N. Zakopoulos

U‐shaped relationship between mortality and admission blood pressure in patients with acute stroke

Objective.  To evaluate the relationship between systolic blood pressure (SBP) or diastolic blood pressure (DBP) on admission and early or late mortality in patients with acute stroke.

Impact of Obesity on 24-Hour Ambulatory Blood Pressure and Hypertension

The purpose of the present study was to determine the relationship between body mass index (BMI) and parameters derived from 24-hour ambulatory blood pressure monitoring including mean 24-hour daytime and nighttime systolic and diastolic blood pressures, 24-hour daytime and nighttime pulse pressure, mean 24-hour daytime and nighttime heart rate, dipping and nondipping status. 3216 outpatient subjects who visited our hypertension center and were never treated with antihypertensive medication underwent 24-hour blood pressure monitoring. BMI was significantly correlated with clinic systolic and diastolic blood pressures. Significant correlations were also found between BMI and mean 24-hour daytime and nighttime systolic blood pressure, 24-hour daytime and nighttime pulse pressure, and mean 24-hour daytime and nighttime heart rate. In multivariate regression analysis, clinic systolic, diastolic blood pressure, mean 24-hour systolic blood pressure, 24-hour pulse pressure, and high-density lipoprotein were independently correlated with BMI. The incidence of white coat hypertension was higher in overweight and obese patients than in normal weight subjects. Confirmed ambulatory blood pressure hypertension was also found to be higher in overweight and obese individuals compared with normal weight subjects. Our data also highlight the higher incidence of nondipping status in obesity. These findings suggest that obese patients had increased ambulatory blood pressure parameters and altered circadian blood pressure rhythm with increased prevalence of nondipping status.

Time Rate of Blood Pressure Variation Is Associated With Increased Common Carotid Artery Intima-Media Thickness

The extent of target-organ damage has been positively associated with the magnitude of blood pressure (BP) variability in essential hypertension. However, the clinical implications of the rate of BP changes have never been investigated. We evaluated the association between the rate of systolic BP (SBP) variation derived from ambulatory BP monitoring (ABPM) data analysis and the extent of common carotid artery (CCA) intima-media thickness (IMT) in normotensive (n=280) and in uncomplicated hypertensive subjects (n=234). The 24-hour rate of SBP variation was significantly (P<0.001) higher in hypertensive (0.608 mm Hg/min; 95% confidence interval [CI], 0.595 to 0.622) than in normotensive individuals (0.567 mm Hg/min; 95% CI, 0.555 to 0.578), even after adjusting for baseline characteristics, day–night BP changes, 24-hour heart rate (HR), SBP, and HR variability. In the entire group of patients, multiple linear regression models revealed independent determinants of CCA-IMT in the following rank order: age (P<0.001), 24-hour rate of SBP variation (P<0.001), male gender (P=0.004), cholesterol (P=0.009), and smoking (P=0.014). A 0.1 mm Hg/min increase in the 24-hour rate of SBP variation was associated to an increment of 0.029 mm (95% CI, 0.018 to 0.040) in CCA-IMT independent of BP and HR levels, BP and HR variability, and dipping status. The rate of SBP variation during the morning BP surge correlated independently (P<0.001) to larger CCA-IMT values after adjustment for baseline characteristics and other ABPM parameters. Thus, the rate of BP fluctuations is greater in hypertensive patients and correlates to increased CCA-IMT. This finding indicates that steeper BP variations may produce a greater stress on the vessel wall and consequently result in medial hypertrophy of the large arteries.

