Risk Stratification in Cardiac Sarcoidosis With Cardiac Positron Emission Tomography: A Systematic Review and Meta-Analysis.

BACKGROUND: Although positron emission tomography (PET) imaging is well established for its diagnostic role in cardiac sarcoidosis, less is known about the prognostic value of PET and its use in risk stratification for major adverse cardiac events (MACE). OBJECTIVES: The goal of this study was to perform a systematic review and meta-analysis looking at the prognostic value of PET imaging in patients with cardiac sarcoidosis. METHODS: Study investigators systematically searched EMBASE (Excerpta Medica dataBASE), MEDLINE, PubMed, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, CINAHL (Cumulative Index to Nursing and Allied Health Literature), ClinicalTrials.gov, and the European Union Clinical Trial Registry for cardiac sarcoidosis and PET imaging. The primary outcome of interest was MACE. RESULTS: The search revealed 3,010 records, of which 55 studies were included. This represented 5,250 patients. Factors associated with MACE included the following: the combination of abnormal fluorodeoxyglucose (FDG) uptake and perfusion defect, which had an OR of 2.86 (95% CI: 1.74-4.71; P < 0.0001); abnormal perfusion or FDG uptake, which had an OR of 2.69 (95% CI: 1.67-4.33); abnormal FDG uptake, which had an OR of 2.61 (95% CI: 1.51-4.50); focal abnormal right ventricular uptake, which had an OR of 6.27 (95% CI: 3.19-12.32; P < 0.00001); and a lack of response to immunosuppression on serial PET, which had an OR of 8.43 (95% CI: 3.25-21.85; P < 0.0001). A QUIPS (Quality in Prognostic Studies) tool analysis found a low to moderate risk of bias, particularly given the small sample sizes in the individual studies. CONCLUSIONS: Multiple cardiac PET parameters provide risk stratification value in cardiac sarcoidosis. Focal right ventricular uptake and a lack of response to immunosuppressive therapy on serial PET imaging were particularly predictive of MACE.