Comparison of Clinical Outcomes Between Incomplete and Complete Revascularization in NSTEMI Patients With Multivessel Disease

Background The optimal revascularization strategy for patients with non–ST-segment elevation myocardial infarction (NSTEMI) and multivessel disease remains controversial. Objectives This study aimed to compare the 3-year clinical outcomes of incomplete revascularization (IR) vs complete revascularization (CR) in NSTEMI patients with multivessel disease. Methods Among 29,625 patients enrolled in the nationwide pooled registry of the KAMIR-NIH (Korea Acute Myocardial Infarction Registry–National Institutes of Health) and KAMIR-V, 6,987 NSTEMI patients with multivessel disease who underwent percutaneous coronary intervention were analyzed. CR was defined as residual stenosis <30% in all vessels ≥2.25 mm with TIMI flow grade 3. The primary endpoint was major adverse cardiac events at 3 years, a composite of all-cause death, recurrent myocardial infarction, unplanned repeat revascularization, and hospitalization for heart failure. Results Of 6,987 patients, 3,072 underwent CR and 3,915 IR. The majority of patients underwent percutaneous coronary intervention for non–infarct-related artery during index procedure (6,144 of 6,987; 88.0%). CR was associated with a lower 3-year risk of major adverse cardiac events compared with IR (18.6% vs 26.9%; adjusted HR: 0.75; 95% CI: 0.66-0.85; P < 0.001), driven by reductions in cardiac death or recurrent myocardial infarction (6.9% vs 10.4%; adjusted HR: 0.76; 95% CI: 0.60-0.95; P = 0.015) and unplanned repeat revascularization (8.6% vs 13.1%; adjusted HR: 0.68; 95% CI: 0.56-0.82; P < 0.001). Findings were consistent after adjustment using propensity score matching and inverse probability weighting. Conclusions In NSTEMI patients with multivessel disease, CR was associated with significantly improved 3-year clinical outcomes compared with IR.