Fatal Arrhythmic Risks in Cardiac Sarcoidosis With Mildly Impaired Cardiac Function

Background: The prognosis and later fatal arrhythmia in cardiac sarcoidosis (CS) with relatively preserved cardiac function were unclear.

Objectives: This study aimed to evaluate the prognosis and arrhythmic events in patients with CS and mildly impaired cardiac function.

Methods: Data were collected from a nationwide Japanese cohort survey conducted in 57 hospitals (n = 420); 322 patients with CS with left ventricular ejection fraction (LVEF) >35% were investigated.

Results: Ventricular tachycardia (VT) manifestation was present in 50 patients (16%) and absent in 272 (84%), of whom 36 (72%) and 46 (17%), respectively, had an implantable cardioverter-defibrillator (ICD). Over a median of 5 years, 23 all-cause deaths and 31 appropriate ICD discharges were observed. In Kaplan-Meier analysis, all-cause death did not differ between patients with and without VT manifestation (P = 0.660), although appropriate ICD therapy was significantly less used in patients without VT manifestation than in those with VT manifestation (P < 0.001). Of the 272 patients without VT manifestation, 18 had ventricular arrhythmic events (VAEs), including 3 sudden cardiac deaths and 15 appropriate ICD discharges. In multivariate analysis, concomitant nonsustained ventricular tachycardia (NSVT) with atrioventricular block (AVB), lower LVEF, abnormal gallium-67 scintigraphy or ¹⁸F-fluorodeoxyglucose positron emission tomography of the heart (Ga/PET), and concomitant NSVT with abnormal Ga/PET at CS diagnosis were independent predictors of VAEs (P = 0.008, P = 0.021, P = 0.049, and P = 0.024, respectively).

Conclusions: If concomitant NSVT with AVB, concomitant NSVT with abnormal Ga/PET, or abnormal Ga/PET is observed in patients with CS and mildly impaired cardiac function (LVEF >35%), ICD should be considered as primary prevention.