An abbreviated one month course of dual antiplatelet therapy is an acceptable antithrombotic strategy for patients undergoing percutaneous coronary intervention (PCI) with a drug-eluting stent at high bleeding risk, a trial has shown.
Presented at ESC Congress 2021, results from the MASTER DAPT study showed that 30 days of dual antiplatelet therapy (DAPT) was noninferior to the continuation of therapy for six months with regard to risk of major adverse cardiac or cerebral events
Abbreviated therapy also resulted in a lower incidence of major or clinically relevant nonmajor bleeding, according to findings that are also published in NEJM.
The study was designed to investigate whether in the era of new generation of drug eluting stents a shorter duration of DAPT would be effective in preventing ischaemic complications, while limiting bleeding risk in vulnerable patient groups for bleeding such as those over 75 years or with clinical indication for oral anticoagulant, stroke or TIA.
The trial involved 4579 patients who had received a drug eluting stent (Ultimaster, Terumo), who were randomly assigned to receive 30 days or 6 months of DAPT (predominantly clopidogrel or ticagrelor) and then followed up to 1 year.
The first primary outcome was a composite of net adverse clinical events that incorporated both ischaemic events (death, myocardial infarction, and stroke) and major bleeding.
For this outcome there was no difference between the abbreviated therapy group (7.5%) and the standard-therapy group (7.7%), which met the noninferiority criteria established for the trial (P<0.001).
For the other primary outcomes, in the abbreviated DAPT group 6.1% patients had a major adverse cardiac or cerebral event versus 5.9% of patients in the standard DAPT group (HR 1.02; 95% CI 0.80–1.30) a difference in risk of 0.11 percentage points (p=0.0014 for noninferiority).
Major or clinically relevant nonmajor bleeding was lower in the abbreviated versus standard DAPTgroup (6.5% versus 9.4%]; HR 0.68; 95% CI 0.55–0.84; p<0.001), a difference in risk of −2.82 percentage points.
The study investigators noted that the lower risk of bleeding in the abbreviated-therapy group was mainly due to the lower incidence of clinically relevant nonmajor bleeding events (BARC type 2) in this group than in the standard-therapy group (4.5% vs. 6.8%).
They concluded that a strategy of abbreviated DAPT after PCI in high bleeding risk patients would maintain the ischaemic benefits of therapy while reducing the risk of bleeding.
Principal investigator Professor Marco Valgimigli of Switzerland said the study was notable for not excluding patients with acute coronary syndrome or limiting the number, location, or complexity of the treated lesions.
“Our results can therefore inform treatment decisions on DAPT at one month after PCI in patients at high risk for bleeding without postprocedural ischaemic events, including those with clinical or angiographic high ischaemic risk features,” he said.
An accompanying commentary noted the findings were derived from only one kind of drug eluting stent and may not be applicable to all later-generation drug-eluting stents, “so caution should be used before short dual antiplatelet therapy is adopted more broadly.
Nevertheless, it concluded the findings “are important and move us toward a shorter and simpler antithrombotic strategy after PCI. Concomitant shorter antiplatelet monotherapy in the context of chronic disease after the implantation of a drug-eluting stent represents a major shift. This news is welcome for patients at high risk for bleeding after stent placement,”
Disclosure: The study was funded by Terumo.