6-Month Versus 12-Month Dual-Antiplatelet Therapy Following Long Everolimus-Eluting Stent Implantation: The IVUS-XPL Randomized Clinical Trial.

Objectives: The aim of this study was to investigate whether a 6-month dual-antiplatelet therapy (DAPT) duration was comparable with a 12-month duration in patients who underwent everolimus-eluting stent implantation.

Background: Well-designed studies that determine optimal DAPT strategies after everolimus-eluting stent implantation are limited.

Methods: A total of 1,400 patients (implanted mean total stent length >45 mm) were randomly assigned to receive 6-month (n = 699) or 12-month (n = 701) DAPT between October 2010 and July 2014 at 20 centers in Korea. The primary endpoint was the composite of cardiac death, myocardial infarction, stroke, or TIMI (Thrombolysis in Myocardial Infarction) major bleeding at 1 year, analyzed using an intention-to-treat approach.

Results: The primary endpoint occurred in 15 patients (2.2%) in the 6-month DAPT group and 14 patients (2.1%) in the 12-month DAPT group (hazard ratio [HR]: 1.07; p = 0.854). Definite or probable stent thrombosis occurred in 2 patients (0.3%) in the 6-month DAPT group and in 2 patients (0.3%) in the 12-month DAPT group (HR: 1.00; p = 0.999). There were no significant between-group differences in the primary endpoint in 686 patients with acute coronary syndrome (2.4% in both groups; HR: 1.00; p = 0.994) and in 506 patients with diabetes mellitus (2.2% [6-month] vs. 3.3% [12-month]; HR: 0.64; p = 0.428).

Conclusions: Compared with 12-month DAPT, 6-month DAPT did not increase the composite events of cardiac death, myocardial infarction, stroke, or TIMI major bleeding at 1 year in patients who underwent everolimus-eluting stent implantation. (Impact of Intravascular Ultrasound Guidance on Outcomes of XIENCE PRIME Stents in Long Lesions [IVUS-XPL Study]; NCT01308281).