title: Yield of downstream tests after exercise treadmill testing: a prospective cohort study.
abstract: OBJECTIVE
  The purpose of this study was to estimate the frequency and results of downstream testing after exercise treadmill tests (ETTs).
  
  
  BACKGROUND
  The utility of additional diagnostic testing after ETT is not well characterized.
  
  
  METHODS
  We followed consecutive individuals without known coronary artery disease referred for clinical ETT at a large medical center. We measured the frequency and results of downstream imaging tests and invasive angiography within 6 months of ETT and the combined endpoint of survival free from cardiovascular death, myocardial infarction, and coronary revascularization.
  
  
  RESULTS
  Among 3,656 consecutive subjects who were followed for a mean of 2.5 ± 1.1 years, 332 (9.0%) underwent noninvasive imaging and 84 (2.3%) were referred directly to invasive angiography after ETT. The combined endpoint occurred in 76 (2.2%) patients. The annual incidence of the combined endpoint after negative, inconclusive, and positive ETT was 0.2%, 1.3%, and 12.4%, respectively (p < 0.001). Rapid recovery of electrocardiography (ECG) changes during ETT was associated with negative downstream test results and excellent prognosis, whereas typical angina despite negative ECG was associated with positive downstream tests and adverse prognosis (p < 0.001). Younger age, female sex, higher metabolic equivalents of task achieved, and rapid recovery of ECG changes were predictors of negative downstream tests.
  
  
  CONCLUSIONS
  Among patients referred for additional testing after ETT, the lowest yield was observed among individuals with rapid recovery of ECG changes or negative ETT, whereas the highest yield was observed among those with typical angina despite negative ECG or a positive ETT. These findings may be used to identify patients who are most and least likely to benefit from additional testing.
authors: Harvard Medical School, Boston, Massachusetts.
authors: Mitalee P
authors: MP
authors: Christman
authors: Department of Medicine (Cardiovascular Division) and Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
authors: Marcio Sommer
authors: MS
authors: Bittencourt
authors: Department of Medicine (Cardiovascular Division) and Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
authors: Edward
authors: E
authors: Hulten
authors: Boston University, Boston, Massachusetts.
authors: Ekta
authors: E
authors: Saksena
authors: Department of Medicine (Cardiovascular Division) and Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
authors: Jon
authors: J
authors: Hainer
authors: Department of Medicine (Cardiovascular Division) and Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
authors: Hicham
authors: H
authors: Skali
authors: Department of Medicine (Cardiovascular Division), Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
authors: Raymond Y
authors: RY
authors: Kwong
authors: Department of Medicine (Cardiovascular Division), Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
authors: Daniel E
authors: DE
authors: Forman
authors: Department of Medicine (Cardiovascular Division) and Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
authors: Sharmila
authors: S
authors: Dorbala
authors: Department of Medicine (Cardiovascular Division), Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
authors: Patrick T
authors: PT
authors: O'Gara
authors: Department of Medicine (Cardiovascular Division) and Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
authors: Marcelo F
authors: MF
authors: Di Carli
authors: Department of Medicine (Cardiovascular Division) and Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts. Electronic address: rblankstein@partners.org.
authors: Ron
authors: R
authors: Blankstein
mesh_terms: D002423:Cause of Death / Q000639:trends; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology; D003326:Coronary Circulation / Q000502:physiology*; D004562:Electrocardiography; D005080:Exercise Test / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008404:Massachusetts / Q000453:epidemiology; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D020127:Recovery of Function; D015203:Reproducibility of Results; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon
keywords: downstream testing; exercise testing; imaging