GIANT-CELL MYOCARDITIS

Background: Giant cell myocarditis is a rare and frequently fatal diso rder of unknown origin that is defined histopathologically as diffuse myocardial necrosis with multinucleated giant cells in the absence of sarcoidlike granulomata. The clinical and pathologic features of lymph ocytic myocarditis have been described in several recent publications, but the features of idiopathic giant cell myocarditis have not been a dequately addressed. Methods and Results: We describe five patients wi th idiopathic giant cell myocarditis who were seen at Stanford Univers ity over the past 10 years. In each case the onset was subacute conges tive heart failure. After diagnosis each patient received immunosuppre ssive therapy and was evaluated for heart transplantation. Progressive heart failure and ventricular arrhythmias developed in all. Three die d rapidly, two of progressive heart failure and one of sudden cause. T wo patients underwent orthotopic heart transplantation and are current ly alive, one with disease recurrence. Pathologic studies, including e ndomyocardial biopsy and evaluation of postmortem or explanted materia l at transplantation were reviewed. The pathologic studies provided ad ditional support that the giant cells derive from a monocytic/histiocy tic lineage. Segmental wall motion abnormalities suggest giant cell my ocarditis can be a focal, as well as diffuse process at certain stages of its course. This experience is compared with published cases and i mplications for diagnosis and treatment are discussed. Conclusions: In view of the uniformly fatal nature of the disease, heart transplantat ion should be a serious consideration, and the patients evaluated once the diagnosis is established. Triple-drug immunosuppressive therapy s hould be considered at the time of diagnosis.