Are Anticoagulants Useful for CKD Patients with Atrial Fibrillation?

Anticoagulants don’t reduce the risk of stroke in older adults with atrial fibrillation and chronic kidney disease, suggests a study in Kidney International.

The researchers analyzed data on 6544 Ontario residents aged 66 years or older with advanced CKD—estimated glomerular filtration rate less than 45 mL/min/1.73 m2—and atrial fibrillation. Of these, 1475 filled an anticoagulant prescription, mainly for vitamin K antagonists. Propensity matching was used to identify 1417 matched pairs with or without anticoagulation; median follow-up was 269 and 254 days, respectively. Risks of ischemic stroke, hemorrhagic events, or death were compared between groups.

The rate of ischemic stroke was not significantly different for patients with and without an anticoagulant prescription: 41.3 and 34.4 per 1000 person-years, respectively. But hemorrhagic events were significantly more frequent in the anticoagulation group: 61.3 versus 34.3 per 1000 person-years, hazard ratio (HR) 1.42. In contrast, all-cause mortality was significantly lower in patients receiving anticoagulants: 122.6 versus 136.3 per 1000 person-years, HR 0.74.

In competing risk models, there was still no significant difference in ischemic stroke risk. For hemorrhagic events, the HR increased to 1.60 in the anticoagulation group. Sensitivity analysis accounting for variations in time of anticoagulant exposure yielded similar patterns.

It has been unclear whether anticoagulant therapy reduces the risk of stroke related to atrial fibrillation in patients with CKD. No studies have addressed this issue specifically in elderly CKD patients, who have a high incidence of atrial fibrillation.

This matched case-control study finds no reduction in ischemic stroke risk with anticoagulants among patients with atrial fibrillation and advanced CKD. Anticoagulation is also associated with increased bleeding risk, but lower all-cause mortality. Decisions about anticoagulation in elderly patients with atrial fibrillation and stage 3b to 5 CKD should be based on individual assessment of risks and benefits [Keskar V, et al. The association of anticoagulation, ischemic stroke, and hemorrhage in elderly adults with chronic kidney disease and atrial fibrillation. Kidney Int 2017; 91:928–936].

April 2017 (Vol 9, Number 4)