Long-term monitoring of arrhythmias with cardiovascular implantable electronic devices in patients with cardiac sarcoidosis

BACKGROUND Risk stratification for sudden cardiac death (SCD) in cardiac sarcoidosis (CS) is challenging in patients without overt car-diac symptoms.& nbsp;OBJECTIVE The purpose of this study was to determine the inci-dence of ventricular arrhythmias (VAs) and mortality after long-term monitoring with a cardiovascular implantable electronic device (CIED) in CS patients identified after systematic screening of pa-tients with extracardiac sarcoidosis (ECS).& nbsp;METHODS A retrospective study was performed in 547 predomi-nantly Caucasian patients with ECS screened for cardiac involve-ment. If CS was diagnosed, risk stratification (high vs low risk) for SCD was performed by a multidisciplinary team. The primary endpoint was defined as sustained VA, appropriate implantable cardioverter-defibrillator (ICD) therapy, or cardiac death.& nbsp;RESULTS In total, 105 patients were included (mean follow-up 33 6 16 months). An ICD was implanted in 17 high-risk patients (16.2%), whereas 80 low-risk patients (76.1%) received an implant-able loop recorder (ILR). Eight low-risk patients (7.6%) did not receive a device. The primary endpoint occurred in 4.8% (n 5 5), with an overall annualized event rate of 1.7%. The annualized event rate was 9.8% in high-risk patients and 0.4% in low-risk patients. Nine low-risk patients received an ICD during follow-up, in 7 pa-tients as a result of the ILR recordings. None of these patients required ICD therapy.CONCLUSION In CS patients without overt cardiac symptoms at initial presentation the annualized overall event rate was 1.7%; 10% in high-risk patients, but only 0.4% in low-risk patients. In low-risk patients long-term arrhythmia monitoring with an ILR enabled early detection of clinically important arrhythmias without showing impact on prognosis. (C) 2021 Heart Rhythm Society.All rights reserved.