Postexercise systolic blood pressure response: Association with the presence and extent of perfusion abnormalities on thallium-201 scintigraphy

We sought to determine whether the 3-minute postexercise systolic blood pressure response (SBPR) would be an indicator of a greater extent of hypoperfusion on quantitative thallium-201 scintigraphy. Previous studies have suggested that the 3-minute postexercise SBPR, defined as the ratio of the systolic blood pressure measured 3 minutes after exercise to the systolic blood pressure at peak exercise, is an ischemic response to exercise that indicates both the presence and extent of coronary artery disease. We prospectively studied the myocardial perfusion imaging correlates of the 3-minute postexercise SBPR in 133 patients referred for symptom-limited exercise testing and quantitative thallium-201 scintigraphy. The mean 3-minute postexercise SBPR was 0.85 ± 0.14 in patients with normal scans compared to 0.91 ± 0.14 in patients with redistribution defects (p = 0.04) and 0.92 ± 0.17 in patients with persistent defects (p = 0.02). Patients with>3 abnormal scan segments had significantly higher 3-minute postexercise SBPR values compared to patients with ≤3 abnormal scan segments (p = 0.0005). Multiple linear regression evaluating the 3-minute postexercise SBPR, exercise-induced ST depression, and the level of exercise in metabolic equivalents indicated an association only between the 3-minute postexercise SBPR and the number of abnormal scan segments (p = 0.0004). An abnormal 3-minute postexercise SBPR is reflective of myocardial perfusion abnormalities, comprising regions of ischemia and scar. Higher values of the 3-minute post-exercise SBPR are associated with greater degrees of myocardial hypoperfusion.