Postischemic blood flow response in hypercholesterolemic patients.
We undertook this cross-sectional study to compare the mechanical behavior and postischemic response of the radial artery of 15 newly diagnosed hypercholesterolemic patients with those of 15 age- and sex-matched normocholesterolemic control subjects and 21 hypercholesterolemic patients treated for 2 years with an 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (simvastatin, 10 to 20 mg/d). At the time of the study total cholesterol levels were at 7.9 +/- 0.2, 4.9 +/- 0.2, and 6.0 +/- 0.3 mmol/L in the three groups, respectively (mean +/- SEM, P < .001). High-resolution, noninvasive echotracking for assessment of internal arterial diameter was combined with measurements of blood flow velocity by Doppler and blood pressure by photoplethysmography. Radial cross-sectional compliance and distensibility were similar in all groups. Forearm blood flow and flow-mediated dilation were measured after a 5-minute upper arm occlusion. Flow was calculated from the vessel diameter and blood flow velocity recorded simultaneously at the same site. Flow-mediated dilation after ischemia was not significantly different among the three groups. However, forearm blood flow increase was markedly blunted (P < .01) in untreated hypercholesterolemic patients (211%) compared with the normocholesterolemic control subjects (411%) and treated patients (365%). These findings suggest that the distensibility of the radial artery, a muscular conduit vessel usually devoid of atherosclerotic lesions, and its flow-mediated dilation are preserved in hypercholesterolemic patients. In contrast, forearm resistance vessels exhibit a markedly reduced postischemic blood flow response that may be restored by prolonged lipid-lowering intervention.
Hayoz
D
D
Division d'Hypertension, CHUV, Lausanne, Switzerland.
Weber
R
R
Rutschmann
B
B
Darioli
R
R
Burnier
M
M
Waeber
B
B
Brunner
H R
HR
D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006937:Hypercholesterolemia / Q000188:drug therapy / Q000503:physiopathology*; D007511:Ischemia / Q000503:physiopathology*; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D017534:Radial Artery / Q000503:physiopathology*; D012039:Regional Blood Flow
D008055:Lipids