Renal function and adverse cardiovascular events in patients with non-valvular atrial fibrillation.

Background: Both atrial fibrillation and renal dysfunction are associated with increased cardiovascular risk. The current study examined the association between renal function and incident ischemic stroke or myocardial infarction in patients with atrial fibrillation treated with direct oral anticoagulants (DOACs).

Methods: This study was conducted using the electronic health record database of Clalit Health Services in Israel. Included were 19,713 patients with first time diagnosis of non-valvular atrial fibrillation treated with DOACs between 2010-2018. Patients were categorized into 4 groups according to the estimated glomerular filtration rate (eGFR) (<30, 30-59,60-89, ≥90ml/min/1.73m²). Ischemic stroke and acute myocardial infarction rates were compared between the 4 groups.

Results: During 55,086 person-years of follow-up there were 2,295 (11.6%) cases of ischemic stroke and 1,158 (5.9%) cases of acute myocardial infarction. There was a significant inverse association between eGFR and the risk of myocardial infarction. A multivariate analysis using the group with eGFR≥90ml/min/1.73m² as a reference demonstrated an increased risk of myocardial infarction with lower eGFR. (HR=1.2 95% CI 0.9-1.4, HR=1.4, 95%CI 1.2-1.7 and HR=2.5, 95% CI 1.8-3.4 for patients with eGFR 60-89, 30-59, and <30ml/min/1.73m² respectively, p<0.001). Each 10ml decrease in eGFR was associated with an 8% increase in the risk of myocardial infarction. There was no association between eGFR and the risk of ischemic stroke (HR=0.9 95% CI 0.8-1.1, HR=0.93, 95% CI 0.8-1.1 and HR=1.1, 95% CI 0.8-1.4 for patients with eGFR 60-89, 30-59, and <30ml/min/1.73m² respectively, p=0.325).

Conclusions: Renal dysfunction is associated with an increased risk of myocardial infarction but not of ischemic stroke among patients with non-valvular atrial fibrillation treated with DOACs.