F. Michas

Time rate of blood pressure variation is associated with impaired renal function in hypertensive patients

Objectives The rate of blood pressure (BP) variation has been positively associated with intima–media thickness of common carotid arteries and left ventricular mass. We evaluated the association between the rate of BP variation derived from ambulatory blood pressure monitoring (ABPM) data analysis and impaired renal function. Methods Twenty-four-hour ABPM was performed in 803 untreated hypertensive patients. The estimated glomerular filtration rate (eGFR) was assessed using the abbreviated equation of the Modification Diet for Renal Disease study. Patients were divided into two groups: those with an eGFR less than 60 ml/min per 1.73 m2 (group A) and those with an eGFR 60 ml/min per 1.73 m2 or more (group B). Results The 24-h rate of systolic BP variation was significantly (P = 0.004) higher in group A [0.616 mmHg/min; 95% confidence interval (CI) 0.596–0.636] than in group B patients (0.585 mmHg/min; 95% CI 0.578–0.591), even after adjusting for baseline characteristics and ABPM parameters. In the entire study population, the multiple logistic regression models revealed the following variables as independent determinants of impaired renal function: age, male sex, office systolic BP and 24-h rate of systolic BP variation. In this model, the odds ratio for impaired renal function associated with each 0.1 mmHg/min increase in 24-h rate of systolic BP variation was 1.49 (95% CI 1.18–1.88, P = 0.001). Conclusion The 24-h rate of SBP variation is independently associated with impaired renal function. Target-organ damage in hypertensive patients, in addition to BP levels, dipping status and BP variability, may also be related to a steeper rate of BP fluctuations.

Time rate of blood pressure variation: a new factor associated with coronary atherosclerosis.

Objectives Previous studies have demonstrated that the time rate of blood pressure (BP) variation was associated with early carotid atherosclerosis, independent of peripheral and central BP levels. We evaluated the association between the rate of BP variation, derived from ambulatory BP monitoring (ABPM) data analysis, and the severity and topography of coronary artery lesion in a cohort of normotensive patients with suspected coronary artery disease. Methods ABPM and coronary angiography were performed in 162 normotensive patients with suspected coronary artery disease. The topography and severity of coronary artery lesions were assessed by Gensini score. The time rate of BP variation was defined as the first derivative of the BP values against time. Results Patients with coronary artery disease (n = 123) presented significantly (P = 0.005) higher daytime rate of systolic BP variation than control patients (n = 39). Multiple linear regression models revealed independent determinants of Gensini score in the following rank order: diabetes mellitus (β: +0.286, P < 0.001), daytime rate of systolic BP variation (β: +0.277, P < 0.001), daytime systolic BP (β: +0.216, P = 0.002), smoking (β: +0.178, P = 0.008) and hypercholesterolemia (β: +0.158, P = 0.020). A 0.1 mmHg/min increase in the daytime rate of systolic BP variation correlated with an increment of 4.935 in the Gensini score (95% CI 2.432–7.438). Conclusion Steeper BP variations may produce a greater stress on the arterial wall and may have an additive role to vascular risk factors and BP parameters in the detection of the severity of coronary artery lesions in normotensive individuals with suspected coronary artery disease.

Baroreceptor reflex sensitivity is associated with arterial stiffness in a population of normotensive and hypertensive patients.

