Coronary Stenosis Location, Revascularization Strategy, and Sudden Cardiac Death in Chronic and Acute Coronary Syndromes

BACKGROUND: Coronary stenosis location may influence the risk of malignant arrhythmias and sudden cardiac death (SCD), with specific anatomical sites conferring varying degrees of risk. OBJECTIVES: The goal of this study was to determine the association between the anatomical location of significant flow-limiting coronary artery stenoses and the occurrence of SCD events. METHODS: This study was based on a registry of consecutive patients who underwent elective coronary angiography (n = 12,695) for suspected or known coronary artery disease or for acute coronary syndrome (n = 9,800) between 2007 and 2018 at Tampere Heart Hospital in Finland. Baseline details of coronary anatomy were recorded, and patients were followed until December 31, 2022, for the occurrence of SCD or equivalent events (true fatal SCD, SCD aborted by successful resuscitation, or adequate implantable cardioverter-defibrillator therapy for ventricular arrhythmia resulting in hemodynamic collapse; n = 1,048 SCDs; median follow-up time 8.1 years; Q1-Q3: 5.1-11.6 years), identified through in-depth review of medical records, including accounts of circumstances leading to deaths. RESULTS: In adjusted survival analysis accounting for treatment strategy, clinical characteristics, and full anatomical information, right coronary artery (RCA) stenosis (HR: 1.53; 95% CI: 1.31-1.80; P < 0.001) was most strongly associated with SCD, followed by left circumflex coronary artery stenosis (HR: 1.34; 95% CI: 1.15-1.57; P < 0.001). Left anterior descending coronary artery stenosis was associated with SCD in patients with acute coronary syndromes (HR: 1.37; 95% CI: 1.09-1.72; P = 0.007). Revascularization strategy influenced vessel-specific SCD risk: RCA stenosis was associated with the highest risk in percutaneous coronary intervention-treated patients, no stenosis site was associated with excess risk after coronary artery bypass graft, and left main stenosis conferred the greatest risk in noninvasively managed patients (HR: 1.53; 95% CI: 1.03-2.27; P = 0.036). CONCLUSIONS: Left main and RCA stenoses were associated with the greatest SCD risk, with vessel-specific risk modified by revascularization strategy.