Individualizing Dual Antiplatelet Therapy (DAPT) Duration Based on Bleeding Risk, Ischemic Risk, or Both: An Analysis From the DAPT Study.

BACKGROUND:Guidelines recommend individualization of dual antiplatelet therapy (DAPT) duration. Whether to guide decisions based on bleeding risk, ischemic risk or a combination is not known. AIMS:To compare a bleeding prediction model, an ischemic prediction model, and the DAPT score in guiding DAPT duration. METHODS:11,648 patients in the DAPT Study were categorized into higher and lower risk using a bleeding model, an ischemic model, and the DAPT score. Effect of 30 vs. 12 months of DAPT on bleeding events, ischemic events, and the combination (net-adverse clinical events [NACE]) was assessed. RESULTS:Among patients stratified with the bleeding model, 30 vs. 12 months of DAPT resulted in similar ischemic and bleeding event rates. With the ischemic model, however, higher risk patients had a greater reduction in ischemic events with extended duration of DAPT (difference in risk differences [DRD]: -2.6%, 95% CI: -3.9 to -1.3%; p < 0.01), and a smaller increase in bleeding (DRD: -1.0%, 95% CI: -2.1-0.0%; p = 0.04). Similarly, high DAPT score patients had a greater reduction in ischemic events with extended DAPT duration (DRD: -2.4%, 95%: CI: -3.6 to -1.1%; p < 0.01) and a smaller increase in bleeding (DRD: -1.2%, 95%: CI: -2.2-0.0%; p = 0.02). Although NACE was similar for bleeding risk groups, NACE was significantly reduced with extended DAPT in the higher ischemic risk and high DAPT score groups. CONCLUSIONS:In this low-bleeding risk population, stratifying patients based on predicted ischemic risk and the DAPT score best discerned benefit versus harm of extended DAPT duration on ischemic events, bleeding events, and NACE. CONDENSED ABSTRACT:Duration of dual antiplatelet therapy (DAPT) should be guided by an individualized risk assessment. Bleeding risk tools have emerged to identify patients at high bleeding risk for whom truncated DAPT therapy may be safest. In a lower bleeding risk population, however, whether DAPT duration should be guided by bleeding risk, ischemic risk, or a combination is unknown. In this analysis, implementation of a score based on ischemic risk prediction and the DAPT score (a combination of ischemic and bleeding risk) best predicted ischemic events, bleeding events, and net-adverse clinical events (NACE).