Warfarin Benefited AFib Patients With Kidney Disease

Atrial fibrillation patients with kidney disease may safely lower heart risks with warfarin

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) For those with atrial fibrillation, warfarin helps reduce stroke and heart attack risk. While some have questioned the safety of its use with kidney patients, the medication appears to improve outcomes.

Warfarin (brand names Coumadin, Jantoven) is a blood thinner commonly used to prevent blood clotting in those living with atrial fibrillation (AFib), a common heart rhythm abnormality. The medication, however, has been linked to an increased risk of bleeding, especially among those with chronic kidney disease (CKD).

Although some research has suggested that warfarin increases the likelihood of heart attack, stroke and death for CKD patients, a new study found that the medication did not heighten these risks nor the risk of bleeding among those with impaired kidney function.

"Work with a cardiologist to prevent complications of AFib."

Juan Jesús Carrero, PhD, assistant professor in the Division of Renal Medicine at the Karolinska Institutet in Stockholm, Sweden, and colleagues examined data on 24,317 individuals with atrial fibrillation from a Swedish registry of patients who had experienced a heart attack. Of these patients, 5,292 individuals were treated with warfarin after leaving the hospital.

More than half (52 percent) had moderate CKD or worse. The authors evaluated kidney health based on estimated glomerular filtration rates (eGFRs), a measure of kidney function.

Dr. Carrero and team discovered that patients taking warfarin had a lower one-year composite risk of death, heart attack and stroke without a higher risk of bleeding compared to those who did not take warfarin. They also noted the lower risk among patients with moderate, severe or end-stage CKD.

For those with severe CKD (measured as an eFGR of 15 to 30), 53.2 percent of the patients taking warfarin experienced death, heart attack, or stroke versus 61 percent of those who did not take warfarin.

For those with end-stage renal failure (eGFR less than or equal to 15), death, heart attack and stroke happened in 53 percent in the warfarin group versus 66 percent in the non-warfarin group.

The researchers also found that CKD patients had no greater risk of bleeding compared to those without CKD.

Dr. Carrero told dailyRx News, “Our study may suggest that patients with atrial fibrillation and renal disease not requiring dialysis can also benefit from warfarin therapy and thus should not be excluded from this treatment option.”

He added, “This study includes individuals with kidney disease not requiring dialysis. The evaluation of warfarin safety in dialysis patients still is not fully established.”

The study was published March 5 in the Journal of the American Medical Association (JAMA). The work was supported by a grant from the Swedish Foundation for Strategic Research.

Review Date: 
March 4, 2014
Last Updated:
March 6, 2014