P2Y12 Inhibitor Monotherapy vs Dual Antiplatelet Therapy After Percutaneous Coronary Intervention

To the Editor Dr Hahn and colleagues reported noninferiority of P2Y12 inhibitor monotherapy compared with dual antiplatelet therapy (DAPT) among patients receiving current-generation drug-eluting stents. The primary end point was major adverse cardiac and cerebrovascular events. Assuming a 12-month event rate of 4.0% for the DAPT group, the noninferiority margin for the event rate difference (monotherapy minus DAPT) was set at 1.8%. In the intention-to-treat analysis, the 12-month cumulative incidence of the primary outcome was 2.9% for monotherapy and 2.5% for DAPT. Since the upper bound of the confidence interval for the event rate difference was 1.3%, the authors concluded that monotherapy was noninferior to DAPT. However, only 79.3% of patients in the monotherapy group received the assigned treatment compared with 95.2% in the DAPT group. Moreover, the proportion of patients receiving aspirin beyond 3 months in the monotherapy group was 14.4% at 6 months and 8.9% at 12 months. With these adherence issues, the intention-to-treat analysis likely underestimated the true event rate difference. In the per-protocol analysis, the 12-month cumulative incidence of major adverse cardiac and cerebrovascular events was 3.1% for monotherapy and 2.5% for DAPT. However, the per-protocol analysis is potentially biased because it does not preserve randomization.

Source: JAMA - October 22, 2019 Category: General Medicine Source Type: research