Real-World Comparative Study of Ultra-Low-Dose Rivaroxaban in Very Elderly Patients with Atrial Fibrillation

Area of Science:

• Cardiology
• Pharmacology
• Geriatrics

Background:

• Optimal rivaroxaban dosing in very elderly patients (≥80 years) with nonvalvular atrial fibrillation (AF) is debated.
• Clinician-judged ultra-low-dose (5 mg daily) regimens require real-world outcome evaluation.

Purpose of the Study:

• To compare real-world outcomes of clinician-selected rivaroxaban doses in very elderly nonvalvular AF patients.
• To assess the efficacy and safety of 5 mg, 10 mg, and 15/20 mg daily rivaroxaban doses.

Main Methods:

• Retrospective study of 1389 very elderly nonvalvular AF patients (2018-2022).
• Patients received rivaroxaban 5 mg, 10 mg, or 15/20 mg daily.
• Stabilized inverse probability of treatment weighting (IPTW) balanced baseline characteristics.

Main Results:

• No significant difference in composite efficacy outcomes (stroke, embolism, MI, CV death) across the three rivaroxaban dose groups after IPTW.
• Major bleeding rates increased dose-dependently: 1.6% (5 mg), 3.6% (10 mg), and 6.1% (15/20 mg).
• The 15/20 mg group had significantly higher major bleeding risk (HR: 4.27) versus the 5 mg group.

Conclusions:

• Ultra-low-dose rivaroxaban (5 mg daily) demonstrated comparable efficacy to higher doses in very elderly AF patients.
• The 5 mg daily regimen significantly reduced major bleeding compared to higher doses.
• Clinician-selected ultra-low-dose rivaroxaban may offer a balanced efficacy-safety profile for high-risk elderly populations.