Washington, Aug 28 (ANI): The blood thinner warfarin should be prescribed with caution in some heart patients with kidney failure, say researchers who found that the drug was linked to an increased risk of stroke.

Wafarin is prescribed to reduce the risk of strokes in people with atrial fibrillation, the most common type of abnormal heart rhythm.

However, few studies have looked at whether warfarin also helps prevent strokes in atrial fibrillation patients who are on kidney dialysis.

To find out, Kevin Chan, Michael Lazarus, Raymond Hakim (Fresenius Medical Care North America); and Ravi Thadhani, (Massachusetts General Hospital), studied 1,671 end stage renal disease (ESRD) patients with a diagnosis of atrial fibrillation who started dialysis in clinics operated by Fresenius Medical Care North America. Patients’ health was monitored for an average of 1.6 years after dialysis was started.

The researchers found that patients who took warfarin increased their risk of stroke; however, the increase in risk was related to the degree of blood thinning in response to the drug.

Dialysis patients whose blood was not monitored for warfarin levels after they received the drug had the highest risk of stroke.

Notably, clopidogrel and aspirin-two other types of blood thinners-did not increase dialysis patients’ risk of stroke.

The researchers say that additional research is needed to determine why warfain has the opposite effect on stroke risk in kidney disease patients on dialysis compared with other individuals.

One possible explanation maybe because bleeding is a well-known complication of kidney failure and the concomitant use of blood thinners may exaggerate the risk of stroke from bleeding in the head.

The study appears in an upcoming issue of the Journal of the American Society Nephrology (JASN). (ANI)