A 56-year-old man is brought to the emergency department due to severe, crushing midsternal chest pain accompanied by diaphoresis and shortness of breath. The patient had been having exertional angina for several months, and, 10 days ago, he underwent coronary angiography that revealed a 90% stenosis of the proximal left anterior descending artery. A drug-eluting stent was placed, and the postprocedural course was uncomplicated. Echocardiogram at discharge was normal. Medical history is also significant for hyperlipidemia, type 2 diabetes mellitus, obesity, and gout. The patient is currently unemployed and uninsured. ECG reveals sinus tachycardia with 2-mm ST-segment elevations in leads V1-V4. Which of the following is the most likely cause of this patient's current condition?

Question

A 56-year-old man is brought to the emergency department due to severe, crushing midsternal chest pain accompanied by diaphoresis and shortness of breath.  The patient had been having exertional angina for several months, and, 10 days ago, he underwent coronary angiography that revealed a 90% stenosis of the proximal left anterior descending artery.  A drug-eluting stent was placed, and the postprocedural course was uncomplicated.  Echocardiogram at discharge was normal.  Medical history is also significant for hyperlipidemia, type 2 diabetes mellitus, obesity, and gout.  The patient is currently unemployed and uninsured.  ECG reveals sinus tachycardia with 2-mm ST-segment elevations in leads V1-V4.  Which of the following is the most likely cause of this patient's current condition?

Quizplus · Accepted Answer

This patient has severe midsternal chest pain and ST-segment elevation on ECG consistent with acute coronary syndrome (ACS); given recent coronary angiography and drug-eluting stent placement, stent thrombosis should be highly suspected. Both bare metal and drug-eluting stents are thrombogenic, and following placement, there is a period of increased thrombotic risk (eg, 6-12 months) until stent endothelization occurs. This increased thrombotic risk is mitigated by the administration of dual antiplatelet therapy (DAPT) with aspirin and a P2Y₁₂ receptor blocker (eg, clopidogrel, prasugrel, ticagrelor). The most common cause of stent thrombosis is poor adherence to, or inability to take, the recommended DAPT, a concern for patients with limited access to medical care (eg, those who are uninsured). stent endothelization ACS due to stent thrombosis most commonly presents as an ST-segment elevation myocardial infarction (STEMI) but can manifest as non-STEMI or unstable angina. It is associated with high morbidity and mortality; therefore, patients should be screened for barriers to medication adherence and counseled regarding the importance of taking DAPT consistently, both at the time of stent placement and during follow-up. (Choice A) Peri-infarction pericarditis can occur within days of an MI. It is characterized by pleuritic chest pain, pericardial friction rub on examination, and diffuse ST-segment elevation on ECG. (Choice B) Aortic dissection typically presents with sudden-onset, tearing chest and back pain in the setting of severe uncontrolled hypertension. ST-segment elevation is rare and does not occur unless the dissection extends to the coronary arteries. (Choice C) Atherosclerotic plaque rupture with thrombotic occlusion is the typical cause of STEMI. However, the localization of this patient's ST-segment elevation in leads corresponding with his recently stented left anterior descending artery (ie, V1-V4) makes stent thrombosis much more likely; pathologically, the occlusion is not due to plaque rupture but rather to stent thrombosis. If this patient had developed ST-segment elevation in the lateral (ie, I, aVL, V5-V6) or inferior (ie, II, III, aVF) leads, this would have suggested new atherosclerotic plaque rupture. leads (Choice D) Left ventricular aneurysm is a mechanical complication that can occur up to several months following transmural MI. It usually manifests with heart failure (after the fibrotic aneurysm becomes dyskinetic with the remaining healthy myocardium) and can cause persistent ST-elevation on ECG. However, 10 days is a relatively short period for aneurysm development, and it is unlikely to present with crushing substernal chest pain. Educational objective: Not taking dual antiplatelet therapy (DAPT) is the most common cause of intracoronary stent thrombosis. Patients receiving an intracoronary stent should be counseled regarding the importance of taking DAPT, both at the time of stent placement and in follow-up. References: Predictors of coronary stent thrombosis: the Dutch Stent Thrombosis Registry. (http://www.ncbi.nlm.nih.gov/pubmed/19371823) Incidence, predictors, and outcome of thrombosis after successful implantation of drug-eluting stents. (http://www.ncbi.nlm.nih.gov/pubmed/15870416)

A 56-Year-Old Man Is Brought to the Emergency Department Due