Long-term follow-up of patients with cardiac sarcoidosis and implantable cardioverter-defibrillators

BACKGROUND Ventricular tachyarrhythmias are an important cause of morbidity and mortality in cardiac sarcoidosis. To date, the prevalence and incidence of ventricular tachycardia/ventricular fibrillation (VT/VF) in this population remain unknown. OBJECTIVES To determine the prevalence and incidence of ventricular tachyarrhythmias in patients with cardiac sarcoidosis and to identify the clinical attributes associated with appropriate implantable cardioverter-defibrillator (ICD) therapies. METHODS We studied 45 patients with ICDs, biopsy-proven systemic sarcoidosis, and cardiac involvement, as evidenced by histopathology, cardiac magnetic resonance imaging, and/or F-18-fluoro-2-deoxyglucose-positron emission tomography imaging. Device logs and medical records were retrospectively reviewed. RESULTS Appropriate ICD therapies for VT/VF were observed in 37.8% of the patients with an incidence of 15% per year. Inappropriate ICD therapies occurred in 13.3% of the patients. Longer ICD follow-up (4.5 +/- 3.1 years vs 1.5 +/- 1.5 years; P = .001), depressed left ventricular ejection fraction (35.5% +/- 15.5% vs 50.9% +/- 15.5%; P = .002), and complete heart block (47.1% vs 17.9%; P = .048) were associated with appropriate ICD therapy. While there was no significant difference in the total number of shocks/antitachycardia pacing-terminated events between primary (n = 29) and secondary (n = 16) prevention groups, there was a trend toward more events in the secondary prevention arm after 2 years. CONCLUSIONS Ventricular tachyarrhythmias requiring ICD therapy were common in patients with cardiac sarcoidosis, with an estimated incidence rate of 15% per year. Longer follow-up, left ventricular systolic dysfunction, and complete heart block were associated with VT/VF. Patients with primary prevention ICDs had high rates of appropriate ICD therapy but not as high as did secondary prevention patients. In the absence of reliable risk stratification techniques, consideration should be given to prophylactic ICD implantation in patients with cardiac sarcoidosis.