Quality of life and acceptance of the extravascular implantable cardioverter‐defibrillator

The implantable cardioverter-defibrillator (ICD) provides a life-saving therapy by decreasing cardiac mortality and sudden arrhythmic death.1, 2 However, because the transvenous ICD (TV-ICD) can potentially give rise to several implantation risks and complications, it is necessary to consider alternative devices with lower morbidity and mortality rates.3, 4 The subcutaneous ICD (SC-ICD) was designed to mitigate vascular complications and has demonstrated its efficacy in arrhythmic protection.5-7 Yet, due to its position in the subcutaneous tissue layer, the pacing procedure necessitates a significant amount of current, requiring a larger device and leading to extracardiac stimulation. Therefore, the extravascular implantable cardioverter-defibrillator (EV ICD) was developed. The EV-ICD provides intracardiac therapy without the need for a transvenous lead. Instead, it utilizes a substernal lead to enable high defibrillation efficacy with lower energies and minimal risks.8-10 Unlike the SC-ICD, it enables the delivery of antitachycardia and temporary pause-prevention pacing.8, 10 After several recent studies demonstrated its primary efficacy and safety, it became important to assess patient experience with this novel device. In this issue of the Journal of Cardiovascular Electrophysiology, Sears et al. conducted a pivotal prospective, nonrandomized, single-arm premarket approval trial.11 The study evaluated standardized patient-reported outcome (PRO) metrics of quality of life (QOL) using the 12-Item Short Form Survey (SF-12) physical and mental QOL surveys in patients with the EV ICD. It also assessed patient acceptance of the device using the Florida Patient Acceptance Survey (FPAS) QOL survey. Results demonstrated that after 6 months of follow-up in 247 patients, there was a significant improvement in physical QOL but no change in the mental SF-12 QOL score. Younger patients (<50 years) were found to have higher physical but lower mental QOL scores, consistent with previous studies.12 As for patient acceptance, 109 patients who completed the FPAS survey had significantly better acceptance than historical norms of patients with TV-ICD or SC-ICD at 6 months post-implant, indicating the benefits of using the EV ICD. Patients with the EV ICD also reported less device-related distress and more positive appraisal, possibly due to the small device size and its imperceptible positioning. Unfortunately, the study had several limitations including short follow-up period, small sample size, and comparison with historical data of the other ICDs. Also, the selective recruitment of patients who were willing to accept this innovative modality might have led to positive bias, consequently limiting the study generalizability. Despite this, the EV ICD can be perceived to be experienced positively and to be better accepted by patients than previous ICD modalities. Overall, the authors should be praised on their efforts in conducting the first pilot study to address patient experience with the EV ICD device and its impact on their daily lives. The results of the study will have important clinical and therapeutic implications and will help in the implementation and acceptance of this novel technology. This will benefit patients by offering an effective ICD alternative with minimal adverse events. However, future studies with larger participant cohorts and extended follow-up periods are recommended for a more generalizable picture of patient QOL and experience implications.