Study on the Efficacy and Safety of Off-Label Dosing of Rivaroxaban in Chinese Nonvalvular Atrial Fibrillation Patients

Objective: This prospective cohort study aimed to systematically evaluate the clinical outcomes associated with off-label rivaroxaban regimens (10 mg vs. 15 mg daily) in elderly Chinese patients with nonvalvular atrial fibrillation (NVAF).

Methods: A hospital-based observational cohort was established at Pudong Hospital, Shanghai, in 2021, enrolling 247 consecutive NVAF patients receiving rivaroxaban therapy after obtaining institutional ethics approval and informed consent. Multivariable logistic regression analyses were performed to identify independent predictors of clinical outcomes.

Results: The cohort comprised 155 patients in 10 mg daily group and 92 patients in 15 mg daily group, with a mean age of 79 years. During 12-month follow-up, the 15 mg daily group demonstrated superior antithrombotic efficacy with significantly lower incidence of thrombotic events (15 mg: 1.50% vs. 10 mg: 5.90%, p = 0.017). Both regimens showed comparable safety profiles regarding bleeding events (15 mg: 10.90% vs. 10 mg: 13.90%, p = 0.302). Multivariate analysis identified CHA2DS2-VASc score as the primary predictor of thrombosis, while lower BMI, elevated HAS-BLED score, and diabetes mellitus emerged as independent bleeding predictors (all p < 0.05).

Conclusion: Rivaroxaban 15 mg daily showed better thromboembolic protection than 10 mg without increasing bleeding risk, supporting its use in selected high-risk elderly NVAF patients.