Improval of outcome in patients with endocarditis

The incidence of infectious endocarditis is increasing.1 This is considered to relate to several factors, including changes in demographics with an ageing population, improved survival of patients with congenital heart diseases, and more patients living with a cardiac implantable electronic device (CIED) or a prosthetic heart valve. Other factors affecting the increase include better access to diagnostic work-up for endocarditis [e.g. transoesophageal echocardiography and hybrid imaging of position emission tomography (PET) together with computed tomography (CT) (PET-CT)], and increased awareness of the diagnosis, e.g. that patients on dialysis with fever and patients with bacteraemia with gram-positive cocci may need echocardiographic screening for endocarditis.2,3 There has also been a generally intensified focus on diagnostic work-up and treatment of for example patients more prone to bacterial infections and patients at risk of complications to endocarditis; patients with severe co-morbidities and immune-compromised patients including seriously affected patients in cancer therapy and the increasing number of patients in immune-modulating therapy (Graphical Abstract). Endocarditis is associated with an in-hospital mortality of ∼15–20% and up to 50% need valve surgery during the acute disease-course.4 Antibiotic treatment for up to 6 weeks has traditionally necessitated long hospital stays. The endocarditis disease-course is associated with several temporary and several permanent complications (Graphical Abstract). These aspects strongly indicate that better prevention of endocarditis and better treatment are urgently needed to reduce complications and reduce the high mortality. One specific complication is that the infection may involve the atrioventricular (AV) node and the His bundle in the fibrous skeleton of the heart, or the area may be harmed during surgery leading to temporary or permanent conduction abnormalities. Due to the close proximity of the aortic root and aortic valve annulus to the AV node, conduction abnormalities are mainly related to aortic valve endocarditis. Hill et al.5 report from the Cleveland Clinic that between 2007 and 2013 13% of 444 consecutive patients without a pre-existing CIED and undergoing cardiac surgery during acute endocarditis and surviving to hospital discharge, required post-operative pacemaker implantation due to AV block. In a multivariable analysis, they identified several factors associated with need for pacemaker implantation; pre-operative conduction abnormality, Staphylococcus aureus infection, abscess formation, tricuspid valve involvement, and prior valve surgery. As CIED per se increase these patients’ future risk for endocarditis all these risk factors probably should be included in the consideration of whether to perform surgery or not. In another paper from this issue,6 from the European Georges Pompidou Hospital in Paris reported an overall in-hospital mortality of 12.7% in 142 consecutive episodes of endocarditis in adult patients with congenital heart diseases treated between 2000 and 2018. The diagnostic delay after first symptom was 9.5 days (1–76). This cohort was compared to 529 consecutive episodes of endocarditis in patients without congenital heart disease. The patients with congenital heart disease were much younger than those without (36 vs. 67 years) and had undergone three times more redo cardiac surgery. Surprisingly, the mortality in the patients with congenital heart disease was less than half the mortality in those with endocarditis not associated with congenital heart disease, and this was independent of age, gender, obesity, renal function, and localization (left or right) of the endocarditis. However, the mortality in those without congenital heart disease seemed above average, and numerically even higher than in the group of patients with complex congenital heart disease. In their multivariable analysis, they identified complexity of the congenital heart disease as a very strong predictor for in-hospital death. From these two studies, we will be able to predict the risk of permanent pacemaker implantation and learn that despite it is well-known that the risk of endocarditis in patients with congenital heart disease is increased many folds; the diagnostic delay is still considerable. Late initiation of treatment is expected to increase the complication rate. This calls for better patient education and also seems to support the concept of endocarditis prophylactics in persons with previous endocarditis, prosthetic heart valves, and persons with certain congenital heart diseases. The two studies represent many publications in this field; retrospective local, regional, national, or international registry studies. These studies are invaluable for increasing our knowledge and understanding of this complex disease entity. There is, however, a lack of randomized interventional clinical studies that could help us improve the outcome. Hitherto only four randomized trials have been conducted in patients with endocarditis.7–10 The resulting lack of evidence is strongly reflected in the European guidelines where only 1 out of 100 recommendation has a grade A level of evidence11 (the recommendation of preoperative screening patients for S. aureus in the nose prior to heart valve surgery). The present and earlier findings clearly pointing at risk factors for endocarditis and factors associated with the broad range of complications to endocarditis (Graphical Abstract) literally lists some of the clinical studies we need to perform, in order to improve the serious outcome in patients with endocarditis. Conflict of interest: none declared. The opinions expressed in this article are not necessarily those of the Editors of the European Heart Journal: Acute Cardiovascular Care or of the European Society of Cardiology.