Risk of Mortality in Midlife? Adult Coronary Heart Disease Outcomes of Three Decades of Congenital Heart Disease Surgery

Abstract

Background: In New Zealand, the vast majority of congenital heart disease (CHD) surgery is undertaken by a single unit. The adult CHD population is growing rapidly and there is a pressing need to better understand clinical outcomes, including trends in survival at late follow-up. Method: Details of surgery for CHD from the Paediatric and Congenital Cardiac Service at Green Lane, Auckland City and Starship Children's Hospitals were retrieved from departmental databases if the first operation occurred between 1985 and 2014. Mortality was verified by regular downloads from the Ministry of Health matching for each patient's unique National Health Identity (NHI) code. Few patients had reached late adulthood by the end of the study period, hence trends in late mortality were examined up to the age of 50 years. Results: A total of 6,128 patients underwent 8,091 operations. Of these, 5,884 were aged < 50 years at data review. Beyond infancy the slope of the hazard function for mortality was observed to maintain a relatively stable slope until a steeper late hazard phase from midway through the fourth decade (Figure 1). The type of surgical procedure was a significant predictor (p < 0.001) for late survival, but there was an increase in hazard from the fourth decade, even in those with two ventricle circulation (Figure 2). Conclusion: In this contemporary cohort, the risk for late mortality in postsurgical adult CHD appeared to rise from the fourth decade. Further work may better define risk factors for mortality in these late survivors.