ObjectivesBaroreceptor reflex sensitivity (BRS) is an important factor in the homeostatic regulation of the cardiovascular system. Arterial stiffening also provides direct evidence of target organ damage in hypertensive patients. The aim of the present study was to evaluate a possible association between BRS and pulse wave velocity (PWV) in a population of normotensive and hypertensive patients. Patients and methodsA consecutive series of 160 patients underwent office blood pressure (BP) measurements, 24-h ambulatory BP monitoring, a 15-min electrocardiographic and noninvasive BP monitoring, and carotid–femoral PWV measurements. Power spectral analysis was carried out to calculate cardiac BRS, expressed as the alpha-index. The study population was divided into two groups according to the office BP values: patients with systolic and diastolic BP<140/90 mmHg were defined as normotensives, whereas patients with systolic BP≥140 mmHg and/or diastolic BP≥90 mmHg were defined as hypertensives. ResultsHypertensive patients (79%) had significantly higher PWV values (P=0.004) and a lower alpha-index (P<0.001) than the normotensive patients (21%). Multivariate linear regression analyses showed significant and independent associations of PWV with the following factors: age [0.510, 95% confidence interval (CI): 0.260–0.760; P<0.001], 24-h systolic BP (0.320, 95% CI: 0.120–0.520; P=0.002), and log(alpha-index) (−1.465, 95% CI: −2.686 to −0.244; P=0.019). A 1 ms/mmHg decrease in the log(alpha-index) correlated to an increment of 1.465 m/s (95% CI: 0.244–2.686) in the PWV of the study population. ConclusionIncreased arterial stiffness is significantly and independently associated with impaired BRS in normotensive and hypertensive patients.

Impact of prehypertension on carotid artery intima-media thickening: actual or masked?

BACKGROUND Recent studies have reported that prehypertension is associated with increased values of common carotid artery intima-media thickness (CCA-IMT). The aim of this study was to assess the impact of daytime ambulatory blood pressure (BP) levels on the association of prehypertension with CCA intima-media thickening in prehypertensive subjects. METHODS A total of 807 subjects with office systolic BP<140 and diastolic BP<90mmHg, underwent 24h ambulatory BP (ABP) monitoring and carotid artery ultrasonographic measurements. The study population was divided into 3 groups according to office and daytime ABP levels: (1) normotensives: subjects with office BP<120/80mmHg and daytime ambulatory BP values within the normal range, (2) actual prehypertensives: individuals with office SBP (120-139mmHg) and/or DBP (80-89mmHg) and daytime ambulatory BP values within the normal range and (3) prehypertensives with masked hypertension (MH): patients with office SBP (120-139mmHg) and/or DBP (80-89mmHg) and elevated daytime ambulatory BP values. RESULTS Prehypertensive patients with MH had higher (p<0.01) CCA-IMT values (0.712mm; 95%CI: 0.698-0.725) than actual prehypertensives (0.649mm; 95%CI: 0.641-0.656) and normotensives (0.655mm; 95%CI: 0.641-0.670) even after adjustment for baseline characteristics. Normotensives and actual prehypertensives did not differ significantly regarding CCA-IMT values (p>0.05). After adjusting for potential confounders, (including demographic characteristics, vascular risk factors, and office BP) prehypertension with MH was independently (p<0.01) associated with a 0.06mm increment in CCA-IMT (95%CI: 0.03-0.09). CONCLUSIONS Patients with office BP levels in the prehypertensive range, who also have elevated daytime ABP levels, had higher CCA-IMT values than patients with prehypertension with normal daytime ABP values and normotensive individuals.

Brain edema formation is associated with the time rate of blood pressure variation in acute stroke patients.

ObjectivesBoth brain edema and increased blood pressure (BP) variability are associated with poor outcome after stroke. The aim of the present study was to evaluate a possible association between edema formation and a relatively new index of BP variability defined as time rate (TR) of BP variation. Patients and methodsA total of 128 first-ever acute stroke patients underwent 24-h ambulatory BP monitoring within 24 h from onset of stroke. All patients were imaged with computed tomography scan on admission and after 5 days to determine the presence of brain edema. The TR of BP variation was defined as the first derivative of the BP values against time. Known risk factors and neurological severity on admission were documented. ResultsThe 24-h TR of systolic BP variation was significantly higher (P<0.001) in stroke patients with brain edema (0.69±0.15 mmHg/min) compared with those without edema (0.57±0.12 mmHg/min). The multivariate logistic regression model showed that a 0.1 mmHg/min increase in the TR of 24-h systolic BP variation was associated with a 13.9% increased probability of the presence of brain edema (odds ratio=1.139, 95% confidence interval: 1.058–1.225, P<0.001), after adjusting for history of diabetes mellitus, hypercholesterolemia, type of stroke, neurological deficit, and 24-h systolic BP. ConclusionIncreased values of 24-h TR of systolic BP variation are associated independently with formation of edema in acute stroke patients.

