Coronary Artery Disease and Stable Angina
- Coronary artery disease (CAD) refers to the atherosclerotic narrowing of the epicardial coronary arteries. It may manifest insidiously as angina pectoris or as an acute coronary syndrome (ACS).
- Stable angina is a chest discomfort due to myocardial ischemia that is predictably reproducible at a certain level of exertion or emotional stress.
- The spectrum of ACS includes unstable angina (UA), non–ST elevation myocardial infarction (NSTEMI), and ST elevation myocardial infarction (STEMI). See “Acute Coronary Syndromes: NSTEACS (Unstable Angina and NSTEMI)” for further information.
- Typical angina: exhibits three classical characteristics: (i) substernal chest pressure, pressure or heaviness that may radiate to the jaw, back, or arms and generally lasts from 2 to 15 minutes; (ii) occurs at a certain level of myocardial oxygen demand from exertion, emotional stress, or increased sympathetic tone; and (iii) relieved with rest or sublingual nitroglycerin
- Atypical angina: exhibits two of the above typical characteristics
- Noncardiac chest pain: exhibits ≤1 of the above typical characteristics
- Anginal equivalent: Patients may present without chest discomfort but with nonspecific symptoms such as dyspnea, diaphoresis, fatigue, belching, nausea, light-headedness, or indigestion that occur with exertion or stress.
- UA: anginal symptoms that are new or more frequent, more severe, or occurring with lessening degrees of myocardial demand; considered ACS but do not present with cardiac biomarker elevation. (See “Acute Coronary Syndromes: NSTEACS [Unstable Angina and NSTEMI].”)
- NSTEMI: elevation of cardiac biomarker (troponin I or T) with either anginal symptoms, ischemic ECG changes other than ST elevation, or both. (See “Acute Coronary Syndromes: NSTEACS [Unstable Angina and NSTEMI].”)
- STEMI: presents with typical symptoms as mentioned above with ST elevations noted on ECG; generally caused by acute plaque rupture and complete obstruction of culprit vessel and may present prior to laboratory detection of troponin. (See “Acute Coronary Syndromes: STEMI.”)
The elderly may present with atypical symptoms. Physical limitations may delay recognition of angina until it occurs with minimal exertion or at rest. Maintain a high degree of suspicion during evaluation of dyspnea and other nonspecific complaints.
- CAD is the leading cause of death for adults both in the United States and worldwide.
- The cost of CAD in the United States was $555 billion in 2016 and is expected to rise to $1.1 trillion by 2035.
- ~80% of CAD is preventable with a healthy lifestyle.
In the United States, the lifetime risk of a 40-year-old developing CAD is 49% for men and 32% for women.
In the United States, 28.4 million people carry a diagnosis of CAD, whereas 7.12 million have angina pectoris.
Etiology and Pathophysiology
- Anginal symptoms occur during times of myocardial ischemia caused by a mismatch between coronary perfusion and myocardial oxygen demand.
- Atherosclerotic narrowing of the coronary arteries is the most common etiology of angina, but it may also occur in those with significant aortic stenosis, pulmonary hypertension, hypertrophic cardiomyopathy, coronary spasm, or volume overload.
- Traditional risk factors: hypertension, ↓ HDL, ↑ LDL, smoking, diabetes, premature CAD in first-degree relatives (men <55 years old; women <65 years old), age (>45 years for men; >55 years for women)
- Nontraditional risk factors: obesity, sedentary lifestyle, chronic inflammation, abnormal ankle-brachial indices, renal disease
- Smoking cessation
- Regular aerobic exercise program and weight loss for obese patients (goal body mass index [BMI] <25 kg/m2); a plant-based or a Mediterranean-like diet is recommended as a healthful diet.
- Blood pressure (BP) control (goal <140/90 mm Hg; consider <130/80 mm Hg for those with 10-year ASCVD risk ≥10%).
- Type 2 diabetes management: Consider more aggressive hemoglobin A1c (HbA1c) goal of 6.5–7% in younger, recently diagnosed individuals.
- At least moderate-intensity statin therapy for those with diabetes aged 40 to 75 years and those with 10-year ASCVD risk ≥7.5–20% (Recommendations of advisory organizations vary, and the American College of Cardiology/American Heart Association [ACC/AHA] risk calculator overestimates risk in many by as much as 50–100%.)
- Low-dose aspirin should not be recommended for routine primary prevention of myocardial infarction (MI) without objective evidence of CAD. It may be used for those with high clinical suspicion in the interim prior to stress testing/catheterization.
Commonly Associated Conditions
Hyperlipidemia, peripheral vascular disease, cerebrovascular disease, hypertension, obesity, diabetes
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