P2243The effect of age on the efficacy and safety of dabigatran dual therapy in atrial fibrillation after PCI: a subgroup analysis from the RE-DUAL PCI trial

Abstract

Background: The RE‐DUAL PCI study (NCT02164864) compared dabigatran dual antithrombotic therapy (D‐DAT) with warfarin triple antithrombotic therapy (WTAT) in patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI). As previously reported D‐DAT reduced bleeding compared with W‐TAT and was non‐inferior with regard to thromboembolic events. Aim: The aim of this subgroup analysis of RE‐DUAL was to assess the treatment effects of D‐DAT and W‐TAT on bleeding and thromboembolic outcomes in older and younger patients. Methods: Patients were randomized to receive W‐TAT (warfarin, clopidogrel or ticagrelor, and aspirin) or D‐DAT (dabigatran 110 or 150 mg twice daily with clopidogrel or ticagrelor; D110‐ or D150‐DAT). Younger patients (aged <80 yrs [<70 yrs in Japan]) and US patients irrespective of age received D110‐DAT, D150‐ DAT or W‐TAT; older patients (aged ≥80 yrs in non‐US countries [≥70 yrs in Japan]) received only D110‐DAT or W‐TAT. Bleeding and thromboembolic outcomes were assessed according to treatment group and these age categories (older vs younger). Results: A total of 2725 patients were randomized: 458 patients were older and 2267 patients were younger. At baseline, 69.2% of the older group were male compared with 77.3% of the younger group. The mean CHA2DS2‐VASc and modified HAS‐BLED score was 4.6 and 3.0, respectively, in older patients compared with and 3.4 and 2.6, respectively, in the younger patients. Age did not change the treatment effect of D110‐ or D150‐DAT vs W‐TAT with regard to the composite efficacy endpoint of death, thromboembolic events or unplanned revascularization (interaction p values were not significant; figure). Consistent treatment effects of D110‐DAT vs W‐TAT for the primary safety endpoint of major bleeding events or clinically relevant non‐major bleeding events were observed for both older and younger patients (older HR 0.67, 95% CI 0.47‐0.97, younger: HR 0.46, 95% CI 0.37‐0.59); no interaction between treatment and age subgroup. For the primary safety endpoint, a risk reduction was also seen with D150‐DAT vs W‐TAT in younger patients (HR 0.69, 95% CI 0.55‐0.85). Although an interaction was observed for D150‐DAT vs W‐TAT in older patients (with potential increased bleeding in the older patients and reduced bleeding in the younger), the number of older patients in the D150‐DAT group were only eight. Conclusion: The benefit of dabigatran 110 mg dual therapy vs warfarin triple therapy was consistent across age groups, and dabigatran 150 mg dual therapy was beneficial compared to warfarin triple therapy in younger patients aged <80 yrs [<70 yrs in Japan]. The very small group of patients ≥80 years (≥70 in Japan) treated with dabigatran 150mg dual therapy had high bleeding rates which may suggest that dabigatran 110 mg dual therapy should be preferred in those older patients. However, the small number of older patients was too small to draw any firm conclusion.