Myocardial infarction secondary to coronary embolism: aetiology, clinical characteristics, and prognosis

AIMS: Limited data are available regarding aetiology, clinical characteristics, and prognosis of coronary embolism (CE). This study aimed to describe the clinical features of embolic myocardial infarction (MI) and compare them with non-embolic MI. METHODS AND RESULTS: All admissions for acute MI in a single tertiary centre between January 2010 and December 2023 were reviewed. Coronary embolism was diagnosed by established criteria. Among 8160 patients, 89 (1.1%) were diagnosed with CE. The most common attributable cause was atrial fibrillation (AF) (52.8%), followed by prosthetic valve thrombosis (11.2%) and endocarditis (7.9%). Compared with the remaining patients, those with CE were more frequently female, had a lower prevalence of cardiovascular risk factors, and presented more often with ST-segment elevation (79.8 vs. 58.6%, P < 0.001). Coronary embolism patients had a high frequency of unsuccessful reperfusion and higher rates of mechanical complications (5.6 vs. 2.2%, P = 0.031) and strokes/transient ischaemic attacks (6.7 vs. 1.3%, P < 0.001) than those with non-CE MI, although in-hospital mortality was not statistically different (9.0 vs. 6.4%, respectively, P = 0.321). In a propensity-matched analysis among hospital survivors (77 in each group), no differences were observed over a median follow-up of 59.6 months in overall mortality or thrombo-embolic events after discharge, although more patients in the CE group were admitted for heart failure. CONCLUSION: Coronary embolism is mostly caused by AF, usually presents with ST-segment elevation, and is associated with higher rates of mechanical complications and in-hospital embolic events, but not of recurrent thromboembolism after discharge. No significant differences in mortality were observed between CE and non-CE MI.