Cardiac hypertrophy in hypertension: relation to 24-h blood pressure profile and arterial stiffness

Baseline Framingham risk score does not predict future ECG-derived QRS duration over an average of 3.3 years

Background

Prolonged electrocardiogram (ECG) QRS duration has been associated with increased cardiovascular risk. It is unclear whether the main predictor of cardiovascular risk, the Framingham risk score also predicts short-term changes in ECG QRS duration. Our aim is to determine whether baseline Framingham risk score is associated with baseline or changes in QRS duration.

Methods

A retrospective cross-sectional analysis was performed using observational data obtained from two hundred two participants. Framingham risk score was calculated using an online risk calculator. QRS duration was obtained using a 10 s trace from a Welch Allyn PC-based 12-lead ECG system.

Results

Average follow-up duration was 3.3 ± 1.1 years. Mean QRS change was 1.8 ± 11.4 ms. Specifically, among two hundred two participants, there are 104 subjects with a greater QRS duration at follow-up, while 98 subjects had the same or a shorter follow-up QRS duration. Baseline Framingham risk score did not significantly predict an increase in QRSd with an odds ratio of 1.04 (P = 0.230). Regression analysis of QRS duration at baseline and Framingham risk at baseline had a weak association (R2 = 0.020; P = 0.043). The Framingham risk score at follow-up was likewise has a weak association with follow-up QRS duration (R2 = 0.045; P = 0.002).

Conclusions

Our results do not demonstrate a statistically significant association between Framingham risk parameters and future QRS duration changes over longitudinal time. QRS duration had variable changes between baseline and follow-up. This might suggest that a longer period of follow-up is required to document more stable increases in QRS duration associated with ventricular pathology. A larger population study is needed to confirm our observations.

Relation of blood pressure and organ damage: comparison between feasible, noninvasive central hemodynamic measures and conventional brachial measures

OBJECTIVE

The present cross-sectional study investigated whether central SBP and pulse pressure (PP) measured noninvasively with a novel cuff-based stand-alone monitor are more strongly associated with hypertensive end-organ damage than corresponding brachial measures.

METHODS

We investigated the cross-sectional association of central versus brachial SBP and PP with echocardiographic left ventricular mass index (LVMI), LV hypertrophy (LVH), carotid intima-media thickness (IMT), and increased IMT (IMT ≥ 75th percentile) among 246 participants drawn from the general population (mean age 57.2 years, 55.3% women).

RESULTS

All blood pressure (BP) measures were positively correlated with LVMI and IMT (P < 0.001 for all). Brachial and central SBP correlated equally strongly with LVMI (r = 0.42 versus 0.40, P for difference 0.19) and IMT (r = 0.32 versus 0.33, P = 0.60). However, brachial PP correlated more strongly than central PP with LVMI (r = 0.34 versus 0.27, P = 0.03) and IMT (r = 0.40 versus 0.35, P = 0.04). In multivariable-adjusted logistic models, all four BP measures were significantly associated with LVH and increased IMT (P ≤ 0.03 for all). However, the diagnostic accuracy of logistic regression models that included brachial or central hemodynamic parameters was similar for LVH [area under curve (AUC) for SBP: 0.74 versus 0.76, P = 0.16; AUC for PP: 0.75 versus 0.73, P = 0.35] and IMT (AUC for SBP: 0.61 versus 0.61, P = 0.67; AUC for PP: 0.63 versus 0.61, P = 0.29).

CONCLUSION

Our findings suggest that central SBP and PP measured with a stand-alone noninvasive BP monitor do not improve diagnostic accuracy for end-organ damage over corresponding brachial measures.

