Catheter ablation for ventricular tachycardia in patients with cardiac sarcoidosis: a systematic review

Aims Cardiac sarcoidosis (CS) is associated with a poor prognosis. Important features of CS include heart failure, conduction abnormalities, and ventricular arrhythmias. Ventricular tachycardia (VT) is often refractory to antiarrhythmic drugs (AAD) and immunosuppression. Catheter ablation has emerged as a treatment option for recurrent VT. However, data on the efficacy and outcomes of VT ablation in this context are sparse. Methods and results A systematic search was performed on PubMed, EMBASE, and Cochrane database (from inception to September 2016) with included studies providing a minimum of information on CS patients undergoing VT ablation: age, gender, VT cycle length, CS diagnosis criteria, and baseline medications. Five studies reporting on 83 patients were identified. The mean age of patients was 50 +/- 8 years, 53/30 (males/females) with a maximum of 56 patients receiving immunosuppressive therapy, mean ejection fraction was 39.1 +/- 3.1% and 94% had an implantable cardioverter defibrillator in situ. The median number of VTs was 3 (2.6-4.9)/patient, mean cycle length of 360 ms (326-400 ms). Hundred percent of VTs received endocardial ablation, and 18% required epicardial ablation. The complication rates were 4.7-6.3%. Relapse occurred in 45 (54.2%) patients with an incidence of relapse 0.33 (95% confidence interval 0.108-0.551, P < 0.004). Employing a less stringent endpoint (i. e. freedom from arrhythmia or reduction of ventricular arrhythmia burden), 61 (88.4%) patients improved following ablation. Conclusions These data support the utilization of catheter ablation in selected CS cases resistant to medical treatment. However, data are derived from observational non-controlled case series, with low-methodological quality. Therefore, future well-designed, randomized controlled trials, or large-scale registries are required.