Outcomes in VKA-treated patients with atrial fibrillation and chronic kidney disease: Clinical trials vs 'real-world'

BACKGROUND: Our objectives were to evaluate the risk of adverse events in a 'real-world' vs 'clinical trial' cohort of atrial fibrillation (AF) patients with chronic kidney disease (CKD).

METHODS: We studied patient-level data for vitamin K antagonist-treated AF patients with a creatinine clearance <60 mL/min from the Murcia AF Project and AMADEUS trial. The study end-points were ischaemic stroke, major bleeding, all-cause mortality, myocardial infarction and intracranial haemorrhage.

RESULTS: This study included 1,108 AF patients with CKD. The annual rate of the composite study outcome of ischaemic stroke, major bleeding and all-cause mortality was higher in the real-world (13.4%) vs AMADEUS (6.6%) cohort with an IRR of 2.04 (95% CI,1.34-3.09), P < .001. Individual annual rates of major bleeding, all-cause mortality and non-cardiovascular mortality were significantly greater in the real-world cohort. Similar findings were demonstrated even after multivariable adjustment, with the composite outcome HR of 2.85 (95% CI,1.74-4.66), P < .001. In a propensity score matched cohort, this risk remained significantly higher in the real-world cohort (IRR 2.95 [95% CI,1.03-10.28], P = .027), as did the risk of major bleeding and all-cause mortality.

CONCLUSION: Vitamin K antagonist-treated AF patients with CKD are exposed to significant annual rates of major adverse events including all-cause mortality. This risk may be under-appreciated in the idealised environment of randomised controlled trials.