title: Relationship between coronary artery calcification detected by electron-beam computed tomography and abnormal stress echocardiography: association and prognostic implications.
abstract: OBJECTIVE
  The purpose of this study was to compare the results and prognostic value of electron-beam computed tomography (EBCT) and exercise echocardiography.
  
  
  BACKGROUND
  Although patients with elevated coronary artery calcium scores (CACS) might be referred for exercise echocardiography, the association of EBCT CACS with wall motion score index (WMSI) is not known.
  
  
  METHODS
  Patients without known coronary artery disease who underwent both clinically indicated EBCT and exercise echocardiography within a 3-month period were identified. Exercise WMSI was based on a 16-segment model (normal = 1; abnormal >1). The EBCT CACS was derived with the Agatston scoring system. Follow-up was obtained for the combined end point of death and myocardial infarction.
  
  
  RESULTS
  The study population included 556 patients (age 54 +/- 10 years; 65% male). Correlation between EBCT CACS and exercise WMSI was limited (r = 0.17, p < 0.0001) but statistically significant. The proportion of patients with abnormal exercise WMSI increased with increasing CACS severity (chi-square = 19.1, p < 0.001). However, even in those with CACS >400, 66% had normal exercise WMSI. Age, CACS, and chest pain were independently associated with abnormal exercise WMSI. Events occurred in 12 (2%) patients. Wall motion score index (risk ratio [RR] 3.7, p = 0.023) and age (RR 1.9, p = 0.019) were associated with events.
  
  
  CONCLUSIONS
  Electron-beam computed tomography CACS was predictive of abnormal exercise WMSI, but the majority of patients with elevated CACS had normal WMSI. Wall motion score index and age were the best predictors of events. Prospective studies are indicated to establish the relative roles of these tests in risk stratification.
authors.affiliation: Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: Gautam
authors.initials: G
authors.lastname: Ramakrishna
authors.forename: Jerome F
authors.initials: JF
authors.lastname: Breen
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Mulvagh
authors.forename: Robert B
authors.initials: RB
authors.lastname: McCully
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Pellikka
mesh_terms: D000368:Aged; D000375:Aging; D002114:Calcinosis / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology / Q000628:therapy; D002637:Chest Pain / Q000209:etiology; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology / Q000628:therapy; D025401:Echocardiography, Stress; D005260:Female; D005500:Follow-Up Studies; D006321:Heart / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000209:etiology; D009204:Myocardial Revascularization; D011379:Prognosis; D014057:Tomography, X-Ray Computed