[Infective endocarditis caused by coagulase-negative staphylococci: a review of 19 cases]

The clinical, microbiological and echocardiographical features as well as the response to therapy of 19 cases of infective endocarditis (IE) caused by coagulase-negative staphylococci (CNS) are reported. Six patients had native valve IE, 11 had prosthetic valve endocarditis and 2 were associated with catheters in right cardiac chambers. In the group of native valve IE, 11 patients were heroin abusers and 4 had previous valvular disease. IE was left sided in 3 cases, mixed in 2 and right sided in 1. All CNS were methicillin-sensitive. The echocardiogram detected vegetations in 5 of the 6 cases. One patient required surgery and another died. In the group of prosthetic valve IE, 5 patients had early endocarditis and 6 had late endocarditis. A bioprosthesis was involved in 5 cases, a mechanical prosthesis in another 5, and an annuloplasty annulus in one. The involved prosthesis was aortic in 5 cases and mitral in 6. The echocardiogram detected vegetations in 3 cases (27%) and prosthetic dysfunction in 4. One patient had a relapse, 8 (73%) required valve replacement and 3 died. Although the greatest incidence of IE caused by CNS is found among patients with prosthetic valves, it can also be seen in patients with underlying valvular heart disease, drug abusers and patients with indwelling catheters in right cardiac chambers.