title: Use and timing of coronary angiography and associated in-hospital outcomes in Canadian non-ST-segment elevation myocardial infarction patients: insights from the Canadian Global Registry of Acute Coronary Events.
abstract: BACKGROUND
  Although an early invasive approach has become standard strategy for the management of non-ST-segment elevation myocardial infarction (NSTEMI), the frequency and timing in Canada is uncertain.
  
  
  METHODS
  We examined the use and timing of coronary angiography, revascularization, and cardiovascular outcomes of NSTEMI patients: (1) admitted on weekdays vs weekends; and (2) stratified according to presentation risk level, in the Canadian Global Registry of Acute Coronary Events (GRACE)/Expanded GRACE (GRACE(2))/Canadian Registry of Acute Coronary Events (CANRACE) population.
  
  
  RESULTS
  Of 6711 NSTEMI patients, 1956 (29.1%) were admitted on the weekend. The median (interquartile range) wait time for coronary angiography was 58 (32-106) and 70 (50-112) hours for weekday and weekend patients, respectively (P = 0.32). Compared with lower-intermediate risk, higher-risk patients were less likely to undergo angiography (44.7% vs 69.7% for weekdays and 45.2% vs 69.6% for weekends; both P < 0.0001) and waited longer for angiography (median 71 vs 61 hours; P < 0.0001). Weekend admission was independently associated with higher mortality (adjusted odds ratio [OR], 1.52; 95% confidence interval [CI], 1.15-2.01; P = 0.004), recurrent ischemia (adjusted OR, 1.16; 95% CI, 1.01-1.32; P = 0.03), and heart failure (adjusted OR, 1.28; 95% CI, 1.00-1.63; P = 0.048) but not with reinfarction.
  
  
  CONCLUSIONS
  Median wait time for angiography in Canadian NSTEMI patients admitted on the weekend was not significantly longer than for those who presented on a weekday. Patients admitted on weekends had higher adjusted mortality and cardiovascular event rates. Higher-risk patients were less likely to undergo angiography and waited longer, with higher observed in-hospital event rates. Systematic, guideline-recommended risk stratification should be considered to ensure that optimal management strategies (eg, timely coronary angiography in higher-risk patients) are matched to level of risk.
authors.affiliation: Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Gabor T
authors.initials: GT
authors.lastname: Gyenes
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Yan
authors.forename: Mary
authors.initials: M
authors.lastname: Tan
authors.forename: Robert C
authors.initials: RC
authors.lastname: Welsh
authors.forename: Keith A A
authors.initials: KA
authors.lastname: Fox
authors.forename: Francois R
authors.initials: FR
authors.lastname: Grondin
authors.forename: J Paul
authors.initials: JP
authors.lastname: Deyoung
authors.forename: Barry F
authors.initials: BF
authors.lastname: Rose
authors.forename: Richard
authors.initials: R
authors.lastname: Gallo
authors.forename: Jan M
authors.initials: JM
authors.lastname: Kornder
authors.forename: Graham C
authors.initials: GC
authors.lastname: Wong
authors.forename: Shaun G
authors.initials: SG
authors.lastname: Goodman
mesh_terms: D000368:Aged; D002170:Canada / Q000453:epidemiology; D006328:Cardiac Catheterization; D017023:Coronary Angiography / Q000706:statistics & numerical data*; D005260:Female; D006333:Heart Failure / Q000453:epidemiology; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000453:epidemiology / Q000628:therapy*; D017202:Myocardial Ischemia / Q000453:epidemiology; D009204:Myocardial Revascularization; D010343:Patient Admission / Q000706:statistics & numerical data*; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D013997:Time Factors