Abbreviated vs prolonged DAPT: Is shorter better for at-risk patients?

One-month treatment with dual antiplatelet therapy (DAPT) results in similar adverse events and a reduction in total bleeding risk when compared with prolonged DAPT, a study has shown.

A group of researchers compared an abbreviated (median duration 34 days) with a prolonged DAPT (median duration 192 days) regimen on total events in 4,579 high bleeding risk (HBR) patients in the MASTER DAPT trial.

The primary outcomes at 335 days were net adverse clinical events (NACE), the composite of all-cause death, myocardial infarction (MI), stroke, and Bleeding Academic Research Consortium (BARC) 3 or 5 bleeding events; major adverse cardiac and cerebral events (MACCE), including all-cause death, MI, and stroke; and major or clinically relevant nonmajor bleeding (MCB, types 2, 3, or 5 BARC bleeding).

Researchers examined the differences between abbreviated and prolonged DAPT regimens using the Prentice, Williams, and Peterson model to account for recurrent events. They also performed further analyses using the Andersen-Gill and the Poisson incidence rate models.

Overall, 214 NACEs occurred in 172 patients in the abbreviated DAPT arm (n=2,295) as opposed to 227 NACEs in 182 patients in the prolonged DAPT arm (n=2,284; hazard ratio [HR], 0.95, 95 percent confidence interval [CI], 0.78‒1.16; p=0.64).

For MACCEs, a total of 156 events occurred in 138 patients in the abbreviated group relative to 160 events in 138 patients in the prolonged group (HR, 0.96, 95 percent CI, 0.76‒1.20; p=0.69). Likewise, MCBs occurred less frequently in the abbreviated DAPT (180 events in 148 patients) than the prolonged DAPT regimen (240 MCBs in 211 patients; HR, 0.78, 95 percent CI, 0.64‒0.94; p=0.011).

Patients in the abbreviated DAPT arm also experienced fewer total cerebrovascular accidents (34 events in 32 patients; HR, 0.51, 95 percent CI, 0.28‒0.91; p=0.023) and fewer total strokes (25 events in 24 patients; HR, 0.49, 95 percent CI, 0.25‒0.98; p=0.04) than those in the prolonged DAPT arm.

Additionally, one MACCE every five occurred after a bleeding, and one bleeding occurred every 25 following a MACCE, indicating bleeding as a sentinel event.

“Providing a more comprehensive assessment of the total clinical burden, our findings support the use of an abbreviated duration of DAPT after PCI in HBR patients,” the researchers said.