Target Organ Damage in “White Coat Hypertension” and “Masked Hypertension”

BACKGROUND In this study we investigated (i) the prevalence of white coat hypertension (WCH) and masked hypertension (MH) in patients who had never been treated earlier with antihypertensive medication, and (ii) the association of these conditions with target organ damage. METHODS A total of 1,535 consecutive patients underwent office blood pressure (BP) measurements, 24-h ambulatory BP monitoring (ABPM), echocardiography, and ultrasonography of the carotid arteries. Subjects who showed normotension or hypertension on the basis of both office and ambulatory BP (ABP) measurement were characterized as having confirmed normotension or confirmed hypertension, respectively. WCH was defined as office hypertension with ambulatory normotension, and MH as office normotension with ambulatory hypertension. RESULTS WCH was found in 17.9% and MH in 14.5% of the subjects. The prevalence of WCH was significantly higher in subjects with obesity, while the prevalence of MH was significantly higher in normal-weight subjects. The confirmed hypertensive subjects as well as the masked hypertensive subjects had significantly higher left ventricular mass (LVM) (corrected for body surface area) and carotid intima media thickness (cIMT) than the confirmed normotensive subjects did (108.9 +/- 30.6, 107.1 +/- 29.1 vs. 101.4 +/- 29.9 g/m(2) and 0.68 +/- 0.16, 0.68 +/- 0.21 vs. 0.63 +/- 0.15 mm, respectively, P < 0.005). White coat hypertensive subjects did not have a significantly higher LVM index than confirmed normotensive subjects (101.5 +/- 25.9 vs. 101.4 +/- 29.9 g/m(2)); they tended to have higher cIMT than the confirmed normotensive subjects, but the difference was not statistically significant (0.67 +/- 0.15 vs. 0.63 +/- 0.15 mm). CONCLUSIONS WCH and MH are common conditions in patients who visit hypertension outpatient clinics. Confirmed hypertension and MH are accompanied by increased LVM index and cIMT, even after adjusting for other risk factors.

Oral L-arginine improves endothelial dysfunction in patients with essential hypertension.

BACKGROUND L-Arginine is a nitric oxide precursor, which augments endothelium-dependent vasodilatation in hypercholesterolemic humans and animals. Endothelium-dependent vasodilation is attenuated in patients with hypertension; however the effects of oral L-arginine on endothelial function of the conduit arteries in patients with essential hypertension have not previously been investigated. METHODS In a prospective randomized double blind trial, 35 patients with essential hypertension received either 6 g L-arginine (18 subjects) or placebo (17 subjects). Patients were examined for flow-mediated endothelium-dependent dilatation of the brachial artery before and 1.5 h after administration of L-arginine or placebo. At the end of the protocol the nitrate-induced, endothelium-independent vasodilatation was evaluated. RESULTS Two groups of L-arginine and placebo were similar regarding age, sex, blood lipids, smoking, diabetes, coronary artery disease, body mass index, intima-media thickness of the common carotid artery, clinics blood pressure and baseline brachial artery parameters. Administration of L-arginine or placebo did not change significantly heart rate, blood pressure, baseline diameter, blood flow or reactive hyperemia. L-Arginine resulted in a significant improvement of flow-mediated dilatation (1.7+/-3.4 vs. 5.9+/-5.4%, P=0.008) while placebo did not significantly change this parameter (3.0+/-2.7 vs. 3.1+/-2.2%, P=ns). The effect of L-arginine on flow-mediated dilatation was significantly different from the effect of placebo (P=0.05). L-Arginine did not significantly influence nitrate-induced dilatation (16+/-6.9 vs. 17.7+/-6.7%, P=ns). CONCLUSIONS Oral administration of L-arginine acutely improves endothelium-dependent, flow-mediated dilatation of the brachial artery in patients with essential hypertension. The long-term effects of L-arginine in these patients require further investigation.

Impact of obesity in intima media thickness of carotid arteries

Objective: To explore differences in intima media thickness (IMT) of the carotid arteries induced by differences in BMI.

Factors influencing acute blood pressure values in stroke subtypes.

