Predictors of Ischemia in Patients Referred for Evaluation of Exertional Dyspnea: A Stress Echocardiography Study

Abstract

There are conflicting data on the incidence of ischemia by stress echocardiography in patients referred for dyspnea without accompanying chest pain. A total of 311 consecutive patients with exertional dyspnea (without chest pain) referred to the echocardiography lab for ischemia evaluation from August 2008 to March 2012 were evaluated. Exercise by Bruce protocol or dobutamine stress echocardiography was performed. Resting left ventricular ejection fraction and segmental wall motion abnormalities were assessed. Multivariate logistic regression analysis was used to identify independent predictors of ischemia on stress echocardiography. The mean age was 61 years (range, 20-96 years), with 196 women (63%). Exercise stress was performed in 114 patients (37%); the rest of the patients underwent dobutamine stress. The patient population had a high burden of obesity, diastolic dysfunction, and pulmonary hypertension. Thirty patients (10%) had evidence of stress-induced ischemia (nine [8%] with exercise and 21 [11%] with dobutamine). In multivariate analysis, male gender (odds ratio, 2.8; P = .03), history of coronary artery disease (odds ratio, 3.5; P = .02), and resting wall motion abnormalities (odds ratio, 16.6; P < .01) were independent predictors of inducible ischemia. The incidence of stress-induced ischemia is low in patients referred for stress echocardiography with exertional dyspnea (without chest pain). Ischemia is more likely to be present in men with histories of coronary artery disease and resting wall motion abnormalities.