, Buszman P, Camici PG, Crea F, Daly C, de Backer G, Hjemdahl P, López-Sendón J, Morais J, Pepper J, Sechtem U, Simoons M, Thygesen K, and Grupo de trabajo de la sociedad europea de cardiologia sobre el manejo de la angina estable. [Guidelines on the management of stable angina pectoris. Executive summary]. Rev Esp Cardiol. 2006 Sep;59(9):919-70. DOI:10.1157/13092800 | PubMed ID:17162834 | HubMed [REFNAME11]
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