# Long‐term safety and efficacy of subcutaneous implantable cardioverter‐defibrillator compared with transvenous implantable cardioverter‐defibrillator in propensity score‐matched patients from Japan

## TL;DR

This study compares the long-term safety and effectiveness of two types of implantable cardioverter-defibrillators in Japanese patients.

## Contribution

The study provides new long-term clinical data on subcutaneous ICDs compared to transvenous ICDs in a Japanese population.

## Key findings

- Subcutaneous ICDs had fewer lead-related complications than transvenous ICDs.
- There was no significant difference in mortality or appropriate shock rates between the two groups.
- Inappropriate shocks were more common with subcutaneous ICDs but not significantly.

## Abstract

Subcutaneous implantable cardioverter‐defibrillator (S‐ICD) has been reported to be non‐inferior to transvenous ICD (TV‐ICD) in terms of device‐related complications and inappropriate shock (IAS). We aimed to evaluate the long‐term clinical outcomes of S‐ICD compared with TV‐ICD in Japanese patients.

We studied 315 consecutive patients (TV‐ICD, 167; S‐ICD, 148) who underwent ICD implantation. A propensity score matching analysis was performed to select patient subgroups for comparison (104 patients in each group). Clinical outcomes, including appropriate and inappropriate ICD therapy, procedure‐ and lead‐related complications, and mortality, were compared between the two groups.

During follow‐up (median, 1458 [interquartile range, 1353–1572] days), the cumulative incidence of appropriate shock therapy was 9.6% and 8.7% in the S‐ICD and TV‐ICD groups, respectively (p = 0.94). Although the S‐ICD group tended to have a higher IAS than the TV‐ICD group (5.8% vs. 1.9%), the difference was not significant (p = 0.19). Conversely, the cumulative incidence of procedural and lead‐related complications was significantly lower in the S‐ICD group (2.9% vs. 9.6%, p = 0.02). Notably, lead‐related complications were more common in the TV‐ICD group (p = 0.05). There was no difference in all‐cause mortality between the two groups (p = 0.75), and heart failure exacerbation was the most common cause of death in both groups.

In propensity score‐matched Japanese patients with S‐ICD, the cumulative incidence of appropriate shock and mortality was comparable to those with TV‐ICD. There was no significant difference in the rate of IAS. Notably, patients with S‐ICD had fewer lead‐related complications than those with TV‐ICD.

In propensity score‐matched Japanese patients with S‐ICD, the cumulative incidence of ICD shock therapies and mortality was comparable to those with TV‐ICD. Notably, patients with S‐ICD had fewer lead‐related complications than those with TV‐ICD.