Assessment of Coronary Flow Reserve by Adenosine Stress Myocardial Perfusion Imaging in Patients with Hypertension.

Abstract

In this study, our aim was to assess the coronary flow reserve (CFR) by performing the adenosine stress (99m)Tc-MIBI single-photon computed tomographic (SPECT) myocardial perfusion imaging in patients with hypertension. 47 hypertensive patients with normal coronary angiography were divided into 2 groups, defined by the presence (LVH, n=22) and absence (non-LVH, n=25) of left ventricular hypertrophy with 17 normal cases as controls. All patients were administered the adenosine stress-rest (99m)Tc-MIBI scintigraphy. 0.14mg/kg/min adenosine was administered by continuous infusion for 6min. We found that adenosine-induced myocardial ischemia was present in 26 cases (55.3%) with 87 segments (20.6%) showing abnormal distribution in the hypertensive group versus a single case (5.9%) (χ (2)=31.12, P<0.001) and segment (0.7%) (χ (2)=32.90, P<0.001) in the control group by SPECT perfusion. In the LVH group, 17 cases (77.3%) and 67 segments (33.8%) of myocardial ischemia were present. In the non-LVH group, there were 9 cases (36.0%) (χ (2)=8.06, P<0.001), 20 segments (8.9%) (χ (2)=40.13, P<0.001). There was a significant decrease in coronary reserve in the hypertensive groups following adenosine infusion with a fourfold decrease in cases and a sixfold decrease in segments (P<0.001). Our study suggests that assessing CFR by the (99m)Tc-MIBI adenosine stress by SPECT imaging is a relatively easy, safe, and non-invasive test in patients with hypertension. We noted a decrease in CFR in patients with hypertension. This decrease was especially remarkable for hypertensive patients with LVH. This study shows that administering the (99m)Tc-MIBI adenosine stress by SPECT imaging is a safe, simple, and non-invasive test for detecting CFR in patients with hypertension.