CONTEMPORARY DIAGNOSIS OF CARDIAC SARCOIDOSIS

Abstract

BACKGROUND: Patients with systemic sarcoidosis manifest symptomatic cardiac involvement in approximately 5% of cases. With the availability of advanced cardiac imaging, including cardiacMRI and FDG-PET, evidence of asymptomatic cardiac sarcoidosis (CS) has been detected in up to 50% of patients. Cardiac involvement in patients with sarcoidosis portends a poor prognosis. PURPOSE: To evaluate contemporary practice patterns for the diagnosis of CS compared to current 2014 HRS expert consensus recommendations. METHODS: Retrospective cohort study of patients from the St. Paul’s Hospital CS Clinic. Baseline characteristics, diagnostic imaging and pathology were reviewed for patients between January 2013 andMarch 2015. Patients were analyzed according to 2014 HRS guidelines. Group 1 (22 patients) consisted of patients with biopsy proven extra-cardiac sarcoidosis referred for cardiac screening. Group 2 (13 patients) included those under the age of 60, with unexplainedMobitz II or third degree heart block. Group 3 (12 patients) consisted of patients with unexplained VT and Group 4 (13 patients) included all others, particularly unexplained LV dysfunction. RESULTS: Of the 115 patients referred to theCS clinic, 25 remain incompletely evaluated, 12 refused further evaluation, and18were discharged after initial triage. Complete data was available for 60 patients. The median age was 57 years (IQR 18) and 58.3% were males. Overall, there were 27 (45.0%) patients with an ICD and 17 (28.3%)with a pacemaker. Themean LVEFwas 46.1% (95% CI 34.0-58.2). Endomyocardial biopsy was performed in 24 (40.0%) of patients, cardiacMRI in 39 (65.0%) andFDG-PET in 54 (90.0%). According to 2014 HRS recommendations, patients were considered to have probable cardiac involvement in 15 (68.2%), 10 (76.9%), and 11 (91.7%) cases inGroups 1, 2 and 3, respectively. Similarly, advanced imaging was performed, but not recommendedby current guidelines, in 6 (27.3%), 1 (7.7%) and4 (33.3%) patients for Groups 1, 2 and 3, respectively. FDG-PET was negative for CS in 7/9 (77.8%) Group 4 patients with LV dysfunction and an abnormal biopsy or cardiac MRI. We found FDG-PET to be positive in a pattern consistent with active CS in 3/8 (37.5%) of cases where ordering FDG-PET was not recommended by current guidelines. CONCLUSION: In our study, contemporary screening and diagnosis of CS would often be considered not recommended by current HRS expert consensus recommendations. More liberal use of FDG-PET in patients evaluated for CS may help stratify this high risk population. 548 CINE MRI-BASED 4D-STRAIN ANALYSIS OF THE LEFT VENTRICLE FOR THE EVALUATION OF MYOCARDIAL FIBROSIS IN PATIENTS WITH HYPERTROPHIC CARDIOMYOPATHY