Cardiac sarcoidosis in the modern era: continued challenges of presentation, management and adverse outcomes

Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): New Zealand Heart Foundation Background Detection of cardiac sarcoidosis (CS) has increased with improved availability of imaging modalities including cardiovascular magnetic resonance imaging (cardiac MRI) and positron emission tomography (CT-PET). However, clinical presentation remains highly variable ranging from asymptomatic incidental findings to malignant ventricular arrhythmias. Improved awareness of heterogenous presentations and markers of adverse outcomes is pivotal to guide a consistent and optimal management approach. Methods Retrospective observational study of patients with confirmed CS defined according to Heart Rhythm Society (HRS) consensus criteria (2014) between 2004–2022. Data on demographics, mode of presentation, serum and imaging biomarkers, and treatments regimens was assessed. Adverse clinical outcomes defined as heart failure hospitalization, ventricular arrhythmia (VA), new conduction disease, antitachycardic device therapies (ATD), death, cardiac transplant, atrial arrhythmias and strokes were evaluated. Results A confirmed diagnosis of CS was identified in 99 patients; n=23 (23%)isolated CS, median age 55 years ±11 years, 52% male). The common clinical presentations were; symptomatic conduction disease 53%, heart failure 24% and ventricular arrhythmia 16%, incidental 6%. Diagnosis was confirmed by imaging studies; cardiac MRI n=85 (86%) with late gadolinium enhancement in n=77 (78%) and / or positive CT-PET n=47 (47%). Concomitant cardiac biopsy was performed in 25%. Advanced device therapies were prescribed in 84 patients; bradycardic pacemaker n=17, defibrillator capable devices n=67 with 22 patients outside of standard Class I HRS Consensus (LVEF >35%). In total, 69 patients (70%) had a total of 158 adverse outcomes including heart failure (28%), VA’s (27%), ATD’s 21%, death 8%, conduction disease 7%, transplant 4%, atrial arrhythmias 3% and stroke in 1%. Treatment regimens for metabolically active disease included immunosuppression with 30–40mg prednisone in 65% with a tapering regimen after 12–36 weeks. An additional steroid sparing agents (methotrexate, azathioprine, mycophenolate, infliximab) were used in 55% of patients. Complete suppression of active disease assessed by repeat PET scan at 3 months after initiation of high dose steroid was observed in 55% of treated patients. One patient refused treatment had remission of activity seen on follow up CTPET. Overall 13% died and 6% patients required transplantation. Conclusion Presentation with conduction disease in a young patient should be considered a red flag for potential CS diagnosis. Multimodality imaging is pivotal in the diagnosis and PET scanning can aid management decisions by assessing disease activity pre and during treatment. Adverse events with CS are frequent and warrant close follow-up and longer-term collaborative studies to ensure a consistent and optimal management.