Abbreviated dual antiplatelet therapy after percutaneous coronary intervention with ultrathin-strut drug-eluting stents in South Korea: 3-year outcomes of the multicentre, randomised HOST-IDEA trial.

Background: The HOST-IDEA trial demonstrated non-inferiority of 3-to-6-month dual antiplatelet therapy (DAPT) to 12-month DAPT for net adverse clinical event (NACE) at 1 year in patients undergoing percutaneous coronary intervention (PCI) with third-generation drug-eluting stents (DES). We evaluated the long-term outcomes of abbreviated antiplatelet therapy following PCI with third-generation DES. Methods: In the open-label, adjudicator-blinded, multicentre, randomised HOST-IDEA trial, 2013 patients from 37 hospitals in South Korea were randomly allocated to 3-to-6-month (n = 1002) or 12-month (n = 1011) DAPT between January 2016 and May 2021. The primary outcome was NACE at 3 years, comprising cardiac death, target vessel myocardial infarction (TVMI), clinically driven target lesion revascularisation (CD-TLR), stent thrombosis, and major bleeding (Bleeding Academic Research Consortium type 3 or 5). Major secondary outcomes were target lesion failure (TLF)-comprising cardiac death, TVMI, and CD-TLR-and major bleeding at 3 years. To evaluate the efficacy and safety of >1-year DAPT, patients event-free at 1 year were classified into >1-year and ≤1-year DAPT groups and matched using a propensity score. These 3-year clinical outcomes were prespecified in the published protocol as mandatory clinical follow-up. HOST-IDEA is registered with ClinicalTrials.gov, NCT02601157. Findings: At 3 years, clinical follow-up was completed in 955 patients (95.3%) and 966 patients (95.5%) in the 3-to-6-month and 12-month DAPT groups, respectively. The median follow-up duration was 1095 days (IQR 1095-1095). The primary outcome occurred in 7.7% and 8.2% of patients in the 3-to-6-month and 12-month DAPT groups, respectively (HR 0.94; 95% CI 0.69-1.29; Interpretation: 3-to-6-month and 12-month DAPT showed comparable 3-year clinical outcomes in patients undergoing PCI with third-generation DES. However, extending DAPT beyond 1 year was associated with increased major bleeding without additional ischemic benefits. Further studies are warranted to validate these findings and identify patient subsets who may benefit from extended DAPT. Funding: Biotronik Korea (Seongnam si, Gyeonggi-do, South Korea) and B. Braun Korea (Seoul, South Korea).