Rivaroxaban preserves renal function better than warfarin in NVAF patients

In treating nonvalvular atrial fibrillation (NVAF) patients, rivaroxaban carries a lower risk of renal decline than warfarin, a recent study has found.

Drawing from primary care electronic health records from the UK, researchers assessed NVAF patients treated with either rivaroxaban (n=5,338) or warfarin (n=6,314). Only those with preserved renal function at baseline (estimated glomerular filtration rate [eGFR] ≥50 mL/min/1.73m²) were eligible; those with end-stage renal disease (ESRD) or without available eGFR measurements were excluded.

The primary outcomes of interest were the doubling of serum creatinine (SCr), a ≥30-percent decline in eGFR, and progression to ESRD. After a mean follow-up of 2.5 years, the number of incident cases for the respective outcome measures were 322, 1,179, and 22.

Looking at cumulative incidence estimates and performing Cox proportional hazards regression analyses revealed the significant advantage of rivaroxaban over warfarin. For instance, doubling of SCr occurred more frequently in the warfarin arm, corresponding to a significantly higher risk estimate (128.9 vs 77.8 events per 10,000 person-years; adjusted hazard ratio [HR], 0.63, 95 percent confidence interval [CI], 0.49–0.81).

The same was true for a ≥30-percent decline in eGFR (469.1 vs 359.8 person-years; adjusted HR, 0.76, 95 percent CI, 0.67–0.86), but not for progression to ESRD (adjusted HR, 0.77, 95 percent CI, 0.29–2.04).

Slope analysis likewise showed that rivaroxaban significantly slowed renal function decline relative to warfarin (mean rate, 1.65 vs 2.03 mL/min/1.72m² per year; difference, 0.39, 95 percent CI, 0.04–0.74; p=0.03).