What is known:
• Hypoplastic left heart syndrome has the highest mortality among congenital cardiac defects during the first year of life.
• Limited studies on patients’ comorbidities and mortality rates trends over last two decades.
What is new:
• The study utilized a national database to compare in-hospital mortality and length of stay between the two time periods 1998–2005 and 2006–2014.
• The recent group had more comorbidities (prematurity, chromosomal anomalies, total anomalous pulmonary venous return, and kidney anomalies), and there was higher rate of ECMO and longer length of stay, while mortality rates decreased by 20%.