The RE-DUAL PCI trial reported that dabigatran dual therapy (110/150 mg twice daily, plus clopidogrel or ticagrelor) reduced bleeding events versus warfarin triple therapy (warfarin plus aspirin and clopidogrel or ticagrelor) in patients with atrial fibrillation who underwent percutaneous coronary intervention, with noninferiority in composite thromboembolic events. In this prespecified analysis, risks of first major or clinically relevant nonmajor bleeding event and composite end point of death, thromboembolic events, or unplanned revascularization were compared between dabigatran dual therapy and warfarin triple therapy in older (≥ 75 years) and younger (< 75 years) patients, using Cox proportional hazard regression. Of 2,725 patients randomized to treatment, 1,026 (37.7%) were categorized into older and 1,699 (62.3%) into younger age groups. Dabigatran 110 mg dual therapy lowered bleeding risk versus warfarin triple therapy in older (hazard ratio [HR] 0.67; 95% confidence interval [CI] 0.51 to 0.89) and younger patients (HR 0.40; 95% CI 0.30 to 0.54); interaction p value: 0.0125. Dabigatran 150 mg dual therapy lowered bleeding risk versus warfarin triple therapy in younger patients (HR 0.57; 95% CI 0.44 to 0.74), whereas no benefit could be observed in older patients (HR 1.21; 95% CI 0.83 to 1.77); interaction p value: 0.0013. For the thromboembolic end point, there was a trend for a higher risk with dabigatran 110 mg dual therapy in older patients, compared with warfarin triple therapy, whereas the risk was similar in younger patients. For dabigatran 150 mg dual therapy, the thromboembolic risk versus warfarin triple therapy was similar in older and younger patients. In conclusion, the benefits of dabigatran dual therapy differed in the 2 age groups, which may help dose selection when using dabigatran dual therapy.