Dual antiplatelet therapy (DAPT) for 1 month after percutaneous coronary intervention (PCI) lowered bleeding rates and was non-inferior for ischemic events compared with 3-month DAPT in patients at high bleeding risk, according to results of the MASTER DAPT trial.

Among the 4,579 patients in the intention-to-treat (ITT) population, major or clinically relevant non-major bleeding occurred in 6.5% of the 1-month group and in 9.4% of the 3-month group (P<0.001 for superiority), reported Marco Valgimigli, MD, PhD, of the Cardiocentro Ticino Foundation in Lugano, Switzerland.

“One month of dual antiplatelet therapy after percutaneous coronary intervention in high bleeding risk patients maintained the ischemic benefits of therapy while reducing the risk of bleeding,” he said during a press conference at the European Society of Cardiology (ESC) virtual meeting. “Unlike other studies, we did not exclude patients with acute coronary syndrome or limit the number, location, or complexity of the treated lesions.” Results were simultaneously published in the New England Journal of Medicine (NEJM).

Valgimigli pointed out that the trial population was “highly selected” because of their high bleed risk, “and in that space, this is an all-comers HBR [high bleeding risk] population. We have already seen from prior studies that if you are HBR, you don’t derive ischemic benefit by prolonged DAPT, you only derive bleeding risks; however, that has never been prospectively tested.”

The other primary endpoints of the non-inferiority study indicated that 1-month DAPT did not increase the risk of major adverse cardiovascular events (MACE), with net adverse clinical events (NACE) occurring in 7.5% of the 1-month group and 7.7% of the 3-month group (95% CI −1.80 to 1.33, P<0.001 for non-inferiority). Also, a major adverse cardiac or cerebral event occurred in 6.1% and 5.9%, respectively (95% CI −1.29 to 1.51, P=0.0014 for non-inferiority).

The positive results will likely be reflected in the next version of the ESC guidelines for stenting, suggested Carlos Aguiar, MD, of the Hospital Santa Cruz, Centro Hospitalar Lisboa Ocidental in Lisbon, Portugal. Aguiar was not involved in the trial.

“We are likely to see a change in the level of evidence in the guidelines from expert opinion to a more scientific level of evidence, and time for treatment could be pushed back to 1-month for acute coronary syndrome patients,” Aguiar, who is also head of the ESC communications committee, told MedPage Today. “It should be noted that this is a stent-specific study [biodegradable-polymer sirolimus-eluting stent, Ultimaster, Terumo]. I would not generalize these results to other stents.”

ESC spokesperson Kurt Huber, MD, of the Wilhelminen hospital in Vienna, noted that “With this stent, we know that the re-endothelial vascularization is complete in 3-4 weeks, which in theory makes it possible to stop [DAPT] early, and this should usually be done in patients with a high bleeding risk.”

“We give these patients 1 to 3 months of dual antiplatelet therapy, especially in patients with acute coronary syndrome [ACS],” he told MedPage Today. “It will be interesting to see if the acute coronary syndrome patients did as well as the stable patients on 1-month of therapy” when the study is further analyzed.

MASTER DAPT was conducted from February 2017 to December 2019 at 140 sites in 30 countries. Mean patient age was 76, and 69.3% of the patients were men. A little over a third had diabetes. Nearly half had undergone coronary intervention for an acute ACS.

Valgimigli explained that the three ranked primary outcomes were:

• NACE: a composite of death from any cause, myocardial infarction, stroke, or major bleeding
• MACE: a composite of death from any cause, MI, or stroke
• Major or clinically relevant non-major bleeding

Cumulative incidences were assessed at 335 days. The first two outcomes were assessed for non-inferiority in the per-protocol population, and the third outcome for superiority in the ITT population.

Study limitations included the open-label design and the fact that the “duration of dual antiplatelet therapy in the two trial groups was longer than is now recommended in patients receiving oral anticoagulation,” such as those from the ESC/European Association for Cardio-Thoracic Surgery.

In an NEJM accompanying editorial, E. Magnus Ohman, MBBS, of the Duke Clinical Research Institute in Durham, North Carolina, noted that “The findings of Valgimigli and colleagues 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.”