Background
Previous risk stratification of patients with predisposing cardiac diseases in groups with a high, medium or low IE risk is based on a few representative studies with a small number of cases. In addition, there has not yet been a study that directly compared the risk of different predisposing diseases.

Method
Selective literature research.

Results
IE incidence in children reported stable at approximately 0,43 (adults: 3 to 12 per 100.000 people/year).
CHD related pediatric IE is approximately 60% to 68% of the cases.
The cumulative observed risk of IE is 6,1 cases/1000 CHD patients 0 to 18 of age.
Cyanotic CHD lesions, left-sided lesions, and AVSD were associated with increased risk of IE, acquisition in childhood. The relative risk of developing IE was substantially elevated during the 6-month-posoperative period of cardiac surgery, and in children younger than 3 years of age.

Previous lifetime assumptions for IE: clientele/frequency : 100000 patient years: normal population 5-7; MVP without (with insufficiency) 4.6 (52); CHD 145-271; Rheumatic heart defects 380-440; Valvular prostheses 308-383; Valvular replacement after IE 630; after IE 740; Valvular replacement due to valvular prosthesis endocarditis 2160.

In a large retrospective study in Great Britain, NHS data of all inpatient admissions between January 2000 and March 2013 were used. The presence of IE-predisposing heart disease was determined by means of ICD-10 discharge diagnoses and OPCS-4 procedure codes. A logistic regression analysis was used to calculate the relative risk of the different patient groups, classified according to the risk groups of the IE guidelines of the ESC and the AHA, of developing or dying from IE over the next 5 years. The IE-related inpatient admissions or deaths of the entire English population during the same period were used as a reference value. The incidence of IE in the English population was 36 cases/1 million inhabitants/ year, the mortality rate in the context of IE-related hospitalization was 6.3/1 million inhabitants/year (17%). The incidence of IE was highest in patients with previous IE (266x higher than the reference group) and after valve replacement (70x) or valve reconstruction (77x). It was also high in patients with congenital heart defects who had been treated with a shunt / conduit (86x). The incidences for subgroups with a previously unclear risk were very different - very high for patients with an artificial heart/left ventricular assist device (LVAD, 124x), significantly lower for patients with an implanted pacemaker/cardioverter-defibrillator (10x) and for heart transplant recipients (6x).

Conclusion
For the first time, the study provides a valid risk comparison and thus important new aspects that should be taken into account in future IE prophylaxis recommendations. In everyday clinical practice, the initial suspicion of IE in the identified high-risk groups should be correspondingly high; adequate diagnostic work-up is essential.