Congenital heart disease makes up for one third of all serious congenital anomalies; the exact number of children born with congenital heart defects is hard to estimate due to differences in the availability and quality of health care and diagnosis in different parts of the world. Data indicate a prevalence of over 8 per 1000 newborns. (1)

Survival rates for children born with congenital heart defects were very poor in the past, with only up to 20% of such children reaching adulthood in the 1940s. This has changed drastically. During the second half of the 20th century, pioneers of cardiac surgery came up with surgical solutions for almost all complex heart defects. With advancements in cardiac surgery and pediatric care, today over 90% of children with complex defects survives into adulthood. It is estimated that the number of adult patients is now twice as large as the number of children with congenital heart defects. (2)

Although this is an outstanding success in the treatment of these patients, most cannot be considered cured, but rather palliated. This is supported by the fact that during last 15 years, the number of hospitalizations for these patients increased by over 80%. These are chronic conditions that require long-term monitoring and treatment, and commonly also re-interventions due to anatomical and functional abnormalities. Many of these patients are at high risk for the development of arrhythmia, heart failure, and endocarditis. (3) In Croatia we expect to have about 10,000 such patients of different complexity.

This growing group of patients that was once exclusively under pediatric care, now requires the development of a new subspecialty in adult cardiology and presents new challenge in this field. The need for adequate care for this growing patient group has been recognize at the global and European levels, and guidelines have been issued by the European Society of Cardiology on the organization of care for adult patients with congenital heart disease (ACHD; or Grown-up Congenital Heart Disease, GUCH), as well as the education of cardiology subspecialists in Europe on that topic. (4)

A specialized center must be located in a place with access to adult and pediatric cardiac care, as well as congenital heart surgery. Furthermore, due to the ageing of the population the whole spectrum of adult medicine must be available. In addition to a cardiologist specializing in ACHD, having an expert in echocardiography with knowledge of advanced techniques is also important, as well as a having an interventional cardiologist with expertise in structural heart disease and knowledge of complex interventional procedures. Access to electrophysiology and electrotherapy (pacemakers, cardiac resynchronization therapy, defibrillators, complex ablation) is of great importance because of the possibility of arrhythmia, which is a common cause of mortality and hospitalization in patients with ACHD. The team must also include a radiologist – imaging method specialist (magnetic resonance imaging, multislice computed tomography) and a specialist in gynecology and obstetricity regarding the care of women in generative age. Pregnancy is an additional risk factor in this group of patients and requires advisement and careful monitoring. A large contribution to such a center can be expected from medical nurses specializing in ACHD.

Opening such centers has been shown to reduce mortality and morbidity (primarily hospitalization rates) in patients with ACHD. (5) The best care model is that in which patients undergo at least once examinations in a specialized center where a subspecialist for ACHD can give them further recommendations on the level of care and monitoring intervals depending on individual patient characteristics. In any case, a working network between the specialized center, the local general adult cardiology center, and the family physician is of critical importance. (6) Based on the estimated number of patients with ACHD, Croatia would need 1 to 2 such specialized centers. Pediatric cardiologists have a great knowledge and experience on congenital heart defects in children, but even their knowledge is limited when it comes to long-term monitoring and further treatment of adults, especially since that can include also the potential development of acquired heart diseases. Thus, a transitional period in the care of patients with congenital heart diseases is important. The best model is joint care in the period between 16 and 18 years of age. During that period, pediatric cardiologists can inform ACHD specialists on the course of treatment so far, and the patient will get to know and trust the physician that will be taking care of them in the next phase of their life.

Despite the fact that the need for additional education in ACHD has been recognized among cardiologists, most still have little experience. According to European recommendations, a training period of two years is needed to complete subspecialty training in GUCH. During that period, 18 months must be spent in a specialized center, and 6 months at a pediatric cardiology department.

In conclusion, a specialized ACHD center must be a supra-regional center serving as a center of excellence with the highest standard of care. It must also allow education in that field and promote research and innovation. (7)