Case report: First-in-human combined low-dose whole-heart irradiation and high-dose stereotactic arrhythmia radioablation for immunosuppressive refractory cardiac sarcoidosis and ventricular tachycardia.

Background: Cardiac sarcoidosis is associated with heart failure, conduction abnormalities, and life-threatening arrhythmias including ventricular tachycardia (VT). Radiotherapy has been suggested as a treatment for extra-cardiac sarcoidosis in patients refractory to immunomodulatory treatment.
Methods: The effectiveness and safety of low-dose whole-heart radiotherapy for therapy refractory cardiac sarcoidosis were evaluated in a pre- and post-intervention case report comparing the 54 months before and after treatment. Immunomodulatory low-dose whole-heart irradiation as sarcoidosis treatment consisted of a 2 × 2 Gy scheme. Additionally, high-dose single-fraction stereotactic arrhythmia radioablation of 1 × 20 Gy was applied to the pro-arrhythmic region to manage the ventricular tachycardia episodes. Cardiac sarcoidosis disease activity was measured by hypermetabolic areas on repeated fluorodeoxyglucose ([ ¹⁸ F]FDG)-PET/computed tomography (CT) scans and by evaluating changes in ventricular tachycardia episodes before and after treatment.
Results: One patient with therapy refractory progressive cardiac sarcoidosis and recurrent ventricular tachycardia was treated. The cardiac sarcoidosis disease activity showed a durable regression of inflammatory disease activity from 3 months onwards. The [ ¹⁸ F]FDG-PET/CT scan at 54 months did not show any signs of active cardiac sarcoidosis, and a state of remission was achieved. The number of sustained VT episodes was reduced by 95%. We observed that the development of moderate aortic valve regurgitation was likely irradiation-related. No other irradiation-related adverse events occurred, and the left ventricular ejection fraction remained stable.
Conclusion: We report here for the first time on the beneficial and lasting effects of combined immunomodulatory low-dose whole-heart radiotherapy and high-dose stereotactic arrhythmia radioablation in a patient with therapy refractory cardiac sarcoidosis and recurrent VT.
Competing Interests: CS received educational grants through her institution from Biosense Webster and Abbott and speaker fees from Daiichi Sankyo. EP received educational grants through his institution from Medtronic and research grants from the Swiss National Science Foundation and the European Community (H2020). The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
(© 2023 van der Ree, Herrera Siklody, Le Bloa, Pascale, Porretta, Teres, Solana Munoz, Luca, Domenichini, Ozasahin, Jumeau, Postema, Ribi, Bourhis, Schiappacasse and Pruvot.)