Staphylococcus (S.) aureus left-sided native valve infective endocarditis (LNVIE) has higher complication and mortality rates compared with endocarditis from other pathogens. Whether echocardiographic variables can predict prognosis in S. aureus LNVIE is unknown.
Methods and Results
Consecutive patients with LNVIE, enrolled between January 2000 and September 2006, in the International Collaboration on Endocarditis were identified. Subjects without S. aureus IE were matched to those with S. aureus IE by the propensity of having S. aureus. Survival differences were determined using log-rank significance tests. Independent echocardiographic predictors of mortality were identified using Cox-proportional hazards models that included inverse probability of treatment weighting and surgery as a time-dependent covariate. Of 727 subjects with LNVIE and 1-year follow-up, 202 had S. aureus IE. One-year survival rates were significantly lower for patients with S. aureus IE overall (57% S. aureus IE vs. 80% non-S. aureus IE, p<0.001) and in the propensity-matched cohort (59% S. aureus IE vs. 68% non-S. aureus IE, p<0.05). Intracardiac abscess (HR 2.93; 95%CI 1.52–5.40, p<0.001) and left ventricular ejection fraction (LVEF)<40% (OR 3.01; 95%CI 1.35–6.04, p=0.004) were the only independent echocardiographic predictors of in-hospital mortality in S. aureus LNVIE. Valve perforation (HR 2.16; 95% CI 1.21–3.68, p=0.006) and intracardiac abscess (HR 2.25; 95%CI 1.26–3.78, p=0.004) were the only independent predictors of one-year mortality.
S. aureus is an independent predictor of one-year mortality in subjects with LNVIE. In S. aureus LNVIE, intracardiac abscess and LVEF<40% independently predicted in-hospital mortality and intracardiac abscess and perforation independently predicted one-year mortality.