Usefulness of an exaggerated systolic blood pressure response to exercise in predicting myocardial perfusion defects in known or suspected coronary artery disease

The clinical importance of an exaggerated systolic blood pressure (BP) response to exercise, or exercise hypertension, is unclear. We have previously reported that exercise hypertension is associated with less severe angiographic coronary artery disease. This study sought to examine the association between exercise hypertension and ischemic "burden," as assessed by thallium-201 single-photon emission computed tomography. The cohort was comprised of consecutive adults (2,216 men, 1,229 women) referred for symptom-limited exercise thallium testing to evaluate known or suspected coronary artery disease. The main variable measured was exercise hypertension, defined as a peak systolic BP greater than or equal to 210 mm Hg in men and greater than or equal to 190 mm Hg in women. Thallium perfusion defects were described as: (1) any perfusion abnormality, (2) reversible abnormalities, and (3) any abnormality in greater than or equal to 3 of 12 myocardial segments ("extensive abnormalities"). Exercise hypertension was present in 1,319 subjects (39%). Patients with exercise hypertension were less likely to have any thallium perfusion abnormality (16% vs 25%, odds ratio [OR] 0.58, 95% confidence intervals [CI] 0.49 to 0.69, p <0.001), reversible thallium abnormalities (7% vs 12%, OR 0.71, 95% CI 0.57 to 0.90, p <0.001), and extensive abnormalities (8% vs 14%, OR 0.53, 95% CI 0.42 to 0.67, p <0.001). After adjusting for possible confounders, the same trend was seen. During 6 years of follow-up there were 283 deaths with no association between exercise hypertension and mortality risk. Thus, exercise hypertension is associated with a lower likelihood of myocardial perfusion abnormalities and is not associated with an increased mortality rate. (C) 1999 by Excerpta Medica, Inc.