Three-Year Outcomes of Contemporary Left Main Coronary Intervention in Patients With and Without Acute Coronary Syndrome.

We evaluated 3-year clinical outcomes after contemporary left main percutaneous coronary intervention in patients with and without acute coronary syndrome (ACS) in a real-world cohort, in which intracoronary imaging guidance was routinely used. Among 758 consecutive patients undergoing left main percutaneous coronary intervention for unprotected de novo lesions, 97.6% received imaging guidance. Patients were categorized by presenting ACS (n = 241) or without ACS (n = 516). Three-year major adverse cardiovascular and cerebrovascular events (MACCEs), including all-cause mortality, clinically driven revascularization, myocardial infarction, and cerebrovascular events were analyzed. Patients with ACS presented more true bifurcation lesions (31.9% vs 24.2%), cardiogenic shock (18.3% vs 0.2%), and increased mechanical circulatory support use (40.2% vs 5.6%). They had significantly higher MACCE (40.7% vs 28.5%; hazard ratio [HR] 1.81) and mortality rates (25.8% vs 10.2%; HR 3.09), primarily due to higher mortality within 30 days (HR 9.05), while revascularization rates were similar (13.4% vs 15.8%). MACCE predictors in ACS included male (HR 2.62), mechanical circulatory support (HR 2.44), and radial access (HR 0.42). In patients without ACS, left ventricular ejection fraction <40% (HR 2.27), severe calcification requiring coronary atherectomy (HR 1.86), two-stent implantation (HR 1.99), and radial access (HR 0.59) were predictive. In this cohort with extensive use of intracoronary imaging, rates of two-stent implantation (8.9%), target lesion revascularization (4.0%), myocardial infarction (3.0%), and stent thrombosis (0.3%) were low. In conclusion, in contemporary left main percutaneous coronary intervention practice, patients presenting with ACS experienced worse 3-year outcomes, largely attributable to early mortality. After the early phase, longer-term outcomes, including revascularization, were comparable between ACS and non-ACS presentations.