Variability in the accuracy of the exercise ST-segment in predicting the coronary angiogram: how good can we be?

In order to evaluate the variability in the diagnostic accuracy of the exercise electrocardiogram, a meta-analytic database derived from a review of 147 publications and a multicenter database derived from 2,826 angiographic referrals were analyzed. Wide variability in sensitivity and specificity were found from the meta-analytic review (standard deviations of 16% and 15%, respectively). No improvement in reported sensitivities and specificities has been seen over the past 22 years. The sensitivities and specifities derived from the multicenter database also showed wide variability (standard deviation 13% and 5%). These results suggest that despite obvious technologic strides in acquiring, processing, and interpreting exercise ECG signals, the accuracy of the exercise induced ST depression has not increased greatly and is difficult to ascertain a priori in a given laboratory. Individual anatomic and physiologic differences are postulated as limiting factors in the accuracy that can be obtained from this noninvasive test.