Abstract 15953: Stressed Into a STEMI

Abstract

Introduction: Chest pain is the second most common presenting symptom in the emergency department (ED). 5.1% of all presentations with chest pain are acute coronary syndrome (ACS). ACS includes ST-segment elevation myocardial infarction (STEMI), non-ST segment elevation myocardial infarction (NSTEMI), and unstable angina (UA). We present a case of UA that progressed to STEMI after a regadenoson stress test. Case: A 55 years old male with 30 pack-year smoking history presented to the ED with sudden onset, sharp, left-sided chest pain associated with diaphoresis that lasted a few minutes. EKG showed sinus rhythm with premature ventricular complexes without ischemic changes. High sensitivity troponin at 0, 1, and 3 hours were within normal limits. While he was undergoing a radionucleotide stress test, he reported severe chest pain immediately after the regadenoson injection. Bedside telemetry showed ST elevation in inferior leads. EKG was consistent with 1mm ST-elevation in leads II, III, and aVF. He underwent an emergent coronary angiogram which revealed 100% occlusion in the mid-right coronary artery (RCA) and 80% in the second marginal distribution. He received a drug-eluting stent to RCA with the resolution of his chest pain. Discussion: Rupture or erosion of atherosclerotic plaque exposes the underlying thrombogenic core which can lead to occlusion of the coronary artery. A partial occlusion due to an unstable plaque can lead to UA or NSTEMI. STEMI results from complete occlusion of the coronary circulation. In our case, the patient presented with unstable angina however undergoing a stress test triggered him to STEMI. The administration of regadenoson led to coronary vasodilation, resulting in the redistribution of coronary blood flow away from the nearly occluded RCA but what led to plaque rupture at the same time leading to a STEMI is unclear. Conclusions: A regadenson stress test can trigger STEMI in patients with unstable angina however the mechanism is unclear