Short-term beat-to-beat but not ambulatory blood pressure variability is correlated to carotid intima-media thickness.

ObjectivesSeveral studies have shown that blood pressure (BP) variability derived from ambulatory blood pressure monitoring (ABPM) is associated with target organ damage development. However, the use of discontinuous ABPM to assess rapid BP changes is unavoidably limited by the long frequency at which automated measures are scheduled. The aim of our study was to identify whether ABPM-derived variability or short-term beat-to-beat BP variability is better associated with common carotid artery intima-media thickness (CCA-IMT) in untreated hypertensive patients. Participants and methodsA total of 85 individuals underwent 24-h ABPM and carotid artery ultrasonographic measurements. Three 5-min recordings of noninvasive beat-to-beat BP were made under standardized conditions. The time rate (TR) of BP variation was defined as the first derivative of the BP values against time. The study population was divided into normotensive and hypertensive participants according to 24-h BP values (130/80 mmHg). ResultsHypertensive patients (n=45) presented significantly higher TR of 24-h BP variation (P<0.05) and beat-to-beat TR of systolic BP variation (P<0.05) than their normotensive counterparts (n=40). The multivariate linear regression analyses in hypertensive patients showed significant and independent associations of CCA-IMT with the following factors: 24-h systolic blood pressure (SBP) (B=0.065, 95% confidence interval: 0.006–0.124; P=0.033) and TR of beat-to-beat SBP (B=0.013, 95% confidence interval: 0.005–0.020; P=0.002). A 10 mmHg/min increase in the TR beat-to-beat SBP variation correlated to an increase of 0.013 mm in the CCA-IMT values. ConclusionShort-term beat-to-beat TR of BP variation is associated independently with CCA-IMT values and presents a better predictor of target organ damage involvement than BP variability indexes derived from ABPM.

White-Coat Isolated Systolic Hypertension Is a Risk Factor for Carotid Atherosclerosis

The clinical importance of white‐coat hypertension (WCH) remains a controversial issue. The aim of this study was to evaluate the association of isolated systolic, isolated diastolic, and systolic/diastolic WCH with common carotid artery intima‐media thickness (CCA‐IMT) and to compare each subgroup of WCH against other blood pressure (BP) phenotypes in terms of CCA‐IMT values. A total of 1382 consecutive patients underwent 24‐hour ambulatory BP monitoring and carotid artery ultrasonographic measurements. According to the type of elevated office BP, WCH was divided into three groups: isolated systolic, isolated diastolic, and systolic/diastolic WCH. Patients with isolated systolic WCH (n=112) had significantly higher CCA‐IMT values (0.737 mm) than those with isolated diastolic WCH (n=66) (0.685 mm) and nonsignificantly greater compared with those with systolic/diastolic WCH (n=228) (0.708 mm). Patients with isolated systolic WCH had CCA‐IMT values similar to those with hypertension, patients with isolated diastolic WCH had similar values to those with normotension, and patients with systolic/diastolic WCH had an intermediate risk between normotension and hypertension.

The impact of nocturnal hypertension and nondipping status on left ventricular mass: a cohort study.

