Association between quantitative flow ratio and clinical outcomes in multivessel disease STEMI patients with diabetes mellitus

Background: Among patients with multivessel disease and ST-elevation myocardial infarction (MVD-STEMI), complete revascularization (CR) has been shown with improved outcomes. However, it is controversial whether diabetes mellitus (DM) status affects the outcomes. Quantitative flow ratio (QFR), as a newer non-invasive tool for identifying functional coronary stenosis and determining the presence of functional CR (FCR), may open up a new perspective for studying the above issues. The aim of this retrospective study was to investigate an association between QFR-based FCR and clinical outcomes in MVD-STEMI patients under DM status. Methods: A total of 623 patients were included in the final analysis. The patients were divided into nonDM cohort and DM cohort. Within each cohort, patients were further stratified into functional CR (FCR) layer and functional incomplete revascularization (FIR) layer based on QFR assessment. The primary outcomes were 3-year major adverse cardiovascular events (MACEs), encompassing cardiac death, ischemia-driven revascularization (target vessel and non-target vessel), rehospitalization due to unstable angina pectoris, and non-fatal myocardial infarction. Results: The incidence of MACEs was significantly lower in the FCR layer than in the FIR layer (12.6% vs 24.0%, log-rank P