One Month Dual Antiplatelet Therapy Followed by Aspirin Monotherapy after Drug Eluting Stent Implantation (Short DAPT)

Presented during the AHA Scientific Sessions 2020 by Meyong-Ki Hong, Seoul, Korea.

Introduction and methods

After drug-eluting stent (DES) implantation, 6-12 months dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor is recommended to prevent ischemic events, such as stent thrombosis or MI. Prolonged DAPT is associated with increased risk of bleeding and noncompliance, therefore efforts are undertaken to shorten the duration of DAPT.

This non-inferiority trial examined the effect of one-month DAPT followed by aspirin monotherapy compared to 6-12 months DAPT on the composite endpoint of CV events or major bleeding at follow-up of 1 year.

The trial enrolled 3020 patients who presented to the cardiac catheterization laboratory for elective PCI. They were randomized to 1-month DAPT followed by aspirin monotherapy after polymer-free drug-coated stent implantation or 6-12 months DAPT followed by aspirin monotherapy after contemporary DES implantation. The primary endpoint was a composite of cardiac death, nonfatal MI, target-vessel revascularization, cerebrovascular accident or major bleeding (STEEPLE criteria) at 12 months.

Main results

• The primary endpoint occurred in 5.9% in the 1-month DAPT group vs. in 6.5% in the 6-12 DAPT group (absolute difference -0.7%, P<0.001 for non-inferiority, HR 0.90, 95%CI: 0.68-1.20, P=0.475 for superiority).
• Individual components of the primary endpoints were not different between the two groups.

Conclusion

One-month DAPT followed by aspirin monotherapy after polymer-free DCS implantation was non-inferior to 6-12 months of DAPT after DES implantation with regard to the primary endpoint, a composite of ischemic events and bleeding, at 12 months. The authors state that discontinuing a P2Y12 inhibitor rather than aspirin in daily clinical practice may be associated with better compliance, lower costs and lower risk of bleeding.

Discussion

The discussant Róisín Colleran (Dublin , Ireland) noted that two different strategies (DAPT duration and type of stent) were tested without a factorial design, which makes interpretation more difficult. She discussed the types of stents that were used in the trial (BioFreedom, BioMatrix, UltiMaster); none of these have FDA approval, which limits extern validity. The BioFreedom polymer-free stent has shown to have lower efficacy than contemporary DES. Other points she raised were the high rates of reverse non-compliance in the one-month DAPT arm and the majority of patients in the control arm received 12 months DAPT despite low rate of ACS, which would not be standard practice in US or Europe.

- Our reporting is based on the information provided during AHA Scientific Sessions 2020 -