Is rest or exercise hypertension a cause of a false-positive exercise test?

Study objectives: To determine if a history of hypertension or an exaggerat ed rise in exercise systolic BP is associated with a false-positive exercis e EGG. Design, setting, and patients: Retrospective analysis of the associations b etween exercise-induced ST-segment depression and a history of hypertension , exercise systolic BP, and several other clinical and exercise test variab les, Among 20,097 patients refer-red for exercise tomographic thallium imag ing in a nuclear cardiology laboratory at a tertiary care center, 1,873 pat ients met inclusion criteria for this study, which included no history of m yocardial infarction or coronary artery revascularization, a normal resting EGG, and normal exercise thallium images, Results: False-positive ST-segment depression occurred in 20% of the popula tion. A history of hypertension was actually associated with a lower likeli hood of ST-segment depression (odds ratio, 0.70; 95% confidence interval [C I], 0.55 to 0.89; p = 0.004), A higher peak exercise systolic BP was associ ated with a higher likelihood of ST-segment depression (odds ratio, 1.0S fo r each 10-mm Hg increase in systolic BP; 95% CI, 1.03 to 1.11; p < 0.001). However, the association between peak exercise systolic BP and ST-segment d epression was so weak that this measurement could not be predictive in the individual patient (R-2 = 0.2%). For every 10-mm Hg increase in peak exerci se systolic BP, the percentage of patients with ST-segment depression incre ased by only 3%. Conclusions: In patients with normal resting ECGs, we conclude the followin g: (1) a history of hypertension is not a cause of a false-positive exercis e test, and (2) higher exercise systolic BP is a significant but weak predi ctor of ST-segment depression.