title: Early surgery in patients with infective endocarditis: a propensity score analysis.
abstract: 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.
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, NC, USA.
authors.forename: Olcay
authors.initials: O
authors.lastname: Aksoy
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Sexton
authors.forename: Andrew
authors.initials: A
authors.lastname: Wang
authors.forename: Paul A
authors.initials: PA
authors.lastname: Pappas
authors.forename: Wissam
authors.initials: W
authors.lastname: Kourany
authors.forename: Vivian
authors.initials: V
authors.lastname: Chu
authors.forename: Vance G
authors.initials: VG
authors.lastname: Fowler
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Woods
authors.forename: John J
authors.initials: JJ
authors.lastname: Engemann
authors.forename: G Ralph
authors.initials: GR
authors.lastname: Corey
authors.forename: Tina
authors.initials: T
authors.lastname: Harding
authors.forename: Christopher H
authors.initials: CH
authors.lastname: Cabell
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002404:Catheterization / Q000009:adverse effects; D015331:Cohort Studies; D003920:Diabetes Mellitus; D004696:Endocarditis / Q000188:drug therapy / Q000401:mortality* / Q000601:surgery*; D005260:Female; D006349:Heart Valve Diseases / Q000382:microbiology* / Q000601:surgery; D006350:Heart Valve Prosthesis / Q000382:microbiology*; D006351:Heart Valves / Q000382:microbiology* / Q000601:surgery; D006801:Humans; D016013:Likelihood Functions; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012307:Risk Factors; D016019:Survival Analysis; D017741:Survivors; D016896:Treatment Outcome