Interventional treatments and risk factors in patients born with hypoplastic left heart syndrome in England and Wales from 2000 to 2015

Abstract

ObjectiveTo describe the long term outcomes, treatment pathways and risk factors for patients diagnosed with Hypoplastic Left Heart Syndrome (HLHS) in England and Wales. MethodsThe UKs national audit database captures every procedure undertaken for congenital heart disease and updated life status for patients resident in England and Wales. HLHS patients born between 2000 and 2015 were identified using codes from the International Paediatric and Congenital Cardiac Code. ResultsThere were 976 patients with HLHS. Of these, 9.6% had a pre-pathway intervention, 89.5% underwent a traditional pathway of staged palliation and 6.4% of infants underwent a hybrid pathway. Patients undergoing pre-pathway procedures or the hybrid pathway were more complex, exhibiting higher rates of prematurity and acquired comorbidity. Pre-pathway intervention was associated with the highest in-hospital mortality (34.0%).44.6% of patients had an off pathway procedure after their primary procedure, most frequently stenting or dilation of residual or re-coarctation and most commonly occurring between Stage 1 and 2.The survival rate at 1 year and 5 years was 60.7% (95% CI 57.5-63.7) and 56.3% (53.0-59.5) respectively. Patients with an antenatal diagnosis (multivariable hazard ratio (MHR) 1.63 (95% CI 1.12-2.38)), low weight (<2.5kg) (MHR 1.49 (1.05-2.11)) or the presence of an acquired comorbidity ) were less likely to survive. ConclusionTreatment pathways amongst HLHS patients are complex and variable. It is essential that the long term outcomes of conditions like HLHS that require serial interventions are studied to provide a fuller picture and to inform quality assurance and improvement. 3 KEY MESSAGES

Hypoplastic left heart syndrome: the importance of phenotypic diagnosis

“…Winlaw is to be congratulated on his thoughtful and timely editorial comment1 regarding the recent review of the outcome of treatment for patients diagnosed with hypoplastic left heart syndrome in England and Wales 2. It is possible, however, that he has taken a step too far when suggesting that ‘HLH is the end result of a pan-cardiac developmental disorder including the cardiomyocyte’ 1.…”

“…So as to justify this statement, those producing the reference he cited in support of his statement should have investigated models that matched the definitions used for the diagnosis of hypoplastic left heart syndrome as chosen by the authors of the review of outcomes for patients undergoing treatment in England and Wales. In this regard, all patients chosen for inclusion for the clinical study were required to have had ‘a small left ventricle, left-sided valvar stenosis or atresia, normally related great arteries and no common atrioventricular junction’ 2. Assessment of the described phenotypes for all the mice included in the investigation of Liu and colleagues3 shows that these alleged ‘mouse models’ had either discordant or double outlet ventriculo-arterial connections, or else a common atrioventricular junction.…”

Morphogenetic clarity in considerations of hypoplastic left heart syndrome

“…I thank Professor Anderson for his comments1  noting a discrepancy between the animal model described by Liu et al 2 and the clinical presentation of ‘hypoplastic left heart syndrome’ (HLHS) which was the focus of the study by Rogers et al 3…”

Hypoplastic left heart: the next chapter in our unsolved problem

“…In their  Heart  paper, 1 Rogers and colleagues bring the second chapter to a close and foreshadow the next chapter for a specialty which, in the UK, is never far from newspaper headlines.…”

“…Rogers and colleagues1 describe the multiple pathways children follow to achieve a total cavopulmonary connection (the Fontan operation). This is the last of the planned operations for children with HLH and other morphologies where a single ventricle supports the entire circulation.…”