Comparison Of 3-6 Month Versus 12 Month Dual Antiplatelet Therapy After Coronary Intervention Using the Contemporary Drug-eluting Stents With Ultrathin Struts: The HOST-IDEA Randomized Clinical Trial.

Background: Limited data are available on short-term dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) using third-generation drug-eluting stents (DES) with ultrathin struts and advanced polymer technology. We investigated whether 3-6 month DAPT was non-inferior to 12 month one after implantation of DES with ultrathin struts and advanced polymer technology. Methods: We performed an open-label, randomized trial at 37 centers in South Korea. We enrolled patients undergoing PCI using the Orsiro biodegradable-polymer sirolimus-eluting stents (SES) or the Coroflex ISAR polymer-free SES. Patients with ST-segment elevation myocardial infarction were excluded. Patients were randomized to receive either 3-6 month or 12 month DAPT after PCI. The choice of antiplatelet medications was at the physician's discretion. The primary outcome was a net adverse clinical event (NACE), a composite of cardiac death, target vessel myocardial infarction (TVMI), clinically driven target lesion revascularization (CD-TLR), stent thrombosis, or major bleeding, defined as Bleeding Academic Research Consortium type 3 or 5 at 12 months. The major secondary outcomes were target lesion failure (TLF), a composite of cardiac death, TVMI, CD-TLR, and major bleeding. Results: A total of 2,013 patients (mean age 65.7±10.5, 1,487 male [73.9%], 1,110 [55.1%] presented with acute coronary syndrome) were randomized to 3-6 month DAPT (n=1,002) or 12 month DAPT (n=1,011). The primary outcome occurred in 37 (3.7%) patients in the 3-6 month DAPT group and 41 (4.1%) in the 12 month DAPT group. The non-inferiority of the 3-6 month DAPT group to the 12 month DAPT group was met (absolute risk difference, -0.4% [1-sided 95% confidence interval (CI), -∞% to 1.1%; P<0.001 for non-inferiority]). There were no significant differences in TLF (hazard ratio [HR] 0.98, 95% CI 0.56-1.71, P=0.94) or major bleeding (HR 0.82, 95% CI 0.41-1.61, P=0.56) between the two groups. Across various subgroups, the treatment effect of 3-6 month DAPT was consistent for NACE. Conclusions: Among patients undergoing PCI using third-generation DES, 3-6 month DAPT was non-inferior to 12 month DAPT for NACE. Further research is needed to generalize this finding to other populations and to determine the ideal regimen for 3-6 month DAPT.