Prosthetic valve endocarditis: analysis of risk factors formortality

Between 1975 and 1990, 70 episodes of prosthetic valve endocarditis(PVE) were diagnosed in 65 patients at Leiden University Hospital. Theoverall mortality rate was 27%. Antecedent endocarditis attributable to thesame micro-organism (mortality 63%, P = 0.02) and Staphylococcus aureus asthe causative micro-organism (mortality 100%, P = 0.001) were significantpredictors for mortality. Sex, type and position of the valve and therapyhad no significant influence on the mortality. All patients infected withS. aureus died, irrespective of whether they received medical treatmentalone or in combination with surgery. None of the patients with streption,endocarditis had abscesses at reoperation; the mortality rate for thisgroup was 14%. Abscess formation, especially in aortic valves, was the mostimportant finding at reoperation and corresponded with a mortality rate of55%. Ring abscesses occurred equally in patients with mechanical andbioprosthetic valves. Seven of the 15 patients (47%) with significantprosthetic valve dehiscence died. In patients with mitral valveendocarditis, localized dehiscence of the valve was observed. In conclusiona previous endocarditis attributable to the same micro- organism and thecausative micro-organism (S. aureus) were important risk factors formortality due to PVE.