AUTHOR: Maheswara Satya Gangadhara Rao Golla, MD
Angina pectoris is a term used to describe a clinical syndrome, typically characterized by chest, jaw, shoulder, back, or arm discomfort that is caused by myocardial ischemia. This is most commonly related to atheromatous plaque in one or more than one large epicardial coronary artery; however, myocardial ischemia may occur in the absence of obstructive coronary artery disease (CAD), such as uncontrolled hypertension, microvascular disease, valvular heart disease, hypertrophic cardiomyopathy, coronary spasm, or endothelial dysfunction. Any situation that causes an imbalance in myocardial oxygen supply and demand can cause an angina syndrome. Angina can be classified as follows:
Stable angina should be classified using a grading system. The most commonly adopted is that of the Canadian Cardiovascular Society (CCS):
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Figure 1 Stress test algorithm.
ACS, Acute coronary syndrome; BBB, bundle branch block; DM, diabetes mellitus; ECG, electrocardiogram; echo, echocardiography; ED, emergency department; GTX, graded exercise test; LVH, left ventricular hypertrophy; NSTE, non-ST-segment elevation; NSTEMI, NSTE myocardial infarction; STE, ST-segment elevation; y/o, years old.
From Adams JG et al: Emergency medicine: clinical essentials, ed 2, Philadelphia, 2013, Saunders.
2b, Cardiac CTA Showed Normal Coronary Arteries. 2c, Cardiac CTA Showed Proximal to Mid-Left Anterior Descending Artery Stenosis (80%) (Red Arrow).
Courtesy Maheswara Satya Gangadhara Rao Golla, MD.
TABLE 1 Risk Stratification Based on Noninvasive Testing
High Risk (>3% Annual Risk for Death or Myocardial Infarction) | |||
Intermediate Risk (1%-3% Annual Risk for Death or Myocardial Infarction) | |||
Low Risk (<1% Annual Risk for Death or Myocardial Infarction) | |||
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CCTA, Cardiac computed tomography angiography; LVEF, left ventricular ejection fraction; VF, ventricular fibrillation; VT, ventricular tachycardia. Assessment of coronary artery calcium can also be used to contribute to risk assessment.
∗Although the published data are limited, patients with these findings will probably not be at low risk in the presence of either a high-risk treadmill score or severe resting LV dysfunction (LVEF <35%).
Modified from Fihn SD et al: ACCF/AHA/ACP/AATS/PCNA/SCAI/STS guideline for the diagnosis and management of patients with stable ischemic heart disease: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines, and the American College of Physicians, American Association for Thoracic Surgery, Preventive Cardiovascular Nurses Association, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons, Circulation 126:e354, 2012; in Zipes DP: Braunwalds heart disease: a textbook of cardiovascular medicine, ed 11, Philadelphia, 2019, Elsevier.
Treatment can be classified based on medications that prevent MI and death.
The value of enhanced external counterpulsation (EECP) was assessed with the MUST-EECP trial, which randomly assigned 139 outpatients with angina, documented CAD, and a positive stress test to 35 h of active EECP. The results indicated the following regarding EECP: (1) Was well tolerated; (2) exercise duration increased in both groups; (3) active EECP patients had a significant increase in time to 1-mm ST-segment depression, whereas there was no change in the inactive group; (4) more patients undergoing active EECP had a decrease in angina episodes, and fewer had an increase in angina symptoms compared with the active group. These data corroborate similar data from multicenter registries. The American Heart Association, American College of Cardiology, Society for Cardiovascular Angiography and Interventions, American Thoracic Society, and Society of Thoracic Surgeons focused update states that EECP may be considered for relief of refractory angina.
The following treatments have NOT been shown to be beneficial in reducing cardiovascular risk or improving clinical outcomes: Estrogen therapy, vitamin C, vitamin E, and beta-carotene supplementation; treatment of elevated homocysteine with folate or vitamins B6 and B12; chelation therapy; garlic; coenzyme Q10; selenium; and chromium.
CABG or PCI to improve symptoms is beneficial in patients with one or more significant (>70% diameter) coronary artery stenosis amenable to revascularization and unacceptable angina despite maximal medical treatment, or in whom increasing medical therapy cannot be implemented because of medication contraindications, adverse effects, or patient preferences. In 2017, ORBITA trial showed no significant improvement in angina score after PCI for optimally treated stable angina patients. However, 85% of study patients in placebo group underwent PCI within 6 wk after ORBITA trial completed. In 2020, the Ischemia trial showed no benefit with routine invasive therapy compared to conservative treatment in moderate to severe ischemia patients. However, this study excludes patients with ACS, severe and frequent symptoms, EF <35%, and left main stenosis. Hybrid coronary revascularization: LIMA-to-LAD artery grafting and of >1 non-LAD coronary artery can be used in patients who have an unfavorable aorta, have poor target vessels for CABG, have unsuitable graft conduits, or have unfavorable LAD for PCI.
Figure E3 Coronary angioplasty procedure.
A, Critical stenosis in midsegment of a right coronary artery. B, Inflation of a 3.5-mm-diameter angioplasty balloon. C, Angiographic control after balloon inflation. D, Placement of a 3.5-mm-diameter, 18-mm-long metal stent. E, Inflation of the balloon. F, Final result.
From Vincent JL et al: Textbook of critical care, ed 6, Philadelphia, 2011, Saunders.
Figure E4 Implantation of a coronary stent.
A, Placement of balloon catheter. B, Predilation with balloon catheter. C, Balloon is withdrawn. D, Placement of coronary stent, which has been crimped on a balloon catheter. E, Inflation of balloon and expansion of stent. F, Withdrawal of balloon catheter and final result.
From Vincent JL et al: Textbook of critical care, ed 6, Philadelphia, 2011, Saunders.
Unstable Angina (Patient Information)
Acute Coronary Syndrome (Related Key Topic)
Coronary Artery Disease (Related Key Topic)
Myocardial Infarction (Related Key Topic)