A clinical analysis of 25 cases of prosthetic valve endocarditis

OBJECTIVE: To report the clinical characteristics of prosthetic valve endocarditis (PVE). METHODS: All 25 cases of definite PVE (Duke criteria) diagnosed at our hospital between January 1992 to December 2008 were retrospectively analyzed. Among them, 7 cases were pathologically confirmed and the others were clinically confirmed with either 2 major criteria or 1 major and ≥ 3 minor criteria. Their clinical characteristics, underlying heart diseases, previous heart operations, presenting manifestations, causative microbes, echocardiographic findings and prognosis, were studied. RESULTS: (1) Although most cases underwent valve transplantations for underlying heart diseases of rheumatic heart diseases and congenital heart diseases, 10 patients were complicated with infectious endocarditis (IE) prior to the operations, 4 of them were PVE. (2) Eleven of them developed PVE within 2 months postoperatively. Fever (100%), major vessel embolism (48%), and anemia (36%) were the most frequently manifestations. Fourteen cases (56%) had positive culture results with 15 causative pathogens, including 5 coagulase-negative Staphylococcus (CNS, 3 were methicillin-resistant coagulase-negative Staphylococcus, MRSCoN), 4 fungi, 2 Enterococcus faecalis, 2 Burkholderia cepacia, 1 Stenotrophomonas maltophilia, and 1 Streptococcus. (3) Prosthetic valve vegetations, periannular leakage, regurgitation, were the main echocardiographic findings. Transesophageal echocardiography (TEE) revealed 13 PVE who had no positive findings on previous transthoracic echocardiography (TTE). (4) Eighteen PVE (72%) developed peri-annular complications (12 leakage, 3 dehiscence, 2 abscesses, 1 fistula), major vessel embolism, congestive heart failure (16%) were frequently observed, 9 of the 17 patients died in hospital, in spite of intensive managements. CONCLUSIONS: PVE has a high mortality and is a severe complication for patients who underwent heart surgery. Its causative pathogen spectrum is quite different from that of native valve endocarditis. TTE is not sensitive for some PVE cases.