Efficacy and safety of rivaroxaban compared with warfarin among elderly patients with nonvalvular atrial fibrillation in the Rivaroxaban Once Daily, Oral, Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF)

Background—Nonvalvular atrial fibrillation is common in elderly patients, who face an elevated risk of stroke but difficultysustaining warfarin treatment. The oral factor Xa inhibitor rivaroxaban was noninferior to warfarin in the Rivaroxaban OnceDaily, Oral, Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trialin Atrial Fibrillation (ROCKET AF). This prespecified secondary analysis compares outcomes in older and younger patients.Methods and Results—There were 6229 patients (44%) aged ≥75 years with atrial fibrillation and ≥2 stroke risk factorsrandomized to warfarin (target international normalized ratio=2.0–3.0) or rivaroxaban (20 mg daily; 15 mg if creatinineclearance <50 mL/min), double blind. The primary end point was stroke and systemic embolism by intention totreat. Over 10 866 patient-years, older participants had more primary events (2.57% versus 2.05%/100 patient-years;P=0.0068) and major bleeding (4.63% versus 2.74%/100 patient-years; P<0.0001). Stroke/systemic embolism rateswere consistent among older (2.29% rivaroxaban versus 2.85% warfarin per 100 patient-years; hazard ratio=0.80; 95%confidence interval, 0.63–1.02) and younger patients (2.00% versus 2.10%/100 patient-years; hazard ratio=0.95; 95%confidence interval, 0.76–1.19; interaction P=0.313), as were major bleeding rates (≥75 years: 4.86% rivaroxaban versus4.40% warfarin per 100 patient-years; hazard ratio=1.11; 95% confidence interval, 0.92–1.34; <75 years: 2.69% versus2.79%/100 patient-years; hazard ratio=0.96; 95% confidence interval, 0.78–1.19; interaction P=0.336). Hemorrhagicstroke rates were similar in both age groups; there was no interaction between age and rivaroxaban response.Conclusions—Elderly patients had higher stroke and major bleeding rates than younger patients, but the efficacy andsafety of rivaroxaban relative to warfarin did not differ with age, supporting rivaroxaban as an alternative for theelderly. (