Cardiac structural and functional alterations in infants and children with biliary atresia, listed for liver transplantation

Abstract

Background & aims: Cirrhotic liver diseases are associated with abnormalities in cardiac geometry and function in adults (cirrhotic cardiomyopathy) but rarely explored in cirrhotic infants or children. We proposed that features of cirrhotic cardiomyopathy are present in infants with cirrhosis due to biliary atresia (BA) as early as the time of evaluation for liver transplant and will correlate with mortality and postoperative morbidity.

Methods: Two-dimensional echocardiography (2DE) of infants with BA (n=40; median age, 8 months), listed for transplantation at the Texas Children's Hospital from 2004 to 2010, were reviewed and compared with age- and sex-matched infants without cardiac or liver disease (controls). Length of stay and correlation with 2DE results were assessed.

Results: Compared with controls, children with BA had significant increases in multiple 2DE parameters, notably left ventricle wall thickness (23% increase), left ventricular (LV) mass indexed to body surface area (51% increase), and LV shortening fraction (8% increase). Overall, features of cirrhotic cardiomyopathy were observed in most infants (29/40; 72%); 17 had hyperdynamic contractility, and 24 had altered LV geometry. After liver transplantation (33), infants with abnormal 2DE results had longer stays in the intensive care unit (median, 6 vs 4 days) and the hospital (21 vs 11 days) compared with infants who had normal 2DE reports. On univariate analysis, the length of hospital stay correlated with LV mass index.

Conclusions: Cardiomyopathy is a prevalent condition in infants with end-stage cirrhotic liver disease due to BA (>70%). This underrecognized condition likely contributes to the prolongation of posttransplant hospitalization.

Fig.1. Patients with BA selected for study

Flow chart depicting patients listed for liver transplantation during the study period of January 2004 to June 2010. Note: BA (Biliary atresia); LT (Liver Transplantation); TCH (Texas Children’s Hospital); 2DE (2-Dimensional Echocardiography).

Fig.2. Prevalence of abnormal 2DE reports in children with BA

Pie chart depicting prevalence of abnormal 2DE findings in children with BA listed for LT (n=40). 11/40 (28%) had normal (N) 2DEs, 5/40 (12%) had functional (hyperdynamic) 2DEs (F), structural (S) abnormality was seen in 12/40 (30%) while both functional as well as structural (F+S) abnormality was seen in 12/40 (30%) of children.

Fig.3. Effect of abnormal pre-operative 2DE reports on post-operative course

(A) Depicts distribution of post-operative Pediatric Intensive care Unit (PICU) , post-operative hospital and total hospital length of stay (LOS) in patients with normal (N) (n=7) and abnormal (ABN) (n=26) pre-operative 2DEs in all those with BA who were successfully transplanted (total n=33). (B) Depicts distribution of PICU, Post-op Hospital and total Hospital LOS in successfully transplanted children with BA (n=33) when children with Normal (N; n=7) 2DE were compared with those with Functional abnormality alone (F; n=3), Structural abnormality alone (S; n=11) or both (F+S;n=12). (* p<0.04; Stats: 2-tailed Mann-Whitney-Wilcoxon-Rank Sum Test; Results: Box (25-75%^ile) and Whiskers (10-90%^ile) depicts median in days.

Fig.4. Univariate Correlation of LVMI to post-operative PICU, hospital and total hospital LOS

Among all the clinically relevant continuous variables studied by linear regression analysis, only LVMI revealed a positive correlation with LOS. (Statistics: Univariate Pearson’s correlation)