Vascular Dysfunction in Peripheral Arteries
Background: It is well established that endothelial dysfunction is present in patients with ischemic heart disease and hypercholesterolemia. Some of these patients will have signs of transient myocardial ischemia during Holter monitoring. We sought to describe the correlation between daily life ischemia and signs of endothelial dysfunction as assessed by means of brachial vasoreactivity.
Methods: We included in the study 131 patients with documented ischemic heart disease and a serum cholesterol level of ≥5 mmol/L before the institution of lipid-lowering treatment and dietary intervention.
Results: Satisfactory 48-hour Holter recordings and ultrasound scans of the brachial artery were obtained in 119 patients. During 5712 hours of ambulatory monitoring, 181 episodes of transient ST-segment depression with a mean duration of 52 ± 66 minutes were recorded in 31 patients. The mean percentage dilatation of the brachial artery after occlusion was 4.38% ± 5.66%; after nitroglycerin administration, it was 13.86% ± 7.06%. By means of Spearman correlation analysis, the number of ischemic episodes and degree of flow-mediated vasodilatation and nitroglycerin-mediated vasodilatation were significantly negatively correlated (r = -0.249, P = .006 and r = -0.302, P = .02, respectively). In a linear regression model, the presence of ischemic episodes was a significant predictor of impaired flow-mediated vasodilatation (
= -3.31, P < .01), even after the adjustment for vessel size and classic cardiovascular risk factors.
Conclusions: These results indicate a significant relationship between ischemic episodes and vascular dysfunction in patients with ischemic heart disease and hypercholesterolemia and may justify an aggressive preventive therapy targeted directly at the endothelium.
Endothelial dysfunction is a key early event in the atherosclerotic process and is strongly related to ischemic heart disease (IHD), showing itself as impaired flow-mediated dilatation (FMD) of the brachial artery or impaired response to intercoronary acetylcholine infusion. It seems that both the endothelial response and the degree of atherosclerosis in the peripheral and the coronary arteries correlate closely. Endothelial dysfunction may lead to unopposed constriction at coronary stenoses, which is of importance when myocardial ischemia is precipitated. Transient ischemic episodes during daily life can be assessed with ambulatory Holter recordings, and such episodes may be silent or symptomatic.
Hyperlipidemia is strongly related to endothelial dysfunction, because oxidized low-density lipoprotein (LDL) cholesterol seems to impair the dilating properties of the endothelium. It has been shown that cholesterol-lowering can significantly improve endothelium-mediated responses in the coronary arteries and resolve episodes of myocardial ischemia during daily life.
This study investigated whether there is any relation between signs of impaired FMD assessed by means of ultrasound scans of the brachial artery and transient ischemic episodes assessed by means of Holter recordings in a population of patients with documented IHD and hypercholesterolemia before any intervention with diet and lipid-lowering therapy.
Background: It is well established that endothelial dysfunction is present in patients with ischemic heart disease and hypercholesterolemia. Some of these patients will have signs of transient myocardial ischemia during Holter monitoring. We sought to describe the correlation between daily life ischemia and signs of endothelial dysfunction as assessed by means of brachial vasoreactivity.
Methods: We included in the study 131 patients with documented ischemic heart disease and a serum cholesterol level of ≥5 mmol/L before the institution of lipid-lowering treatment and dietary intervention.
Results: Satisfactory 48-hour Holter recordings and ultrasound scans of the brachial artery were obtained in 119 patients. During 5712 hours of ambulatory monitoring, 181 episodes of transient ST-segment depression with a mean duration of 52 ± 66 minutes were recorded in 31 patients. The mean percentage dilatation of the brachial artery after occlusion was 4.38% ± 5.66%; after nitroglycerin administration, it was 13.86% ± 7.06%. By means of Spearman correlation analysis, the number of ischemic episodes and degree of flow-mediated vasodilatation and nitroglycerin-mediated vasodilatation were significantly negatively correlated (r = -0.249, P = .006 and r = -0.302, P = .02, respectively). In a linear regression model, the presence of ischemic episodes was a significant predictor of impaired flow-mediated vasodilatation (
= -3.31, P < .01), even after the adjustment for vessel size and classic cardiovascular risk factors.
Conclusions: These results indicate a significant relationship between ischemic episodes and vascular dysfunction in patients with ischemic heart disease and hypercholesterolemia and may justify an aggressive preventive therapy targeted directly at the endothelium.
Endothelial dysfunction is a key early event in the atherosclerotic process and is strongly related to ischemic heart disease (IHD), showing itself as impaired flow-mediated dilatation (FMD) of the brachial artery or impaired response to intercoronary acetylcholine infusion. It seems that both the endothelial response and the degree of atherosclerosis in the peripheral and the coronary arteries correlate closely. Endothelial dysfunction may lead to unopposed constriction at coronary stenoses, which is of importance when myocardial ischemia is precipitated. Transient ischemic episodes during daily life can be assessed with ambulatory Holter recordings, and such episodes may be silent or symptomatic.
Hyperlipidemia is strongly related to endothelial dysfunction, because oxidized low-density lipoprotein (LDL) cholesterol seems to impair the dilating properties of the endothelium. It has been shown that cholesterol-lowering can significantly improve endothelium-mediated responses in the coronary arteries and resolve episodes of myocardial ischemia during daily life.
This study investigated whether there is any relation between signs of impaired FMD assessed by means of ultrasound scans of the brachial artery and transient ischemic episodes assessed by means of Holter recordings in a population of patients with documented IHD and hypercholesterolemia before any intervention with diet and lipid-lowering therapy.