Relationship of ST elevation in lead aVR with angiographic findings and outcome in non-ST elevation acute coronary syndromes

Background Limited data suggest that ST elevation (ST up arrow) in aVR is associated with higher mortality and more extensive coronary artery disease in the setting of non-ST up arrow 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 up arrow in aVR and (2) its association with significant (>= 50% stenosis) left main or 3-vessel disease (LM/3-vd). Results Among 5064 patients with non-ST I ACS, 4696 had no ST I in aVR, 292 (5.8%) had minor (0.5-1 mm) ST I in aVR, and 76 (1.5%) had major (>1 mm) ST up arrow 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 up arrow 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 I in aVR, respectively (P for trend <.001). After adjusting for other clinical characteristics, major ST I in aVR remained an independent predictor of LM/3-vd (adjusted odds ratio, 2.68,95% confidence interval, 1.29-5.58; P =.008). Conclusion ST up arrow 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 T greater than I mm in aVR may be useful in the early identification of LM/3-vd in ACS patients with ST depression.