Introduction: Cardiac sarcoidosis (CS) is a rare and likely underrecognized manifestation of sarcoidosis. CS typically occurs in the context of systemic sarcoid, but isolated cases may exist. We present two cases of patients with nonischemic cardiomyopathy (NICM) who underwent heart transplantation (HT) and were subsequently found to have evidence of CS on explant pathology. 

Clinical Case Description: Patient 1

A 58-year-old woman presented with exertional dyspnea due to complete heart block requiring permanent pacemaker implantation. Four years later, she developed heart failure and NICM with LVEF 20-25%; her device was upgraded to a biventricular system. She experienced progression to end stage heart failure necessitating HT. No extra-cardiac manifestations were notable, and advanced imaging was not pursued. Explant pathology demonstrated noncaseating granulomas and extensive fibrosis. She was maintained on tacrolimus and long-term low-dose steroids.

Patient 2

A 61-year-old man with a history of NICM secondary to severe mitral regurgitation (MR) underwent surgical mitral valve repair. Following discharge, the patient had progressive symptoms of end stage heart failure. CMR demonstrated LVEF 10% and small, focal, mid-wall LGE along the basal inferior RV insertion site. He ultimately underwent HT with explant pathology demonstrating noncaseating granulomas of the LV and interventricular septum. He was maintained on tacrolimus and long-term low-dose steroids.

Conclusions: These cases highlight the diagnostic difficulty of CS and management dilemma with incidental discovery. Patient 1 did not undergo advanced cardiac imaging; this highlights the importance of maintaining a high index of suspicion for CS, particularly when presenting with unexplained conduction disease. Patient 2 likely represents a perplexing case of mixed cardiomyopathy due to both CS and valve disease. His minimal LGE on CMR may reflect a lack of active inflammation or extensive fibrosis. Interestingly, neither patient exhibited evidence of extra-cardiac sarcoidosis. Finally, these incidental findings highlight the immunosuppressive considerations of patients with CS post-HT.