Myocardial perfusion abnormalities in treated hypertensive patients without known coronary artery disease.

Abstract

Myocardial perfusion abnormalities may occur in hypertensive patients in absence of significant coronary artery disease. However, it is not well established whether hypertensive patients without known coronary artery disease have a higher prevalence or extent of myocardial perfusion abnormalities compared with normotensive patients with similar clinical features. This study compares the prevalence and extent of rest and stress-induced myocardial perfusion abnormalities in patients with and without hypertension. Dobutamine (up to 40 microg/kg per min) stress technetium-99m myocardial perfusion SPECT imaging was performed for evaluation of myocardial ischaemia in 350 patients (mean age = 60+/-13 years, 146 men) without known coronary artery disease. One hundred and forty-eight patients were hypertensive. Rest SPECT images were acquired 24 h after the test Abnormal perfusion was defined as the presence of reversible or fixed perfusion defects. No significant difference was detected between patients with and without hypertension regarding gender, prevalence of symptoms, risk factors, pretest probability of coronary artery disease (52+/-28 versus 53+/-29%), peak rate pressure product (21040+/-4755 versus 20774+/-4865) or number of patients achieving the target heart rate during stress (85 versus 86%). Hypertensive patients were significantly older (62+/-11 versus 58+/-13 years, P = 0.005) and were receiving beta-blockers more frequently (34 versus 18%, P = 0.0001). The prevalence of myocardial perfusion abnormalities was similar in patients with and without hypertension (28 versus 31% in patients with low, 38 versus 33% in patients with intermediate and 60 versus 58% in patients with high pretest probability of coronary artery disease, respectively). No significant difference was detected between the two groups regarding stress perfusion defect score (1.45+/-2.5 versus 1.50+/-2.6) or rest score (0.72+/-1.8 versus 0.68+/-1.6). Treated hypertensive patients without known coronary artery disease have a similar prevalence and severity of myocardial perfusion abnormalities at rest and at dobutamine stress compared with normotensive patients with similar clinical characteristics.