False-positive exercise echocardiograms: impact of sex and blood pressure response

Abstract

Background Factors related to false-positive results of exercise echocardiography (ExE) to diagnose coronary disease have not been extensively studied. In addition, previous studies were performed before routine use of digital and tissue harmonic imaging. We evaluated the clinical and echocardiographic predictors of false-positive results during ExE. Methods Four hundred sixty-four patients who had both coronary angiography and ExE were enrolled retrospectively. Significant coronary disease was defined by stenoses ≥50% lumen diameter. Results Fifty-eight (13%) had false-positive results. Thirty-one (53%) of these patients were women, which was significantly higher than the percentage of women (25%) in the true-positive group ( P < .001). Average peak systolic blood pressure (BP) in the false-positive group was significantly higher than in the true-positive group. Test specificity was decreased at higher levels of BP without change of sensitivity. Men demonstrated a decrease in specificity at peak systolic BP ≥200 mm Hg, whereas women showed a sharp decrease in specificity at BP ≥180 mm Hg. Wall motion score index (WMSI) after peak exercise and the proportion of high- and intermediate-risk patients according to Duke score were significantly lower in the false-positive than in the true-positive group. Conclusions The factors predictive of false-positive results during ExE to diagnose coronary disease were female sex, higher BP at peak exercise, lower risk by Duke score and lower number of abnormal segments and wall motion score index after peak exercise. Women appear to be susceptible to wall motion abnormalities caused by elevated exercise BP. These variables should be considered in the interpretation of ExE.