Usefulness of programmed ventricular stimulation in predicting future arrhythmic events in patients with cardiac sarcoidosis

The utility of programmed ventricular stimulation to predict future arrhythmic events in patients with cardiac sarcoidosis is unknown. Similarly, the long-term benefit of implantable cardioverter-defibrillators (ICDs) in cardiac sarcoidosis has not been established. Thirty-two consecutive patients with cardiac sarcoidosis underwent programmed ventricular stimulation. Patients with spontaneous or inducible sustained ventricular arrhythmias (n = 12) underwent ICD insertion. All study patients were followed for the combined arrhythmic event end point of appropriate ICD therapies or sudden death. Mean length of follow-up to sustained ventricular arrhythmia or sudden death was 32 ± 30 months. Five of 6 patients (83%) with spontaneous sustained ventricular arrhythmias and 4 of 6 patients (67%) without spontaneous but with inducible sustained ventricular arrhythmias received appropriate ICD therapy. Two of 20 patients (10%) with neither spontaneous nor inducible sustained ventricular arrhythmias experienced sustained ventricular arrhythmias or sudden death. Programmed ventricular stimulation predicted subsequent arrhythmic events in the entire population (relative hazard 4.47, 95% confidence interval [CI] 1.30 to 15.39) and in patients who presented without spontaneous sustained ventricular arrhythmias (relative hazard 6.97, 95% CI 1.27 to 38.27). No patient with an ICD died of a primary arrhythmic event. In patients with spontaneous or inducible sustained ventricular arrhythmias, mean survival from first appropriate ICD therapy to death or cardiac transplant was 60 ± 46 months, with only 2 patients dying or reaching transplant at study end. In conclusion, programmed ventricular stimulation identifies patients with cardiac sarcoidosis at high risk for future arrhythmic events. ICDs effectively terminate life-threatening arrhythmias in high-risk patients, with significant survival after first appropriate therapy.