Internal Medicine Exam Acute Coronary Syndromes 5 — Questions and Answers
Question 1: A 68-year-old man on warfarin (INR 2.4) for atrial fibrillation presents with NSTEMI. He undergoes PCI with a drug-eluting stent. What is the optimal antithrombotic regimen post-procedure?
- Warfarin + aspirin + P2Y12 inhibitor (triple therapy) indefinitely
- Warfarin alone long-term
- Short course of triple therapy, then DOAC + P2Y12 inhibitor (dual therapy) for 12 months (Correct answer)
- Aspirin + P2Y12 inhibitor without anticoagulation
Correct answer: Short course of triple therapy, then DOAC + P2Y12 inhibitor (dual therapy) for 12 months
Current guidelines recommend minimizing triple therapy duration (≤1 month) and transitioning to dual therapy with a DOAC plus P2Y12 inhibitor to reduce bleeding while maintaining thrombotic protection.
Question 2: Which of the following is a contraindication to fibrinolytic therapy in STEMI?
- Age >75 years
- Prior CABG >10 years ago
- Ischemic stroke within the past 3 months (Correct answer)
- Diabetes mellitus with proliferative retinopathy
Correct answer: Ischemic stroke within the past 3 months
Ischemic stroke within 3 months is an absolute contraindication to fibrinolysis due to risk of hemorrhagic transformation; prior CABG and advanced age are relative considerations but not absolute contraindications.
Question 3: The GRACE risk score is used in ACS to predict which outcome?
- Likelihood of successful thrombolysis
- In-hospital and 6-month mortality to guide invasive vs. conservative strategy (Correct answer)
- Risk of contrast-induced nephropathy during angiography
- Probability of requiring CABG vs. PCI
Correct answer: In-hospital and 6-month mortality to guide invasive vs. conservative strategy
The GRACE score stratifies ACS mortality risk (low/intermediate/high) using variables like age, heart rate, BP, creatinine, cardiac arrest, ST deviation, troponin, and Killip class to guide invasive strategy timing.
Question 4: A patient with inferior STEMI is brought to the cath lab. Coronary angiography reveals 100% occlusion of a large dominant RCA. After successful PCI to the RCA, which hemodynamic complication is most likely to respond to IV fluids?
- Cardiogenic shock from LV dysfunction
- Right ventricular failure from RV infarction (Correct answer)
- Flash pulmonary edema
- Ventricular free wall rupture
Correct answer: Right ventricular failure from RV infarction
RV infarction causes preload-dependent hemodynamics; aggressive IV fluid resuscitation is the mainstay of treatment, as the failing RV needs adequate filling pressure to maintain forward output.
Question 5: Which duration of dual antiplatelet therapy (DAPT) is generally recommended after drug-eluting stent (DES) placement for ACS?
- 1 month
- 3 months
- At least 12 months (Correct answer)
- Lifelong DAPT
Correct answer: At least 12 months
Current ACC/AHA guidelines recommend at least 12 months of DAPT after DES placement in ACS patients to reduce stent thrombosis and recurrent ischemic events.
Question 6: A 72-year-old woman with STEMI who received successful primary PCI develops new sustained ventricular tachycardia (VT) on day 4 of hospitalization. What is the most likely underlying mechanism?
- Hyperkalemia-induced automaticity
- Re-entry through scar tissue at the infarct border zone (Correct answer)
- Proarrhythmic effect of aspirin
- Drug-induced QT prolongation from heparin
Correct answer: Re-entry through scar tissue at the infarct border zone
Late VT after MI (days 3-5+) is typically caused by re-entrant circuits formed at the border between infarcted and viable myocardium, distinct from early reperfusion arrhythmias.
Question 7: A post-ACS patient is intolerant of ACE inhibitors due to cough. Which agent provides equivalent mortality benefit in patients with reduced ejection fraction?
- Hydralazine alone
- Angiotensin receptor blocker (ARB) such as valsartan (Correct answer)
- Long-acting nitrate
- Calcium channel blocker
Correct answer: Angiotensin receptor blocker (ARB) such as valsartan
ARBs (e.g., valsartan, losartan) provide equivalent cardiovascular mortality reduction post-MI with reduced EF and are the recommended alternative when ACE inhibitors are not tolerated due to cough.
Internal Medicine Exam Acute Coronary Syndromes 5
A 68-year-old man on warfarin (INR 2.4) for atrial fibrillation presents with NSTEMI.
He undergoes PCI with a drug-eluting stent.
What is the optimal antithrombotic regimen post-procedure?