Barbara JM Mulder is Professor of Cardiology in the Academic Medical Center in Amsterdam, the Netherlands. In 2001 she initiated the nationwide registry and DNA bank for congenital heart disease, named CONCOR ( CONgenital CORvitia), in which presently 17.000 patients have been included. She chaired the European Heart Survey on congenital heart disease with 79 participating centers from 24 countries. From 2010 until 2012 she was president of the International Society of Adult Congenital Cardiology, ISACHD. From 2015 until 2017 she served as president of the Netherlands Society of Cardiology.
An ACHD patient registry can be a powerful tool to observe the long term course of disease; to understand variations in treatment and outcomes; to examine factors that influence prognosis and quality of life; to describe care patterns; to assess effectiveness; to monitor safety and harm; and to measure quality of care. Registries collect data in a comprehensive manner (with few excluded patients) and therefore produce hard outcome results that may be generalizable to a wide range of patients. Although randomized controlled trials (RCTs) are generally considered the gold standard for clinical evidence, in ACHD RCTs are often not feasible, due to the large heterogeneity of the ACHD population. Small patient numbers and a low event rate during a relatively short trial duration may necessitate surrogate endpoints. Registries evaluate care as it is actually provided and may be more representative of what is achieved in real-world practice. However, interpreting the results from registry studies correctly requires analytic methodology geared to address the potential sources of bias that challenge observational studies. For optimal development of guidelines and decision making real-world data from registries and RCTs should be seen as having complementary roles in evaluating ACHD patient outcomes.