ObjectiveAmbulatory blood pressure monitoring provides a unique tool in the evaluation of night-time blood pressure (BP), having a critical role in the detection of a blunted nocturnal fall and of elevated night-time BP. Both nondipping status and nocturnal hypertension are associated with increased cardiovascular risk and target organ damage. The aim of our study was to investigate the impact of both nondipping status and nocturnal hypertension on left ventricular mass (LVM), assessed by means of echocardiography in a consecutive cohort of untreated participants. MethodsA total of 937 individuals were assessed by means of ambulatory blood pressure monitoring and echocardiography. Participants were divided into dippers and nondippers with or without systolic nocturnal hypertension (SNH). SNH was defined as night-time systolic blood pressure of 120 mmHg or more, and nondipping status was defined as an average reduction in systolic blood pressure at night less than 10% compared with the daytime BP. ResultsDippers and nondippers with SNH presented significantly higher values of left ventricular mass index compared with dippers and nondippers without SNH, respectively. Multiple regression analysis revealed that age (&bgr;=0.182, P<0.001), male gender (&bgr;=0.168, P<0.001), body mass index (&bgr;=0.080, P=0.011), and nocturnal SBP (&bgr;=0.174, P=0.037) were significant and independent determinants of LVM. Nondipping status was not found as an independent factor associated with LVM (P=0.136). ConclusionNocturnal hypertension rather than nondipping status seems to be an independent factor associated with left ventricular mass index. The concomitant presence of both nondipping status and nocturnal hypertension is associated with higher LVM, indicating an enhanced cardiovascular risk.

Differential associations of systolic and diastolic time rate of blood pressure variation with carotid atherosclerosis and plaque echogenicity

In the current study, the authors sought to assess whether the time rate of systolic and diastolic blood pressure variation is associated with advanced subclinical stages of carotid atherosclerosis and plaque echogenicity assessed by gray scale median. The authors recruited 237 consecutive patients with normotension and hypertension who underwent 24‐hour ambulatory blood pressure monitoring and carotid artery ultrasonography. There was an independent association between low 24‐hour systolic time rate and increased echogenicity of carotid plaques (adjusted odds ratio for highest vs lower tertiles of gray scale median, 0.470; 95% confidence interval, 0.245–0.902 [P = .023]). Moreover, increased nighttime diastolic time rate independently correlated with the presence (adjusted odds ratio, 1.328; P = .015) and number of carotid plaques (adjusted odds ratio, 1.410; P = .003). These results indicate differential associations of the systolic and diastolic components of time rate of blood pressure variation with the presence, extent, and composition of carotid plaques and suggest that when blood pressure variation is assessed, both components should be considered.

Association of Ambulatory Blood Pressure Monitoring parameters with the Framingham Stroke Risk Profile

The Framingham Stroke Risk Profile (FSRP) is a novel and reliable tool for estimating the 10-year probability for incident stroke in stroke-free individuals, while the predictive value of ambulatory blood pressure monitoring (ABPM) for first-ever and recurrent stroke has been well established. We sought to evaluate cross-sectionally the association of ABPM parameters with FSRP score in a large sample of 2343 consecutive stroke-free individuals (mean age: 56.0±12.9, 49.1% male) who underwent 24-hour ABPM. True hypertensives showed significantly higher FSRP (11.2±5.0) compared to the normotensives (8.2±5.0, p<0.001), while subjects with white coat hypertension also had higher FSRP (10.2±4.7) than normotensives (8.2±5.0, p<0.001). Compared to dippers that exhibited the lowest FSRP, non-dippers and reverse-dippers exhibited significantly higher FSRP (9.8±4.8 for dippers vs 10.6±5.2 and 11.5±5.0 for non-dippers and reverse-dippers respectively, p≤0.001 for comparisons). In univariate analyses, the ABPM parameters that had the strongest correlation with FSRP were 24-hour (r=0.440, p<0.001), daytime (r=0.435, p<0.001) and night-time (r=0.423; p<0.001) pulse pressure (PP). The best fitting model for predicting FSRP (R2=24.6%) on multiple linear regression analyses after adjustment for vascular risk factors not included in FSRP comprised the following parameters in descending order: 24-hour PP (β=0.349, p<0.001), daytime SBP variability (β=0.124, p<0.001), 24-hour HR variability (β=-0.091, p<0.001), mean 24-hour HR (β=-0.107, p<0.001), BMI (β=0.081, p<0.001) and dipping percentage (β=-0.063, p=0.001). 24-hour PP and daytime SBP variability are the two ABPM parameters that were more strongly associated with FSRP-score. Reverse dippers had the highest FSRP among all dipping status profiles.