Arterial Stiffness in Patients With Renal Transplantation; Associations With Co-morbid Conditions, Evolution, and Prognostic Importance for Cardiovascular and Renal Outcomes

Patients with chronic kidney disease (CKD), particularly those with end-stage renal disease (ESRD), are at increased risk of cardiovascular events and mortality. The spectrum of arterial remodeling in CKD and ESRD includes atheromatosis of middle-sized conduit arteries and, most importantly, the process of arteriosclerosis, characterized by increased arterial stiffness of aorta and the large arteries. Longitudinal studies showed that arterial stiffness and abnormal wave reflections are independent cardiovascular risk factors in several populations, including patients with CKD and ESRD. Kidney transplantation is the treatment of choice for patients with ESRD, associated with improved survival and better quality of life in relation to hemodialysis or peritoneal dialysis. However, cardiovascular mortality in transplanted patients remains much higher than that in general population, a finding that is at least partly attributed to adverse lesions in the vascular tree of these patients, generated during the progression of CKD, which do not fully reverse after renal transplantation. This article attempts to provide an overview of the field of arterial stiffness in renal transplantation, discussing in detail available studies on the degree and the associations of arterial stiffness with other co-morbidities in renal transplant recipients, the prognostic significance of arterial stiffness for cardiovascular events, renal events and mortality in these individuals, as well as studies examining the changes in arterial stiffness following renal transplantation.

Relationships between blood pressure measurements and target organ damage: Data from the Korea women's chest pain registry

This study was performed to investigate the association between four BP measurements (systolic blood pressure [SBP], diastolic blood pressure [DBP], mean arterial pressure [MAP], and pulse pressure [PP]) and four TOD parameters (left ventricular mass index [LVMI], E/e', estimated glomerular filtration rate [eGFR], and obstructive coronary artery disease [CAD]). Data were obtained from a nation-wide registry, composed of 652 patients (471 women, 58.4 ± 10.5 years) with suspected CAD who underwent elective invasive coronary angiography (CAG). A total of 217 patients (33.2%) had obstructive CAD (≥50%). In multivariable analyses, E/e' was associated with SBP, MAP and PP, and CAD was associated with SBP and PP (P < 0.05 for each). All four BP measurements were not associated with LVMI and eGFR (P > 0.05 for each). In patients undergoing elective invasive CAG, SBP, and PP had stronger relationships with E/e' and CAD than DBP and MAP.

Central Blood Pressure Parameters Correlate with Cardiac Structure and Function in Healthy Chinese Individuals without Cardiovascular Disease

PURPOSE

To explore the relationship between central blood pressure (BP) parameters and cardiac structure and function parameters in healthy individuals.

METHODS

Four hundred Chinese participants with no overt cardiovascular disease participated in this study. One hundred and seventy-one participants (42.8%) were male and the mean age was 60 years. Central BP was measured with the SphygmoCor system. Cardiac structure and function were assessed by echocardiography.

RESULTS

We showed a significant association of left atrial volume and left ventricular mass index (LVMI) with brachial and central systolic BP (SBP) and pulse pressure (PP; r = 0.189-0.0.39, p < 0.001). Left ventricular diastolic function and the E/A ratio were significantly associated with brachial and central BP (r = 0.228-0.469, p < 0.001). Multivariate regression analysis revealed that central SBP and PP were independently correlated with LVMI after normalization for age and other confounding variables (sex, body mass index, smoking, and alcohol intake, and the levels of triglycerides, high-density lipoprotein, low-density lipoprotein, creatinine, uric acid, fasting blood glucose, log C-reactive protein, and fibrinogen. However, only central SBP was found to be independently correlated with the E/A ratio.

CONCLUSIONS

Cardiac structure and diastolic function were associated with brachial and central BP. However, after normalization, cardiac structure parameters were independently correlated with central SBP and PP. Diastolic function was the only cardiac function parameter that correlated with central SBP.

Contributions of aortic pulse wave velocity and backward wave pressure to variations in left ventricular mass are independent of each other

