title: Association of Early Stress Testing with Outcomes for Emergency Department Evaluation of Suspected Acute Coronary Syndrome.
abstract: Professional society guidelines suggest early stress testing (within 72 hours) after an emergency department (ED) evaluation for suspected acute coronary syndrome (ACS). However, there is increasing concern that current practice results in over-testing without evidence of benefit. We test the hypothesis that early stress testing improves outcomes.
  
  
  
  We analyzed prospectively collected data from 9 EDs on patients with suspected ACS, 1999-2001. We excluded patients with an ED diagnosis of ACS. The primary outcome was 30-day major adverse cardiac events (MACEs), including all-cause death, acute myocardial infarction, and revascularization. We used the HEART score to determine pretest ACS risk (low, intermediate, and high). To mitigate potential confounding, patients with and without early stress testing were matched within pretest risk strata in a 1:2 ratio using propensity scores.
  
  
  
  Of 7127 potentially eligible patients, 895 (13%) received early stress testing. The analytic cohort included 895 patients with early stress testing matched to 1790 without early stress testing. The overall 30-day MACE rate in both the source and analytic population was 3%. There were no baseline imbalances after propensity score matching (P > 0.1 for more than 30 variables). There was no association between early stress testing and 30-day MACE [odds ratio, 1.0; 95% confidence interval (CI), 0.6-1.7]. There was no effect modification by pretest risk (low: odds ratio, 1.0; 95% CI, 0.2-3.7; intermediate: 1.2; 95% CI, 0.6-2.6; high: 0.4; 95% CI, 0.1-1.6).
  
  
  
  Early stress testing is not associated with reduced MACE in patients evaluated for suspected ACS. Early stress testing may have limited value in populations with low MACE rate.
authors.affiliation: From the *Department of Emergency Medicine, †Division of Cardiovascular Medicine, Oregon Health and Science University, Portland, OR; ‡Department of Emergency Medicine, University of Cincinnati, Cincinnati, OH; §Department of Emergency Medicine, University of Texas Southwestern, Dallas, TX; ¶Department of Emergency Medicine, Wake Forest Baptist Medical Center, Winston-Salem, NC; ‖Department of Emergency Medicine, Thomas Jefferson University, Philadelphia, PA; **Department of Emergency Medicine, University of California Davis Medical Center, Sacramento, CA; ††Department of Emergency Medicine, Baylor College of Medicine, Houston, TX; and ‡‡Department of Emergency Medicine, Singapore General Hospital, Singapore.
authors.forename: Benjamin C
authors.initials: BC
authors.lastname: Sun
authors.forename: Amber
authors.initials: A
authors.lastname: Laurie
authors.forename: Rongwei
authors.initials: R
authors.lastname: Fu
authors.forename: Maros
authors.initials: M
authors.lastname: Ferencik
authors.forename: Michael
authors.initials: M
authors.lastname: Shapiro
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Lindsell
authors.forename: Deborah
authors.initials: D
authors.lastname: Diercks
authors.forename: James W
authors.initials: JW
authors.lastname: Hoekstra
authors.forename: Judd E
authors.initials: JE
authors.lastname: Hollander
authors.forename: J Douglas
authors.initials: JD
authors.lastname: Kirk
authors.forename: W Frank
authors.initials: WF
authors.lastname: Peacock
authors.forename: W Brian
authors.initials: WB
authors.lastname: Gibler
authors.forename: Venkataraman
authors.initials: V
authors.lastname: Anantharaman
authors.forename: Charles V
authors.initials: CV
authors.lastname: Pollack
mesh_terms: D054058:Acute Coronary Syndrome / Q000175:diagnosis* / Q000453:epidemiology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002423:Cause of Death / Q000639:trends; D004562:Electrocardiography; D004636:Emergency Service, Hospital; D005080:Exercise Test / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012720:Severity of Illness Index; D012846:Singapore / Q000453:epidemiology; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D014481:United States / Q000453:epidemiology