Background: Subclinical atrial high rate episodes (AHREs) detected by implanted devices in patients with no history of atrial fibrillation (AF) have been associated with an increased risk of stroke and systemic embolism. Data regarding the long-term survival of patients with permanent pacemakers and newly detected AHREs are limited.
Objective: This study aimed to assess whether newly detected AHREs in pacemaker patients predict mortality outcomes.
Methods: We evaluated 224 patients (mean age 74 ± 12 years; 118 men [53%]) with no history of AF who underwent dual-chamber pacemaker implantation from 2002 through 2004. During follow-up, patients with AHREs of ≥5-minute duration were identified. Mortality data were obtained from the National Death Index.
Results: Thirty-nine patients (17%) had AHREs of ≥5-minute duration within 6 months of pacemaker implantation. Over a mean follow-up period of 6.6 ± 2.0 years, the rate of all-cause mortality was 29%. In multivariate analysis adjusted for age, sex, and cardiovascular diseases, AHREs were associated with a significant increase in cardiovascular mortality (hazard ratio [HR] 2.80; 95% confidence interval [CI] 1.24-6.31; P = .013) and stroke mortality (HR 9.65; 95% CI 1.56-59.9; P = .015), with a trend toward increased all-cause mortality (HR 1.79; 95% CI 0.98-3.26; P = .059). The subgroup of patients with AHREs of ≥5-minute but <1-day duration still had a significantly increased cardiovascular mortality (HR 3.24; 95% CI 1.37-7.66; P = .007).
Conclusion: AHREs are commonly encountered in pacemaker patients with no history of AF and are independent predictors of cardiovascular mortality.
Keywords: Atrial fibrillation; Mortality; Permanent pacemaker.
Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.