This article is more than 5 years old. Information may no longer be current.
Warfarin may confer renal function decline vs. newer agents in AF
Decline in renal function is common in patients with atrial fibrillation treated with oral anticoagulants, but the extent may depend on which anticoagulant is used, researchers reported.
Direct oral anticoagulants, especially dabigatran (Pradaxa, Boehringer Ingelheim) and rivaroxaban (Xarelto, Janssen), may be less likely to cause adverse renal outcomes than warfarin, Xiaoxi Yao, PhD, from the Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery at Mayo Clinic in Rochester, Minnesota, and colleagues wrote.
The researchers analyzed 9,769 patients with nonvalvular AF from a U.S. administrative database who began one of four oral anticoagulants between Oct. 1, 2010, and April 30, 2016: apixaban (Eliquis, Bristol-Myers Squibb/Pfizer), dabigatran, rivaroxaban or warfarin.
The outcomes of interest were an at least 30% decline in estimated glomerular filtration rate (eGFR), doubling of serum creatinine level, acute kidney injury and renal failure.
Kidney risks
In the overall cohort, at 2 years, the cumulative risk was 24.4% for an at least 30% decline in eGFR, 4% for doubling of serum creatinine, 14.8% for acute kidney injury and 1.7% for renal failure, Yao and colleagues wrote.
“Regardless of treatment with warfarin or [direct oral anticoagulants], renal function decline is very common,” Yao and colleagues wrote. “Maintaining adequate renal function is particularly important in patients with AF treated with oral anticoagulant agents because worsening renal function has been shown to increase the risks of both stroke and bleeding further.”
Compared with patients assigned warfarin, patients assigned one of the three direct oral anticoagulants had reduced risk for an at least 30% decline in eGFR (HR = 0.77; 95% CI, 0.66-0.89), doubling of serum creatinine (HR = 0.62; 95% CI, 0.4-0.95) and acute kidney injury (HR = 0.68; 95% CI, 0.58-0.81), according to the researchers.
When Yao and colleagues compared each direct oral anticoagulant individually with warfarin, they found dabigatran conferred lower risk for an at least 30% decline in eGFR and acute kidney injury, and rivaroxaban conferred lower risk for an at least 30% decline in eGFR, doubling of serum creatinine and acute kidney injury, but there were no significant differences in outcomes between apixaban and warfarin.
“When choosing an oral anticoagulant agent, the impact of the drug on subsequent renal function may need to be considered,” the researchers wrote. “These data may shift the tipping point in many patients because some kidney outcomes (eg, 30% decline in eGFR and [acute kidney injury]) are often more common than stroke and major bleeding.”
Consistent findings
In a related editorial, Michael Walsh, MD, PhD, and Stuart J. Connolly, MD, both from the Population Health Research Institute and the department of medicine at McMaster University in Hamilton, Ontario, Canada, wrote that the findings “broadly agree with the findings of the randomized controlled trial data.”
“These analyses add a degree of refinement to the effect of [direct oral anticoagulants] on renal outcomes by showing consistency across a number of commonly accepted outcome definitions,” they wrote. “However ... it is unlikely that even the most sophisticated attempts cannot remove the biases that go into prescribing newer medications (typically prescribed to healthier individuals), or the differences in care given by health care providers for those prescribed newer agents.” – by Erik Swain
Disclosures: Yao and Walsh report no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures. Connolly reports he has received research support, consultant fees and lecture fees from Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Daiichi Sankyo, Janssen, Pfizer and Portola.