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Assessment of coronary vasomotion by intracoronary ultrasound
P Dupouy1, H J Geschwind, G Pelle
1Unité d'hémodynamique, INSERM U2, University Hospital Henri Mondor, University of Paris, XII, France.
Insights
Intravascular ultrasound accurately assesses coronary artery vasomotion and endothelial function in atherosclerosis patients. This imaging technique reveals the relationship between arterial wall thickness and vasomotor responses.
Area of Science:
- Cardiovascular Imaging
- Vascular Biology
- Diagnostic Ultrasound
Background:
- Atherosclerosis is characterized by luminal irregularities and elevated cholesterol levels.
- Assessing coronary artery vasomotion and endothelial function is crucial for understanding atherosclerosis progression.
- Intravascular ultrasound (IVUS) offers high-resolution imaging of coronary arteries.
Purpose of the Study:
- To evaluate the accuracy of intravascular ultrasound (IVUS) in assessing coronary artery vasomotion and endothelial function.
- To investigate the relationship between intimal thickness and vasomotor response in patients with and without atherosclerosis.
- To compare endothelial function in patients with high cholesterol and luminal irregularities versus those with normal cholesterol and smooth arteries.
Main Methods:
- Twenty patients with atherosclerosis (high cholesterol, luminal irregularities) and six control patients were studied.
- Intravascular ultrasound (IVUS) was used to measure lumen area and calculate intimal thickness.
- Endothelial function was assessed using sympathetic stimulation (cold pressor test), intracoronary papaverine, and linsidomine administration.
Main Results:
- Patients with atherosclerosis exhibited significantly higher mean intimal thickness compared to controls (1.52 +/- 0.64 mm vs. 0.18 +/- 0.08 mm).
- Sympathetic stimulation induced vasoconstriction in the atherosclerosis group but vasodilation in controls.
- Intracoronary papaverine showed a trend towards vasoconstriction in the atherosclerosis group, while linsidomine induced vasodilation in both groups.
Conclusions:
- Intravascular ultrasound (IVUS) is a valuable tool for evaluating endothelial function in large coronary arteries.
- IVUS enables precise measurement of the relationship between arterial wall thickness and vasomotor response.
- Findings highlight impaired endothelial function and altered vasomotor responses in patients with atherosclerosis.
Abstract:
This study was performed to evaluate the accuracy of intravascular ultrasound for the assessment of coronary artery vasomotion and endothelial function in patients with atherosclerosis. Twenty patients with luminal irregularities on the coronary angiogram and a high cholesterol level (287 +/- 19 mg/dl) (group 1) and six patients with angiographically smooth arteries and a minimally elevated cholesterol level (197 +/- 12 mg/dl) (group 2) were studied. A mechanical intravascular ultrasound probe (4.3F) was placed into the proximal segment of the coronary artery. The ultrasound images were recorded on super VHS videotape and were then digitized allowing the measurement of the lumen area and then the calculation of a mean intimal thickness index. Endothelial function was studied during sympathetic stimulation by a cold pressor test and, after increasing coronary blood flow, by intracoronary papaverine administration; a 1 mg bolus of linsidomine was then administered into the coronary artery. Patients in group 1 had a higher mean intimal thickness (1.52 +/- 0.64 mm) than those in group 2 (0.18 +/- 0.08 mm) (p < 0.001). In response to sympathetic stimulation, a vasoconstricting effect occurred in group 1 (9.5 +/- 1.3 mm2 vs 11.4 +/- 1.2 mm2 at baseline, p < 0.05), while a vasodilating action was observed in the control group (11.6 +/- 2.1 mm2 vs 10.4 +/- 1.8 mm2 at baseline, p < 0.05). After papaverine infusion, a trend toward a vasoconstricting effect was observed in response to increased flow in group 1 (10 +/- 1.3 mm2 vs 11.4 +/- 1.2 mm2 at baseline, p < 0.05). that was not observed in group 2 (9.4 +/- 2 mm2 vs 8.9 +/- 1.9 mm2, p = NS). Linsidomine infusion induced a significant vasodilating effect in both groups (p < 0.001). In conclusion, intravascular ultrasound may be considered a useful tool to assess endothelial function of large coronary arteries and to obtain the precise relationship between wall thickness and the vasomotor response.