Exercise-Induced Coronary Artery Vasodilation Is Not Impaired by Stent Placement

Abstract

Background-Stenting has proved beneficial for treating threatened closure and reducing restenosis after balloon angioplasty. However, the implantation of a coronary metallic prosthesis has been related to impaired vasomotion distal to the stent as assessed by acetylcholine infusion. Thus, the purpose of the present study was to determine the vasomotion of stented coronary arteries and to assess its influence on the vasomotion of adjacent vessel segments during bicycle exercise. Methods and Results-Biplane quantitative coronary angiography was performed at rest and during bicycle exercise in 26 patients with coronary artery disease. Twelve patients had single vessel disease with stable angina pectoris (controls; group 1). Fourteen patients underwent coronary stenting for therapeutic reasons and were studied 10Ϯ3 months after the intervention (group 2). Minimal luminal area, stent area, and proximal and distal vessel areas were determined. In controls (group 1), vasoconstriction of the stenotic artery (Ϫ29Ϯ4%; PϽ0.001) was observed during exercise, whereas the normal segment showed vasodilation (15Ϯ4%; PϽ0.05). In group 2, vasomotion of the stented segment was eliminated (0Ϯ1%), whereas the proximal and distal segments showed exercise-induced vasodilation (8Ϯ2% and 11Ϯ3%, respectively; PϽ0.005), which was not different from control segments (10Ϯ2%). Sublingual nitroglycerin was associated with maximal vasodilation of the proximal and distal vessel segments (30Ϯ8% and 38Ϯ13%, respectively; PϽ0.005). Conclusions-In contrast to the vasoconstriction of vessels in control patients, normal vasodilation of proximal and distal segments occurred during the physiological stress of exercise in patients with coronary stent placement. As expected, vasomotion was abolished in the stented region.

Deleterious Effect of Coronary Brachytherapy on Vasomotor Response to Exercise

“…Gage et al 21 and Gordon et al 25 have shown vasoconstriction of stenotic but vasodilation of normal coronary vessel segments in response to exercise. Recently, we reported that stent implantation does not impair exercise-induced coronary artery vasodilation proximal and distal to the stented vessel, 17 as it was reported by Caramori et al 26 Sabate et al 19 have reported preserved endothelium-dependent vasodilation 6 months after brachytherapy, assessed by the vasomotor response to acetylcholine infusion. The contrary findings may be related to (1) the different techniques for measuring coronary vasomotor response (ie, pharmacological assessment of endothelial function by acetylcholine infusion versus flow-mediated changes induced by bicycle exercise) and (2) the different radiation dose (our brachytherapy group received 20 Gy, the brachytherapy group studied by Sabate et al, 19 14 Gy).…”

“…22 Stent implantation abolishes paradoxical vasoconstriction of coronary stenosis and renders a previous vasoresponsive vessel into a rigid tube. 17 A diminished vasomotor response to exercise has also been reported in patients with hypercholesterolemia, 23 hypertension, or left ventricular hypertrophy. 24 The mechanisms of abnormal coronary vasomotion is different in various disease entities, namely, endothelial dysfunction induced by hypercholesterolemia, media hypertrophy followed by endothelial dysfunction in hypertension, and increased oxygen demand with reduced vasodilatory capacity in patients with LV hypertrophy.…”

“…At our center, intraobserver variability is Յ0.15 mm for minimal luminal diameter and Յ7% for stenosis severity. 16,17 An independent observer blinded to the study protocol performed the measurements. The diameter of defined vessel segments was determined at baseline and at the various steps of the protocol.…”

Predictors of Sub-Acute Stent Thrombosis in Acute Myocardial Infarction Patients Following Primary Coronary Stenting With Bare Metal Stent

“…Coronary vasomotion has been found to be intact after stent implantation and long-term clinical and angiographic follow-up have attested to the durability of stents. 11,12 Although rare, SAT is associated with a high frequency of major adverse clinical consequences, including markedly increased rates of reinfarction, prolonged hospitalization, and increased costs. The reported incidence of SAT after elective stenting ranges from 0.4 to 3.2%, [13][14][15][16][17] and can be up to 6% in patients with acute coronary syndrome.…”

Magnetic resonance angiography of the human middle meningeal artery: Implications for migraine

“…Friberg et al (10) estimated that a mean 20% increase of the diameter of the middle cerebral artery using transcranial Doppler and administration of sublingual NTG resulted in a mean 30%% Ϯ 8% increase in the human coronary artery (11). The mean diameter of the MMA in healthy volunteers was 1.4 mm with an SD of 0.18 (pilot study).…”