Gender-Specific Criteria and Performance of the Exercise Electrocardiogram

Abstract

Background Significant gender differences have been found in performance of the exercise ECG for the identification of coronary artery disease. However, identical exercise ECG ST segment criteria have been used in men and women, which might contribute to the lower accuracy of these methods in women than in men. Methods and Results To assess the effect of gender-specific test partitions on relative performance of standard and heart rate–adjusted ST segment depression criteria in men and women, the exercise ECGs of 143 women and 477 men were examined. Non–gender-specific test partitions, selected to have matched specificities of 96% for each test method, were determined in all 283 normal subjects, and gender-specific test partitions with identical specificity were determined separately in the 52 normal women and 231 normal men; sensitivity of these criteria was then examined in the 91 women and 246 men with coronary disease. Standard ST segment depression criteria (0.1 mV of additional horizontal or downsloping ST segment depression at end exercise) with identical 96% specificity in the entire group of normal subjects and separately in women and men had a significantly lower sensitivity of 51% in women compared with 67% in men ( P <.01). Among women, performance of the ST segment/heart rate (ST/HR) slope was more improved than that of the ST/HR index by the use of gender-specific criteria. Compared with the performance of non–gender-specific criteria, application of gender-specific ST/HR slope partitions with matched specificity of 96% resulted in a significant increase in sensitivity in women from 84% to 91% ( P <.01), with no significant change in sensitivity in men (89% to 88%) and with no residual difference in sensitivity between men and women. Although the use of gender-specific ST/HR slope criteria significantly improved sensitivity in both men and women with respect to standard criteria (each P <.0001), the relative increase in sensitivity provided by heart rate adjustment was significantly greater in women than in men (40% versus 21%, P <.001). Similar gender differences in improvement in performance using gender-specific criteria for the ST/HR slope were observed when analysis of test performance was restricted to the detection of three-vessel coronary disease (50% versus 9%, P =.002). Conclusions At high specificity, gender-specific test partitions improve sensitivity of the ST/HR slope for the identification of coronary disease in women, with no decrease in sensitivity in men. In contrast, gender-specific partitions do not change performance of standard test criteria, which is lower in women than in men. Accordingly, the relative benefit of heart rate adjustment by the ST/HR slope method is greater in women than in men. These findings support use of the ST/HR slope with use of gender-specific partitions for the identification and quantification of coronary artery disease in both men and women.