Abstract 17907: Atrial Arrhythmias in ICD Versus CRT-D Subjects
The relationship between device type (ICD or CRT-D) and incidence or burden of atrial fibrillation (AF) is unknown. IMPACT is a single-blind trial randomizing patients with dual-chamber ICDs or resynchronization devices (CRT-ICDs) to use remote monitoring of atrial high rate events (AHRE) or no monitoring for prevention of stroke and bleeding. In the monitoring group, anticoagulation is initiated or terminated based on the AHRE burden and the CHADS2 score. We explored the relationship between device type, incidence and burden of AHRE among the first 2,161 subjects observed for 3,166 patient-years. Of 585 subjects with AHRE, 392 had ICD devices, compared to 193 with CRT-D devices. The left ventricular ejection fraction was lower among patients with CRT (27.3% ± 10.0%) than ICD devices (31.2% ± 11.6%). There was no significant relationship between device type and number of AHRE episodes (Table). The figure shows AHRE burden for all subjects with AHRE. Although the distribution appears similar for both groups, the difference between groups (3.0% ± 9.2% for patients with CRT-D vs 2.8%± 9.7% for patients with ICD devices) was statistically significant (p = 0.027; Mann-Whitney U Test). In conclusion, the number of AHRE episodes is similar in patients with ICD and CRT-D devices, but AHRE burden was slightly higher in those with CRT-D devices. These results suggest that clinical variables associated with CRT-D versus an ICD implantation may be more important than electrical remodeling related to resynchronization therapy in determining AHRE burden.
- © 2012 by American Heart Association, Inc.