Early Surgery in Patients with Infective Endocarditis: A Propensity Score Analysis

• Published in: Clinical infectious diseases 2007-02, Vol.44 (3), p.364-372
• Main Authors: Aksoy, Olcay, Sexton, Daniel J., Wang, Andrew, Pappas, Paul A., Kourany, Wissam, Chu, Vivian, Fowler, Vance G., Woods, Christopher W., Engemann, John J., Corey, G. Ralph, Harding, Tina, Cabell, Christopher H.
• Format: Article
• Language: English
• Subjects: Abscesses; Adult; Aged; Aged, 80 and over; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Articles and Commentaries; Biological and medical sciences; Cardiology. Vascular system; Cardiovascular disease; Catheterization - adverse effects; Catheters; Cohort Studies; Congestive heart failure; Diabetes Mellitus; Dialysis; Emergency and intensive care: renal failure. Dialysis management; Endocardial and cardiac valvular diseases; Endocarditis; Endocarditis - drug therapy; Endocarditis - mortality; Endocarditis - surgery; Female; Heart; Heart failure, cardiogenic pulmonary edema, cardiac enlargement; Heart surgery; Heart Valve Diseases - microbiology; Heart Valve Diseases - surgery; Heart Valve Prosthesis - microbiology; Heart Valves - microbiology; Heart Valves - surgery; Humans; Infections; Intensive care medicine; Likelihood Functions; Longitudinal Studies; Male; Medical sciences; Medical treatment; Middle Aged; Mortality; Proportional Hazards Models; Risk Factors; Surgical specialties; Survival Analysis; Survivors; Treatment Outcome
• ISSN: 1058-4838; 1537-6591
• DOI: 10.1086/510583

Background. An accurate assessment of the predictors of long-term mortality in patients with infective endocarditis is not possible using retrospective data because of inherent treatment biases and predictable imbalances in the distribution of prognostic factors. Largely because of these limitations, the role of surgery in long-term survival has not been adequately studied. Methods. Data were collected prospectively from 426 patients with infective endocarditis. Variables associated with surgery in patients who did not have intracardiac devices who had left-side-associated valvular infections were determined using multivariable analysis. Propensity scores were then assigned to each patient based on the likelihood of undergoing surgery. Using individual propensity scores, 51 patients who received medical and surgical treatment were matched with 51 patients who received medical treatment only. Results.The following factors were statistically associated with surgical therapy: age, transfer from an outside hospital, evidence of infective endocarditis on physical examination, the presence of infection with staphylococci, congestive heart failure, intracardiac abscess, and undergoing hemodialysis without a chronic catheter. After adjusting for surgical selection bias by propensity score matching, regression analysis of the matched cohorts revealed that surgery was associated with decreased mortality (hazard ratio, 0.27; 95% confidence interval, 0.13–0.55). A history of diabetes mellitus (hazard ratio, 4.81; 95% confidence interval, 2.41–9.62), the presence of chronic intravenous catheters at the beginning of the episode (hazard ratio, 2.65; 95% confidence interval, 1.31–5.33), and paravalvular complications (hazard ratio, 2.16; 95% confidence interval, 1.06–4.44) were independently associated with increased mortality. Conclusions. Differences between clinical characteristics of patients with infective endocarditis who receive medical therapy versus patients who receive surgical and medical therapy are paramount. After controlling for inherent treatment selection bias and imbalances in prognostic factors using propensity score methodology, risk factors associated with increased long-term mortality included diabetes mellitus, the presence of a chronic catheter at the onset of infection, and paravalvular complications. In contrast, surgical therapy was associated with a significant long-term survival benefit.