Lesion-Specific Factors Contributing to Inhospital Costs in Adults With Congenital Heart Disease

Predicting 30-day readmission after congenital heart surgery across the lifespan

INTRODUCTION

Hospital readmission is an important driver of costs among patients with CHD. We assessed predictors of 30-day rehospitalisation following cardiac surgery in CHD patients across the lifespan.

METHODS

This was a retrospective analysis of 981 patients with CHD who had cardiac surgery between January 2011 and December 2012. A multivariate logistic regression model was used to identify demographic, clinical, and surgical predictors of 30-day readmission. Receiver operating curves derived from multivariate logistic modelling were utilised to discriminate between patients who were readmitted and not-readmitted at 30 days. Model goodness of fit was assessed using the Hosmer-Lemeshow test statistic.

RESULTS

Readmission in the 30 days following congenital heart surgery is common (14.0%). Among 981 patients risk factors associated with increased odds of 30-day readmission after congenital heart surgery through multivariate analysis included a history of previous cardiac surgery (p < 0.001), longer post-operative length of stay (p < 0.001), as well as nutritional (p < 0.001), haematologic (p < 0.02), and endocrine (p = 0.04) co-morbidities. Patients who underwent septal defect repair had reduced odds of readmission (p < 0.001), as did children (p = 0.04) and adult (p = 0.005) patients relative to neonates.

CONCLUSION

Risk factors for readmission include a history of cardiac surgery, longer length of stay, and co-morbid conditions. This information may serve to guide efforts to prevent readmission and inform resource allocation in the transition of care to the outpatient setting. This study also demonstrated the feasibility of linking a national subspecialty registry to a clinical and administrative data repository to follow longitudinal outcomes of interest.

HAND1 Loss-of-Function Mutation Causes Tetralogy of Fallot

As the most prevalent form of birth defect in humans worldwide, congenital heart disease (CHD) is responsible for substantial morbidity and is still the leading cause of birth defect-related demises. Increasing evidence demonstrates that genetic defects play an important role in the pathogenesis of CHD, and mutations in multiple genes, especially in those coding for cardiac core transcription factors, have been causally linked to various CHDs. Nevertheless, CHD is a genetically heterogeneous disease and the genetic determinants underpinning CHD in an overwhelming majority of patients remain elusive. In the current study, genomic DNA was extracted from venous blood samples of 165 unrelated patients with CHD, and the coding exons and splicing junction sites of the HAND1 gene, which encodes a basic helix-loop-helix transcription factor essential for cardiovascular development, were sequenced. As a result, a novel heterozygous mutation, p.R118C, was identified in a patient with tetralogy of Fallot (TOF). The missense mutation, which was absent in 600 referential chromosomes, altered the amino acid that was completely conserved evolutionarily. Biological assays with a dual-luciferase reporter assay system revealed that the R118C-mutant HAND1 protein had significantly reduced transcriptional activity when compared with its wild-type counterpart. Furthermore, the mutation significantly decreased the synergistic activation of a downstream target gene between HAND1 and GATA4, another cardiac core transcription factor associated with TOF. To our knowledge, this is the first report on the association of a HAND1 loss-of-function mutation with enhanced susceptibility to TOF in humans. The findings provide novel insight into the molecular etiology underlying TOF, suggesting potential implications for the improved prophylactic and therapeutic strategies for TOF.