Abstract P036: Little Evidence Of Association Between Kidney Function And Subclinical Arrhythmias Measured By Extended Ambulatory Cardiac Monitoring: The Multi-Ethnic Study Of Atherosclerosis (MESA)
Authors: Wiggins Kerri L , Floyd James S , Bansal Nisha , Kestenbaum Bryan , Heckbert Susan R 
Published: May 2021

Introduction:
Chronic kidney disease (CKD) patients are at high risk for atrial fibrillation (AF) and ventricular arrhythmias. Arrhythmias are often asymptomatic and not detected clinically, so the true prevalence among CKD patients is unknown. Extended ambulatory cardiac monitoring is a sensitive and unbiased method for detecting arrhythmias.

Hypothesis:
We assessed the hypothesis that impaired kidney function is associated with atrial and ventricular arrhythmias as measured by extended ambulatory cardiac monitoring.

Methods:
In the Multi-Ethnic Study of Atherosclerosis (MESA), kidney function was assessed at the 2016-2018 study visit: estimated glomerular filtration rate (eGFR) using the 2009 Chronic Kidney Disease Epidemiology Collaboration creatinine equation and urinary albumin-creatinine ratio (UACR). UACR was log
2
transformed for analysis. At the same visit, extended ambulatory cardiac monitoring was conducted for up to two 14-day periods per participant using the Zio Patch XT (iRhythm Technologies, Inc., San Francisco, CA). Device information was consolidated for participants with 2 devices, and 7 arrhythmia outcomes were studied: presence of monitor-detected AF (>30 seconds), presence of subclinical AF (in those with no history of clinically detected AF), frequency of premature atrial contractions, frequency of runs of ≥ 4 beats of supraventricular tachycardia (SVT), frequency of premature ventricular contractions, presence of runs of ≥ 4 beats of ventricular tachycardia (VT), and frequency of runs of VT. Continuous outcome variables were natural log transformed. Analyses used logistic regression for binary outcomes and linear regression for continuous outcomes, adjusted for demographic and clinical risk factors.

Results:
A total of 1459 participants had eGFR measures and 1369 had UACR measures; 178 had a history of clinically detected AF. Mean (standard deviation (SD)) age was 74 (8) years; with 52% women. Median (interquartile range) kidney function measures were eGFR 77 (62, 88) ml/min/1.73 m
2
and UACR 6 (3, 18) mg/g, and total monitoring duration was 14 (14, 26) days. AF was detected in 7%, all but one participant had supraventricular ectopy, and 99% had ventricular ectopy. A doubling of UACR was associated with increased odds of monitor-detected AF (odds ratio 1.18; 95% confidence interval (CI): 1.06-1.32) while eGFR was not significantly associated. Neither eGFR nor UACR was associated with subclinical AF or with ventricular arrhythmias. The analysis of eGFR and frequency of runs of SVT yielded results opposite of the expected direction: a 10 ml/min/1.73 m
2
greater eGFR was associated with a 7% greater frequency of SVT (95% CI: 1%-12%).

Conclusion:
In summary, in a large population of older individuals across a wide range of kidney function, we found little evidence that impaired kidney function was associated with increased monitor-detected arrhythmias.