Coronary Artery Disease and Stable Angina
Basics
- CAD is atherosclerotic narrowing of epicardial coronary arteries causing ischemia.
- Stable angina: chest discomfort predictable with exertion or stress; relieved by rest or nitroglycerin.
- ACS spectrum: unstable angina (UA), NSTEMI, STEMI.
- Typical angina: substernal chest pressure lasting 2-15 minutes, triggered by exertion, relieved by rest or nitrates.
- Atypical angina: two of typical features.
- Anginal equivalents: dyspnea, fatigue, nausea, lightheadedness during exertion.
- Elderly often present atypically.
Epidemiology
- Leading cause of death in US and worldwide.
- Estimated lifetime risk at age 40: 49% men, 32% women.
- ~5% US adults have CAD.
- 80% preventable with healthy lifestyle.
Etiology and Pathophysiology
- Ischemia from mismatch between myocardial oxygen supply and demand.
- Most commonly caused by atherosclerosis.
- Other causes: aortic stenosis, pulmonary hypertension, hypertrophic cardiomyopathy, coronary spasm, volume overload.
Risk Factors
- Traditional: hypertension, high LDL, smoking, diabetes, premature family history, older age, low HDL.
- Nontraditional: obesity, sedentary lifestyle, chronic inflammation, abnormal ankle-brachial index, renal disease.
Prevention
- Smoking cessation.
- Regular aerobic exercise; weight loss to BMI <25.
- Plant-based or Mediterranean diet.
- BP goal <140/90 mm Hg (consider <130/80 mm Hg if ASCVD risk β₯10%).
- Intensive diabetes management (HbA1c 6.5-7% for younger/early disease).
- High-intensity statins for CAD patients regardless of lipid levels.
- Avoid aspirin for routine primary prevention unless high clinical suspicion.
Common Associated Conditions
- Hyperlipidemia, peripheral vascular disease, cerebrovascular disease, hypertension, obesity, diabetes.
Diagnosis
History
- Chest pain: typical (Levine sign), atypical, or anginal equivalents.
- Dyspnea on exertion may be sole symptom.
- Symptoms mimicking GI upset possible.
- Atypical presentations more common in women, elderly, diabetics.
Physical Exam
- May be normal.
- Possible murmurs, dysrhythmias, gallops, signs of heart failure.
Differential Diagnosis
- Vascular: aortic dissection, pericarditis, myocarditis, MI, vasospasm.
- Pulmonary: pleuritis, PE, pneumothorax.
- GI: reflux, esophageal spasm, ulcer.
- Musculoskeletal: costochondritis, arthritis, muscle strain.
- Others: anxiety, cocaine abuse.
Diagnostic Tests
- Serial troponins for acute presentations.
- CBC, lipid profile, HbA1c, metabolic panel.
- ECG: may be normal or show ischemia; LBBB or pacing complicates interpretation.
- Chest X-ray for alternative diagnoses.
- Stress testing (exercise or pharmacologic) for intermediate risk.
- CT coronary angiography or cardiac MRI if inconclusive or continued symptoms.
- Cardiac catheterization with angiography is gold standard for diagnosis and guiding intervention.
Treatment
General Measures
- BP control goal <130/80 mm Hg.
- Complete smoking cessation.
- Moderate aerobic exercise: 30-60 minutes, 5-7 days/week.
Medication
- Ξ²-Blockers: first-line; reduce HR, BP, contractility; improve angina and mortality post-MI/HF.
- Calcium channel blockers: dihydropyridines (amlodipine, nifedipine) and nondihydropyridines (diltiazem, verapamil); avoid in EF <40% (negative inotropy).
- Nitrates: sublingual nitroglycerin for acute angina; long-acting nitrates for prophylaxis.
- Lipid-lowering agents: high-intensity statins (atorvastatin, rosuvastatin); ezetimibe or PCSK9 inhibitors if needed.
- Antiplatelets: aspirin first line; clopidogrel if aspirin contraindicated; dual therapy post-MI or PCI.
- ACE inhibitors/ARBs: especially with LV dysfunction or diabetes.
- Ranolazine: second-line adjunct, no effect on HR/BP.
- Low-dose colchicine may improve outcomes in established CAD.
Surgery/Procedures
- Revascularization (CABG preferred in left main, multivessel disease).
- PCI for significant lesions refractory to medical therapy.
- PCI first line in UA/NSTEMI/STEMI.
Ongoing Care
- Aggressive lifestyle counseling at every visit.
- Diet: plant-based or Mediterranean recommended; fatty fish preferred over omega-3 supplements.
Prognosis
- Depends on extent of disease, symptom severity, LV function.
Complications
- Acute coronary syndrome, arrhythmias, heart failure, cardiac arrest.
ICD10: - I25.119 Atherosclerotic heart disease of native coronary artery with unspecified angina pectoris - I25.118 Atherosclerotic heart disease of native coronary artery with other angina pectoris - I20.9 Angina pectoris, unspecified
Clinical Pearls: - Maximize antianginal therapy with Ξ²-blockers, calcium channel blockers, and nitrates. - Use high-intensity statins and antiplatelet therapy. - PCI is reserved for stable angina refractory to medical therapy and first-line for ACS.