Impact of atrial fibrillation in an implantable cardioverter defibrillator cohort

Abstract

Purpose: Atrial fibrillation (AF) is the most common supraventricular arrhythmia in patients with an implantable cardioverter defibrillator (ICD). We evaluated the prognostic significance of AF in ICD patients with ischemic or dilated heart disease. Methods: 647 consecutive patients with ischemic or dilated heart disease (81% male, mean age 64±10 years, 70% primary prevention) receiving an ICD in the Thoraxcenter Twente were included. Demographic data, including existence and type of AF (permanent or non-permanent) was collected. Primary endpoints were all cause mortality and ICD discharge (appropriate or inappropriate). Results: At implantation, 183 (28%) had a history of AF (13% non-permanent and 15% permanent. During 41±15 months follow up, 135 (21%) patient died, 142 (22%) patients experienced an ICD shock, of which 104 (16%) appropriate and 58 (9%) inappropriate. After multivariate analysis permanent AF was significantly related to mortality (HR 1.63 (95% CI: 1.08-2.47)) and shock therapy (HR 2.10 (95% CI 1.39-3.15), both appropriate (HR 1.67 (95% CI 1.03-2.71) and inappropriate (HR 3.62 (95% CI 1.92-6.84)). Non-permanent AF was only related to inappropriate shock therapy (HR 2.43 (95% CI 1.21-4.87)). During follow up, 29 patients (6.3%) with sinusrhythm developed AF, this was related to inappropriate shock therapy (HR 2.83 (95% CI 1.08-7.41). Conclusion: In real-world ICD recipients, almost a third have a history of permanent or non-permanent AF, which leads to higher rates of mortality and ICD discharge. Especially permanent AF is associated with higher rates of mortality and ICD discharge (both appropriate and inappropriate). Non-permanent AF and new onset AF are associated with inappropriate ICD discharge.