title: Underuse of evidence-based treatment partly explains the worse clinical outcome in diabetic patients with acute coronary syndromes.
abstract: BACKGROUND
  Diabetes-related differences in treatment and clinical outcome of patients across the entire spectrum of acute coronary syndromes (ACSs) have potential clinical implications but have not been well studied.
  
  
  METHODS
  The multicenter, prospective, Canadian ACS Registry enrolled 4578 patients hospitalized for ACS between 1999 and 2001 across 9 provinces in Canada. We compared baseline characteristics, in-hospital and post-discharge treatments, and clinical outcome of diabetic and non-diabetic patients. The impact of diabetes on use of thrombolytic therapy and coronary revascularization; and the independent association between diabetes, treatments, and diabetes-treatment interactions on outcome were examined.
  
  
  RESULTS
  Diabetic patients with ACS had more cardiovascular risk factors and higher-risk clinical presentation. They paradoxically received less evidence-based medications in-hospital, at discharge, and at 1-year. Although diabetes independently predicted higher 1-year mortality (OR 1.47, 95% CI 1.15-1.87; P = .002) after adjustment for validated prognosticators, it was also an independent predictor of not receiving thrombolytic therapy (OR 0.72, 95% CI 0.54-0.95; P = .021) and coronary revascularization (OR 0.69, 95% CI 0.59-0.82; P < .001). These underused therapies were all independently associated with reduced 1-year mortality, with no significant diabetes-related treatment-outcome heterogeneity. Importantly, diabetes remained an independent adverse prognosticator even after further adjustment for these differences in treatment.
  
  
  CONCLUSIONS
  Evidence-based therapies are underused in the contemporary management of diabetic patients with ACS, which partly explains their worse outcome. Diabetes should be considered a high-risk feature in ACS risk stratification that encourages more intensive treatments. Continued efforts to promote adherence to existing proven therapies and to develop novel treatment strategies targeting diabetes-specific cardiovascular pathophysiology are imperative to improve their adverse prognosis.
authors.affiliation: Terrence Donnelly Heart Centre, Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Raymond T
authors.initials: RT
authors.lastname: Yan
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Yan
authors.forename: Mary
authors.initials: M
authors.lastname: Tan
authors.forename: Darren K
authors.initials: DK
authors.lastname: McGuire
authors.forename: Lawrence
authors.initials: L
authors.lastname: Leiter
authors.forename: David H
authors.initials: DH
authors.lastname: Fitchett
authors.forename: Claude
authors.initials: C
authors.lastname: Lauzon
authors.forename: Kevin
authors.initials: K
authors.lastname: Lai
authors.forename: Chi-Ming
authors.initials: CM
authors.lastname: Chow
authors.forename: Anatoly
authors.initials: A
authors.lastname: Langer
authors.forename: Shaun G
authors.initials: SG
authors.lastname: Goodman
mesh_terms: D000208:Acute Disease; D000368:Aged; D000553:Ambulatory Care; D002170:Canada; D002318:Cardiovascular Diseases / Q000209:etiology; D003327:Coronary Disease / Q000401:mortality / Q000628:therapy*; D048909:Diabetes Complications / Q000401:mortality / Q000628:therapy*; D003920:Diabetes Mellitus / Q000628:therapy*; D019317:Evidence-Based Medicine; D005260:Female; D006801:Humans; D007297:Inpatients; D008297:Male; D008875:Middle Aged; D009204:Myocardial Revascularization / Q000706:statistics & numerical data*; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D013577:Syndrome; D015912:Thrombolytic Therapy / Q000706:statistics & numerical data*; D016896:Treatment Outcome