Unlike in the 1970s, a congenital heart defect is no longer a death sentence today. On the contrary. Thanks to many advances in cardiac medicine, most of those affected by this most common organ malformation reach adulthood.

According to estimates, around 300,000 adults with congenital heart defects live alone in Germany . But even after a successful correction by surgery or catheter intervention: the underlying disease remains. And it carries risks. Of particular concern is the high risk of infective endocarditis associated with valve defects and their treatment. This inflammation of the inner lining of the heart, which in the majority of cases is caused by bacteria, can quickly become life-threatening.

At Risk Regardless of CHD Severity

Results of a new nationwide study at the Competence Network Congenital Heart Defects show that older male CHD patients are particularly at risk of dying from endocarditis, independant of the severity of their congenital heart defect. However in the presence of endocarditis, even younger patients are at significant risk of myocardial infarction, stroke, pulmonary embolism, sepsis, or sudden cardiac death, regardless of the severity of their congenital heart defect. "These are risks that can be significantly reduced by continuous specialized CHD care," says study author Maarja Maser, a specialist in cardiology at the ACHD (Adult Congenital Heart) Center of Münster University Hospital (UKM).

Lower Mortality in CHD

Comparative analysis of patients without congenital heart defects and those with congenital heart defects showed that the risk of dying as a result of endocarditis was significantly lower in adult CHD patients despite their underlying disease.

Professor Gerhard Paul-Diller, ACHD specialist and senior physician at UKM, is not surprised: "On the one hand, the hospitalized CHD patients are on average younger than the comparison cohort. They are also more likely to be affected by right-sided cardiac damage, the effects of which are serious but relatively less threatening. Their treatment is also more likely to take place in specialized centers." Another factor that he believes may play a role is that "awareness of the possibility of developing infective endocarditis tends to be greater among both people with congenital heart defects and the treating physicians." 

Age, Gender and Concomitant Diseases are Key Risk Drivers

At the same time, the analysis was able to clarify that the severity of a congenital heart defect plays a rather subordinate role as a risk factor. "In addition to being male, concomitant diseases, which are more common from the age of 40, are associated with a fatal course. These include diabetes, heart failure, kidney disease, diseases of the lungs or cancer diagnoses. In the prevention and treatment of the disease, we should therefore look beyond the obvious underlying cardiac anatomy and focus on physiological factors, such as age and gender, as well as end-organ diseases in these patients at risk," says Professor Gerhard-Paul Diller.

Using Data from more than 300,000 CHD Patients.

The study is a sub-project of OptAHF. The project, which is funded by the Innovation Fund of the Joint Federal Committee of the G-BA and headed by Professor Gerhard Paul Diller, comprises several studies and is the largest health care analysis ever conducted on congenital heart defects.

With the support of anonymized data from Barmer GEK and pseudonymized data donations from participants in the National Registry and as part of the Endocarditis Study, researchers were able to follow up the courses of the disease in a total of 309,245 hospitalized CHD patients over a period of ten years. 2,512 of the CHD patients had been admitted with iinfective endocarditis. Fifty-five percent of them had a mild, 23 percent a moderate, and 22 percent had a severe congenital heart defect. Fifty-five percent of all hospitalized patients were male. The average age at hospital admission was 14 years.

Number of Young Endocarditis Patients with CHD Significantly Larger

Even though endocarditis was only in a fraction (0.8 percent) the reason for hospitalization of CHD patients, it cannot be taken lightly, says Maarja Maser: "Regardless of the severity of the congenital heart defect, almost half of them, 46 percent, suffered serious cardiopulmonary impairment. Surgical intervention was required in 41.5 percent of cases. And six percent of all CHD patients did not survive the inflammation of the inner lining of the heart."

Yet, when compared by different age groups, children with congenital heart defects accounted for more than one-third of their peers hospitalized for endocarditis, at 36 percent. Among adults, by contrast, the proportion of CHD patients was only 1.2 percent. The researchers link this to the fact that in the population with increasing age acquired valve diseases are more common than CHD-related damage to the valves.