EFFORTLESS S-ICD registry: another step in the right direction

Abstract

This editorial refers to ‘Worldwide experience with a totally subcutaneous ICD: early results from the EFFORTLESS S-ICD registry’[†][1], by P.D. Lambiase et al. , on page 1657 While the clinical significance of the implantable cardioverter defibrillator (ICD) in the reduction of sudden cardiac arrest remains unequivocal, the quest for the best implantable system continues. The first successful, yet experimental ICD system involved two electrodes between the pectoralis muscle and the rib cage, two sensing electrodes in the chest wall musculature, with a pulse generator and capacitor implanted intra-abdominally in animals.1 The first ICD implanted in a human in 1980 consisted of epicardial patches and sensing leads.2 Subsequently, the advent of transvenous ICD leads significantly reduced the morbidity of the procedure and complication rates, while improving clinical outcomes. The transvenous leads, however, came with the cost of a spectrum of vascular complications as well as design faults. Therefore, the quest for a better implantable system has continued. The totally subcutaneous ICD (S-ICD), an innovative strategy obviating the need for vascular access, has come on as a contender to fill this void.3 Evidence favouring the clinical use of the S-ICD came from the feasibility studies and European registries that preceded the Food and Drug Administation (FDA) approval of the device.3–5 Most of these studies have comprised smaller numbers with limited follow-up, calling into question the applicability of these results in real-world practice. The study now presented by Lambiase et al. ,6 reporting on early data from the multicentre EFFORTLESS S-ICD registry, provides valuable information on system performance and inappropriate shock rates. This registry is a laudable effort and comprises an observational, non-randomized, standard of care evaluation of S-ICD in countries outside the USA. The term ‘worldwide experience’ in the title, however, may be a misnomer, as … [1]: #fn-2