title: Effect of exercise treadmill testing and stress imaging on the triage of patients with chest pain: CHEER substudy.
abstract: OBJECTIVE
  To determine whether stress imaging for patients who are unsuitable for exercise treadmill testing (ETT) as part of a chest pain unit (CPU) triage strategy resulted in incremental benefit in clinical outcomes and relative costs compared with patients randomized to routine hospital admission.
  
  
  METHODS
  Clinical outcomes and medical resource utilization were examined at the Mayo Clinic in Rochester, Minn, for 212 intermediate-risk patients with unstable angina randomized to a CPU and compared with 212 patients randomized to routine admission from November 21, 1995, to March 18, 1997. Patients in stable condition in the CPU underwent ETT; if patients were unsuitable for ETT, stress imaging was performed. Costs for CPU evaluation and outcomes were assessed during a 6-month follow-up.
  
  
  RESULTS
  During the observation period, 60 patients (28%) were admitted to the hospital. Of the 152 remaining patients, 125 (82%) underwent ETT (91 had normal results), and 27 (18%) underwent stress imaging (3 had normal results). Patients with normal ETT or stress imaging results had no primary events at 6-month follow-up. Patients admitted to the hospital who underwent stress imaging had an insignificantly higher 6-month event rate compared with patients who underwent ETT (16.7% vs 8.1%; P=.38). The standardized resource-based relative-value units (RBRVUs) for patients who underwent ETT and stress imaging during follow-up were 19.4 and 56.4 RBRVUs, respectively, compared with 51.4 (ETT) and 52.1 (stress imaging) RBRVUs for similar numbers of patients randomized to routine admission.
  
  
  CONCLUSIONS
  Exercise treadmill testing safely stratified most intermediate-risk patients with unstable angina and was less costly than routine admission. Patients not suitable for ETT are likely to have abnormal stress imaging results. They represent a higher-risk cohort that could be routinely admitted to the hospital without reducing the effectiveness of the CPU strategy.
authors.affiliation: Department of Internal Medicine and Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, Rochester, Minn 55905, USA.
authors.forename: Gautam
authors.initials: G
authors.lastname: Ramakrishna
authors.forename: James J
authors.initials: JJ
authors.lastname: Milavetz
authors.forename: Alan R
authors.initials: AR
authors.lastname: Zinsmeister
authors.forename: Michael E
authors.initials: ME
authors.lastname: Farkouh
authors.forename: Roger W
authors.initials: RW
authors.lastname: Evans
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Allison
authors.forename: Peter A
authors.initials: PA
authors.lastname: Smars
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Gibbons
mesh_terms: D000789:Angina, Unstable / Q000191:economics / Q000628:therapy*; D003362:Cost-Benefit Analysis; D025401:Echocardiography, Stress; D004636:Emergency Service, Hospital / Q000191:economics; D005080:Exercise Test / Q000191:economics; D006760:Hospitalization / Q000191:economics; D006801:Humans; D016015:Logistic Models; D008910:Minnesota; D009203:Myocardial Infarction; D017063:Outcome Assessment, Health Care; D016032:Randomized Controlled Trials as Topic; D018570:Risk Assessment; D015899:Tomography, Emission-Computed, Single-Photon / Q000191:economics; D014218:Triage / Q000379:methods*