Net Clinical Benefit of Antithrombotic Therapy in Patients With Atrial Fibrillation and Chronic Kidney Disease: A Nationwide Observational Cohort Study | Journal Scan
What is the net clinical benefit of warfarin anticoagulation in patients with atrial fibrillation (AF) and chronic kidney disease (CKD)?
Using a nationwide Danish registry, all hospitalized patients with AF and CKD were identified. Patients were stratified by CHA2DS2-VASc scores and the need for renal replacement therapy (RRT). The risk of stroke and net clinical benefit were estimated using Cox regression analyses. The net clinical benefit of warfarin was assessed using: 1) a composite endpoint of death/hospitalization from stroke/bleeding, 2) a composite endpoint of fatal stroke/fatal bleeding, 3) cardiovascular death, and 4) all-cause death.
Of the 154,259 patients with nonvalvular AF, 11,128 (7.2%) had non–end-stage CKD and 1,728 (1.1%) received RRT. In all CHA2DS2-VASc risk groups, RRT use was independently associated with a higher risk of stroke and thromboembolism. In AF patients receiving RRT with a CHA2DS2-VASc score ≥2, warfarin use was associated with a lower risk of all-cause death (hazard ratio [HR], 0.85; 95% confidence interval [CI], 0.72-0.99). In AF patients with non–end-stage CKD and a CHA2DS2-VASc score ≥2, warfarin use was associated with a lower risk of the composite endpoint including fatal stroke/fatal bleeding (HR, 0.71; 95% CI, 0.57-0.88), a lower risk of cardiovascular death (HR, 0.80; 95% CI, 0.74-0.88), and a lower risk of all-cause death (HR, 0.64; 95% CI, 0.60-0.69).
The authors concluded that CKD is associated with an increased risk of stroke and thromboembolism in AF patients. They also concluded that high-risk patients (CHA2DS2-VASc score ≥2) benefit from warfarin therapy for stroke prevention.
This nationwide cohort study confirms the association between CKD and the risk of stroke or thromboembolism in AF patients, as has been described in the R2CHADS2 score. However, unlike recent reports questioning the benefit of warfarin therapy in AF patients with CKD, this report suggests net clinical benefit for a number of important clinical outcomes. However, none of the assessed outcomes included nonfatal major bleeding, which is known to be highly prevalent in CKD patients treated with warfarin. Clinicians should be aware that their patients with CKD and AF are at high risk for both stroke and bleeding outcomes, necessitating careful risk/benefit discussions.
Keywords: Atrial Fibrillation, Fibrinolytic Agents, Hemorrhage, Hospitalization, Registries, Renal Insufficiency, Chronic, Renal Replacement Therapy, Risk, Stroke, Thromboembolism, Warfarin
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