Giant Cell Myocarditis: A Brief Review

Abstract

Giant cell myocarditis (GCM) is a rapidly progressive and frequently fatal disease that mainly affects young to middle-aged previously healthy individuals. Early diagnosis is critical, as recent studies have shown that rapidly instituted cyclosporine-based immunosuppression can reduce inflammation and improve transplant-free survival. Before the 1980s, GCM was mainly a diagnosis made at autopsy. Owing to advancements in diagnostic and therapeutic options, it is now increasingly diagnosed on the basis of endomyocardial biopsies, explanted hearts, or apical wedge sections removed at the time of ventricular assist device placement. Histologic examination remains the gold standard for diagnosis; however, there are many possible etiologies for cardiac giant cells. Having a working knowledge of the clinicopathologic features that distinguish GCM from other giant cell–containing lesions is essential, since such lesions can have widely divergent management and outcome.

A giant mystery in giant cell myocarditis: navigating diagnosis, immunosuppression, and mechanical circulatory support

“…GCM is often associated with refractory ventricular arrhythmias or other conduction abnormalities . Only 14–29% of patients initially present with VT compared with more than 75% of patients presenting with acutely decompensated heart failure . These figures are likely a reflection of historical findings when GCM was only identified at the time of autopsy.…”

“…GCM pathophysiology is linked to a T-cell-mediated process, characterized by infiltration of cardiomyocytes by lymphocytes, histocytes, multinucleated giant cells, eosinophils with necrosis of cardiomyocytes, and notable absence of granulomas. 1,4,[11][12][13] Saltykow first described GCM in 1905, and the role of immunosuppression was reported in 1987. 14,15 There are no prospective clinical trials to guide management of this rare disease; however, retrospective reports and case series suggest maintenance immunosuppressive therapy with or without induction.…”

“…4,7,9,10 Only 14-29% of patients initially present with VT compared with more than 75% of patients presenting with acutely decompensated heart failure. 1 These figures are likely a reflection of historical findings when GCM was only identified at the time of autopsy. A change in the acuity of patients diagnosed with GCM may be seen with increasing utilization of prospective endomyocardial biopsy and apex biopsy at the time of LVAD implantation.…”

“…Giant cell myocarditis (GCM) is a rare, incompletely understood disease. Severe, rapidly progressive heart failure in young to middle‐aged adults characterizes the most frequently reported presentation of GCM . Prognostic differences have been suggested on the basis of initial presentation of myocarditis, with patients in fulminant myocarditis and histologically proven GCM both highly associated with short‐term mortality .…”

Giant cell myocarditis causing refractory ventricular tachycardia in a pediatric patient

“…Further studies distinguished GCM from sarcoidosis, both histologically and clinically . Pathologically, GCM will have diffuse or multifocal infiltrate consisting of lymphocytes and eosinophils with multinucleated giant cells at the periphery and various degree of fibrosis and damaged myocytes .…”