Prosthetic valve endocarditis (PVE) is considered a feared complication in the postoperative period of cardiac valve surgery due to high mortality rates (up to 70%). The aim of this study is to assess the predictors of mortality related to PVE in a population with high prevalence of rheumatic heart disease (RHD).
The study comprised 100 patients with PVE admitted in a tertiary Brazilian Referral Center from 2006 to 2012. Data were collected retrospectively and based on demographic, clinical and laboratory characteristics; echocardiographic findings; microbiological profile (etiology); treatment modality and in-hospital mortality. The diagnosis of PVE was made according to the modified Duke criteria. Statistical comparisons were performed using Student’s t test or Fisher’s exact test, as appropriate. Multivariate analyses were obtained through logistic regression.
The mean age at diagnosis was 56.9 ± 16.7 years, with male preponderance (73%). RHD was observed in 48%. The majority of patients had a biological prosthesis (87%), with prevalence of late PVE (90%). Blood cultures were positive in 77% of the cases: Staphylococcus sp and Streptococcus sp infection had exactly the same incidence (29%), followed by Enterococcus sp (8%), HACEK group (8%), fungus (2%) and other agents (4%). The overall mortality was 40%. Surgical treatment was performed in 58% of the patients, mainly due to heart failure and mitroaortic junction abscess, with a mortality rate of 41%. In the group that received clinical therapy alone, mortality was 38%. Factors associated with mortality were circulatory shock at presentation (p<0.001), female gender (p=0.02), high levels of C reactive protein (CRP) at presentation (88.9 ± 55 mg/dL vs. 124.2 ± 98.3 mg/dL, p < 0.001), lower hemoglobin level (11.9 ± 2 g/dL vs. 10.5 ± 2.1 g/dL, p=0.002) and high systolic pulmonary artery pressure (SPAP) (43.7 ± 11.7 mmHg vs. 54.4 ± 16.7 mmHg, p=0.007). Cardiac rheumatic disease was not a risk factor for mortality (p=0.68). On multivariate analysis, circulatory shock was the only independent predictor or mortality (p=0.05).
Overall in-hospital mortality after PVE remains high. Female gender, circulatory shock at presentation, lower hemoglobin level, high CRP levels and high SPAP were predictors of mortality on the univariate analysis. Circulatory shock at presentation was an independent predictor of mortality in PVE.