Wearable cardioverter defibrillator after ICD-system explantation: data from a multicenter registry

Abstract Background Data on the use of wearable cardioverter defibrillator (WCD) among patients after cardiac implantable electronic device explantation of 1- to 3-chamber Implantable Cardioverter-defibrillator system (ICD) are sparse. Subsequently several guidelines give a different recommendation regarding WCD indication in this cohort. Objectives We aimed to study the baseline characteristics and outcome of patients treated with WCD after ICD explantation. The primary outcome is appropriate WCD shock. Methods 1104 patients were included in a multicenter registry from seven European centers. Among this cohort 109 patients received a WCD to bridge the time after ICD-system explantation until reimplantation due to a persistent ICD-indication. The mean follow-up time of the whole cohort was 824±773 days. Cardiovascular history and non-cardiovascular morbidities were evaluated. In addition, the presence of ventricular tachyarrhythmias and/or WCD shocks was evaluated in the explantation group. Furthermore, after ICD-reimplantation the rate of rehospitalization for ventricular tachyarrhythmias, atrial fibrillation, stroke and congestive heart failure was followed. Results In the explantation group patients were older (65±14 versus 59±15; p<0.001) and were hospitalized longer (21±15 days versus 14±12 days; p<0.001). The index LVEF differed significantly (35.7±14.1% versus 29.3±11.5%; p<0.001). The LVEF value did not differ significantly over short-term follow-up (35.7±14.2% versus 37.9±11.9%; p=0.204). Wear days among patients after ICD-system explantation were 61±46 days. An appropriate WCD shock was documented in 7.3% after ICD-system explantation during WCD use. Up to 80.6% of patients after ICD-system explantation received a reimplantation. The rate of rehospitalization due to ventricular tachyarrhythmias was 7.3%, due to heart failure 6.8% and due to atrial fibrillation 4.1%. After ICD-implantation the rate of appropriate shocks was 12/89 (13.4%). In the multivariable regression analysis myocarditis and ICD-system explantation were positive predictors for the risk of ventricular tachyarrhythmias, but nevertheless an improved left ventricular ejection fraction (LVEF) and use of aldosterone antagonists were negative predictors for the risk of ventricular tachyarrhythmias. Conclusions Cccurrence of malignant arrythmia after ICD-system explantation is high and the use of WCD among these patients could be beneficial in preventing sudden cardiac death.