Recovery of Echocardiographic Function in Children With Idiopathic Dilated Cardiomyopathy
Key result
Children with idiopathic DCM achieved a 22% 2-year cumulative incidence of LV normalization, independently predicted by lower LVEDD z-score (HR 0.75, 95% CI 0.68-0.84) and younger age (HR 0.90).
Why the study?
Most children with idiopathic DCM have poor outcomes, though some improve. The incidence of and predictors for recovery of normal echocardiographic LV function and size were undetermined.
Key Points
- To determine the incidence of and predictors for recovery of normal echocardiographic ventricular size and function in children with idiopathic dilated cardiomyopathy.
- Analyzed children younger than 18 years from the Pediatric Cardiomyopathy Registry diagnosed between 1990 and 2012 with depressed left ventricular function (fractional shortening or ejection fraction z-score <-2) and left ventricular dilation (end-diastolic dimension [LVEDD] z-score >2).
- Included 741 of 868 eligible patients (85%) who had follow-up echocardiographic data available between 30 days and 2 years after diagnosis.
- Estimated the cumulative incidence and multivariable predictors of echocardiographic normalization over a 2-year follow-up period.
- At 2 years, 22% of children recovered normal left ventricular size and function (median time to normalization, 9.5 months), 51% died or underwent heart transplant (median, 3.2 months), and 27% had persistently abnormal echocardiograms.
- Younger age (hazard ratio [HR], 0.90; 95% CI, 0.86 to 0.95) and lower baseline LVEDD z-score (HR, 0.75; 95% CI, 0.68 to 0.84) independently predicted normalization.
- Among the children who recovered normal left ventricular size and function within 2 years, 9% (9 of 96) subsequently died or underwent heart transplantation.
Study Design
Type
Cohort (n=741)
Multicenter
Yes
Structured PICO
P
Population
741 children (<18 years) with idiopathic dilated cardiomyopathy, baseline LV dilation (LVEDD z-score >2), and depressed LV systolic function (FS or EF z-score <-2) across 98 North American centers, followed for 2 years.
O
Outcome
Recovery of normal echocardiographic LV function and size (both LVEDD and LV fractional shortening or LVEF z-scores within normal range of -2 to +2 SD) within 2 years from initial diagnosis, analyzed in the presence of competing risks (death or heart transplant, and persistently abnormal echocardiogram).surrogate
Main Result
Hazard Ratio: 1.3 (95% CI 1.19–1.47)
p-value: p=<0.001
Despite presenting with marked LV dilation and depressed systolic function, 22% of children with idiopathic dilated cardiomyopathy recover normal LV size and function within 2 years—particularly those who are younger and have less LV dilation at diagnosis—though 9% of normalized patients subsequently die or require heart transplantation, warranting continued long-term follow-up.
Limitations
- Lack of standardized follow-up and timing at which echocardiograms were obtained (abstracted annually, resulting in left-censored timing)
- 15% (127/868) of eligible subjects with abnormal baseline LV function and dilation were excluded due to insufficient follow-up information
- Insufficient data on tricuspid or mitral regurgitation and family history of sudden death or heart disease to include in multivariable models
- Insufficient detailed information on specific medications (e.g., beta-blockers, ACE inhibitors) to analyze the association between medical therapy or its discontinuation and recovery
- Lack of standardized follow-up and timing at which echocardiograms were obtained (data abstracted annually, resulting in left-censored timing and potential overestimation of time to recovery).
- 15% of eligible subjects (127 of 868) were excluded due to insufficient follow-up information; these excluded patients were slightly older at diagnosis, which may cause reported recovery rates to be mildly overestimated.
- Information on tricuspid or mitral regurgitation and family history of sudden death or heart disease was available for only a few children and could not be included as candidate predictors.
- Insufficient information on specific medication use (such as beta-blockers and ACE inhibitors) to analyze the association between medical therapy or its discontinuation and recovery of echocardiographic function.
Key expert perspectives
Captured external expert commentary on this paper, strongest first. Original sources are linked where available.
“The really exciting thing about this study is that it gives us a way to begin predicting which children diagnosed with DCM are most likely to survive the disease with normal heart size and function. Knowing how to predict that could also be crucial in determining which children can be expected to survive without requiring heart transplants – a breakthrough that could allow clinicians to reserve that extremely complex and physically demanding procedure for those patients who need it most.”
“But this new study is going to help change that, because it provides some revealing metrics showing that more than 22 percent of DCM-diagnosed children can be expected to regain normal heart size and function, with appropriate medical treatment and management of their condition.”
“It is possible that additional patients in the study by Everitt et al. (8) may have ultimately crossed over into the normalized group because the cutoff for the follow-up interval was only 2 years, and the curve for the cumulative incidence rate of recovery continued to increase while the proportion with persistently abnormal function continued to decline during the final months before study closure.”
Implication
Younger age may aid prognostic stratification in pediatric cardiomyopathy; leaves open whether it should guide management or trials.
Abstract
Objectives To determine the incidence of and predictors for recovery of normal echocardiographic function among children with idiopathic dilated cardiomyopathy (DCM). Background Most children with idiopathic DCM have poor outcomes; however, some improve. Methods We studied children less than 18 years old in the Pediatric Cardiomyopathy Registry who had both depressed left ventricular (LV) function (fractional shortening [FS] or ejection fraction [EF] z-score <−2) and LV dilation (end-diastolic dimension [LVEDD] z-score >2) at diagnosis and who had at least one follow-up echocardiogram 30 days to 2 years from the initial echocardiogram. We estimated the cumulative incidence and predictors of normalization. Results Among 868 children who met inclusion criteria, 741 (85%) had both echocardiograms. At 2 years, 22% had recovered normal LV function and size; 51% had died or undergone heart transplant (median, 3.2 months), and 27% had persistently abnormal echocardiograms. Younger age (hazard ratio, 0.90; 95% CI, 0.86 to 0.95) and lower LVEDD z-score (0.75; 95% CI, 0.68 to 0.84) independently predicted normalization. Nine children (9%) with normal LV function and size within 2 years of diagnosis later underwent heart transplant or died. Conclusions Despite marked LV dilation and depressed function initially, children with idiopathic DCM can recover normal LV size and function, particularly those younger and with less LV dilation at diagnosis. Investigations related to predictors for recovery, such as gene associations, serum markers, and the impact of medical therapy or ventricular unloading with assist devices are important next steps. Longer follow-up after normalization is warranted as cardiac failure can recur.
Discussion
No takes yet. Share an insight, caveat, or question.
Cite This Study
Everitt et al. (2014) conducted a cohort in Idiopathic dilated cardiomyopathy (n=741). Younger age and lower LVEDD z-score at diagnosis vs. Older age and higher LVEDD z-score at diagnosis was evaluated on Recovery of normal echocardiographic LV function and size within 2 years (predicted by lower LVEDD z-score per 1-unit decrease) (HR 1.3, 95% CI 1.19-1.47, p=<0.001). Children with idiopathic DCM achieved a 22% 2-year cumulative incidence of LV normalization, independently predicted by lower LVEDD z-score (HR 0.75, 95% CI 0.68-0.84) and younger age (HR 0.90).