Latent infective endocarditis: epidemiology and clinical characteristics of patients with unsuspected endocarditis detected after elective valve replacement.
BACKGROUND
The diagnosis of infective endocarditis is usually made on the basis of clinical and laboratory criteria and may be confirmed by histologic examination or culture of excised valves. We tried to determine the incidence and significance of inflammatory changes in valves excised during operations for reasons other than infective endocarditis.


METHODS
The charts and histopathology of all patients undergoing valve replacement during a 10-year period (1993-2002) were reviewed. A total of 868 patients underwent a total of 970 valve replacements during this period, of whom 11 patients (1.3%) were for endocarditis, with the remaining 857 (98.7%) for other indications. All excised valves were cultured and examined histologically for the presence of inflammatory infiltrates, vegetations, and microorganisms.


RESULTS
In 8 of 857 patients (0.9%), the histologic examination unexpectedly demonstrated an infiltrate suggestive of endocarditis. Blood and valve cultures, and serologic tests for Mycoplasma, Chlamydia, Legionella, Q fever, Brucella, Rickettsiae, VDRL, and Bartonella were negative in all but 1 patient, who was found to have Q fever. All received a prolonged course of antibiotics. Six patients had an uneventful recovery; 1 had intramyocardial abscesses and expired during cardiac reoperation; and 1 had recurrent fever and dehiscence of the aortic and mitral valve prostheses and after two cardiac reoperations remains in severe heart failure.


CONCLUSIONS
The presence of an unexpected inflammatory infiltrate in heart valves excised for reasons other than endocarditis may occur in 0.9% of such operations; these infiltrates could indicate presence of endocarditis. A microbial origin should be sought, and patients should receive empiric antibiotic treatment for endocarditis.
Shapira
Nadiv
N
Department of Cardiothoracic Surgery, Shaare Zedek Medical Center, Jerusalem, Israel.
Merin
Ofer
O
Rosenmann
Eliezer
E
Dzigivker
Ilia
I
Bitran
Dan
D
Yinnon
Amos M
AM
Silberman
Shuli
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents; D003131:Combined Modality Therapy; D004359:Drug Therapy, Combination / Q000627:therapeutic use; D017558:Elective Surgical Procedures; D004697:Endocarditis, Bacterial / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology* / Q000601:surgery; D005260:Female; D006349:Heart Valve Diseases / Q000150:complications / Q000601:surgery; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D033162:Incidental Findings; D007557:Israel / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy; D011778:Q Fever / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy; D012189:Retrospective Studies
D000900:Anti-Bacterial Agents