Atrial fibrillation (AFib) patients taking non-vitamin K antagonist oral anticoagulants (DOACs) experience less renal function decline than those taking warfarin, according to a new study published in the Journal of the American College of Cardiology
Xiaoxi Yao, PhD, and colleagues of the Mayo Clinic in Rochester, Minnesota, compared the safety of dabigatran, rivaroxaban, apixaban, and warfarin in 9769 patients with nonvalvular AFib from the nationwide Optum Labs Data Warehouse. At 2 years, the cumulative risk for a 30% or more decline in estimated glomerular filtration rate (eGFR), doubling of serum creatinine, acute kidney injury (AKI), and kidney failure was 24%, 4%, 14.8%, and 1.7%, respectively, according to Cox proportional hazards regression. Compared with warfarin, the 3 DOACs were associated with a 23%, 38%, and 32% lower risk for eGFR decline, doubled serum creatinine, and AKI, respectively. Compared with warfarin, dabigatran was associated with a lower risk of a 30% or greater decline in eGFR and AKI, and rivaroxaban was associated with lower risks of a 30% or greater decline in eGFR, doubling of serum creatinine, and AKI. Apixaban was not significantly associated with any of the renal outcomes.
The findings “underscore the need for periodic monitoring of renal function and comprehensive efforts to prevent and treat progressive CKD,” Dr Yao and the team stated. With regard to choice of oral anticoagulant and dosing, each drug’s relative risks and benefits need to be weighed. The investigators suggested that it is premature to prefer dabigatran and rivaroxaban to apixaban, given apixaban’s merits. The jury is still out on the vitamin K agonist (VKA) warfarin. Patients taking warfarin with international normalized ratios above 3 may have higher risks for adverse renal outcomes. Since these data are observational, confirmatory clinical trials are needed.
“Just as I do with my own patients, I encourage conversations on these risks and benefits between patients and their providers,” senior author Peter Noseworthy, MD, stated in a Mayo Clinic press release. “Each patient’s situation is different, so each medication decision must be made based on the individual’s lifestyle and diet, other illnesses and medications, out-of-pocket costs, and so forth.”
“Switching patients from VKAs to DOACs to preserve their renal function is probably not broadly warranted at this time given the unclear magnitude of effects,” Michael Walsh, MD, PhD, and Stuart J. Connolly, MD, commented in an accompanying editorial. “However, for patients at high risk of progressive loss of kidney function who do not have a contraindication to a DOAC, the putative renal benefits are 1 more reason to choose a DOAC over a VKA.”
Yao X, Tangri N, Gersh BJ, et al. Renal outcomes in anticoagulated patients with atrial fibrillation. J Am Coll Cardiol 2017;70:2621–32. doi: 10.1016/j.jacc.2017.09.1087
Walsh M and Connolly SJ. Another dimension of safety in the prescription of anticoagulants for nonvalvular atrial fibrillation. J Am Coll Cardiol 2017. doi: 10.1016/j.jacc.2017.09.1103
New oral anticoagulant drugs associated with lower kidney risks [news release]. Mayo Clinic; November 20, 2017.