Abstract 9783: Echocardiographic Normalization in Children With Idiopathic Dilated Cardiomyopathy: Results From the Pediatric Cardiomyopathy Registry

Abstract

Background: Children with idiopathic dilated cardiomyopathy (IDCM) commonly have a poor outcome; however, some improve with normalization of ventricular size and systolic function at follow-up. The incidence of and predictors for such normalization are largely unknown. Methods: All children age ≤18 years with IDCM who had both depressed left ventricular (LV) function (FS or EF z-score<-2) and LV dilation (end diastolic dimension [LVEDD] z-score>2) on the first echo were identified. At least 1 follow-up echo within 2 years of diagnosis was required for inclusion. Competing risks methodology was used to estimate cumulative incidence and predictors for normalization (FS/EF z-score>-2 and LVEDD z-score<2) within 2 yrs of diagnosis. Results: Among 1387 children with IDCM enrolled from 1990-2009 in the Pediatric Cardiomyopathy Registry (PCMR), 868 (63%) met inclusion criteria of depressed LV function and dilation. Of these, 773 (89%) had echo follow-up and were included for analysis. Echo normalization occurred in 25% by 2 yrs, at a median of 9.4 months. Fig. 1 shows cumulative incidence of the following competing outcomes: (1) normalization; (2) death or transplantation (51% by 2 yr); and (3) persistently abnormal echo (24% by 2 yr). Younger age (RR:0.90, 95% CI:0.86-0.94, p<0.001) and lower LVEDD z-score (RR:0.74, 95% CI:0.66-0.82, p<0.001) were independent predictors for normalization. Nine patients (9%), who had echo normalization within 2 yrs of diagnosis, later deteriorated and underwent heart transplant or died. Conclusions: Echo normalization of LV size and systolic function occurred by 2 yrs in 25% of children with IDCM in this large multi-site registry. Younger children and those with less LV dilation at presentation were more likely to normalize. Continued follow-up of children with echo normalization after IDCM is warranted since a subset of these children had subsequent deterioration leading to death or transplantation.