Impact of Revascularization Completeness on Cardiovascular Outcomes in STEMI With Multivessel Disease

BACKGROUND: Complete revascularization is superior to culprit lesion-only percutaneous coronary intervention (PCI) in reducing ischemic events in patients with ST-segment-elevation myocardial infarction and multivessel disease. However, the relationship between the extent of revascularization and the benefits of a complete revascularization strategy remains unclear. The aim of this substudy of the COMPLETE trial (Complete versus Culprit-Only Revascularization Strategies to Treat Multivessel Disease after Early PCI for STEMI) was to evaluate how the degree of anatomic completeness of revascularization, measured by the core laboratory-derived modified residual SYNTAX score (R'SS), relates to major cardiovascular events. METHODS: We conducted an exploratory post hoc analysis of the COMPLETE trial (N=3738), stratifying patients randomized in the complete revascularization group based on the R'SS assessed after staged nonculprit lesion-PCI. Complete revascularization was defined by an R'SS=0, whereas incomplete revascularization was defined by an R'SS>0. A stratified Cox proportional hazards model was used, with the culprit-only PCI arm designated as the reference group for comparison. The first coprimary outcome was a composite of cardiovascular death or new myocardial infarction. The second coprimary outcome was a composite of cardiovascular death, new myocardial infarction, or ischemia-driven revascularization. RESULTS: Among patients randomized to a complete revascularization strategy, 90% achieved complete revascularization (R'SS=0), whereas 10% did not (R'SS>0). In patients with R'SS=0, the first coprimary outcome occurred less frequently (6.6%) compared with those randomized to the culprit lesion-only PCI strategy (10.7%; adjusted hazard ratio, 0.61 [95% CI, 0.47-0.78]). Among patients with an R'SS>0, the first coprimary outcome was similar (10.7%) to those in the culprit lesion-only PCI group (10.7%; adjusted hazard ratio, 1.01 [95% CI, 0.61-1.67]). A similar result was observed for the second coprimary outcome. CONCLUSIONS: This exploratory analysis of the COMPLETE trial suggests that the benefit of a complete revascularization strategy in patients with ST-segment-elevation myocardial infarction and multivessel disease may be related to the extent of anatomic completeness of revascularization. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01740479.