title: Emboli in infective endocarditis: the prognostic value of echocardiography.
abstract: OBJECTIVE
  To determine whether vegetations visualized on two-dimensional echocardiography are an independent risk factor for the development of subsequent emboli in patients with infective endocarditis and to assess the timing of emboli relative to the initiation of antimicrobial therapy.
  
  
  METHODS
  Investigator-blinded, retrospective incidence cohort study.
  
  
  METHODS
  Tertiary referral center.
  
  
  METHODS
  Patients with left-sided native valve infective endocarditis who had two-dimensional echocardiography within 72 hours of beginning antimicrobial therapy.
  
  
  RESULTS
  The crude incidence rate of first embolic events in patients receiving antimicrobial therapy was 6.2 per 1000 patient-days (95% CI, 4.2 to 9.2). The rates in patients with and without vegetations were 7.1 and 4.9 per 1000 patient-days, respectively (incidence rate ratio, 1.4; 95% CI, 0.6 to 3.3). The relation between vegetations and risk for emboli was microorganism-dependent: Stratified incidence rate ratios were 6.9 (95% CI, 1.1 to 42.5; P less than 0.05) and 1.0 (95% CI, 0.2 to 3.9) for viridans streptococcal and Staphylococcus aureus endocarditis, respectively. The rate of first embolic events diminished over time (P less than 0.001), falling from 13 per 1000 patient-days during the first week of therapy to less than 1.2 per 1000 patient-days after completion of the second week of therapy.
  
  
  CONCLUSIONS
  Overall, the presence of vegetations on echocardiography was not associated with a significantly higher risk for embolus in patients with left-sided native valve infective endocarditis. The relative risk for embolic events associated with echocardiographically visualized vegetations may be microorganism-dependent, with a significantly increased risk seen only in patients with viridans streptococcal infection. The rate of embolic events declines with time after initiation of antimicrobial treatment.
authors.affiliation: Mayo Clinic and Foundation, Rochester, Minnesota.
authors.forename: J M
authors.initials: JM
authors.lastname: Steckelberg
authors.forename: J G
authors.initials: JG
authors.lastname: Murphy
authors.forename: D
authors.initials: D
authors.lastname: Ballard
authors.forename: K
authors.initials: K
authors.lastname: Bailey
authors.forename: A J
authors.initials: AJ
authors.lastname: Tajik
authors.forename: C P
authors.initials: CP
authors.lastname: Taliercio
authors.forename: E R
authors.initials: ER
authors.lastname: Giuliani
authors.forename: W R
authors.initials: WR
authors.lastname: Wilson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D015331:Cohort Studies; D004452:Echocardiography / Q000379:methods; D004617:Embolism / Q000453:epidemiology / Q000209:etiology* / Q000517:prevention & control; D004697:Endocarditis, Bacterial / Q000150:complications* / Q000000981:diagnostic imaging* / Q000188:drug therapy; D006349:Heart Valve Diseases / Q000150:complications* / Q000000981:diagnostic imaging*; D006801:Humans; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D013223:Statistics as Topic; D014743:Videotape Recording