Post-discharge electrocardiogram Holter monitoring in recently hospitalised individuals with chronic atrial fibrillation to enhance therapeutic monitoring and identify potentially predictive phenotypes

Abstract

Atrial fibrillation (AF) is the most common cardiac arrhythmia managed in clinical practice. Maintenance of intended rate or rhythm control following hospitalisation is a key therapeutic goal.The purpose of this study was to assess post-discharge maintenance of intended AF control and classify potentially predictive heart rate (HR) phenotypes via electrocardiogram (ECG) Holter monitoring.In a sub-study of a multicentre randomised controlled trial comparing AF-specific management with usual care, 24-hour ECG Holter monitoring was undertaken in 133 patients 7-14 days post-discharge. Intended rate and rhythm control were compared to Holter data. Analysis of the frequency distribution of mean hour-to-hour differences identified those with labile HRs.Mean age was 71 ± 10 years, 67 (50%) were male and mean HR was 72 ± 14 bpm. Most (89%) had persistent AF (median time in AF=39% (IQR 0-100%)). Uncontrolled HR (>90 bpm for >10% of recording) occurred in 35 (26%) patients and 49 (37%) patients did not achieve their intended rate (n=26) or rhythm control (n=23). Patients in the upper quartile of mean hour-to-hour HR variability were identified as persistently labile (n=33). A further group (n=22) with periodically labile HRs was identified. Those with coronary artery disease (OR 0.34; 95% CI 0.13-0.91, p=0.033) or renal disease/dysfunction (OR 0.24; 95% CI 0.06-0.98, p=0.047) were less likely to demonstrate HR stability (n=78).Post-discharge ECG Holter monitoring of AF patients represents a valuable tool to identify deviations in intended rhythm/rate control and adjust therapeutic management accordingly. It may also identify individuals who demonstrate labile HRs.