Recurrent Events Analysis of MASTER DAPT: Total Ischemic and Bleeding Events After Abbreviated vs Prolonged DAPT in HBR Patient.

Background: The effect of dual antiplatelet therapy (DAPT) duration on total events in patients at high bleeding risk (HBR) after PCI is unclear.

Objective: We aimed at evaluating an abbreviated (median duration 34 days) versus prolonged DAPT (median duration 192 days) regimen on total events in 4579 HBR patients from the MASTER DAPT trial.

Methods: The MASTER DAPT co-primary outcomes at 335 days were: i) 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; ii) Major adverse cardiac and cerebral events (MACCE), including all-cause death, MI, and stroke, and iii) Major or Clinically Relevant Nonmajor Bleeding (MCB, type 2, 3, or 5 BARC bleeding). The differences between abbreviated and prolonged DAPT regimens were investigated using the Prentice, Williams, and Peterson model to account for recurrent events. Additional analyses were performed using the Andersen-Gill and the Poisson incidence rate models.

Results: In the abbreviated DAPT (n=2295) arm 214 NACEs occurred in 172 patients, compared with 227 NACEs in 182 patients in the prolonged DAPT arm (n=2284, HR 0.95 [0.78-1.16], p=0.64). A total of 156 MACCEs in 138 patients were observed in the abbreviated group compared with 160 MACCEs in 138 patients in the prolonged arm (HR 0.96 [0.76-1.20], p=0.69). Fewer total MCBs were observed in the abbreviated DAPT (180 MCBs in 148 patients) compared with the prolonged DAPT regimen (240 MCBs in 211 patients; HR 0.78 [0.64-0.94], p=0.011). Abbreviated DAPT patients had significantly fewer total cerebrovascular accidents and fewer total strokes compared with prolonged DAPT (34 events in 32 patients, HR 0.51 [0.28-0.91], p=0.023 and 25 events in 24 patients, HR 0.49, [0.25-0.98], p=0.04, respectively). One MACCE every five occurred after a bleeding and one bleeding every 25 occurred after a MACCE, emphasizing bleeding as a sentinel event.

Conclusions: One-month DAPT duration was associated with similar total NACE and MACCE and reduced total bleeding risk compared with prolonged DAPT. 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.