Coronary Artery Disease
Core concepts
Coronary artery disease includes stable obstructive disease, plaque rupture or erosion causing acute coronary syndrome, and microvascular or vasospastic angina. Candidates must distinguish supply-demand ischemia from acute plaque rupture, interpret high-sensitivity troponin kinetics against the 99th percentile, and recognize that one normal ECG does not exclude ACS. Risk stratification combines symptoms, ECG, troponin, renal function, bleeding risk, and comorbidities. Revascularization decisions depend on anatomy, ischemic burden, symptoms despite medical therapy, and left ventricular function. Antiplatelet therapy and high-intensity statin therapy are foundational after ACS.
Question traps
A common trap is calling any troponin elevation a myocardial infarction when demand ischemia, myocarditis, pulmonary embolism, or CKD is present. Another is missing atypical presentations in women, older adults, and patients with diabetes. Do not overrely on exercise testing in patients with known CAD or an uninterpretable ECG. Post-PCI chest pain requires consideration of stent thrombosis. Do not delay reperfusion for STEMI to obtain nonessential tests.
Worked example / rule of thumb
A 58-year-old with 20 minutes of exertional chest pressure, a normal ECG, and two negative high-sensitivity troponins has stable chest pain, not automatically ACS. If pretest probability is intermediate and there is no known CAD, coronary CT angiography is a reasonable first test; with known CAD or high risk, functional testing or invasive angiography may be preferred. Rule: treat the patient and the trajectory, not the single troponin.