Late prosthetic valve endocarditis. Bacteriological findings and prognosis in 29 cases

Of 296 incidences of infectious endocarditis seen between 1971 and 1980, 29 cases of late prosthetic valve endocarditis (10%) occurred in 26 patients who had undergone valve replacement more than two months previously. The prosthesis was mitral in 8 cases, aortic in 9 cases, and multiple in 12 cases. The clinical picture consistently associated fever together with a regurgitation murmur in 12 cases (41%), a splenomegaly in 7 cases, a neurologic accident in 13 cases and other signs of endocarditis in 10 cases. Blood cultures were positive in 28 cases. The diagnosis was confirmed anatomically in 11 cases. Thirty-one causative agents were identified: 15 streptococci (48%), most of them were group D (11/15), 11 staphylococci (35%) 6 Staphylococcus aureus, 5 Staphylococcus coagulase negative and 5 other species. Two relapses and 3 recurrent infections were noted. The death rate was 58% with some factors being associated with a higher death rate: non-streptococcal micro-organism (87%) regurgitation murmur (83%) cardiac failure with dysfunction of the prosthesis (89%) neurologic complication (91%). Eight valve replacements were performed within a mean period of 32 days after the onset of the antibiotherapy with a death rate of 75%. It decreased to 50% for patients treated with antibiotic alone, and as low as 23% for Streptococcal endocarditis. These results suggest that earlier and more frequent indications for cardiac valve replacement could be an alternative to improve the prognosis.