Background/Purpose:

Cardiac sarcoidosis has been noted in 2-7% of patients with sarcoidosis.  However, the incidence is >20% based on necropsy data.  Given the poor yield of biopsy due to patchy involvement of the disease, the diagnosis of cardiac sarcoidosis has increasingly favored the use of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18-FDG PET/CT) and gadolinium enhanced cardiac magnetic resonance imaging (CMR) scans. To date, there is little data to suggest the optimal dose and duration of corticosteroids and steroid-sparing agents, and the efficacy of these agents on cardiac sarcoidosis. We aimed to study whether patients on steroids for presumed or proven cardiac sarcoidosis had fewer ventricular arrhythmias as recorded on Implantable Cardiac Defibrillator (ICD) monitoring.

Methods:

We completed a retrospective review of patients diagnosed with cardiac sarcoidosis between June1, 2006 and June 1, 2016 at our institution.  Patients with evidence of cardiac involvement on either 18FDG-PET/CT, CMR, or endomyocardial biopsy (EMB) were selected. We evaluated the effect of corticosteroids on FDG-PET/ CT and performed paired T test analysis on the number of ventricular tachycardia (VT) and non-sustained ventricular tachycardia (NSVT) events for 3 months in patients on and off high dose corticosteroids (prednisone >30mg). 

Results: 

We identified 1,298 patients diagnosed with sarcoidosis of whom 59 met inclusion criteria for a diagnosis of presumed or proven cardiac sarcoidosis. Among 59 patients, 19 had EMB of whom 8 were positive for sarcoidosis. 25 patients had serial 18-FDG PET/CT before and after treatment with corticosteroids.  Of those, 12 (48%) had complete resolution after corticosteroids, 7 (28.0%) had partial resolution, 4 (16.0%) had increased uptake after corticosteroids, and 2 (1%) had negative serial 18-FDG PET/CT scans. There was a higher mean number of VT events during the corticosteroid free period compared to the high dose corticosteroid treatment period, though not statistically significant (21 vs 1 event, p=0.2, n=16). A similar trend was seen in the number of NSVT events (372 vs 7 events, p=0.3, n=16).

Conclusion:

Our data suggests that treatment of presumed cardiac sarcoidosis with corticosteroids shows improvement in hypermetabolic activity on 18FDG-PET/CT. Although our observations are limited due to a small sample size, we found a trend towards improvement in ventricular arrhythmias while on corticosteroids. Given the difficultly in diagnosing cardiac sarcoidosis by biopsy, treatment of cardiac sarcoid purely based on imaging findings should be considered. Future prospective trials are needed to validate our findings.

References:

Lynch JP, Hwang J, Bradfield J, Fishbein M, Shivkumar K, Tung R. Cardiac involvement in sarcoidosis: evolving concepts in diagnosis and treatment. Semin Respir Crit Care Med. 2014;35(3):372-90.