Dual antithrombotic therapy with dabigatran in patients with atrial fibrillation after percutaneous coronary intervention for ST-segment elevation myocardial infarction: a post hoc analysis of the randomised RE-DUAL PCI trial

Background: Little is known about the optimal antithrombotic  therapy in patients with atrial fibrillation undergoing PCI for ST-elevation myocardial infarction (STEMI).

Aims: The aim of this study was to investigate the safety and efficacy of dabigatran dual therapy (110 or 150 mg twice daily, plus clopidogrel or ticagrelor) versus warfarin triple therapy in patients with atrial fibrillation and STEMI.

Methods: In the RE-DUAL PCI trial, 305 patients with STEMI were randomised to dabigatran 110 mg (n=113 versus 106 warfarin) or 150 mg (n=86 versus 84 warfarin). The primary endpoint was the time to first major/clinically relevant non-major bleeding event (MBE/CRNMBE). The thrombotic endpoint was a composite of death, thromboembolic events, or unplanned revascularisation.

Results: In STEMI patients, dabigatran 110 mg (HR 0.39, 95% CI: 0.20-0.74) and 150 mg (0.43, 0.21-0.89) dual therapy reduced the risk of MBE/CRNMBE versus warfarin triple therapy (p for interaction vs all other patients=0.31 and 0.16). The risk of thrombotic events for dabigatran 110 mg (HR 1.61, 95% CI: 0.85-3.08) and 150 mg (0.56, 0.20-1.51) had p interactions of 0.20 and 0.33, respectively. For net clinical benefit, the HRs were 0.74 (95% CI: 0.46-1.17) and 0.49 (0.27-0.91) for dabigatran 110 and 150 mg (p for interaction=0.80 and 0.12), respectively.

Conclusions: After PCI for STEMI, patients on dabigatran dual therapy had lower risks of bleeding events versus warfarin triple therapy with similar risks of thromboembolic events, supporting dabigatran dual therapy even in patients with high thrombotic risk.