Abstract 2979: A Prospective Treatment Trial of Immunosuppression for Giant Cell Myocarditis
Background: Giant cell myocarditis (GCM) is a rare and highly lethal disorder of unknown cause that usually responds to heart transplantation. Retrospective case series suggest that cyclosporine-based immunosuppression may prolong transplant-free survival.
Methods: We conducted a multicenter, prospective, open-label, treatment trial of multi-drug immunosup-pression including cyclosporine and steroids for acute, pathologically-confirmed GCM of less than 3 months clinical duration.
Results: From June 1999 to June 2005, 12 subjects were enrolled from 6 medical centers. All subjects had pathologic confirmation of GCM before enrollment, and none were on ventricular assist device (VAD) support. Eleven of these 12 subjects received high dose steroids, cyclosporine, and in 9 cases muromonab-CD3. The 11 treated subjects were 63.6% female, had a mean age 60.3 ± 14.8 years, and a mean time from symptom onset of 26.8 ± 32.9 days. One subject died of respiratory complications at day 178, and 2 subjects received heart transplantations on days 2 and 27 respectively, yielding a 89% overall survival and 72% transplant-free survival at 1 year by Kaplan-Meier method. The mean LVEF was only mildly reduced at 42.8 ± 18.2% and did not change significantly after 1 month of treatment (46.8% ± 14.7% p = NS). No subject required VAD support. Compared to 16 subjects enrolled in the retrospective GCM registry (Cooper, LT et al, NEJM, 1997) who were diagnosed by biopsy but received no immunosuppression or steroids alone, 1 year transplant-free survival was better at 72% vs 6.2%, p = .0005 by Log-Rank test.
Conclusions: Immunosuppressive therapy that includes cyclosporine and steroids may increase transplant-free survival in acute GCM.