[Infectious endocarditis of native and prosthetic valves. A comparative analysis based on 155 cases]

In a retrospective study, we compared the characteristics of native valve and prosthetic valve endocarditis.

All 155 cases of left-sided infective endocarditis in 142 patients admitted at our institution between 1986 and 1992 were analyzed based on their medical records. Native valve endocarditis was found in 119 cases (74 men, 45 women; median age 55, range 29 to 80 years), prosthetic valve endocarditis in 36 cases (11 men, 25 women; median age 63, range 38 to 80 years; 29 cases of late infection).

There were more older (P < 0.0005) and more female (P = 0.001) patients with prosthetic valve endocarditis. Most frequently, native aortic valves (53.8%) or mitral prostheses (55.6%) were solely involved. In both groups, Staphylococcus epidermidis was the most frequent isolate followed by Staphylococcus aureus and Enterococci. Symptoms and clinical findings were similar in both groups. In all cases since July 1989, transthoracic echocardiography was suggestive of endocarditis in native valves in 63.9% and in prostheses in 29.2% (P = 0.004), combined with the transesophageal approach in 91.7 and 91.8%, respectively (not significant). Embolism and surgical intervention were about equally frequent in both groups. The in-hospital mortality was 19.3% in native valves and 22.2% in prostheses (not significant).

Native valve and late prosthetic valve endocarditis are now similar in the spectrum of causative microorganisms, echocardiographic diagnostics, clinical course and prognosis.