Congenital heart disease in young adulthood and beyond

Abstract

Over 95% of children with congenital heart defects now reach adulthood and the number of adults with congenital heart disease is estimated to be at least 1.2 million in Europe alone. Despite major developments in diagnostic methods and treatment of congenital heart disease, cure is rarely achieved. In this thesis, the long-term prognosis of adult patients with congenital heart disease is assessed using the Dutch nationwide CONCOR registry that momentarily comprises more than 11,000 patients. Review of current literature confirmed the paucity in studies on long-term prognosis in adults with congenital heart defects. Reports on survival existed mainly up until 40 years of age and showed a decrease in survival compared to their healthy counterparts, which was most pronounced in complex defects. Data on morbidity were sparse; based on the data available, morbidity was substantial. Additionally, gender differences in outcome were evaluated in the CONCOR registry. Women had a higher risk of pulmonary hypertension, and a lower risk of aortic outcomes, endocarditis, and an implantable cardioverter-defibrillator. Subsequently, mortality and causes of death were assessed during a median follow-up of 2.8 years. In total, 2.8% of patients died at a median age of 49 years. Of all deaths, 77% had a cardiovascular origin. Age predicted mortality, as did gender, severity of defect, number of interventions, and number of complications. Several complications predicted all-cause mortality, i.e. endocarditis, supraventricular arrhythmias, ventricular arrhythmias, conduction disturbances, myocardial infarction, and pulmonary hypertension. Furthermore, health care utilization in terms of hospital admissions was determined. During a follow-up of five years, 50% of patients were admitted to hospital at a median age of 39 years. Compared to the general Dutch population, admission rate was two to three times higher; this difference was most pronounced in the older age groups. Moreover, a prediction model was derived for the occurrence of endocarditis in patients at the transition from childhood into adulthood. The overall incidence rate of adult-onset endocarditis was 1.1 case per 1000 patient-years. Predictors were gender, main congenital heart defect, multiple heart defects, and three types of complications in childhood. The prediction model yielded accurate predictions up to age 40 and 60. Finally, a prediction model was derived for the risk of major cardiovascular surgery and valvar surgery in patients who recently entered adulthood. In total, 24% of patients underwent surgery for congenital heart disease at adult age. The cumulative risk of major cardiovascular surgery was 12.6 cases per 1000 patient-years, and 6.5 for valvar surgery. Predictors were gender, main congenital heart defect, multiple heart defects, and four types of complications and (valvar) surgery in childhood. Predictions up to age 40 and age 60 yielded excellent accuracy. Analyses for valvar surgery showed even higher discriminative capacity. In conclusion, the large and ever expanding population of adult patients congenital heart disease has an increased mortality and a high health care consumption in terms of hospital admissions. Moreover, they encounter many complications and interventions that require life-long medical surveillance. This thesis has shown that these clinical events can accurately be predicted.