Aortic pulse wave velocity (PWV) and backward waves, as determined from wave separation analysis, predict cardiovascular events beyond brachial blood pressure. However, the extent to which these aortic hemodynamic variables contribute independent of each other is uncertain. In 749 randomly selected participants of African ancestry, we therefore assessed the extent to which relationships between aortic PWV or backward wave pressures (Pb) (and hence central aortic pulse pressure [PPc]) and left ventricular mass index (LVMI) occur independent of each other. Aortic PWV, PPc, forward wave pressure (Pf), and Pb were determined using radial applanation tonometry and SphygmoCor software and LVMI using echocardiography; 44.5% of participants had an increased left ventricular mass indexed to height^1.7. With adjustments for age, brachial systolic blood pressure or PP, and additional confounders, PPc and Pb, but not Pf, were independently related to LVMI and left ventricular hypertrophy (LVH) in both men and women. However, PWV was independently associated with LVMI in women (partial r = 0.16, P < .001), but not in men (partial r = 0.03), and PWV was independently associated with LVH in women (P < .05), but not in men (P = .07). With PWV and Pb included in the same multivariate regression models, PWV (partial r = 0.14, P < .005) and Pb (partial r = 0.10, P < .05) contributed to a similar extent to variations in LVMI in women. In addition, with PWV and Pb included in the same multivariate regression models, PWV (P < .05) and Pb (P < .02) contributed to LVH in women. In conclusion, aortic PWV and Pb (and hence pulse pressure) although both associated with LVMI and LVH produce effects which are independent of each other.

Association of Central Versus Brachial Blood Pressure With Target-Organ Damage: Systematic Review and Meta-Analysis

Accumulating evidence suggests that central blood pressure (BP) may reflect the hemodynamic stress on target organs more accurately than brachial BP. A systematic review assessing the relationship of central versus brachial BP with preclinical target-organ damage was performed. Meta-analysis of cross-sectional data showed that central compared with brachial systolic BP was more closely associated with (1) left ventricular mass index (12 studies, n=6431; weighted age [SD], 49.9 [13.1] years; 51% hypertensives): pooled correlation coefficients r=0.30; 95% confidence interval (CI), 0.23-0.37 versus r=0.26; 95% CI, 0.19-0.33, respectively; P<0.01 for difference; (2) carotid intima-media thickness (7 studies, n=6136; weighted age, 55.6 [13.2] years; 48% hypertensives): r=0.27; 95% CI, 0.19-0.34 versus r=0.23; 95% CI, 0.16-0.30, respectively; P<0.01 for difference; (3) pulse-wave velocity (14 studies, n=3699; weighted age, 53.9 [13.3] years; 53% hypertensives): r=0.42; 95% CI, 0.37-0.47 versus r=0.39; 95% CI, 0.33-0.45, respectively; P<0.01 for difference. Four studies assessing urine albumin excretion (n=3718; weighted age, 56.4 [5] years; 69% hypertensives) reported similar correlations (P=not significant) with central (r=0.22; 95% CI, 0.14-0.29) and brachial systolic BP (r=0.22; 95% CI, 0.12-0.32). Similar findings were observed for central compared with brachial pulse pressure in terms of relationship with target-organ damage. Metaregression analyses did not reveal any significant effect of age. In conclusion, central compared with brachial BP seems to be more strongly associated with most of the investigated indices of preclinical organ damage.

Association of left ventricular diastolic dysfunction with 24-h aortic ambulatory blood pressure: the SAFAR study

Aortic blood pressure (BP) and 24-h ambulatory BP are both better associated with target organ damage than office brachial BP. However, it remains unclear whether a combination of these two techniques would be the optimal methodology to evaluate patients' BP in terms of left ventricular diastolic dysfunction (LVDD) prevention. In 230 participants, office brachial and aortic BPs were measured by a validated BP monitor and a tonometry-based device, respectively. 24-h ambulatory brachial and aortic BPs were measured by a validated ambulatory BP monitor (Mobil-O-Graph, Germany). Systematic assessment of patients' LVDD was performed. After adjustment for age, gender, hypertension and antihypertensive treatment, septum and lateral E/Ea were significantly associated with office aortic systolic BP (SBP) and pulse pressure (PP) and 24-h brachial and aortic SBP and PP (P ⩽ 0.04), but not with office brachial BP (P ⩾ 0.09). Similarly, 1 standard deviation in SBP was significantly associated with 97.8 ± 20.9, 86.4 ± 22.9, 74.1 ± 23.3 and 51.3 ± 22.6 in septum E/Ea and 68.6 ± 2 0.1, 54.2 ± 21.9, 37.9 ± 22.4 and 23.1 ± 21.4 in lateral E/Ea, for office and 24-h aortic and brachial SBP, respectively. In qualitative analysis, except for office brachial BP, office aortic and 24-h brachial and aortic BPs were all significantly associated with LVDD (P ⩽ 0.03), with the highest odds ratio in 24-h aortic SBP. Furthermore, aortic BP, no matter in the office or 24-h ambulatory setting, showed the largest area under receiver operating characteristic curves (P ⩽ 0.02). In conclusion, 24-h aortic BP is superior to other BPs in the association with LVDD.

