EV ICD in non-ischemic cardiomyopathies

Background

Extravascular implantable cardioverter defibrillators (EV ICD) are an emerging alternative to transvenous and subcutaneous systems, offering effective defibrillation and antitachycardia pacing (ATP) without transvenous leads (1). However, data focusing on patients with cardiomyopathies are still limited.

Purpose

To describe procedural outcomes and follow-up data of patients with non-ischemic cardiomyopathies (NICM) undergoing EV ICD implantation in a single tertiary center.

Methods

Between November 2020 and October 2025, all patients receiving an EV ICD at our institution were prospectively enrolled. For the present analysis, only those with NICM were included, excluding Channelopathies and Myocarditis etiologies. The lead tunnelling was guided by pre-procedural chest TC to target its placement in front of the right ventricle, while the generator placement was intermuscular (2,3). Baseline demographics, echocardiographic parameters, and follow-up data were collected. Appropriate and inappropriate therapies were reviewed using stored electrograms and clinical correlation.

Results

47 patients (17 females, mean age 42±17 years, BMI 23±4 kg/m²) were included. The underlying etiologies were arrhythmogenic cardiomyopathy (n=25), dilated cardiomyopathy (n=10), and hypertrophic cardiomyopathy (n=12). 10/47 patients failed the screening test for the S-ICD Implantation was successful in all cases (100%) without acute complications. Mean LVEF was 48±14% and NYHA class 1.2±0.6. Median follow-up was 22±19 months (median 19 [IQR 11–29]). The mean R wave amplitude at last follow-up is reported in Table 1.

Appropriate therapies occurred in 4 patients (9%), all for sustained ventricular tachycardia, including one case of arrhythmic storm. 3 patients required only ATP (5 episodes). Inappropriate therapies were observed in 2 patients (4%) which represent 2 of the first 4 cases of our experience: one due to non-correctable P-wave oversensing, one related to lead dislodgment with myopotential noise (no further episodes after lead repositioning). No device infections or deaths were reported.

Conclusions

In this cohort of patients with cardiomyopathies, EV ICD implantation was safe and effective, with excellent procedural success and low complication rates also in patients not suitable for the S-ICD. The incidence of inappropriate therapy was limited to the earliest patients and mainly related to sensing issues. These results support EV ICD as a reliable option for defibrillation therapy in NICM patients, combining safety and efficacy with the advantage of an entirely extravascular system.Table 1Picture