title: Relation between ambulatory electrocardiographic monitoring and myocardial perfusion imaging to detect coronary artery disease and myocardial ischemia: an ACIP ancillary study. The Asymptomatic Cardiac Ischemia Pilot (ACIP) Investigators.
abstract: OBJECTIVE
  This study sought to explore the relation between markers of ischemia detected by ambulatory electrocardiographic (AECG) monitoring and stress myocardial perfusion single-photon emission computed tomography (SPECT).
  
  
  BACKGROUND
  Stress myocardial SPECT and AECG monitoring are both utilized in evaluating patients with coronary artery disease. However, information is limited regarding the relation between the presence and extent of ischemia as detected by these two modalities.
  
  
  METHODS
  This was an ancillary study of the Asymptomatic Cardiac Ischemia Pilot (ACIP) trial. One hundred six patients with previous coronary angiography underwent AECG monitoring and stress SPECT within a close temporal time period. The frequency and duration of ischemia as assessed by AECG monitoring and the total and ischemic stress-induced myocardial perfusion defect sizes as assessed by SPECT were quantified in separate core laboratories. Multivariate logistic regression and linear regression analysis were used to determine associations between AECG and SPECT abnormalities with regard to angiographic, demographic and treadmill exercise variables.
  
  
  RESULTS
  Seventy-four percent of patients with significant (> or = 50%) coronary artery stenosis had SPECT abnormalities, whereas 61% had ischemia by AECG monitoring. The most important predictors of SPECT abnormalities were severity (p < 0.001) of coronary artery stenosis, followed by total exercise duration (p = 0.016) and patient age (p = 0.04). The only predictor of AECG abnormalities was the presence of ST segment depression on the initial exercise treadmill test (p = 0.021). Only a 50% concordance for normalcy or abnormalcy was observed between the SPECT and AECG results, and no relation was observed between the frequency or duration of AECG ischemia and the quantified total or ischemic myocardial perfusion defect size as assessed by SPECT.
  
  
  CONCLUSIONS
  Ischemia as detected by AECG monitoring does not correlate with the presence and extent of ischemia as quantified by stress SPECT. Because these techniques appear to detect different pathophysiologic manifestations of ischemia, they may be complementary in more fully defining the functional significance of coronary artery disease and, in particular, which patients are at highest risk for adverse cardiac events.
authors.affiliation: Baylor College of Medicine, Houston, Texas 77030-2716, USA.
authors.forename: J J
authors.initials: JJ
authors.lastname: Mahmarian
authors.forename: R M
authors.initials: RM
authors.lastname: Steingart
authors.forename: S
authors.initials: S
authors.lastname: Forman
authors.forename: B L
authors.initials: BL
authors.lastname: Sharaf
authors.forename: M E
authors.initials: ME
authors.lastname: Coglianese
authors.forename: D D
authors.initials: DD
authors.lastname: Miller
authors.forename: C J
authors.initials: CJ
authors.lastname: Pepine
authors.forename: A D
authors.initials: AD
authors.lastname: Goldberg
authors.forename: M F
authors.initials: MF
authors.lastname: Bloom
authors.forename: S
authors.initials: S
authors.lastname: Byers
authors.forename: L
authors.initials: L
authors.lastname: Dvorak
authors.forename: C M
authors.initials: CM
authors.lastname: Pratt
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002986:Clinical Trials as Topic; D017023:Coronary Angiography; D003327:Coronary Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging; D015716:Electrocardiography, Ambulatory; D005080:Exercise Test; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000000981:diagnostic imaging; D015899:Tomography, Emission-Computed, Single-Photon