Presentation, echocardiographic findings and long-term outcomes in children with familial dilated cardiomyopathy

Background: A potential genetic basis has been identified in around 30% of all childhood dilated cardiomyopathy (DCM). Despite this, the long-term outcomes for children with familial DCM have not been well characterized. This study examines the presentation, outcomes and echocardiographic findings for children with familial DCM enrolled in the National Australian Childhood Cardiomyopathy Study. Methods: NACCS is a longitudinal, population based study which includes all children aged 0-10. years who were diagnosed with primary cardiomyopathy between 1987 and 1996. Details of clinical status at diagnosis, medical therapy and late outcomes were recorded. Serial echocardiographic indices of LV size, fractional shortening and ejection fraction were expressed as Z scores, based on BSA and age. Familial cardiomyopathy was defined as the presence of an affected first or second degree relative with a similar cardiomyopathy. All available echocardiograms were interpreted by a single observer. Results: There were 175 subjects with DCM. Children with familial DCM (27 cases) were younger at diagnosis than those with sporadic DCM (median age 3.2 vs. 8.4. months (p=.004) and were less likely to have congestive heart failure and to be hospitalised at presentation (p≤002 for both). Familial DCM subjects had a higher mortality (62.9% vs. 36.5%; p=.02) and were less likely to be free of medical therapy at latest follow-up (7.4% vs. 52.0%; p<.001). Echocardiographic measurements were similar at presentation but familial DCM subjects had a higher mean LVEDd Z score (4.15 vs. 2.25; p=.006) and a lower FS Z score (-7.35 vs - 3.40; p=.002) score at latest follow-up. Conclusions: Familial DCM subjects are younger and are less likely to have symptomatic heart failure at the time of diagnosis. Despite this they have a higher mortality and worse ventricular function at late follow-up. This study underlines the differing presentations and outcomes among children with familial and sporadic DCM.