title: Impact of delayed presentation on management and outcome of non-ST-elevation acute coronary syndromes.
abstract: BACKGROUND
  The impact of delayed presentation on the management and outcomes of patients with non-ST-elevation acute coronary syndromes (NSTE-ACS) has not been well studied. Furthermore, the prognostic value of initial biomarker level in relation to the time of presentation has not been determined.
  
  
  METHODS
  The Canadian ACS II registry was a national, multicenter, prospective observational study of 1,956 patients with NSTE-ACS (October 2002-December 2003). We compared the baseline characteristics, treatment, and outcomes in early (within 6 hours of symptom onset) versus late presenters (>6 hours). A logistic regression model was developed to examine the independent association of late presentation with 1-year mortality. We also evaluated the prognostic value of initial biomarker level in relation to early versus late presentation.
  
  
  RESULTS
  A total of 1,219 (62.3%) patients presented early, whereas 727 (37.7%) presented late; their rates of in-hospital revascularization were similar (40.5% vs 42.5%, respectively, P = .39). There was also no significant difference in hospital mortality (1.6% vs 2.2%, P = .30) or 1-year mortality (7.6% vs 5.7%, P = .13) between early and late presenters. After adjusting for other prognosticators, late presentation was not an independent predictor of 1-year mortality (adjusted odds ratio 0.78, 95% confidence interval 0.48-1.26, P = .3). Elevated initial biomarker was independently associated with higher 1-year mortality (adjusted odds ratio 2.17, 95% CI 1.31-3.58, P = .002) regardless of whether hospital presentation was early or late (P for interaction = .74).
  
  
  CONCLUSIONS
  There is still considerable delay between symptom onset of NSTE-ACS and hospital presentation in the contemporary era. In contrast to studies of ST-elevation myocardial infarction, we found no significant differences in the management and outcome of early presenters as compared with late presenters with NSTE-ACS. Nevertheless, measures to reduce patient delay time should continue to be implemented. Initial biomarker status is a useful prognosticator irrespective of the delay time.
authors.affiliation: Terrence Donnelly Heart Centre, Division of Cardiology, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Basem
authors.initials: B
authors.lastname: Elbarouni
authors.forename: Shaun G
authors.initials: SG
authors.lastname: Goodman
authors.forename: Raymond T
authors.initials: RT
authors.lastname: Yan
authors.forename: Amparo
authors.initials: A
authors.lastname: Casanova
authors.forename: Abdul
authors.initials: A
authors.lastname: Al-Hesayen
authors.forename: Stephen
authors.initials: S
authors.lastname: Pearce
authors.forename: David H
authors.initials: DH
authors.lastname: Fitchett
authors.forename: Anatoly
authors.initials: A
authors.lastname: Langer
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Yan
mesh_terms: D054058:Acute Coronary Syndrome / Q000145:classification / Q000401:mortality / Q000628:therapy*; D000368:Aged; D015415:Biomarkers / Q000097:blood; D004562:Electrocardiography; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D019370:Observation; D011379:Prognosis; D011446:Prospective Studies; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers