Implantable cardioverter-defibrillator in cardiac sarcoidosis: A propensity-score matched analysis

Implantable cardioverter-defibrillators (ICDs) are used in cardiac sarcoidosis (CS) to prevent sudden cardiac death, but real-world effectiveness remains uncertain and is vulnerable to treatment-selection bias.

We performed a retrospective cohort study using the TriNetX Global Collaborative Network (157 healthcare organisations). Adults (≥18 years) with CS (ICD-10-CM D86.85; 2005-2025) were stratified by ICD implantation. Cohorts were balanced using 1:1 propensity-score matching (caliper 0.1 SD) across demographic, comorbidity, laboratory, and medication variables. The primary endpoint was a composite of all-cause mortality, heart failure exacerbation, cardiac transplantation, and ventricular arrhythmia. Secondary endpoints included heart failure diagnosis, all-cause rehospitalisation, acute myocardial infarction, and ischaemic stroke. Outcomes are reported as risk ratios (RR) with 95% confidence intervals (CI).

A total of 4554 matched patients were analysed (2277 per cohort) over a median follow-up of 2.7 years. ICD use was associated with lower all-cause mortality (RR 0.83, 95% CI 0.71-0.96) and lower cardiac transplantation (RR 0.66, 95% CI 0.49-0.90). Heart failure exacerbation (RR 1.06, 95% CI 1.00-1.12) and ventricular arrhythmia (RR 1.70, 95% CI 1.59-1.81) were higher in ICD recipients. ICD recipients also had higher risks of heart failure diagnosis (RR 1.11, 95% CI 1.07-1.16) and rehospitalisation (RR 1.18, 95% CI 1.13-1.24).

In a large propensity-matched real-world CS cohort, ICD implantation was associated with lower mortality and transplantation. However, these findings occurred alongside higher morbidity and healthcare utilization signals and must be interpreted cautiously due to the potential for selection bias and differential surveillance.