Differences in Presentation and Outcomes Between Children With Familial Dilated Cardiomyopathy and Children With Idiopathic Dilated Cardiomyopathy

Abstract

Background Research comparing the survival of children with familial dilated cardiomyopathy (FDCM) to that of children with idiopathic dilated cardiomyopathy (IDCM) has produced conflicting results. Methods and Results We analyzed data from children with FDCM or IDCM using the National Heart, Lung, and Blood Institute-funded Pediatric Cardiomyopathy Registry. Compared to children with IDCM (n=647), children with FDCM (n=223) were older (mean 6.2 vs. 4.5 years, P <0.001), less often had heart failure (64% vs. 78%, P <0.001), had less-depressed mean left ventricular (LV) fractional shortening z-scores (−7.85 ± 3.98 vs. −9.06 ± 3.89, P <0.001) and lower end-diastolic dimension z-scores (4.12 ± 2.61 vs. 4.91 ± 2.57, P <0.001) at diagnosis. The cumulative incidence of death was lower for patients with FDCM compared with IDCM (P=0.04; hazard ratio 0.64, P=0.06) but no difference in risk of transplant or the combined death or transplant outcome. There was no difference in the proportion of children with echocardiographic normalization at three years of follow-up (FDCM, 30% vs. IDCM, 26%; P=0.33). Multivariable analysis showed no difference in outcomes between FDCM and IDCM but for both groups older age, congestive heart failure (CHF) and increased LV end-systolic dimension z-score at diagnosis were independently associated with an increased risk of death or heart transplantation (all Ps <0.001). Conclusions There was no survival difference between FDCM and IDCM after adjustment for other factors. Older age, CHF, and greater LV dilation at diagnosis were independently associated with increased risk of the combined endpoint of death or transplantation. Clinical Trial Registration https://clinicaltrials.gov; NCT00005391

Genetic aetiologies should be considered in paediatric cases of acute heart failure presumed to be myocarditis

“…Our results support the evidence that children with a hereditary cardiomyopathy who present in acute heart failure tend to have poorer outcomes compared to patients with idiopathic cardiomyopathy. 12 Of note, our study and previous research have not compared mutation-negative, familial cases compared to mutation-positive cases, and this would be of interest for further study. Furthermore, identifying patients who have genetic syndromes allows the health care team to provide appropriate anticipatory guidance to the family and appropriate medical care for the additional sequela that may develop.…”

Genetics of paediatric cardiomyopathies

“…Recent data indicate that in the pediatric population there is no survival difference between familial DCM and idiopathic DCM after adjustment for other factors. (18) However, the majority of patients in this study did not undergo genetic testing and therefore it is unclear whether there might be a survival difference based on genotype. Overall, older age, heart failure, and greater left ventricular dilation at diagnosis were independently associated with increased risk of the combined endpoint of transplantation and death.…”

Lessons learned from the Pediatric Cardiomyopathy Registry (PCMR) Study Group

“…3 The Pediatric Cardiomyopathy Registry found that 1-year survival was significantly better in patients with familial dilated cardiomyopathy (87%) compared with idiopathic dilated cardiomyopathy (60%). 18 In addition, patients with familial isolated cardiomyopathy had higher left ventricular ejection fractions, lower end-diastolic and end-systolic dimensions, and lower left ventricular mass than those with idiopathic dilated cardiomyopathy. Left ventricular end-diastolic dimension z-scores predicted an increased risk of death or transplantation in children with familial isolated cardiomyopathy.…”