Stamatios F. Stamatelopoulos

Ankle-brachial index as a predictor of the extent of coronary atherosclerosis and cardiovascular events in patients with coronary artery disease

Resting ankle-brachial pressure index (ABI) is a noninvasive method to assess the patency of the lower extremity arterial system. This study aimed to examine the relation between ABI and the extent of coronary atherosclerosis, the extracoronary atherosclerosis lesions, and the prognosis of patients referred for elective coronary angiography. One hundred sixty-five consecutive patients underwent coronary angiography, ultrasound imaging for intima-media thickness measurement of carotid and femoral arteries and ABI evaluation; subjects were followed up for 14.5 +/- 2.4 months. With regard to vascular risk factors, only smoking (p = 0.025) and diabetes (p = 0.01) were related to ABI in the multiple regression analysis. ABI was independently and inversely related to carotid bifurcation (p = 0.0002) and common femoral artery intima-media thickness (p = 0.018). ABI was related to the extent of coronary artery disease as measured by number of coronary arteries diseased (analysis of variance, p = 0.04) and Gensini angiographic score (p = 0.01). In the follow-up study ABI < 0.90 was a univariate predictor of cardiovascular events (cardiac death, nonfatal myocardial infarction, unstable angina) and revascularization procedures. The estimated cumulative rate free of cardiovascular events was 90% for ABI > 0.90 and 73% for ABI < 0.90 (p = 0.02). In logistic regression analysis, ABI < 0.90 was an independent predictor for cardiovascular events after adjustment for age, low-density lipoprotein cholesterol, carotid and femoral intima-media thickness, and Gensini score. Further adjustment for the confounding effect of insulin weakened the relation between ABI and cardiovascular events (p = 0.1). In conclusion, ABI is a simple index related to the extent of atherosclerosis in coronary and noncoronary arterial beds, reflecting generalized atherosclerosis. ABI could be useful in assessing the risk for cardiovascular events in patients with coronary artery disease.

Atherosclerotic changes of extracoronary arteries are associated with the extent of coronary atherosclerosis.

The aim of the present study was to examine the association between carotid and femoral artery intima media thickness (IMT) and the extent and severity of coronary artery disease (CAD) as well as the effects of traditional vascular risk factors on the atherosclerotic changes in the carotid and femoral arteries. Two hundred twenty-four patients who underwent coronary angiography for suspected CAD were evaluated by B-mode ultrasound imaging of the common carotid, internal carotid, carotid bifurcation, and femoral artery for measurement of IMT; traditional vascular risk factors were also evaluated in these patients. CAD extent was evaluated by the number of diseased vessels and by Gensini score. Age, male gender, and diabetes were common risk factors for higher CAD extent and higher carotid and femoral IMT. Insulin levels were correlated with femoral IMT and CAD extent, whereas blood lipids were correlated predominantly with carotid IMT. IMT from carotid and femoral arteries increased significantly with an increase in CAD extent. Using multiple stepwise regression analysis, the following parameters were found to be independent predictors of CAD extent: male gender (p<0.0001), common femoral artery IMT (p = 0.0028), common carotid artery IMT (p = 0.015), age (p = 0.02), diabetes mellitus (p = 0.035), and carotid artery bulb IMT (p = 0.04). Common femoral IMT was the only independent parameter for predicting Gensini score (p<0.0001). In conclusion, there are territorial differences in the various arterial beds regarding their response to risk factors. Femoral artery and carotid bulb are independent predictors of CAD extent and the inclusion of these measurements would add information to that provided by the common carotid artery.

Impaired endothelium-dependent vasodilatation in women with previous gestational diabetes.

OBJECTIVE To assess whether otherwise healthy women with a history of gestational diabetes mellitus (GDM) may have abnormalities in endothelial function at a very early stage, before glucose intolerance occurs. RESEARCH DESIGN AND METHODS A total of 33 women with previous GDM (17 nonobese [BMI <27] and 16 obese [BMI ≥27]) and 19 healthy nonobese women were examined. A 75-g oral glucose tolerance test was performed, and insulin levels and biochemical parameters were also measured. Using high-resolution ultrasound, we measured vasodilatory responses of the brachial artery during reactive hyperemia (endothelium-dependent vasodilatation), and after nitroglycerin administration, an endothelium-independent vasodilator. RESULTS Flow-mediated dilatation (FMD) was significantly and equally decreased in both groups of women with previous GDM, compared with control subjects (1.6 ± 3.7% in the nonobese GDM group and 1.6 ± 2.5% in the obese GDM group vs. 10.3 ± 4.4% in control subjects, P <0.001). FMD correlated inversely with serum uric acid levels, BMI, serum total cholesterol, and basal insulin resistance (homeostasis model assessment). Nitrate-induced dilatation was significantly decreased only in the obeseGDM group compared with control subjects (21.4 ± 5.1 vs. 27.9 ± 9.5, P < 0.05). CONCLUSIONS Endothelial dysfunction, which is considered as a very early index of atherogenesis, is alreadypresent in both obese and nonobese women with a history of GDM, even when they have normal glucose tolerance.

