Exercise test predictors of severe coronary artery disease: Role of ST-segment elevation in lead aVR

Background: The role of exercise stress test (EST)-induced ST-segment elevation (STE) in electrocardiographic lead aVR in predicting severe coronary artery disease (CAD) is controversial. Hypothesis: Assessment of lead aVR during EST can be helpful to identify patients with severe CAD. Methods: We performed maximal EST in 200 patients undergoing coronary angiography for suspect of CAD. Four angiographic findings of severe CAD were considered: (1) left main (LM) disease; (2) LM or equivalent LM (LM/EQLM) disease; (3) LM or proximal left anterior descending (LAD) artery (LM/proxLAD) disease; and (4) LM or 3-vessel (LM/3V) disease. Results: LM, LM/EQLM, LM/proxLAD, and LM/3V disease were shown in 6 (3%), 13 (6.5%), 33 (16.5%), and 27 (13.5%) patients, respectively. EST-induced STE in aVR occurred in 41 patients (20.5%). ST-segment depression (STD) in ≥5 leads was the only predictor of LM stenosis (odds ratio [OR]: 6.18, 95% confidence interval [CI]: 1.19-32.2, P = 0.03) and the most significant variable associated with LM/proxLAD stenosis (OR: 4.73, 95% CI: 2.0-11.2, P = 0.0001); maximal STD ≥3 mm was the most significant variable associated with LM/EQLM (OR: 7.58, 95% CI: 2.31-24.9, P = 0.001) and LM/3V (OR: 3.86, 95% CI: 1.47-10.1, P = 0.006) CAD. EST-induced STE in aVR was associated with LM/proxLAD disease only (OR: 3.23, 95% CI: 1.44-7.24, P = 0.004). At multivariate analysis, STD in ≥5 leads was the only independent predictor of LM/proxLAD disease (OR: 3.99, 95% CI: 1.58-10.1, P = 0.003). Conclusions: EST-induced STE in lead aVR does not significantly increase the prediction of severe CAD compared with severity and extension of STD as assessed in the other electrocardiographic leads.