The evolution of Extravascular Cardioverter Defibrillator implantation: feasibility in a purely electrophysiologic setting.

BACKGROUND

extravascular implantable cardioverter-defibrillator (EV-ICD) is a novel non-transvenous system delivering defibrillation shocks and anti-tachycardia pacing through a substernal lead. Despite proven efficacy, implantation has traditionally required general anesthesia and cardiothoracic surgical backup, limiting widespread adoption.

OBJECTIVES

To evaluate feasibility, safety, and workflow efficiency of EV-ICD implantation under cardiologist-directed sedation without anesthesiology support.

METHODS

Prospective observational study including 115 consecutive patients undergoing EV-ICD implantation across two European centers. Three procedural settings were explored sequentially: general anesthesia (GA, n=46), analgosedation without anesthesiology supervision (AS, n=28), and regional block with limited sedation (RBS, n=41). The primary endpoint was successful implantation without conversion to respiratory or circulatory support. Secondary endpoints included procedure duration, procedure-related complications, and device performance at follow-up.

RESULTS

Overall implantation success was 97% (112/115) in a predominantly young population (50±17 years; 70% male). All procedures performed without anesthesiology supervision were completed without conversion to GA or emergency support, with comparable complication rates across groups. RBS was associated with a 27-minute reduction in procedural duration versus GA (p<0.001) and earlier mobilization (97% ambulating within 3 hours vs. 65% after 6 hours with GA; p<0.001). Over a median follow-up of 20 [10-30] months, appropriate ICD therapy was delivered in 13% of patients with 100% arrhythmia termination. Inappropriate therapy occurred in 8.9%, predominantly during the early learning phase.

CONCLUSIONS

EV-ICD implantation can be safely and effectively performed under cardiologist-directed sedation without anesthesiology supervision, achieving a fully electrophysiology-driven workflow. Procedural simplification substantially reduces resource utilization and may facilitate broader adoption of this technology.