Bridging two extravascular defibrillator systems: comparative outcomes of extravascular ICD versus subcutaneous ICD - a single-center experience
A F Badaruddin, S H Kamsani, T Y Beh, N M A S Atan, A P Wikananda, M H Aziman, A Said, R Rebo, N A Sahat, Z Ali, Z Zahir, H J Zamberi, S K Khalae, A HussinAbstract
Background
The subcutaneous implantable cardioverter-defibrillator (S-ICD) provides extravascular protection against sudden cardiac death but lacks pacing and relies on far-field sensing. The newer extravascular ICD (EV-ICD) introduces a substernal lead capable of anti-tachycardia pacing (ATP) and post-shock pacing while avoiding the vasculature.
Objective
To compare real-world procedural and short-term clinical outcomes between EV-ICD and S-ICD systems in a tertiary cardiac center.
Methods
This retrospective single-center study analyzed patients who underwent EV-ICD (n = 12) or S-ICD (n = 18) implantation between September 2015 and July 2025. Demographics, procedural parameters, defibrillation testing, complications, shocks, and hospitalization were reviewed. Data were analyzed descriptively and comparatively between both cohorts.
Results
Mean age was 40 ± 12 years, predominantly male (EV-ICD 75%, S-ICD 83%). Comorbid hypertension and diabetes were more frequent among EV-ICD recipients. EV-ICD implantation required longer procedural (105 ± 30 vs 60 ± 20 min, p = 0.005) and fluoroscopy time (10.7 ± 2.1 vs 0.2 ± 0.1 min, p < 0.001). All implants achieved successful defibrillation testing. One non-device-related death occurred in the S-ICD group; all others survived at one-year follow-up. Appropriate shocks were delivered in two S-ICD patients; no inappropriate therapies occurred. Hospitalization for device-related complications occurred in one EV-ICD and two S-ICD patients.
Conclusion
EV-ICD demonstrates procedural feasibility and safety with reliable defibrillation and pacing capabilities while maintaining an extravascular approach. Compared with S-ICD, the system offers added functionality but requires fluoroscopy and longer procedural duration. Larger and longer-term studies are warranted to validate these early outcomes in Asian populations.Demographic1-year outcome