Recurrent Cardiac Sarcoidosis After Heart Transplantation.

Background: Cardiac sarcoidosis (CS) is a rare but clinically significant condition in heart transplant recipients.

Case summary: A 64-year-old woman with nonischemic cardiomyopathy and heart transplant presented with exertional dyspnea and new reduction in left ventricular ejection fraction. Endomyocardial biopsy, donor-specific antibodies, and imaging were concerning for antibody-mediated rejection versus CS. Empiric treatment for antibody-mediated rejection was initiated, but her left ventricular ejection fraction remained unchanged. Native heart explant was reviewed and was consistent with CS. Methotrexate was started, with clinical and radiographic improvement.

Discussion: Owing to its patchy nature, CS can be difficult to diagnose on biopsy, but cardiac imaging can assist. Heart transplant recipients with known CS have similar outcomes to transplant recipients without CS if they take low-dose steroids indefinitely.

Take-home message: The explanted heart should be extensively examined for CS in transplant recipients; if found, clinicians should prescribe CS-effective therapy indefinitely to prevent recurrence.