Global Practices in Cardiac Imaging for Cardiac Sarcoidosis: A Survey Study of International Experts With Delphi Consensus

Background: Cardiac imaging is a cornerstone in the initial diagnosis, management, and follow-up of cardiac sarcoidosis. However, ordering thresholds, access, and follow-up imaging vary across the globe. Objectives: A Delphi study was conducted to define areas of consensus and areas requiring further study in the use of cardiac imaging in suspected or established cardiac sarcoidosis. Methods: An international, multidisciplinary panel of experts in cardiac sarcoidosis completed a modified 2-round Delphi study. The study evaluated clinical decision making regarding the use of cardiac imaging, including indication thresholds, interpretation, and interval follow-up imaging. Consensus was defined a priori as ≥70% agreement or disagreement. Results: A total of 89 experts in cardiac sarcoidosis (89 in round 1 and 75 in round 2) participated, representing 61 centers in 13 countries. Consensus was reached on 22 of 46 items (48%) in round 1 and 21 of 29 items (72%) in round 2. There was a low threshold to order advanced cardiac imaging for new rhythm abnormalities or ventricular dysfunction detected on echocardiography in patients with established extracardiac sarcoidosis. ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography was an important co-primary modality with cardiac magnetic resonance (CMR) for initial diagnosis. If CMR was the first test, there was consensus to proceed to FDG–positron emission tomography after any abnormal CMR result or even after normal CMR result in the setting of moderate or high pretest probability for cardiac sarcoidosis. There was consensus that late gadolinium enhancement quantification was important, but there was no consensus on the threshold of risk or on how best to quantify late gadolinium enhancement. Similarly, reduction in FDG uptake was an important factor in guiding treatment response, but there was no consensus on how to best quantify FDG uptake or what constituted an adequate radiographic response. Conclusions: Several consensus areas for cardiac imaging in suspected and established cardiac sarcoidosis were identified. This consensus study identified areas of priority for future prospective, controlled, multicenter research studies.