Endocarditis in patients with active malignant disease: a common condition with high rates of morbidity and mortality

Background Echocardiography plays a central role in the diagnosis of infective endocarditis. Vegetations may present in various phenotypes depending on the bacterium involved and the immune state of the patient. Differentiation from thrombus and particularly non-bacterial thrombotic endocarditis (NBTE) in cancer patients can prove challenging. We sought to perform a retrospective morphologic echocardiographic analysis of vegetations and evaluate its association with the clinical and microbiological data in patients with native valve endocarditis. Methods We retrospectively included all patients from our tertiary referral center who were diagnosed with native valve endocarditis and active malignant disease from 01/2019 until 12/2022. Baseline echocardiography was reviewed by two observers, vegetations were classified regarding their morphology. Clinical data was documented from chart analysis. Results From the analyzed total of 131 patients, 35 patients with active malignant disease were included in this preliminary analysis, 18/35 (51.4%) were male, mean age was 65.1 years (±8.2). The underlying malignant diseases included gastrointestinal carcinoma (10), haematologic cancer (9), lung carcinoma (6), genitourinary and brest carcinoma (5 patients each). Blood cultures were positive in 28/35 (80%), the most common microorganisms identified being staphylococcus aureus in 35.7%, other staphylococci species in 28.6%, enterococci in 17.8%, viridans streptococci in 10.7%, and others in 7.2%. Valves affected were aortic valve in 34.2%, mitral valve in 22.8%, tricuspid valve in 17.1%, and more than one valve in 25.9%. Cardioembolic events occurred in 14/35 (40%), most commonly cerebral stroke 11/14 (78%), splenic 2/14 (14.2%) and renal infarction 1/14 (7.1%). A total of 9/35 (25.7%) patients were operated. In-hospital mortality was 22.8%. Median vegetation size area was 1 cm² (0.39; 1.35), mean length was 10.5mm. It was classified as broad-based in 13 (37,1%), raceme in 12 (34,3%), broad-based with filiform foothills in 6 (17.1%), and filiform in 4 (11,5%) patients. Based on a symmetric and broad-based morphology of the vegetation and the absence of positive blood cultures, two (6%) included patients were retrospectively classified as patients with potential NBTE (figure 1). Discussion: Endocarditis is a detrimental disease with high rates of morbidity and mortality, which was once again documented in this cohort. A quarter of the patients had active malignant disease. With port infection as common entry for bacteremia, and immunosuppression due to cancer itself and due to chemotherapy as predisposition, this group is particularly vulnerable. At the same time, NBTE must be on the list of differential diagnoses, particularly if blood cultures and clinical signs of active infection remain negative. In this retrospective analysis, 6% of the included patients were classified as potential NBTE.