Abstract 11826: Device Detected Atrial Fibrillation Poses Significant Risk of Heart Failure Related Hospitalization

Abstract

Background: Implantable cardioverter-defibrillators (ICDs) collect advanced diagnostics on the progression of the patient’s heart disease. Arrhythmia detection algorithms continuously identify atrial arrhythmias. Methods: The CONNECT (Clinical Evaluation of Remote Notification to Reduce Time to Clinical Decision) study was a multicenter, prospective, randomized evaluation involving 1980 randomized patients from 136 clinical sites who underwent an ICD implant and followed for 15 months. Health care utilization data included all CV-related hospitalizations, emergency department visits, and clinic office visits. The analysis here focuses on heart failure (HF) related hospitalizations. Device-detected atrial arrhythmias were collected throughout follow-up. A non-parametric estimate of the nonlinear relationship between average atrial tachycardia / atrial fibrillation (AT/AF) burden per day and hazard of HF-related hospitalization or death was modeled via a third-order P-spline. The number of AT/AF episodes greater than 12 hours long was tested as a time-dependent covariate in a Cox model. Results: Information was available on arrhythmia detection in 1939 of 1980 randomized patients. There were 1540 patients with at least one device-detected AT/AF episode. Estimation of average AT/AF burden per day and risk of HF-related hospitalization or death indicated that the risk of an event increased with increasing AT/AF burden and that the risk was consistently higher with AT/AF episodes ≥ 12 hours per day. The incremental hazard ratio of HF-related hospitalization or death associated with a 12 hour AT/AF episode was 2.58 (CI: 1.57--4.24; p = 0.0002). The risk remains after adjustment for other clinical variables of interest. Conclusions: Device-detected AT/AF episodes of at least 12 hours in duration pose significant and increased risk for HF-related hospitalizations.