Diagnostic and Prognostic Value of CMR and Cardiac PET Imaging in Patients with Cardiac Sarcoidosis

Abstract

Background: Cardiac Magnetic Resonance (CMR) and Positron Emission Tomography (PET) are employed to diagnose Cardiac Sarcoidosis (CS). However, their role in prognosis and guiding treatment is not well established. Objective: To discern the utility of CMR and PET in diagnosing and predicting adverse outcomes in CS. Methods: “Cardiac Sarcoidosis*” AND “Magnetic Resonance Imaging” OR “Positron Emission Tomography” were searched on PubMED, EMBASE and SCOPUS on 21st of September 2018 yielding 1180 articles. After exclusions, 26 studies were included in the meta-analysis. Results: 8 and 13 studies compared diagnostic value of CMR and PET, respectively against the diagnostic criteria of either the Japanese Ministry of Health or the Heart Rhythm Society. These showed a sensitivity of 75.7% [69.3–81.4] and 81.4% [76.7–85.4] for CMR and cardiac PET, respectively, to diagnose CS. The risk of ventricular arrhythmia was increased in patients with late gadolinium enhancement (LGE) on CMR (HR 3.32 [0.59–18.51], I2 = 58; N = 4) or positive FDG uptake on cardiac PET (HR 2.91 [1.68–5.06]; N = 3). The LVEF in the group with and without LGE on CMR was 54±9 and 57±7%, respectively. Absence of LGE on CMR predicted absence of ventricular arrhythmia (NPV = 96.7% [88.2%–99.1%]). LGE on CMR was also associated with increased risk of major adverse cardiac events (MACE) (HR: 8.20 [2.28–29.45], I2 = 81; N = 5). Conclusion: LGE on CMR and positive FDG uptake on cardiac PET are associated with high risk of ventricular arrhythmia. LGE on CMR imaging predicts high risk for MACE.