The aim of this prospective observational study was to determine the association of acute blood pressure values with independent factors (demographic, clinical characteristics, early complications) in stroke subgroups of different aetiology. We evaluated data of 346 first-ever acute (<24 h) stroke patients treated in our stroke unit. Casual and 24-h blood pressure (BP) values were measured. Stroke risk factors and stroke severity on admission were documented. Strokes were divided into subgroups of different aetiopathogenic mechanism. Patients were imaged with CT-scan on admission and 5 days later to determine the presence of brain oedema and haemorrhagic transformation. The relationship of different factors to 24-h BP values (24-h BP) was evaluated separately in each stroke subgroup. In large artery atherosclerotic stroke (n=59), history of hypertension and stroke severity correlated with higher 24-h BP respectively. In cardioembolic stroke (n=87), history of hypertension, stroke severity, haemorrhagic transformation and brain oedema were associated with higher 24-h BP, while heart failure with lower 24-h BP. History of hypertension and coronary artery disease was related to higher and lower 24-h BP, respectively, in lacunar stroke (n=75). In patients with infarct of undetermined (n=57) cause 24-h BP were mainly influenced by stroke severity and history of hypertension. An independent association between higher 24-h BP and history of hypertension and cerebral oedema was documented in intracerebral haemorrhage (n=68). In conclusion, different factors influence acute BP values in stroke subtypes of different aetiology. If the clinical significance of these observations is verified, a differentiated approach in acute BP management based on stroke aetiology may be considered.

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.

Common carotid arterial stiffness and the risk of ischaemic stroke

In the present case–control study we aimed to investigate the association of common carotid arterial (CCA) stiffness with ischaemic stroke (IS) and to determine whether this relationship was independent of conventional risk factors including CCA intima‐media thickness (CCA‐IMT). CCA distensibility, defined as the change of CCA‐diameter during the cardiac cycle, and CCA‐IMT were evaluated by means of high‐resolution B‐mode carotid ultrasound examination in consecutive, first‐ever IS patients (n = 193) and in age‐ and sex‐matched control subjects (n = 106). The CCA distensibility (inverse of CCA stiffness) was significantly (P = 0.007) lower in IS (0.353 mm, 95% CI: 0.326–0.379) than in control subjects (0.415 mm, 95% CI: 0.378–0.451) even after adjusting for blood pressure values, diastolic CCA‐diameter and height. The multivariate logistic regression procedure selected CCA‐IMT and CCA distensibility as the only independent predictor variables of IS. Each 1 SD increase in the CCA‐IMT and each 1 SD decrease in the CCA distensibility independently increased the likelihood of IS by 167.0% (OR: 2.67, 95% CI: 1.80–3.96, P < 0.001) and 59.0% (OR: 1.59, 95% CI: 1.22–2.07, P = 0.001) respectively. Increased CCA stiffness is associated with IS independent of conventional risk factors and CCA‐IMT. The causal interrelationship between the elastic properties of the CCA and the risk of stroke deserves further investigation by longitudinal studies.

Hypertension and hypothyroidism: results from an ambulatory blood pressure monitoring study.

Objective To examine differences between hypothyroid patients and healthy volunteers in 24-h ambulatory blood pressure parameters. Methods The study population consisted of 100 individuals who were recently diagnosed for hypothyroidism. These patients had never been treated before with antihypertensive treatment or received drugs for hypothyroidism. All participants underwent 24-h ambulatory blood pressure monitoring. The control group consisted of 100 healthy volunteers matched one to one for gender and age with the hypothyroid participants. Results Clinic systolic and diastolic blood pressures were significantly higher in patients with hypothyroidism compared with volunteers. The mean 24-h systolic blood pressure and 24-h pulse pressure were significantly higher in patients with hypothyroidism compared with volunteers. The 24-h systolic blood pressure variability was also significantly higher in patients with hypothyroidism. Fasting serum cholesterol tended to be higher in patients with hypothyroidism compared with volunteers but the difference was not statistically significant, while fasting serum triglycerides were significantly higher. Body mass index was also significantly higher in patients with hypothyroidism. Conclusions These findings indicate that hypothyroidism may be an important predictor of higher mean 24-h systolic blood pressure, 24-h pulse pressure and 24-h systolic blood pressure variability, parameters of ambulatory blood pressure monitoring that have been previously associated with higher cardiovascular target organ damage.