Lead‐related complications fewer with subcutaneous vs transvenous ICD

Implantable cardioverter‐defibrillators (ICDs) that are placed subcutaneously is superior to those that are inserted via the axillary–subclavian venous system and placed endocardially, as the former reduces the risk of lead-related complications, according to a meta-analysis. Additionally, subcutaneous (S)-ICD appears to be more beneficial in the long term with regard to the risk of device-related complications.

Researchers searched multiple online databases for randomized controlled trials (RCT) or propensity score–matched (PSM) studies that evaluated S‐ICD against transvenous (TV)‐ICD in patients with an ICD indication. Of the 1,336 studies identified, one trial and four PSM studies were included in the analysis.

A total of 2,387 patients comprised the overall study population. Their age ranged from 35 to 64 years, and about three-fourths (75.4 percent) of the population received an ICD for primary prevention. Patients in three studies had left ventricular ejection fraction <40 percent, whereas the remaining patients in two studies had >45 percent. Follow-up duration varied between 30 and 60 months.

The primary outcomes were device‐ and lead‐related complications. Secondary outcomes included inappropriate shocks, appropriate shock, all‐cause mortality, and infection. All PSM studies were ranked as good quality (Newcastle‐Ottawa Scale score 7–9), and the RCT was considered to have an overall low risk of bias.

Pooled data showed that compared with TV-ICD, S‐ICD had a similar rate of device‐related complications (risk ratio [RR], 0.59, 95 percent confidence interval [CI], 0.33–1.04; p=0.070) but a much lower rate of lead‐related complications (RR, 0.14, 95 percent CI, 0.07–0.29; p<0.0001).

The use of the more robust individual patient data-based one‐stage stratified Cox model for device‐related complications across four studies yielded no significant difference (shared‐frailty hazard ratio, 0.82, 95 percent CI, 0.61–1.09; p=0.167).

However, visual inspection of the pooled Kaplan–Meier curves suggested a divergence of survival from device‐free complications, which began at ≈4 years of follow‐up, in favour of S-ICD.

There was no significant between-group difference in secondary outcomes.

The findings indicate that S‐ICD may be a suitable substitute for TV‐ICD in patients requiring ICD implantation without a pacing indication.