Effects of acute cigarette smoking on endothelium-dependent arterial dilatation in normal subjects

The effects of acute cigarette smoking on endothelial function were evaluated in the brachial artery of 10 nonsmoking healthy subjects. Endothelial dysfunction observed after cigarette smoking is a phenomenon lasting at least 60 minutes and does not appear to be attenuated with repeat exposure.

Effect of Acute Cigarette Smoking on Endothelium-Dependent Brachial Artery Dilatation in Healthy Individuals

The effect of short-term smoking on endothelium-dependent and endothelium-independent dilatation of the brachial artery was tested in 27 healthy volunteers using high-resolution ultrasound imaging. Short-term smoking led to a significant decrease in endothelium-dependent dilatation.

Peripheral Vascular Endothelial Dysfunction in Patients With Angina Pectoris and Normal Coronary Arteriograms

OBJECTIVES We sought to determine endothelium-dependent vasodilator function in the brachial artery of patients with microvascular angina pectoris. BACKGROUND Previous studies suggest the presence of endothelial dysfunction of the coronary microcirculation in patients with microvascular angina pectoris. It is not known whether endothelial dysfunction in these patients is a generalized process or whether it is confined to the coronary microcirculation only. METHODS In 11 women (mean [+/-SD] age 60.1 +/- 7.8 years) with microvascular angina (anginal pain, normal epicardial coronary arteries, positive exercise stress test), endothelium-dependent vasodilation was assessed in the brachial artery by measuring the change in brachial artery diameter in response to hyperemic flow. Results were compared with 11 age- and gender-matched patients with known three-vessel coronary artery disease and 11 age- and gender-matched healthy control subjects. In all subjects, the intima-media thickness (IMT) of the common carotid artery was also measured. RESULTS Flow-mediated dilation (FMD) was comparable in patients with microvascular angina and coronary artery disease (1.9 +/- 2.5% vs. 3.3 +/- 3.3%, p = NS) but was significantly lower in patients with microvascular angina than in healthy control subjects (1.9 +/- 2.5% vs. 7.9 +/- 3%, p < 0.05). IMT was significantly lower in patients with microvascular angina than in those with coronary artery disease (0.64 +/- 0.08 vs. 1.0 +/- 0.28 mm, p < 0.05) and was comparable between patients with microvascular angina pectoris and healthy control subjects (0.64 +/- 0.08 vs. 0.56 +/- 0.14 mm, p = NS). IMT > or = 0.8 mm was observed in 1 of 11 patients with microvascular angina, 1 of 11 control subjects and 10 of 11 patients with coronary artery disease. CONCLUSIONS These findings suggest that endothelial dysfunction in microvascular angina is a generalized process that also involves the peripheral conduit arteries and is similar to that observed in atherosclerotic disease. IMT could be helpful in discriminating patients with microvascular angina and atherosclerotic coronary artery disease.

Short-term estrogen administration improves abnormal endothelial function in women with systemic sclerosis and Raynaud’s phenomenon

BACKGROUND Morphologic changes of the vascular endothelium are common in patients with systemic sclerosis and Raynauds phenomenon. The aim of this study was to evaluate the endothelium-dependent vasodilatation and endothelium-independent vasodilatation and to examine the effects of short-term estrogen administration on vascular responses in these patients. METHODS AND RESULTS The study included 12 female patients with systemic sclerosis and Raynauds phenomenon (aged 49+/-14 years) and 12 age- and sex-matched healthy control subjects. With the use of high-resolution ultrasound imaging, brachial artery diameter was measured at rest, during reactive hyperemia (endothelium-dependent response), and after administration of sublingual nitroglycerin (endothelium-independent dilatation). Intima-media thickness of the common carotid artery was also measured. Baseline diameter was similar in patients and control subjects; intima-media thickness was significantly higher in patients (0.83+/-0.3 vs 0.46+/-0.2 mm, P= .002) than in control subjects. Flow-mediated dilatation was reduced in patients (3.6%+/-7% vs 11.9%+/- 4.6%, P = .003); endothelium-independent dilatation also was reduced in patients with Raynauds phenomenon (14%+/-7% vs 23%+/-6%, P= .003). Vascular responses in 10 patients were examined 15 minutes after administration of conjugated estrogens (25 mg intravenously); there was a significant increase of endothelium-dependent dilatation after estrogen administration (1.7%+/-4% to 6.3%+/-4%, P= .01), whereas endothelium-independent dilatation did not change (13.4%+/-8% to 15.5%+/-7%, not significant). CONCLUSIONS Endothelium-dependent vasodilatation and endothelium-independent vasodilatation are impaired in patients with Raynauds phenomenon secondary to systemic sclerosis, whereas intima-media thickness is increased. Short-term estrogen administration can improve endothelial dysfunction in this group of patients.

