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Severity of Mitral Regurgitation At Initial Presentation Predicts Risk of Death or Cardiac Transplantation In Children with Idiopathic Dilated Cardiomyopathy

Friday, October 19, 2012: 3:15 PM
Room 275-277 (Morial Convention Center)
Amit Patange, MD, MPH, Pediatric Cardiology, Children's Hospital of Michigan, Wayne State University, Detroit, MI and Robert D. Ross, Pediatrics, Children's Hospital Of Michigan, Detroit, MI

Purpose: Clinical outcomes among children with Idiopathic Dilated Cardiomyopathy (IDC) are diverse, which makes the decision on when to list for a cardiac transplantation challenging. The purpose of this study was to determine echocardiographic and clinical variables at the time of initial presentation that can help identify those at a greater risk of death or cardiac transplantation.

Methods: The study was a retrospective chart review of children with IDC. Inclusion criteria were age <18 years and a diagnosis of IDC as defined by clinical features of heart failure along with a left ventricular end diastolic dimension (LVEDD) z-score >2 and fractional shortening (FS) <28% on the initial echocardiogram. Other parameters studied included left ventricular end systolic dimension (LVESD), ejection fraction (EF), left ventricular posterior wall thickness (PWT), and left atrial (LA) volume calculated by the prolate ellipse method. Mitral regurgitation (MR) was graded as mild, moderate, or severe according to ASE guidelines. The need for inotropes, mechanical ventilation, ECMO and ventricular assist devices (VAD) was assessed. A follow-up echocardiogram performed prior to death or cardiac transplantation or during the most recent follow-up was similarly studied, and the two studies were evaluated by paired t-test. Comparisons between groups were done by Chi-square analysis and unpaired t-test. p<0.05 was considered significant.

Results: Forty-nine children with IDC were studied. Those who died or underwent cardiac transplantation were grouped as “Non-survivors”, the others who either completely recovered or developed chronic dilated cardiomyopathy were grouped as “Survivors”. The number of patients in each group was 26 and 23 respectively. The median age was 1.25 yrs (range 0.1-17 yrs). The median follow-up period was 1 yr (range 2 days-18 yrs). The two groups were similar with respect to age, sex, and BSA. The median time to death or transplantation since diagnosis among non-survivors was 1.5 mos (range 2 days-14yrs). The bar diagram shows the relationship between MR grade at initial presentation and outcome of death or cardiac transplantation.

Presence of a higher grade MR (moderate or severe vs mild) at initial presentation was the only echocardiographic parameter associated with a higher risk of death or cardiac transplantation (p<0.05). There was a significant improvement in LVEDD, LVESD, EF, FS, LA volume and MR grade on the follow-up echocardiogram among Survivors. These parameters did not change within the Non-survivor group. Requirement for inotropes and mechanical ventilation were the only clinical variables that were predictive of a higher risk for death or cardiac transplantation.

Conclusion: In children with IDC, severity of MR at the time of presentation and lack of improvement of MR over time are associated with higher risk of death or cardiac transplantation.