Relationship between Chronic Kidney Disease, Time-in-Therapeutic Range, and Adverse Outcomes in Atrial Fibrillation: A post hoc Analysis from the AMADEUS Trial.

BACKGROUND: The benefit of anticoagulation therapy in atrial fibrillation (AF) and chronic kidney disease (CKD) remains controversial. We aimed to evaluate the impact of renal function on the quality of anticoagulation control, and the effects of both these factors on outcomes in AF. METHODS: Post hoc analysis of the AMADEUS trial. Trial-related outcomes were adjudicated and we studied the composite of first stroke/major bleeding/all-cause mortality, ischaemic stroke, major bleeding, all-cause mortality, and cardiovascular mortality. RESULTS: We included 2,282 vitamin K antagonist (VKA)-treated patients {n = 787 (34.5%) females; median age 72 (interquartile ranges [IQR] 64-77) years}. Median follow-up was 365 (IQR 189-460) days. There were 1,922 (84.2%) non-CKD and 360 (15.8%) CKD patients. Renal function was inversely correlated with time-in-therapeutic range (r = -0.047, p = 0.025). There was no statistical difference in terms of crude study outcomes based on renal function. Multivariable regression analysis demonstrated that moderate renal failure with estimated glomerular filtration rate of less than 60 mL/min/1.73 m2 (p = 0.032) and percentage of time-in-therapeutic range (p = 0.011) were independent predictors for the composite outcome of stroke, major bleeding, and all-cause mortality. CONCLUSION: Deteriorated renal function has a small negative impact on the quality of anticoagulation control with VKA which is linked to poor outcomes in AF. However, moderate renal failure itself was an independent risk factor for increased risk of stroke, major bleeding, and all-cause mortality amongst patients with AF.