Significance of diabetes mellitus status in patients undergoing percutaneous left main coronary artery intervention

Background: Diabetes mellitus (DM) is a modifiable risk factor for patients with coronary artery disease (CAD). Treatment with insulin correlates with advanced disease and has been associated with excess cardiovascular risk, but evidence on outcomes of patients with insulin-treated DM (ITDM) undergoing left main percutaneous coronary intervention (LMPCI) remains scarce. Aims: The aim of the presented study is to evluate the risk attributable to DM and ITDM in patients undergoing LMPCI. Methods: We included 869 patients undergoing PCI for unprotected LMCAD. The cohort was divided into three subgroups based on diabetic status: No DM, ITDM, and Non-ITDM. The primary endpoint was major adverse cardiac and cerebrovascular events (MACCE), defined as a composite of death, spontaneous myocardial infarction (MI), or stroke at 1 year. Results were adjusted for clinically relevant baseline characteristics. Results: Amongst participants, 58.7% had no DM, 25.9% non-ITDM, and 15.4% ITDM. Diabetics were younger and more likely to be female. They also exhibited higher body mass index as well as prevalence of comorbidities, including hypertension, anemia, and chronic kidney disease. The number of bifurcation lesions and stents used was similar between groups. At 1 year, when compared to no DM, ITDM (25.4% vs. 10.0%, p < 0.01) but not non-ITDM (10.8% vs. 10.0%, p = 0.94) demonstrated higher MACCE. This finding was driven by increased risk of MI. Mortality was 8.4%, 7.8%, and 17.2% for no DM, Non-ITDM, and ITDM, respectively. Results remained unchanged after adjustment. Conclusions: In a rather contemporary patient population undergoing PCI for LMCAD, ITDM but not non-ITDM was associated with higher risk of 1-year MACCE, primarily driven by MI.