Dual- vs. single-chamber defibrillators for primary prevention of sudden cardiac death: long-term follow-up of the Défibrillateur Automatique Implantable-Prévention Primaire registry

Abstract

Aims: Implantable cardioverter defibrillators (ICDs) are an effective primary prevention of sudden cardiac death. We examined whether dual-chamber (DC) ICDs confer a greater benefit than single-chamber (SC) ICDs, and compared the long-term outcomes of recipients of each type of device implanted for primary prevention.

Methods and results: Between 2002 and 2012, the DAI-PP registry consecutively enrolled 1258 SC- and 1280 DC-ICD recipients at 12 French medical centres. The devices were interrogated at 4- to 6-month intervals during outpatient visits, with a focus on the therapies delivered. The study endpoints were incidence of appropriate therapies, ICD-related morbidity, and deaths from all and from specific causes. The mean age of the SC- and DC-ICD recipients was 59 ± 12 and 62 ± 11 years, respectively (P< 0.0001). The distribution of genders, New York Heart Association functional classes and glomerular filtration rates, and the rates of ischaemic vs. dilated cardiomyopathies and of defibrillation tests at implant, were similar in both study groups. The rates of periprocedural complications were 12.1% in the DC- vs. 8.8% in the SC-ICD groups (P= 0.008). Over a mean follow-up of 3.1 ± 2.2 years, pulse generators were replaced in 21.9% of the DC- vs. 13.6% of the SC-ICD group (P< 0.0001). The proportions of patients treated with ≥1 appropriate therapies (24.7 vs. 23.8%) and ≥1 inappropriate shocks (8.4 vs. 7.8%), and all-cause mortality (12.4 vs. 13.2%) were similar in both groups.

Conclusion: In this large registry of ICD implanted for primary prevention, DC-ICDs were associated with higher rates of peri-implant complications and generator replacements, whereas the survival and rates of inappropriate shocks were similar in both groups.

Clinical trial number: NCT#01992458.

Keywords: Dual-chamber defibrillator; Implantable cardioverter-defibrillator; Inappropriate shock; Single-chamber defibrillator; Sudden death prevention.