Impact of hypertension on the accuracy of exercise stress myocardial perfusion imaging for the diagnosis of coronary artery disease

Aim - To compare the accuracy of exercise stress myocardial perfusion singl e photon emission computed tomography (SPECT) imaging for the diagnosis of coronary artery disease in patients with and without hypertension. Methods - A symptom limited bicycle exercise stress test in conjunction wit h 99m technetium sestamibi or tetrofosmin SPECT imaging was performed in 33 2 patients (mean (SD) age, 57 (10) years; 257 men, 75 women) without previo us myocardial infarction who underwent coronary angiography. Of these, 137 (41%) had hypertension. Rest SPECT images were acquired 24 hours after the stress test. An abnormal scan was defined as one with reversible or fixed p erfusion defects. Results - In hypertensive patients, myocardial perfusion abnormalities were detected in 79 of 102 patients with significant coronary artery disease an d in nine of 35 patients without. In normotensive patients, myocardial perf usion abnormalities were detected in 104 of 138 patients with significant c oronary artery disease and in 16 of 57 patients without. There were no diff erences between normotensive and hypertensive patients in sensitivity (77% (95% confidence interval (CI) 69% to 86%) v 75% (95% CI 68% to 83%)), speci ficity (74% (95% CI 60% to 89%) v 72% (95% CI 60% to 84%)), and accuracy (7 7% (95% CI 70% to 84%) v 74% (95% CI 68% to 80%)) of exercise SPECT for dia gnosing coronary artery disease. The accuracy of SPECT was greater than ele ctrocardiography, both in hypertensive patients (p = 0.005) and in normoten sive patients (p = 0.0001). For the detection of coronary artery disease in individual vessels, sensitivity was 58% (95% CI 51% to 65%) v 57% (95% CI 51% to 64%), specificity was 86% (95% CI 82% to 90%) v 85% (95% CI 81% to 8 9%), and accuracy was 74% (95% CI 70% to 78%) v 74% (95% CI 70% to 78%) in patients with and without hypertension (NS). Conclusions - In the usual clinical setting, the value of exercise myocardi al perfusion scintigraghy for diagnosing coronary artery disease is not deg raded by the presence of hypertension.