Heart Transplantation in Advanced Heart Failure Due to IgG4-Related Endomyocardial Fibrosis

IgG4-related disease (IgG4-RD) is a systemic fibroinflammatory condition that rarely affects the heart. Cardiac manifestations include pericarditis, coronary arteritis, and myocarditis; endomyocardial fibrosis (EMF) is exceedingly rare.

We report a 66-year-old man with advanced heart failure and recurrent hospitalizations due to restrictive cardiomyopathy, initially attributed to hypereosinophilia from parasitic disease. The patient developed cardiogenic shock requiring inotropes and intra-aortic balloon pump support. Imaging revealed biatrial enlargement, endocardial thickening, and subendocardial fibrosis, suggestive of EMF. Serology was positive for Trichinella spiralis IgG. Because of progressive clinical deterioration, the patient underwent urgent orthotopic heart transplantation. Histology of the explanted heart confirmed IgG4-related EMF. Posttransplant follow-up at 12 months showed preserved graft function and no recurrence.

This case illustrates a rare cause of end-stage heart failure due to IgG4-RD and highlights the importance of including systemic inflammatory conditions in the differential diagnosis of restrictive cardiomyopathy.

IgG4-related disease, though rare, can present as isolated endomyocardial fibrosis with features mimicking tropical EMF or hypereosinophilic cardiomyopathy. In advanced fibrotic stages with isolated cardiac IgG4-RD and cardiogenic shock, orthotopic heart transplantation may be the only lifesaving therapeutic option.