Introduction and methods

One-Month Dual Antiplatelet Therapy Followed by Clopidogrel Monotherapy versus Standard 12-Month Dual Antiplatelet Therapy with Clopidogrel After Drug-Eluting Stent Implantation: STOPDAPT-2 trial

Presented at ACC.19 by Hirotoshi Watanabe (Kyoto University, Kyoto, Japan)

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SMART-CHOICE: P2Y12 Inhibitor Monotherapy Versus Dual Antiplatelet Therapy in Patients Undergoing Implantation of Coronary Drug-eluting Stents

Presented at ACC.19 by Joo-Yong Hahn (Sungkyunkwan University School of Medicine, Seoul, South Korea)

There is uncertainty on the optimal duration of dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor after coronary drug-eluting stent implantation with current generation stents. Short duration of DAPT and subsequent P2Y12 inhibitor monotherapy would be desirable to minimize bleeding events, if not associated with an increase in ischemic events.

In the STOPDAPT-2 trial, a multicenter, physician-initiated, open-label randomized controlled trial, the efficacy and safety of regimen of 1-month DAPT followed by clopidogrel monotherapy was tested in comparison to the standard regimen of 12-months DAPT with aspirin and clopidogrel after everolimus-eluting stents implantation. This was a non-inferiority trial with primary endpoint of net adverse CV events (NACE), a composite of CV death, MI, stroke, definite stent thrombosis, or TIMI major/minor bleeding, at 12 months. From December 2015 to December 2017, 3045 patients were enrolled and randomized in 1:1 ratio to the 2 groups.

The SMART-CHOICE was a prospective, multi-center, randomized, open-label, non-inferiority trial, in which 2993 patients after drug-eluting stent implantation (both everolimus and sirolimus) were assigned to 3 months DAPT followed by P2Y12 monotherapy (clopidogrel, ticagrelor or prasugrel) or at least 12 months DAPT. The primary endpoint was major adverse cardiac or cerebrovascular events (all-cause death, myocardial infarction, or stroke) at 12 months after the index procedure.

Main results

STOPDAPT-2

• Incidence of primary endpoint after 1 year was 2.4% in the 1-month DAPT group vs. 3.7% in the 12-months DAPT group (HR:0.64;95%CI:0.42-0.98, log-rank P=0.037).
• Secondary endpoint of major ischemic events (CV death, MI, stent thrombosis, stroke) was similar in both groups (2.0% in 1-month DAPT group vs 2.5% in 12-months DAPT group, HR:0.79, 95%CI:0.49-1.29, log-rank P=0.34).
• Separate clinical outcomes were similar for both groups, with the exception of TIMI major/minor bleeding (0.4% in the 1-month DAPT group vs. 1.5% in the 12-months DAPT group, P=0.004) and BARC 3 or 5 bleeding (0.5% in the 1-month DAPT group vs. 1.8% in the 12-months DAPT group, P=0.003)

SMART-CHOICE

• Cumulative event rate of primary endpoint was 2.9% in the 3 months DAPT group vs 2.5% in the 12 months DAPT group (absolute risk difference:0.4%, Pnon-inferiority=0.007)
• Rate of BARC bleeding type 2-5 was lower in 3 months DAPT group vs 12 months DAPT (2.0 vs. 3.4%, HR: 0.58; 95% CI, 0.36-0.92; P=0.02).
• NACE, defined as the composite of all-cause death, MI, stroke, or bleeding was not different between the 2 groups (4.5% vs. 5.6%; HR 0.81; 95%CI, 0.58-1.12; P=0.20).

Conclusion

In both trials, shorter duration of DAPT (1 month in STOPDAPT-2 and 3 months in SMART-CHOICE) followed by P2Y12 inhibitor monotherapy was non-inferior to 12 months DAPT with respect to ischemic events in patients after drug-eluting stent implantation, and shorter duration of DAPT reduced bleeding.

• Our coverage of ACC.19 is based on the information provided during the congress –