The dopamine D3 receptor knockout mouse mimics aging-related changes in autonomic function and cardiac fibrosis

Blood pressure increases with age, and dysfunction of the dopamine D3 receptor has been implicated in the pathogenesis of hypertension. To evaluate the role of the D3 receptor in aging-related hypertension, we assessed cardiac structure and function in differently aged (2 mo, 1 yr, 2 yr) wild type (WT) and young (2 mo) D3 receptor knockout mice (D3KO). In WT, systolic and diastolic blood pressures and rate-pressure product (RPP) significantly increased with age, while heart rate significantly decreased. Blood pressure values, heart rate and RPP of young D3KO were significantly elevated over age-matched WT, but similar to those of the 2 yr old WT. Echocardiography revealed that the functional measurements of ejection fraction and fractional shortening decreased significantly with age in WT and that they were significantly smaller in D3KO compared to young WT. Despite this functional change however, cardiac morphology remained similar between the age-matched WT and D3KO. Additional morphometric analyses confirmed an aging-related increase in left ventricle (LV) and myocyte cross-sectional areas in WT, but found no difference between age-matched young WT and D3KO. In contrast, interstitial fibrosis, which increased with age in WT, was significantly elevated in the D3KO over age-matched WT, and similar to 2 yr old WT. Western analyses of myocardial homogenates revealed significantly increased levels of pro- and mature collagen type I in young D3KO. Column zymography revealed that activities of myocardial MMP-2 and MMP-9 increased with age in WTs, but in D3KO, only MMP-9 activity was significantly increased over age-matched WTs. Our data provide evidence that the dopamine D3 receptor has a critical role in the emergence of aging-related cardiac fibrosis, remodeling, and dysfunction.

Arterial and retinal vascular changes in hypertensive and prehypertensive adolescents

INTRODUCTION

Increasing evidence suggests that arterial hypertension (AHT) may begin in childhood and result in the premature development of cardiovascular disease. In view of this, we believed it would be important to investigate the early vascular changes related to early hypertension at the micro- and macrovascular levels both under normal circumstances and after cold-induced sympathetic stimulation.

METHODS

In a cohort of 121 adolescent subjects, we measured peripheral and central blood pressure (pBP and cBP, respectively), pulse pressure (PP), and the augmentation index (AIx), as well as retinal vascular diameters, at baseline and during a cold pressor test (CPT). We measured the central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE) and calculated the retinal arteriolar-to-venular ratio (AVR). We compared macro- and microvascular alterations among normotensive (NT), prehypertensive (PHT), and hypertensive (HT) adolescents.

RESULTS

Of the adolescent subjects in the study, 54.5% were NT, 25.6% were PHT, and 19.8% were HT. With regard to BMI, central systolic BP (cSBP), aortic pulse pressure (AoPP), and CRAE, the PHT adolescents had values similar to those in the HT group but significantly different than those in the NT group. In the studied population, there was a positive and significant correlation of AIx with cSBP and a negative association of CRAE with both cSBP and peripheral SBP (pSBP). We describe the evolution of these parameters during and after sympathetic stimulation.

CONCLUSION

As compared with the prevalence of hypertension and prehypertension in large studies, involving teenagers and children, an alarming percentage (45.5%) of the adolescents in our study were HT or PHT. Higher pSBP and cSBP were associated with narrower retinal arterioles but not with changes of arterial elasticity. With particular regard to CRAE, the PHT group was more closely related to the HT group than to the NT group. There were no differences among the NT, PHT, and HT groups in the results of the CPT.

