Coronary Artery Disease and Acute Coronary Syndromes: Assessment, Reperfusion and Secondary Prevention
Assessment
Stable angina is predictable exertional chest pressure relieved by rest or nitroglycerin. Acute coronary syndrome includes unstable angina, NSTEMI, and STEMI. Obtain a 12-lead ECG within 10 minutes of arrival and repeat it with symptoms. Troponin rises within hours; a single early normal value does not rule out MI. Look for atypical presentations in women, older adults, and people with diabetes: dyspnea, fatigue, nausea, or syncope.
Reperfusion
Primary PCI is preferred for STEMI when it can be delivered promptly; fibrinolysis is an alternative when PCI is unavailable and symptom onset is within 12 hours, with door-to-needle within 30 minutes and door-to-balloon within 90 minutes. Give aspirin and a P2Y12 inhibitor, anticoagulation, and nitrates if not contraindicated. Avoid nitrates with right ventricular infarction, severe aortic stenosis, or recent PDE-5 inhibitor use.
Secondary prevention
High-intensity statin, beta blocker, ACE inhibitor or ARB, smoking cessation, cardiac rehabilitation, blood pressure and glucose control, and weight management reduce recurrent events. Dual antiplatelet therapy duration depends on stent type and bleeding risk.
Traps
Do not withhold reperfusion because troponin is normal. Do not give nitrates for inferior STEMI with hypotension. Post-MI pericarditis is pleuritic and positional; reinfarction is more often recurrent ischemic pain with new ECG changes.
Rule of thumb
Time is muscle: identify STEMI, activate the cath lab, and treat pain, hypoxia, and arrhythmias concurrently.