title: Clinical and detailed angiographic findings in patients with ambulatory electrocardiographic ischemia without critical coronary narrowing: results from the Asymptomatic Cardiac Ischemia Pilot (ACIP) Study.
abstract: BACKGROUND
  Patients with ambulatory electrocardiographic (AECG) ST-segment depression and critical coronary narrowing are known to be at increased risk for adverse outcome, but little is known about patients with AECG ST-segment depression without critical coronary narrowing.
  
  
  OBJECTIVE
  The objectives of this study were to characterize the coronary angiographic pathology in patients with AECG ST-segment depression but without critical (< 50% diameter stenosis) coronary narrowing and to compare demographic and clinical findings in these patients with those enrolled in the Asymptomatic Cardiac Ischemia Pilot Study with AECG ST-segment depression and critical (> or = 50% diameter stenosis) coronary narrowing.
  
  
  METHODS
  Coronary angiograms from patients with AECG ST-segment depression were reviewed in a central laboratory and quantitative measurement of percent stenosis was performed. Clinical and angiographic comparisons were made between patients with and without critical coronary narrowing.
  
  
  RESULTS
  Patients without critical coronary narrowing (n = 64) were younger (p = 0.02), less likely to be male (p < 0.001) or to have risk factors for coronary atherosclerosis or a history of myocardial infarction (p < 0.001), and had fewer ischemic episodes per 24 h on the screening AECG (p = 0.02) than patients with critical coronary narrowing (n = 441). Of patients without critical narrowing, one half had angiographic evidence for coronary artery disease (> or = 20% stenosis) and 60% had an ejection fraction > 70%.
  
  
  CONCLUSIONS
  Patients with AECG ST-segment depression without critical coronary narrowing are heterogeneous, with half having measurable coronary artery disease. Demographically and clinically, they appear to be different than patients with AECG ST-segment depression with critical coronary narrowing.
authors.affiliation: Division of Cardiology, Rhode Island Hospital, Brown University, Providence, USA.
authors.forename: B L
authors.initials: BL
authors.lastname: Sharaf
authors.forename: M G
authors.initials: MG
authors.lastname: Bourassa
authors.forename: R P
authors.initials: RP
authors.lastname: McMahon
authors.forename: C J
authors.initials: CJ
authors.lastname: Pepine
authors.forename: B R
authors.initials: BR
authors.lastname: Chaitman
authors.forename: D O
authors.initials: DO
authors.lastname: Williams
authors.forename: R F
authors.initials: RF
authors.lastname: Davies
authors.forename: M
authors.initials: M
authors.lastname: Proschan
authors.forename: C R
authors.initials: CR
authors.lastname: Conti
mesh_terms: D017023:Coronary Angiography; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000503:physiopathology; D015716:Electrocardiography, Ambulatory; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D010865:Pilot Projects; D011237:Predictive Value of Tests; D012307:Risk Factors; D013318:Stroke Volume