Abstract 12368: Clinical Features, Prognosis and Risk Stratification of Acute Myocardial Infarction Due to Coronary Embolism

Abstract

Introduction: Coronary embolism (CE) is recognized as an important non-atherosclerotic cause of acute myocardial infarction (AMI). Atrial fibrillation (AF) is associated with systemic thromboembolism, and the CHADS2 and CHA2DS2-VASc scores are known to be useful for risk stratification. Therefore, we investigated the clinical features and prognosis of CE, and assessed the potential usefulness of these scores for predicting CE. Methods: We studied a total of 2,115 consecutive patients with AMI (M/F 1,528/587, age 68±12 [SD] years) hospitalized between 2001 and 2013. CE was diagnosed according to the criteria shown in Figure 1 Results: The overall prevalence of CE in AMI was 2.4% (n=51, M/F 31/20, age 65±14 years). Compared with non-CE AMI patients, CE patients were characterized as lower prevalence of risk factors. Most common cause of CE was AF (73%). However, only 15 (41%) out of 37 AF patients were treated with vitamin K antagonists (VKAs) and their PT-INR was low, 1.42 (range, 0.95-1.80) at the onset of AMI. Importantly, among 28 CE patients with nonvalvular AF, 17 patients (59%) had a CHADS2 score of 0 or 1. When those particular patients were re-evaluated by CHA2DS2-VASc score, 10 out of 17 (59%) were categorized into a higher risk category (≥ 2) that would benefit from VKAs therapy. During a median follow-up of 4.1 years (interquartile range, 1.5-7.0 years), 8 patients (16%) had major adverse cardiovascular events and 5 patients (10%) recurred CE or systemic embolization (Figure 2). Conclusions: AF is the major underlying cause of CE, recurrence of which seems to be not rare. The CHA2DS2-VASc score may provide reliable risk stratification with a superior ability to predict CE.