title: Relationship of ST elevation in lead aVR with angiographic findings and outcome in non-ST elevation acute coronary syndromes.
abstract: BACKGROUND
  Limited data suggest that ST elevation (ST elevation) in aVR is associated with higher mortality and more extensive coronary artery disease in the setting of non-ST elevation acute coronary syndromes (ACS).
  
  
  METHODS
  In the prospective Global Registry of Acute Coronary Events (GRACE) electrocardiographic substudy, the admission electrocardiograms were analyzed by a blinded core laboratory. We performed multivariable analysis to determine (1) the independent prognostic significance of ST elevation in aVR and (2) its association with significant (> or = 50% stenosis) left main or 3-vessel disease (LM/3-vd).
  
  
  RESULTS
  Among 5064 patients with non-ST elevation ACS, 4696 had no ST elevation in aVR, 292 (5.8%) had minor (0.5-1 mm) ST elevation in aVR, and 76 (1.5%) had major (>1 mm) ST elevation in aVR; their in-hospital mortality rates were 4.2%, 6.2%, and 7.9%, respectively (P for trend =.03). At 6 months follow-up, the cumulative mortality rates were 7.6%, 12.7%, and 18.3%, respectively (log-rank P for trend <.001). However, minor and major ST elevation in aVR were not independent predictors of in-hospital or 6-month death after adjusting for other validated prognosticators in the GRACE risk model. Of the 2416 patients without prior coronary bypass surgery who underwent cardiac catheterization, the prevalence of LM/3-vd was 26.1%, 36.2%, and 55.9% for the groups with no, minor, and major ST elevation in aVR, respectively (P for trend <.001). After adjusting for other clinical characteristics, major ST elevation in aVR remained an independent predictor of LM/3-vd (adjusted odds ratio, 2.68; 95% confidence interval, 1.29-5.58; P = .008).
  
  
  CONCLUSIONS
  ST elevation in aVR is less prevalent than reported in previous smaller studies. Although it is associated with higher unadjusted in-hospital and 6-month mortality, it does not provide incremental prognostic value beyond comprehensive risk stratification using the validated GRACE risk model. However, ST elevation greater than 1 mm in aVR may be useful in the early identification of LM/3-vd in ACS patients with ST depression.
authors.affiliation: Division of Cardiology, St. Michael's Hospital, University of Toronto, and Canadian Heart Research Centre, Toronto, Ontario, Canada.
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Yan
authors.forename: Raymond T
authors.initials: RT
authors.lastname: Yan
authors.forename: Brian M
authors.initials: BM
authors.lastname: Kennelly
authors.forename: Frederick A
authors.initials: FA
authors.lastname: Anderson
authors.forename: Andrzej
authors.initials: A
authors.lastname: Budaj
authors.forename: José
authors.initials: J
authors.lastname: López-Sendón
authors.forename: David
authors.initials: D
authors.lastname: Brieger
authors.forename: Jeanna
authors.initials: J
authors.lastname: Allegrone
authors.forename: Gabriel
authors.initials: G
authors.lastname: Steg
authors.forename: Shaun G
authors.initials: SG
authors.lastname: Goodman
mesh_terms: D000368:Aged; D017023:Coronary Angiography; D003327:Coronary Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000401:mortality* / Q000628:therapy; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D015233:Models, Statistical; D011379:Prognosis; D011446:Prospective Studies; D012042:Registries; D018570:Risk Assessment; D015996:Survival Rate; D016896:Treatment Outcome