Abstract Rationale Cardiac sarcoidosis (CS) carries high morbidity and mortality. Endomyocardial biopsy, the diagnostic standard, carries low sensitivity and negative predictive characteristics due to the patchy nature of infiltration. Advanced cardiac imaging, particularly Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) is valuable for detecting active granulomatous inflammation but has unclear clinical prognostication. Conventional endpoints such as arrhythmia and death occur late in disease progression. This study investigates whether PET-derived measures of cardiac inflammation predict clinical outcomes. Methods This was a retrospective cohort study of patients diagnosed with sarcoidosis (based on ICD-9/ICD-10 codes) who underwent cardiac PET imaging since 2009 in a single healthcare system. Data abstracted from the electronic health record (EHR) included demographics, comorbidities, and baseline cardiac status, global cardiac PET activity, max standardized uptake value (SUV), and cardiac perfusion abnormalities on PET. Time to first sarcoidosis exacerbation from PET imaging was analyzed using survival analysis with group comparisons using the log-rank test. A SUVmax ≥2.0 was designated cardiac activity. Cox proportional hazards assessed association between SUVmax and exacerbation risk, adjusting for age, and co-morbidities. Effects of co-morbidities on hospital outcomes were further assessed by multivariate linear regression. Analysis was conducted in StataNow SE (version 19.5) with two-sided p 0.05 considered significant. Results A total of 339 patients met inclusion criteria, with a median age at time of inclusion of 57 years old. 180 (53%) were male and 159 (47%) were female. 88 (26%) were White, 225 (66%) were Black, and 26 (8%) identified as Other or declined to answer. A SUVmax greater than 2 was associated with an increased risk of exacerbation (HR 1.49, 95% CI 1.16-1.91, p = 0.002) (Figure 1). Presence of a perfusion defect was not associated with time to exacerbation (HR 0.99, 95% CI 0.78-1.26, p = 0.96). Neither SUVmax nor the presence of a perfusion defect were associated with hospitalization. Pulmonary hypertension as a co-morbidity was associated with a shorter time to hospitalization (HR 2.10, 95% CI 1.22-3.61, p = 0.008), more overall hospitalizations (β = 3.64, 95% CI 1.16-6.12, p = 0.004), and longer total length-of-stay (β = 135.5, 95% CI 11.6-259.5, p = 0.032) during the study period. Conclusion SUVmax in cardiac PET may predict the risk of sarcoidosis exacerbations and should be further studied as a tool to risk stratify sarcoidosis patients. Additionally, pulmonary hypertension in sarcoidosis is associated with worse clinical outcomes. This abstract is funded by: None
Boe et al. (Fri,) studied this question.