Single Month of Dual Antiplatelet Therapy Noninferior to Continued Therapy After PCI

Marco Valgimigli, MD, PhD

Although the effectiveness of drug-eluting stents in those with high bleeding risk receiving dual antiplatlet therapy after percutaneous coronary intervention (PCI) is known, it is still unclear what is the appropriate duration of dual antiplatelet therapy for these patient populations.

As a result, a recent study performed a randomized trial of patients at high risk for bleeding who had undergone implantation of a biodegradable-polymer sirolimus-eluting stent to evaluate 1 month of dual antiplatelet therapy compared with a longer course of dual antiplatelet therapy.

The study was presented online at the European Society of Cardiology (ESC) 2021 Congress.

Investigators, led by Marco Valgimigli, MD, PhD, Cardiocentro Ticino Institute, found 1 month of dual antiplatelet therapy was noninferior to the continuation of therapy for ≥2 additional months in term of the occurrence of net adverse clinical events and major adverse cardiac or cerebral events.

Methods

The team used the Management of High Bleeding Risk Patients Post Bioresorbable Polymer Coated Stent Implantation with an Abbreviated versus Standard DAPT Regimen (MASTER DAPT) trial, a investigator-initiated, multi-center, randomized, open-label, non inferiority trial.

It included patients who had undergone an acute or chronic coronary syndrome, had undergone successful PCI for ≥1 coronary-artery stenoses with implantation of a biodegradable-polymer sirolimus-eluting stent, and met ≥1 criteria for high bleeding risk.

Eligibility also included a requirement to be free from adverse cardiovascular (CV) events during the first month after index PCI. In addition, patients free from ischemic and active bleeding events, as well as dual antiplatelet therapy regimen were screened for inclusion in the trial.

Patients were randomized 1:1 to receive either open-label abbreviated dual antiplatelet therapy (abbreviated therapy) or standard dual antiplatelet therapy (standard therapy). The team noted the abbreviated therapy group discontinued dual antiplatelet therapy and continued single antiplatelet therapy until the completion of the trial, while patients assigned to the standard-therapy group continued dual antiplatelet therapy for ≥5 additional months.

Investigators included 3 ranked primary outcomes as net adverse clinical events, major adverse cardiac or cerebral events, and major or clinically relevant non-major bleeding. The first 2 outcomes were assessed for non-inferiority in the per-protocol population and the 3rd outcome for superiority in the intention-to-treat group.

Results

A total of 5204 patients underwent screening between February 2017 - December 2019, with 4579 patients (88.0%) randomly assigned to either the abbreviated-therapy group (n = 2295) or the standard-therapy group (n = 2284).

In terms of characteristics, the mean age of the patients was 76.0 years, 69.3% of the patients were men, while 33.6% had diabetes, 19.1% had chronic kidney disease (CKD), and 18.9% had heart failure. After patients withdrew from the study, a total of 4434 patients were included in the per-protocol population.

In this patient population, net adverse clinical events occurred in 165 patients (7.5%) in the abbreviated-therapy group and 172 (7.7%) in the standard therapy group (difference, -0.23%; 95% CI, -1.80 to 1.33, P <.001).

Further, in the same population, 133 patients (6.1%) in the abbreviated-therapy group and 132 patients (5.9%) in the standard-therapy group had a major adverse cardiac and cerebral event (HR 1.02, 95% CI, 0.80 - 1.30) for a 0.11 percentage point risk difference (95% CI, -1.29 to 1.51, P = .001 for non-inferiority).

On the other hand, among the 4579 patients in the intention-to-treat population, the incidence of non-major bleeding was lower in patients in the abbreviated-therapy group compared to patients in the standard-therapy group (148 patients versus 211 patients; HR 0.68, 95% CI, 0.55 - 0.84) for a difference in risk of -2.82 percentage points (95% CI, -4.40 to 1.24, P <.001).

Conclusion

Investigators determined a single month of dual antiplatelet therapy was non-inferior to the continuation of therapy for ≥2 additional months, while abbreviated therapy resulted in lower incidence of clinically relevant non-major bleeding.

“The incidences of net adverse clinical events and major adverse cardiac and cerebral events were lower than expected, and non inferiority margins were wide; therefore, a modest increase in the incidence of such events cannot be ruled out with this duration of abbreviated therapy,” investigators wrote.

In a follow-up commentary to the study, Erik M. Ohman, MBBS, Division of Cardiology, Duke Clinical Research Institute, noted that the use of abbreviated therapy may not be applicable to all drug-eluting strengths, so it is important to use caution before short dual antiplatelet therapy becomes more widely available.

However, Ohman noted the findings were important to move treatment toward a shorter anti-thrombotic 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,” Ohman wrote. “This news is welcome for patients at high risk for bleeding after stent placement.”

The study, “Dual Antiplatelet Therapy after PCI in Patients at High Bleeding Risk,” was published in the New England Journal of Medicine.