Blood pressure variables and prevalent electrocardiographic left ventricular hypertrophy in sub-Saharan African individuals with type 2 diabetes

BACKGROUND

The aim of the present study was to investigate whether brachial blood pressure (BP) variables (systolic BP [SBP], diastolic BP [DBP], pulse [PP] and mean arterial pressure [MAP]) are similar determinants of prevalent electrocardiographic left ventricular hypertrophy (LVH) in sub-Saharan Africans with type 2 diabetes (T2D).

METHODS

The study included 420 individuals (49% men) with T2D who were receiving chronic care in two main referral centers in the two major cities (Douala and Yaounde) of Cameroon. Logistic regression models were used to estimate the odds ratio (OR) and 95% confidence intervals (CI) for a standard deviation (SD) higher level of SBP (25 mmHg), DBP (13), PP (18) and MAP (20) with the risk of LVH. Discrimination was assessed and compared with c-statistics and relative integrated discrimination improvement (RIDI; %).

RESULTS

The multivariable adjusted OR (95% CI) for prevalent LVH with each SD higher pressure variable was 1.61 (1.22-2.11) for SBP, 1.27 (0.99-1.63) for DBP, 1.62 (1.23-2.15) for PP and 1.44 (1.11-1.87) for MAP. Comparison of c-statistics revealed no difference in the discrimination power of models with each of the BP variables (P > 0.09). However, RIDI showed enhanced discrimination in the models when other BP variables were replaced with PP. However, this enhancement was marginal for SBP. Using BP combinations modestly improved discrimination.

CONCLUSIONS

The best predictors of prevalent LVH in the present study population were PP and SBP, whereas DBP was the least effective predictor. These findings have implications for cardiovascular risk stratification and monitoring of risk-reducing therapies.

Relations of central and brachial blood pressure to left ventricular hypertrophy and geometry: the Strong Heart Study

OBJECTIVE

We previously demonstrated stronger relations of central vs. brachial blood pressure, particularly pulse pressure, to carotid artery hypertrophy and extent of atherosclerosis. Data regarding the relative impacts of central and brachial pressures on left ventricular hypertrophy and geometry are limited.

METHODS

Echocardiography and radial applanation tonometry were performed in American Indian participants in the 4th Strong Heart Study examination. Left ventricular mass was calculated using an anatomically validated formula and adjusted for height. Brachial blood pressure was measured according to a standardized protocol. Central pressures were derived using a generalized transfer function.

RESULTS

Of 2585 participants in the analysis, 60% were women, 21% had diabetes and 33% were hypertensive; the mean age was 40 +/- 17 years. All blood pressure variables were significantly related to left ventricular absolute and relative wall thicknesses and left ventricular mass index (all P < 0.001), with considerable variation in correlation coefficients (r = 0.135-0.432). Central and brachial systolic pressures were uniformly more strongly related to left ventricular wall thicknesses, diastolic diameter and mass index than their respective pulse pressures (all P < 0.005 by z statistics). Left ventricular relative wall thickness and mass index were more strongly related to central than brachial pressures.

CONCLUSION

Left ventricular hypertrophy is more strongly related to systolic pressure than to pulse pressure. Furthermore central pressures are more strongly related than brachial pressures to concentric left ventricular geometry. These data suggest that absolute (systolic) pressure is more important in stimulating left ventricular hypertrophy and remodeling, whereas pulsatile stress (pulse pressure) is more important in causing vascular hypertrophy and atherosclerosis.

