Implantable Loop Recorder Monitoring and the Incidence of Previously Unrecognized Atrial Fibrillation in Patients on Hemodialysis

INTRODUCTION: Atrial fibrillation (AF) is common in patients with kidney failure on hemodialysis (KF-HD). We determined both AF incidence and burden in patients with KF-HD using implantable loop recorder (ILR) monitoring. METHODS: Patients with KF-HD were enrolled and received an ILR. In 6 monitoring months, the incidence of AF events lasting ≥6 minutes was captured. Demographic, clinical, and dialysis characteristics were collected, and associations with incident AF were estimated using negative binomial regression models and expressed as incidence rate ratios and 95% CIs. RESULTS: We enrolled 66 patients with KF-HD (mean age = 56 years, 70% male); 59 (90%) were without previously diagnosed AF. AF lasting ≥6 minutes was detected in 18 of 59 subjects (31%) without previously diagnosed AF and in 5 of 7 subjects (71%) with a previous AF diagnosis. Among the 23 with detected AF, episodes were present on 16% of patient days. Although 14 of 23 patients (61%) had AF on <5% of monitored days, the average duration of AF episodes was <1 hour in 13 of 23 patients (52%). Among patients with AF ≥6 minutes, 19 of 23 (83%) had a CHA(2)DS(2)-VASc score ≥2. When investigating individual HD parameters, higher dialysate calcium (>2.5 vs. 2.5 mEq/l: incidence rate ratio = 0.62; 95% CI, 0.48–0.80) was associated with lower AF risk whereas higher dialysate bicarbonate concentrations (>35 vs. 35 mEq/l: incidence rate ratio = 3.18; 95% CI, 1.13–8.94) were associated with higher AF risk. CONCLUSION: New AF was detected in approximately one-third of patients with KF-HD. AF affects a substantial proportion of patient days and may be an underappreciated cause of stroke in KF-HD.