Comparison of the 9-Month Intrastent Condition and 30-Month Clinical Outcomes After Resolute Zotarolimus-Eluting Stent Implantation Between Standard-Duration and 1-Month Dual Antiplatelet Therapy Followed by Prasugrel Monotherapy

Background: In this study we investigated the efficacy and safety of very short duration (1-month) dual antiplatelet therapy (DAPT) followed by prasugrel monotherapy. In particular, we compared intrastent conditions using optical coherence tomography (OCT) after second-generation drug-eluting stent implantation between standard-duration and 1-month DAPT followed by prasugrel monotherapy. Methods and Results: Between May 2015 and February 2018, 120 consecutive patients who underwent elective Resolute zotarolimus-eluting stent implantation were enrolled and divided into those receiving standard-duration or 1-month (1M) DAPT followed by prasugrel monotherapy; 47 patients (n=55 stents) and 46 patients (n=54 stents) in the standard and 1M groups, respectively, completed the protocol. The primary endpoint was the prevalence of abnormal intrastent tissue at the 9-month examination, as observed by OCT. The secondary endpoint was the presence of composite adverse events, including all-cause death, myocardial infarction, stent thrombosis, target lesion and vessel revascularization, and major and minor bleeding. The prevalence of abnormal intrastent tissue was similar between the standard and 1M groups (1.6% vs. 1.5%, respectively; non-inferiority P<0.01). There was a tendency for fewer composite events in the 1M than standard group at the 30-month follow-up examination (28.3% vs. 44.7%, respectively; P=0.41). Conclusions: In conclusion, 1M DAPT followed by prasugrel monotherapy after second-generation drug-eluting stent implantation was not inferior to standard-duration DAPT in terms of intrastent thrombus formation and composite adverse events.