Jugular venous pooling during lowering of the head affects blood pressure of the anesthetized giraffe

How blood flow and pressure to the giraffe's brain are regulated when drinking remains debated. We measured simultaneous blood flow, pressure, and cross-sectional area in the carotid artery and jugular vein of five anesthetized and spontaneously breathing giraffes. The giraffes were suspended in the upright position so that we could lower the head. In the upright position, mean arterial pressure (MAP) was 193 ± 11 mmHg (mean ± SE), carotid flow was 0.7 ± 0.2 l/min, and carotid cross-sectional area was 0.85 ± 0.04 cm2. Central venous pressure (CVP) was 4 ± 2 mmHg, jugular flow was 0.7 ± 0.2 l/min, and jugular cross-sectional area was 0.14 ± 0.04 cm2 ( n = 4). Carotid arterial and jugular venous pressures at head level were 118 ± 9 and −7 ± 4 mmHg, respectively. When the head was lowered, MAP decreased to 131 ± 13 mmHg, while carotid cross-sectional area and flow remained unchanged. Cardiac output was reduced by 30%, CVP decreased to −1 ± 2 mmHg ( P < 0.01), and jugular flow ceased as the jugular cross-sectional area increased to 3.2 ± 0.6 cm2 ( P < 0.01), corresponding to accumulation of ∼1.2 l of blood in the veins. When the head was raised, the jugular veins collapsed and blood was returned to the central circulation, and CVP and cardiac output were restored. The results demonstrate that in the upright-positioned, anesthetized giraffe cerebral blood flow is governed by arterial pressure without support of a siphon mechanism and that when the head is lowered, blood accumulates in the vein, affecting MAP.

The influence of wave reflection on left ventricular hypertrophy in hypertensive patients is modified by age and gender

It has been established that a positive association exists between the augmentation index (AIx) and left ventricular mass (LVM) in hypertensives, but it remains unclear whether this association is affected by age or gender. The aim of the study was to assess the effect of age and gender on the association between carotid AIx and LVM in hypertensive patients. We performed arterial tonometry and echocardiography in 512 treated hypertensive patients who were divided into 4 groups by gender and age (older or younger than 65 years). Correlations between carotid AIx and echocardiographic indices were evaluated by univariable and multivariable models. In females, carotid AIx increased with age up to 60 years, but decreased thereafter. In univariable analyses, carotid AIx was positively correlated with the LVM index in younger females (r=0.25, p=0.04) and males (r=0.48, p<0.001), but not in the older age groups. Multivariable analyses showed that this positive correlation in younger males remained significant (beta=0.39, p<0.001) after adjusting for age, body mass index, and mean arterial pressure. In contrast, in the older subjects, carotid AIx was negatively correlated with relative wall thickness in females (beta= -0.14, p=0.034) and males (beta= -0.17, p=0.037) independent of age and mean arterial pressure. A significant association between carotid AIx and LVM index was seen only in younger males. The lack of any such association in older hypertensives can be explained by both the plateau in the values of carotid AIx, and the fact that LVM increased with age.

A mitochondrial mutation A4401G is involved in the pathogenesis of left ventricular hypertrophy in Chinese hypertensives

The left ventricular hypertrophy (LVH) is one of the most important organ damage targets in hypertension. Despite the involvement of multiple factors, the genetic factors have been shown to have an important function in the pathogenesis of LVH. The aim of our study was to evaluate the role of mitochondria in LVH for Chinese hypertensives. A systematic and extended mutational screening for the mitochondrial genome has been initiated in a large cohort of Chinese population by the Geriatric Cardiology Clinic at the Chinese PLA General Hospital, Beijing, China. Specific mutations within the mitochondria were further evaluated. Changes of total RNAs (tRNAs) were measured by northern blotting using nonradioactive digoxigenin (DIG)-labeled oligodeoxynucleotides specific for each RNA. Rates of oxygen consumption in intact cells were determined with av YSI 5300 oxygraph. Sequence analysis of mitochondrial DNA in one Chinese pedigree identified a novel A-G transition at position 4401 (A4401G) at the junction of tRNA(Met) and tRNA(Gln). The noncoding region mutation appeared to affect the processing of precursors in these mitochondrial tRNAs. The reduction in the rate of respiration and marked decreases in the steady-state levels of tRNA(Met) and tRNA(Gln) were detected in the cells carrying this mutation. The novel mutation was absent in 270 Chinese control patients. In conclusion, the noncoding mitochondrial sequence alteration (A4401G) alters mitochondrial function, implicating this mutation in the pathogenesis of LVH in Chinese hypertensives.

