Abbreviated DAPT continues to prevail beyond one year: MASTER-DAPT subanalysis shows

By Wally A. Omar, MD on

Key Points:

  • In this pre-specified MASTER DAPT sub-study, patients with high bleeding risk and high ischemic risk who were treated with PCI with an Ultimaster stent were randomized to either standard care dual antiplatelet therapy (DAPT) or abbreviated DAPT starting after 30 days of DAPT post PCI.
  • The three co-primary endpoints included the following at fifteen months: a) net adverse clinical events (NACE), b) major adverse cardiac and cerebral events (MACCE), and c) major or clinically relevant non-major bleeding (MCB).
  • Treatment with abbreviated DAPT was not significantly different from standard DAPT for NACE and MACCE in patients with high ischemic risk. Abbreviated DAPT resulted in lower major or nonmajor bleeding. There were no significant differences between the patients with high ischemic risk and those without.

Standard of practice after placement of drug-eluting stents involves at least a year of dual antiplatelet therapy (DAPT); however, this strategy may pose considerable harm to patients at high bleeding risk.  Several recent trials have examined the use of abbreviated DAPT, including STOPDAPT-2GLOBAL LEADERS, and Onyx ONE Clear. More recently, the MASTER DAPT (NCT03023020) trial, first presented at the 2021 European Society of Cardiology Conference, evaluated the efficacy and safety of an abbreviated DAPT course on patients with high bleeding risk undergoing PCI with drug-eluting stent. In a Hot Line Session at the 2022 European Society of Cardiology Congress today, Dr. Marco Vagimigli (Cardiocentro Ticino Foundation, Lugano, Switzerland) presented the results of a pre-specified analysis of the MASTER DAPT trial, for which the fifteen-month results are now available.

The MASTER DAPT study was a multicenter, randomized, international clinical trial across 140 hospitals worldwide. Patients were all treated with the sirolimus-eluting Ultimaster stent.  All recruited patients were required to have high bleeding risk. Patients at high bleeding risk were defined as those with at least one of 10 criteria, including a) clinical indication to oral anticoagulants (OAC) for >12 months, b) recent (<12 months) non-access site bleeding episode(s) which required medical attention, c) previous bleeding episode(s) which required hospitalization if the underlying cause has not been definitively treated, d) age >75, e) systemic conditions associated with increased bleeding risk, f) documented anemia (Hb <11g/dL) or transfusion within 4 weeks, g) use of chronic steroids or NSAIDS, h) malignancy with high bleeding risk, i) any previous stroke, or TIA within 6 months, or j) PRECISE DAPT score >25. Relevant exclusion criteria included the placement of stents or treatment of in-stent thrombosis/restenosis within 6 months of the index use of Ultimaster stent, or any previous use of Bioresorbable scaffolds.  The sub-study specifically assessed outcomes in patients with high ischemic risk, which was defined as an MI within 12 months of presentation. 95% of these patients met these criteria due to an MI at the time of PCI, and 5% met them via an MI within the 12 months prior to PCI.

A total of 4,579 patients were randomized, of whom 1780 were designated as “high ischemic risk.” Of these, 914 received abbreviated DAPT therapy, which involved stopping DAPT and then either a) continuing SAPT until the end of the trial or b) up to an additional five months along with ongoing clinically indicated OAC. 866 patients received standard DAPT, which involved either a) continuing DAPT for at least an additional 5 months or b) two months along with clinically indicated OAC, either of which was followed by SAPT. Interestingly, 15% of patients in the standard-treatment arm had continuation of their DAPT or SAPT beyond 12 months, veering from the guideline recommendations.

The three primary endpoints (all evaluated at 335 days) were as follows: a) net adverse clinical events (NACE, defined as a composite of all-cause death, MI, stroke, and major bleeding), b) major adverse cardiac and cerebral events (MACCE, the composite of all-cause death, MI, and stroke), and c) major or clinically relevant non-major bleeding. At 15 months, there was no difference in NACE (HR 0.92 (95% confidence interval [CI] 0.76–1.12; p=0.399) in the abbreviated DAPT group, nor was there a difference in MACCE (HR 0.94; 95% CI 0.76–1.17; p=0.579). C

Major bleeding was previously shown to be significantly reduced in the abbreviated DAPT group and that continues to hold true at 15 months (HR 0.94; 95% CI 0.76–1.17; p=0.579). When discussing the implications of the study, Dr. Valgimigli stated “More than anything this analysis highlights the need for clear definitions of therapy upfront to avoid potentially unnecessary treatment. The consistency of treatment effect beyond 12 months may be attributed to unnecessary continuation of antiplatelets”.