Background: Adults with congenital heart disease (CHD) comprise an increasing proportion of individuals living with CHD in the United States (US). A greater than 20% decrease in adult congenital heart disease (ACHD) related mortality in the US was noted from 1999 to 2006. No recent national data are available evaluating mortality in the ACHD population. Our study aims to estimate US ACHD mortality rates by age and specific CHD lesion over the last two decades. Methods: We conducted a 19-year analysis (1999-2017) of publicly available, de-identified Multiple Cause of Death data compiled and produced by the National Center for Health Statistics. To calculate annual mortality rates due to ACHD (i.e., CHD listed as the underlying cause of death) for US citizens 18 years of age or older, the number of deaths caused by ACHD serve as numerators and bridged-race population estimates from the US Census Bureau serve as denominators. ACHD mortality rates were first evaluated by age (18-34 years, 35-49 years, 50-64 years, and >65 years) and compared to all-cause mortality rates in these same age groups. Age standardized and age-specific mortality rates were then calculated and assessed by specific CHD lesion. Results: Among adults 18 years or older, all-cause mortality decreased by 18% from 1999 to 2017 compared to a 46.7% decrease in CHD-related mortality. All-cause mortality for ages 65 years or older decreased by 21.3%. This group had the largest decline in ACHD-related mortality of 55.9% (Figure 1). All-cause mortality in age groups less than 65 years remained stable, while ACHD-related mortality declined by approximately 40% in each of those same age groups (Figure 1). The CHD lesions resulting in the highest ACHD-related mortality varied by age (Figure 2). Atrial septal defects (ASD), ventricular septal defects (VSD), and congenital aortic valve stenosis became more prominent contributors to ACHD mortality as age increased and were the leading causes of specific ACHD mortality in persons age 65 years or older. The mortality attributed to tetralogy of Fallot remained a top contributor throughout all age groups. Transposition of the great arteries was a leading contributor to mortality in the younger adult age groups, age 18-64 years. Conclusion: Rates of mortality due to ACHD have declined significantly for all adults, most pronounced in those aged 65 years or older. The specific lesions that cause the highest mortality rates for ACHD patients vary by age, but simple left-to-right shunts (ASD and VSD) were prevalent in all ages. As this population of ACHD patients increases, improved tracking using a US national registry would allow for more in-depth research regarding co-morbidities and mortality.

Temporal trends in ACHD mortality in four different adult age groups

Leading CHD lesions attributed to ACHD mortality by specific lesion and age group