Impact of three major risk factors on clinical outcomes in patients with nonvalvular atrial fibrillation receiving rivaroxaban: Sub-analysis from the XAPASS study

Background: To evaluate the impact of three risk factors (age [≥75 years], renal impairment [creatinine clearance <50 ml/min], and low body weight [≤50 kg]) on the risk of any bleeding events, all-cause mortality, and stroke, non-central nervous system (non-CNS) systemic embolism (SE), and myocardial infarction (MI) in patients with nonvalvular atrial fibrillation (NVAF) treated with rivaroxaban in a real-world clinical setting. Methods: The Xarelto Post-Authorization Safety and Effectiveness Study in Japanese Patients with Atrial Fibrillation (XAPASS) is a prospective, single-arm, observational study. Enrolled patients were divided into four subgroups by the number of risk factors. Results: Overall, 9823 patients were included: 4299 with low risk, 2816 with moderate risk, 1574 with high risk, and 1134 with very high risk. The hazard ratios (95% confidence interval) (reference: low risk) for the moderate-, high-, and very-high-risk groups were 1.62 (1.19, 2.21) (p = 0.002), 2.15 (1.47, 3.15) (p < 0.001), and 2.49 (1.60, 3.87) (p <0.001) for major bleeding, and 1.98 (1.47, 2.66), 2.29 (1.59, 3.29), and 2.74 (1.81, 4.16) (p <0.001 for all) for stroke/non-CNS SE/MI, respectively. Conclusions: Age ≥75 years and renal impairment, but not low body weight, were determinants for major bleeding. The accrual of three risk factors was associated with increased risk for major bleeding and stroke/non-CNS SE/MI in patients with NVAF receiving rivaroxaban; there was no increase in the cumulative risk for these with an increasing number of risk factors.