First generation versus new generation drug-eluting stents for the treatment of ostial/midshaft lesions in unprotected left main coronary artery: The Milan and New-Tokyo (MITO) registry

Objectives: To compare the clinical outcomes following unprotected left main coronary artery (ULMCA) percutaneous coronary intervention (PCI) of ostial/midshaft lesions between first and new generation drug-eluting stents (DES). Background: Clinical outcomes after treatment of ostial/midshaft lesions in ULMCA with first generation DES were favorable. However, to date, data regarding treatment for those lesion subsets with new generation DES have not been reported. Methods: A total of 219 patients with ostial/midshaft lesions in ULMCA treated with first (n = 139) or new generation DES (n = 80) were analyzed. Results: There was a higher prevalence of IVUS use (35.2% vs. 50.0%, P = 0.032) and postdilation (70.5% vs. 93.8%, P <0.001) with larger maximum balloon diameter (3.81 ± 0.45 vs. 4.08 ± 0.44, P <0.001) in the new generation DES group. At a median follow-up period of 730 days, there were no significant differences in the propensity-score adjusted analyses, for major adverse cardiac events (MACE) defined as composite endpoint of all-cause death, myocardial infarction, and target vessel revascularization (hazard ratio (HR) [new vs. first generation DES]: 1.22; 95% confidence interval (CI): 0.64-2.31; P = 0.549). Of note, target lesion revascularization rates at 2-years were only 0.9% and 2.7%, for first and new generation DES groups, respectively (P = 0.339). On multivariable analysis, SYNTAX score (HR: 1.06; 95% CI: 1.02-1.11, P = 0.006) and European System for Cardiac Operative Risk Evaluation (HR: 1.14; 95% CI: 1.00-1.31, P = 0.051) were independent predictors for MACE. Conclusions: This study suggests that new generation DES for ostial/midshaft lesions in ULMCA are associated with favorable clinical outcomes, similar to those observed with first generation DES.