Why is this study important?

While dual antiplatelet therapy (DAPT) has long been the standard of care for the management of acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI), there is an increasing awareness of the need to find a more patient-centered approach that strikes a balance between the ischemic protection DAPT offers and the risk of bleeding complications it can create.

The effect of DAPT in dosage and duration on cardiovascular events and bleeding after implantation of drug-coated stents (DCS) in ACS patients, the 4D-ACS trial1, is a Korean trial in which 656 East Asian ACS patients were randomized 1:1 to either a 1-month DAPT with aspirin 100 mg and prasugrel 10 mg (patients ≥75 years or body weight <60 kg received 5 mg of prasugrel) followed by prasugrel 5 mg monotherapy (1M-DAPT) regimen or a 12-month DAPT protocol with aspirin and prasugrel 5 mg (12M-DAPT).

The primary endpoint was 12-month net adverse clinical events (NACE), defined as a composite of death, non-fatal myocardial infarction, stroke, ischemia-driven target vessel revascularization, and Bleeding Academic Research Consortium (BARC) type 2-5 bleeding.

What question was this study supposed to answer?

At 12 months, NACE occurred in 4.9% of the 1M-DAPT group and 8.8% of the 12M-DAPT group meeting criteria for both non-inferiority and superiority.

Major bleeding occurred in 0.6% vs 4.6% (HR 0.13; p=0.007) in the 1M-DAPT vs 12M-DAPT group, respectively. Ischemic outcomes were similar in both groups.

What did the study show?

The study demonstrates the benefit of a 1M prasugrel-based DAPT strategy followed by reduced-dose prasugrel monotherapy in ACS patients implanted with a drug-coated stent.

This approach significantly reduced net adverse clinical events without increasing ischemic events, primarily by lowering major bleeding.