RIVER
Trial question
Is rivaroxaban noninferior to warfarin in patients with AF and a bioprosthetic mitral valve?
Study design
Multi-center
Open label
RCT
Population
Characteristics of study participants
60.0% female
40.0% male
N = 1005
1005 patients (607 female, 398 male).
Inclusion criteria: patients with AF and a bioprosthetic mitral valve.
Key exclusion criteria: contraindication to either rivaroxaban or warfarin; high bleeding risk; transient AF caused by surgery; placement of mechanical valves.
Interventions
N=500 rivaroxaban (oral dose of 20 mg daily).
N=505 warfarin (dose adjustment to maintain a target INR of 2.0 to 3.0).
Primary outcome
Time until death, major CV events, or major bleeding at 12 months
347.5 days
340.1 days
347.5 days
260.6 days
173.8 days
86.9 days
0.0 days
Rivaroxaban
Warfarin
Difference not exceeding
non-inferiority
margin ✓
Difference not exceeding non-inferiority margin in time until death, major CV events, or major bleeding at 12 months (347.5 days vs. 340.1 days; AD 7.4 days, 95% CI -1.4 to 16.3).
Secondary outcomes
No significant difference in CV death or thromboembolic events (3.4% vs. 5.1%; HR 0.65, 95% CI 0.35 to 1.2).
Significant decrease in stroke (0.6% vs. 2.4%; HR 0.25, 95% CI 0.07 to 0.88).
No significant difference in valve thrombosis (1% vs. 0.6%; HR 1.68, 95% CI 0.4 to 7.01).
Safety outcomes
No significant differences in major bleeding, nonmajor bleeding, other serious adverse events.
Conclusion
In patients with AF and a bioprosthetic mitral valve, rivaroxaban was noninferior to warfarin with respect to time until death, major CV events, or major bleeding at 12 months.
Reference
Helio P Guimarães, Renato D Lopes, Pedro G M de Barros E Silva et al. Rivaroxaban in Patients with Atrial Fibrillation and a Bioprosthetic Mitral Valve. N Engl J Med. 2020 Nov 26;383(22):2117-2126.
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