Association of Kidney Function With Risk of Adverse Effects of Therapies for Atrial Fibrillation

INTRODUCTION: Atrial fibrillation (AF) is common in chronic kidney disease (CKD) and is treated with rate control medications, antiarrhythmic medications, as well as anticoagulation and procedures, each of which have associated risks. We aimed to evaluate the association of CKD status with the risks of adverse effects after initiation of AF therapies. METHODS: This was a cohort study of community-based adults who newly initiated rate control medications, antiarrhythmic medications, warfarin, direct oral anticoagulants (DOACs) or received AF procedures in the 1 year after diagnosis of AF. Baseline estimated glomerular filtration rate (eGFR) was calculated using outpatient serum creatinine measures. Adverse effects within 1 year related to each AF therapy or within 1 month of an AF procedure were ascertained from vital sign databases, electrocardiograms (ECGs), and administrative codes. Fine-Gray hazard models were used to study the association of eGFR categories with risk of adverse effects for each AF therapy. RESULTS: Among 115,564 patients with incident AF, lower eGFR (vs. eGFR ≥60 ml/min per 1.73 m(2)) was significantly associated with higher adjusted risk of adverse effects after initiation of rate control therapies (most commonly hypotension and bradycardia) as follows: eGFR 45−59 (hazard ratio [HR] 1.14, 95% confidence interval [CI] 1.07−1.22), 30−44 (HR 1.15, 95% CI 1.06−1.25), and 15−29 (HR 1.29, 95% CI: 1.12−1.47) ml/min per 1.73 m(2). Lower eGFR was associated with higher adjusted risk of adverse effects (most commonly prolonged QRS and QTc intervals) after initiation of an antiarrhythmic medication (vs. eGFR >60 ml/min per 1.73 m(2)) as follows: eGFR 45−59 (HR 1.12, 95% CI 1.01−1.23) and eGFR<15 (HR 1.43, 95% CI 1.01−2.01) ml/min per 1.73 m(2). CONCLUSION: There was a graded association between lower eGFR and risk of major bleeding with warfarin use, with the greatest risk among those with eGFR <15 ml/min per 1.73 m(2) (HR of 2.93, 95% CI 1.99−4.30). There was no association of eGFR with major bleeding in patients receiving DOACs. Rates of adverse effects within 1 month of an AF procedure were low among patients with (n = 18) and without (n = 41) CKD and was underpowered for further analyses. In conclusion, lower eGFR was associated with significantly higher risks of adverse effects after initiation of commonly used therapies to treat AF. These data may help inform the complex therapeutic decisions in patients with CKD and AF.