Relation of Dispersion of QRS and QT in Patients With Advanced Congestive Heart Failure to Cardiac and Sudden Death Mortality

This study examined the usefulness of 01 and QRS dispersion in the prognosis of patients with advanced congestive heart failure (CHF). One hundred four patients in New York Heart Association functional classes II to IV, with a left ventricular ejection fraction of <35%, and untreated with antiarrhythmic drugs, were followed prospectively. QRS and QT dispersion were defined as the maximum difference in QRS and QT interval duration, respectively, measured on all leads of standard 12-lead electrocardiograms. The end points of the study were non-sudden and sudden cardiac mortality. During an average follow-up of 20 months, there were 13 non-sudden and 10 sudden deaths. The average QRS duration was significantly longer in nonsurvivors than in survivors (125 ¿ 34 vs 113 ¿ 34 ms, respectively, p <0.04). Similar results were obtained with 01 dispersion (95 ¿ 48 ms vs 78 ¿ 31 ms, respectively, p <0.03) and QRS dispersion (54 ¿ 17 ms vs 46 16 ms, respectively, p <0.02). Furthermore, patients who died suddenly had significantly greater QRS dispersion than patients who survived (56 ¿ 13 vs 46 ¿ 16 ms, respectively, p <0.02). In a multivariate analysis, QT and QRS dispersion were both independent predictors of non-sudden cardiac death (p = 0.01 and p = 0.001, respectively), and QRS dispersion was also an independent predictor of sudden cardiac death (p = 0.04). Death rate in patients with 01 dispersion >90 ms was 2.8-fold higher than those with 01 dispersion 90 ms (95% confidence intervals [CI] 1.2 to 6.4). Similarly, the death rate in patients with QRS dispersion >46 ms was 3.9-fold higher than in those with QRS dispersion 46 ms (95% Cl 1.6 to 9.5). These findings suggest that QT and QRS dispersion are useful predictors of mortality in patients with advanced CHF. ¿2000 by Excerpta Medica, Inc.

Endothelial dysfunction of conduit arteries in insulin-dependent diabetes mellitus without microalbuminuria

OBJECTIVE Previous studies have shown that endothelial dysfunction, an early sign of atherosclerosis, occurs in animal models of diabetes mellitus and in resistance vessels of patients with insulin-dependent diabetes. In the present study we examined whether young patients with insulin-dependent diabetes without microalbuminuria present abnormal endothelial function of large peripheral arteries. METHODS Twenty-six patients with insulin-dependent diabetes without microalbuminuria were compared with 26 normal controls and 5 patients with insulin-dependent diabetes with microalbuminuria. Brachial artery diameter was measured at rest, during reactive hyperaemic flow (endothelium-dependent dilatation) and after sublingual isosorbide dinitrate (endothelium-independent dilatation). RESULTS Baseline artery diameter and flow as well as the degree of reactive hyperaemia were similar in all groups compared to controls. Flow-mediated dilatation was lower in patients with diabetes without microalbuminuria (5.8 +/- 7 vs 11 +/- 7%. P = 0.01) as well as in patients with diabetes without microalbuminuria (0.75 +/- 2.5 vs 11 +/- 7%, P = 0.003); nitrate-induced dilatation was normal in patients without microalbuminuria and attenuated in patients with microalbuminuria. In the group of diabetes patients without microalbuminuria, those with disease duration > 10 years and HbAlc > 6% had the worse endothelial function. CONCLUSIONS Our results demonstrate that endothelial dysfunction of conduit arteries can be detected in patients with insulin-dependent diabetes mellitus without microalbuminuria, probably contributing to the high prevalence of atherosclerosis in these patients.

Reproducibility of ambulatory blood pressure measurements in essential hypertension.

Background Data on the reproducibility of serial measurements of ambulatory blood pressure in hypertensive patients are lacking. The purpose of this study was to examine (1) the reproducibility of four consecutive ambulatory blood pressure measurements, and (2) the reproducibility of nocturnal falls in blood pressure in hypertensive patients. Methods Twenty patients with mild to moderate essential hypertension underwent four separate ambulatory blood pressure monitorings, on the same day of the week, at 30‐day intervals. Antihypertensive therapy was discontinued for 2 weeks before each recording. Comparing the mean values of blood pressure over 24 h, as well as diurnal, nocturnal and hourly periods, among the four recordings determined the reproducibility of blood pressure measurements. A day/night difference in mean systolic and in mean diastolic blood pressure defined the nocturnal fall in blood pressure. Results No significant differences were observed in either hourly, 24‐h, diurnal or nocturnal systolic blood pressure, diastolic blood pressure and heart rate, or in the nocturnal fall in systolic and diastolic blood pressure among the four recordings. Conclusions Hourly systolic blood pressure, diastolic blood pressure, heart rate, and nocturnal fall in blood pressure were reproducible in four ambulatory blood pressure monitorings recorded over 4 months. These findings suggest that ambulatory blood pressure monitoring is a reliable tool to monitor blood pressure changes.