A Clinical Study of Culture-Negative Endocarditis

Abstract

Culture-negative infective endocarditis (CNE) is a diagnostic problem in spite of improved echocardiographic and blood culturing techniques. We conducted the present study to estimate the proportion of CNE in patients with infective endocarditis, to investigate data regarding risk factors, and to evaluate the Duke and the modified Beth Israel criteria in patients with CNE. We evaluated 820 consecutive suspected episodes of infective endocarditis in adults at the Departments of Infectious Diseases in Göteborg and Borås, Sweden (1984-1996). All patients were diagnosed and treated according to a protocol; 487 episodes were identified as infective endocarditis. Episodes with absence of bacterial growth at blood culture were defined as CNE and were classified with the Duke and the modified Beth Israel criteria. We identified 116 CNE episodes (median age, 67 yr). Mortality was 7%, and in 15%, cardiac surgery was performed. The Duke criteria classified 20 definite, 80 possible, and 16 reject episodes. The modified Beth Israel criteria distinguished 13 definite, 15 probable, 27 possible, and 61 reject episodes. The proportion of CNE among patients with infective endocarditis varied from 19% to 27% at the 2 departments. Antibiotic treatment preceded blood culture in 45% of the CNE episodes. About 20% in a Scandinavian population of infective endocarditis patients have CNE. Antibiotic pretreatment explains less than 50% of all CNE episodes. The Duke criteria are more sensitive but less specific than the modified Beth Israel criteria in classifying patients with CNE.

Post-surgical Infective Endocarditis Involving Chordae Tendinae: A Rare Presentation

“…BCN-IE is an infection with inflammation of the lining of one or more heart valves in which no endocarditis -causing germs can be identified on a blood culture. The reasons for this are that certain germs do not grow well in the laboratory setting, or that some patients may have previously received antibiotics that keep such germs from growing [8]. Other causes include right sided endocarditis, prosthetic valve endocarditis, collagen vascular diseases and because of organisms which are slow growing or fastidious in nature [8].…”

“…In the present case, blood cultures were performed 4 times but no organism was isolated. Hence, it was diagnosed as culture negative endocarditis which is seen in 2.5 to 31% of patients [8]. BCN-IE is an infection with inflammation of the lining of one or more heart valves in which no endocarditis -causing germs can be identified on a blood culture.…”

Excellent Prognosis of Culture Negative Endocarditis in Hemodialysis Patients: A Case Series

“…This is in accord with clinical features reported by other authors. [7,12,13] Although non-specific or diagnostic, new onset heart murmur with fever and leukocytosis may be indications of IE, especially in the absence of a positive blood culture. A physical examination and a leukocyte count are necessary for early diagnosis and timely treatment.…”

“…[9,14,16,17] Third, according to microbiology patterns observed in our own institution, 62% of all S. aureus isolated are methicillin-resistant, and these patients require a thrice-weekly dialysis in a hospital facility; thus, the occurrence of MRSA bacteremia may represent a true nosocomial infection carrying a devastating virulence in an immune dysregulated uremic host. [18][19][20] The mortality rate of CNE in the general population ranges from 7-32% [12,13] ; the outcome is even less optimistic in endocarditis patients with true negative blood culture than in patients with previous antibiotics treatment. [21] Furthermore, mortality is increased in patients receiving delayed treatment and in those still febrile after one week of therapy.…”

“…[21] Furthermore, mortality is increased in patients receiving delayed treatment and in those still febrile after one week of therapy. [5,12,22] The outcome of CNE in a dialysis population is unknown. All five patients in our series survived.…”