Predictive value of exercise-induced ST depression in the diagnosis of restenosis after coronary angioplasty
LaBlanche, J.M.; Magy, J.M.; Pruvost, P.; Fourrier, J.L.; Gommeaux, A.; Bertrand, M.E.
Archives des Maladies du Coeur et des Vaisseaux 82(6): 871-875
1989
ISSN/ISBN: 0003-9683 PMID: 2527021 Document Number: 327620
Exercise tests systematically performed during coronary arteriography in patients who had undergone coronary angioplasty show a very large number of ST depressions in the absence of significant coronary lesion. This could be ascribed either to electrocardiographic traces of chronic ischaemia or to a reduced predictive value of exercise tests due to a combination of low prevalence of coronary disease and poor specificity and/or sensitivity. In order to confirm or infirm these hypotheses, the values observed in a study group of 122 patients who had undergone angioplasty for single lesion of the anterior interventricular artery were compared with the values calculated by Bayes' theorem from a 30 p. 100 theoretical restenosis rate and a sensitivity and specificity calculated from a group of control patients who did not have coronary angioplasty but showed the same coronary arteriographic characteristics as the study group. In the study group as in the control group, sensitivity (60 versus 67 p. 100) and specificity (56 versus 54 p. 100) were low. Positive predictive values were also very low (33 versus 38 p. 100), whereas negative values were acceptable (78 p. 100 in both groups). Differences between groups were not significant. The predictive value of ST depression in the diagnosis of post-angioplasty restenosis is too low to be used alone. This low predictive value can be ascribed to the low prevalence of restenosis and to the extremely low specificity observed in the presence of non significant lesions. However, the finding of a negative exercise test in asymptomatic patients enables coronary arteriography to be avoided with a low risk of error (7.7 p. 100).