Among patients undergoing percutaneous coronary intervention (PCI), 9 months of P2Y12 inhibitor monotherapy after 3 months of dual antiplatelet therapy (DAPT) led to noninferior rates of major cardiovascular events and significantly lower rates of bleeding compared with prolonged DAPT, according to a study published in JAMA.

The SMART-CHOICE trial was a noninferiority, open-label, randomized study conducted in 33 Korean hospitals between March 18, 2014 and July 19, 2018 (ClinicalTrials.gov identifier: NCT02079194), comparing 9 months of P2Y12 inhibitor monotherapy after 3 months of DAPT with 12 months of continuous DAPT in participants undergoing PCI with drug-eluting stents (N=2993; mean age 64 years; 26.6% women).

Participants were randomly assigned to receive 12 months of DAPT (n=1498) or aspirin plus P2Y12 inhibitor therapy for 3 months followed by P2Y12 inhibitor alone for 9 months (n=1495). The primary study end point was major cardiac and cerebrovascular events (a composite of myocardial infarction, stroke, or all-cause death) at 12 months post-procedure. Secondary study end points included individual components of primary end point and bleeding (defined as Bleeding Academic Research Consortium type 2-5). The margin of noninferiority was 1.8%.

Of the 2993 participants, 97.3% (N=2912) completed the trial. Study protocol adherence was 79.3% in the P2Y12 inhibitor monotherapy group compared with 95.2% in the DAPT group.

After 12 months, major cardiac and cerebrovascular events occurred in 42 participants within the P2Y12 group and in 36 in the DAPT group (2.9% vs 2.5%; difference 0.4% [1-sided 95% CI, –∞% to 1.3%]; P =.007 for noninferiority).

No significant differences were seen between the 2 groups in myocardial infarction (11 [0.8%] vs 17 [1.2%]; hazard ratio [HR], 0.66; 95% CI, 0.31-1.40; P =.28), stroke (11 [0.8%] vs 5 [0.3%]; HR, 2.23; 95% CI, 0.78-6.43; P =.14), or all-cause death (21 [1.4%] vs 18 [1.2%]; HR, 1.18; 95% CI, 0.63-2.21; P =.61).

The rate of bleeding in the P2Y12 group was significantly lower compared with the DAPT group (2.0% vs 3.4%; HR, 0.58; 95% CI, 0.36-0.92; P =.02).

The study was limited by a relatively wide noninferiority margin of 1.8%, which may indicate the study was underpowered; however, the margin was not exceptionally wide and is typical compared with previous major DAPT trials. Also, the current study was open-label and not placebo-controlled, and not all consecutive patients were screened, opening up the possibility for selection bias.

Investigators concluded that although the trial indicated that P2Y12 inhibitor monotherapy resulted in noninferior rates of major cardiac and cerebrovascular events, further research is needed.

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Disclosure: This study was supported in part by Abbott Vascular, Biotronik, and Boston Scientific. Joo-Yong Hahn, MD, and Hyeon-Cheol Gwon, MD, disclosed affiliations with pharmaceutical companies. See the reference for complete disclosure information

Reference

Hahn J, Song YB, Oh J, et al. Effect of P2Y12 inhibitor monotherapy vs dual antiplatelet therapy on cardiovascular events in patients undergoing percutaneous coronary intervention: The SMART-CHOICE randomized clinical trial. JAMA. 2019;321(24):2428–2437.