Abstract 2213: Effect of Medical Therapy and Transplantation on the Natural History of Pediatric Dilated Cardiomyopathy: A 25 Year Retrospective Study
Background: The long term transplant-free survival of infants and children with dilated cardiomyopathy (DCM) has been reported to be poor. We assessed the hypothesis that the introduction of angiotensin converting enzyme inhibitor (ACE) or B-andrenoceptor antagonist (BB) treatment has had an impact on the survival of these patients during the last 25 years.
Methods: A retrospective review of all diagnosed cases of DCM at The Hospital for Sick Children between 1980 and 2005 was conducted. Primary end points for survival analysis by the Kaplan-Meier method were either transplant-free survival or death/cardiac transplantation. Analysis for survival benefit by medical treatment strategy (No ACE or BB, ACE but no BB, and ACE with BB), diagnostic category, and during two time eras of treatment (1980 –1989 and 1990 –2005) was also performed. Paired comparison was made of echocardiographic ejection fraction (EF) at presentation and at the most recent assessment for specific diagnostic subgroups.
Results: 189 patients were identified, with a male/female ratio of 1.22 and a mean (SD) age at presentation of 4.5 (5.4) yrs. By the end of 2004, 49 of these had died, 34 had received a cardiac transplant, and 10 were lost to follow-up. Overall 5 and 10 year transplant-free survival rates (95% CI) were 58% (48 – 66) and 52% (42– 62). Transplantation improved 5 and 10 year survival rates to 83% and 73%, respectively. The 5 year transplant-free survival rate in patients treated without ACE or BB (n = 63) was 58%, and was 59% in those treated with ACE alone (n = 64). Combination therapy with ACE and BB (n = 53) was not associated with improved 5 year survival (53%) (p = ns by logrank test). Comparing the two time eras, there was no difference in 5 year survival rate. Of all diagnoses, patients with myocarditis had the highest overall survival (75%) while patients with neuromuscular or metabolic disorders had the most unfavorable prognosis.
Conclusions: DCM in childhood carries a significant mortality, which appears only to be impacted by the availability of transplantation. Transplant-free survival appears not to have changed regardless of the introduction of ACE inhibitor and BB therapy. Patients with myocarditis show the greatest recovery of ejection fraction, and the lowest crude mortality rate.