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

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.

Assessment of lead aVR during EST can be helpful to identify patients with severe CAD.

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.

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).

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.