Sudden Cardiac Death Due to Myocardial Infarction With Obstructive and Nonobstructive Coronary Arteries.

Abstract (English)

BACKGROUND: The total burden of community sudden cardiac deaths (SCDs) attributable to myocardial infarction (MI), including myocardial infarction with nonobstructive coronary arteries (MINOCA), is unclear. OBJECTIVES: The study sought to determine the burden of community SCD due to MI by histopathologic examination. METHODS: The POST SCD (Postmortem Systematic Investigation of Sudden Cardiac Death) study is a prospective countywide study using autopsy to adjudicate presumed SCDs as cardiac (arrhythmic or nonarrhythmic) or noncardiac causes, with trauma deaths as reference control deaths. We defined a case as "SCD due to MI" if histopathological findings of MI without other lethal cause were found, and defined obstructive coronary artery disease as ≥50% stenosis in ≥1 coronary artery. RESULTS: Of 943 presumed SCDs from February 1, 2011, to March 31, 2023, 360 (38%) had noncardiac cause and 583 (62%) were autopsy-confirmed SCDs, of which 237 (41%) were due to MI (MI SCD): 214 (90%) were acute or healed myocardial infarction with obstructive coronary artery disease (MI-CAD) and 23 (10%) were acute MINOCA (highest proportion among Black patients; P < 0.05). Among 173 coronary lesions in acute MI-CAD SCDs (n = 95), the left anterior descending artery (n = 66 [38%]) and right coronary artery (n = 59 [35%]) were most commonly affected, and the right coronary artery was the most common culprit (43%). Nonarrhythmic causes were more common in MINOCA than acute MI-CAD SCDs (35% vs 15%; P = 0.037), with a trend toward being the highest in Asian patients (P = 0.1). The total fibrosis burden was similar in MINOCA and acute MI-CAD SCDs (P = 0.6). CONCLUSIONS: In this 12-year countywide study, one-fourth of all sudden deaths and 41% of autopsy-confirmed SCDs were attributable to MI, with significant racial differences. The left anterior descending artery and right coronary artery were most commonly affected among SCDs due to MI-CAD. Nonarrhythmic causes were twice as common in MINOCA SCDs than acute MI-CAD.