Dec. 18, 2025
What if cardiac sarcoidosis experts around the globe could come together to determine when to optimally use advanced cardiac imaging for patients with a suspected or confirmed diagnosis? An international, multidisciplinary panel of specialists collaborated to resolve the uncertainty of a previous lack of guidelines. The findings were published in JACC: Cardiovascular Imaging.
Cardiac sarcoidosis (CS), a rare autoimmune disorder with no known cure, is characterized by granulomatous infiltration of the myocardium. It can mimic other conditions and remain undiagnosed for years. Making an accurate diagnosis is key. Some patients may not experience symptoms, while others may already have severe heart failure. A multidisciplinary team of experts is dedicated to diagnosing and treating patients at the Cardiac Sarcoidosis Clinic at Mayo Clinic in Minnesota, Florida and Arizona.
A crucial part of diagnosis and management of cardiac sarcoidosis in patients is cardiac imaging. But how it's used, including access and follow-up, varies throughout the world. The researchers did a Delphi study to define areas of consensus and where further study is needed for using imaging in patients with cardiac sarcoidosis.
The panel of 89 CS experts, representing 61 centers in 13 countries, completed a modified two-round Delphi study to develop agreement on how to optimally use advanced cardiac imaging. Clinical decision-making was evaluated in cardiac imaging use, including indication thresholds, interpretation and interval follow-up imaging. Consensus was defined a priori as 70% or greater agreement or disagreement.
High clinical stakes
The experts also sought to determine the future areas of research. "This study represents the first large-scale, international Delphi consensus on the use of cardiac imaging in cardiac sarcoidosis. Until now, imaging practices have been inconsistent across regions and sometimes within the same institutions, creating heterogeneity in clinical management," says Tahir S. Kafil, M.D., a cardiologist in Rochester, Minnesota, and first author of the study. "We were able to establish a consensus on key areas — such as the complementary role of cardiac magnetic resonance (CMR) and fluorodeoxyglucose (FDG) positron emission tomography (PET) for diagnosis — while also identifying unresolved gaps like the quantification of late gadolinium enhancement (LGE) or FDG uptake."
The research delves into how differently experts worldwide use cardiac imaging for suspected or confirmed CS. "Despite the condition's potential for life-threatening arrhythmias, heart block and cardiomyopathy, there are few prospective or randomized trials. With little evidence, the experts vary significantly in deciding what to do," says Dr. Kafil. "Given the absence of standardized practice and the high clinical stakes, this Delphi methodology was an ideal tool to capture expert compromise across the globe and clarify best practices with our current understanding.
Key findings
- When new rhythm disturbances or ventricular dysfunction occur in patients with established extracardiac sarcoidosis, experts agreed there should be a low threshold to order advanced imaging.
- CMR and FDG-PET were identified as co-primary modalities, with agreement that a normal CMR in low pretest probability is sufficient to conclude investigations.
- In moderate or high pretest probability, a normal CMR does not definitively rule out CS and PET should be pursued.
- LGE was consistently recognized as a marker of adverse outcomes, but no agreement was reached on how to quantify it.
- FDG-PET reduction was viewed as an important marker of treatment response. Experts differed on what is clinically meaningful reduction.
"An unexpected finding was that experts didn't recommend routine CMR screening in asymptomatic patients with extracardiac sarcoidosis. The more targeted approach allows for better resource allocation," says Dr. Kafil. "Another surprising point was the lack of consensus that complete FDG uptake resolution should be the treatment target, which highlights uncertainty about the degree of imaging response needed to guide management. And despite universal recognition of LGE's prognostic significance, most centers do not routinely quantify LGE burden, underscoring a gap between knowledge and actual practice."
Next steps
This research reinforces the value of a multidisciplinary team approach, and it can help avoid unnecessary imaging. "It will directly influence clinical care by providing practical algorithms and consensus-driven recommendations on when to order advanced cardiac imaging and how to interpret it in the context of pretest probability," says Dr. Kafil.
The study offers much needed clarity on building the key areas of research. Priorities include:
- CMR and PET research.
- Standardizing LGE and FDG quantification and reporting.
- Determining imaging thresholds linked to outcomes.
"Our study provides a foundation for collaborative trials leading to more evidence-based management of CS," says Dr. Kafil. "Prospective multicenter trials and expanded access to CMR and PET will be essential to validate these findings and extend them around the globe."
For more information
Kafil TS, et al. Global practices in cardiac imaging for cardiac sarcoidosis: A survey study of international experts with Delphi consensus. JACC: Cardiovascular Imaging. 2025;18:679.
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