Central blood pressure measurement may improve risk stratification

Central systolic blood pressure (SBP) may differ between individuals with similar brachial SBP, which may have implications for risk assessment. This study aimed to determine the variation and potential clinical value of central SBP between patients with similar brachial SBP. Brachial SBP was measured by sphygmomanometer and central SBP by radial tonometry in 675 people (430 men), comprising healthy individuals (n = 222), patients with known or suspected coronary artery disease (n = 229) and diabetes (n = 224). Individuals were stratified by brachial SBP in accordance with European Society of Hypertension guidelines (optimal, normal, high-normal, grades 1, 2 and 3 hypertension). The potential clinical value of central SBP was determined from the percentage of patients re-classified into different brachial SBP groups due to the difference between brachial and aortic SBP (defined as brachial SBP-central SBP). Central SBP increased with each brachial SBP level (optimal to grade 3 hypertension; P < 0.001 for all). However, large variation in brachial-aortic SBP difference occurred within each brachial SBP group (range 2-33 mm Hg), resulting in sizeable overlap of central SBP between brachial SBP groups. For patients with normal brachial SBP, 96% had central SBP within the range of patients with high-normal brachial SBP, as well as 64% within the range of patients with grade 1 hypertension. We conclude that wide variation in brachial-aortic SBP difference occurs between patients with similar brachial SBP. This results in a significant overlap of central SBP scores between brachial SBP risk groups. This is likely to have treatment implications but remains to be tested.

Different role of wave reflection magnitude and timing on left ventricular mass reduction during antihypertensive treatment

OBJECTIVE

Regression of left ventricular (LV) mass during antihypertensive treatment has been associated with reduction in aortic augmentation index, a composite measure of peripheral wave reflection. The aim of this study was to clarify which of the two reflection factors, that is magnitude or timing, plays the dominant role in this regression.

METHODS

We evaluated the reflection magnitude (RM; the reflected-to-forward pressure wave amplitude ratio), the round-trip travel time of the pressure wave (a parameter for reflection timing), and the aortic pulse wave velocity (PWV) with echocardiographic LV mass in 61 hypertensive patients before and after 1-year standard medical treatment.

RESULTS

Antihypertensive therapy significantly (P < 0.01) decreased brachial and aortic blood pressures and aortic PWV, reduced LV mass, and increased travel time. Neither increase in travel time nor decrease in PWV, however, was related to the reduction in LV mass. By contrast, treatment-induced change in RM was significantly correlated with change in LV mass; the correlation was particularly close in patients with LV hypertrophy (r = 0.61, P < 0.001). Only a marginal correlation was observed between the changes in RM and travel time. The association between RM decrease and LV mass reduction was independent of age, sex, changes in travel time and blood pressure, and use of renin-angiotensin system inhibitors (beta = 0.41, P = 0.001).

CONCLUSION

Decreased wave RM contributes to LV mass regression more strongly than, and independently of, delayed reflection timing. Peripheral muscular arteries (from which reflection arises) appear to be more important therapeutic targets in regressing LV mass than central elastic arteries.

Acute combined effects of olive oil and wine on pressure wave reflections: another beneficial influence of the Mediterranean diet antioxidants?

OBJECTIVES

Combined consumption of olive oil and wine is common in the Mediterranean diet, but there are no data concerning their synergistic haemodynamic response. We sought to determine the combined postprandial effects of wine and olive oil on wave reflections and central haemodynamics.

METHODS

Fifteen healthy subjects consumed four standard meals on different days, containing 50 g of olive oil and 250 ml of wine, in a randomized cross-over study design. Two types of wine [red (R) and white (W)] and two types of olive oil [green (G) and refined (O) (rich and poor in antioxidants, respectively)] were used in all possible combinations (RO, RG, WO and WG). Applanation tonometry and aortic pulse wave analysis were performed when fasting and 1, 2 and 3 h postprandially. A second group of 15 healthy individuals matched for age, gender and body mass index served as the control group.

RESULTS

All meals decreased AIx (RO and RG, P < 0.001; WO, P = 0.007; and WG, P = 0.039). The AIx reduction after RG, RO, WO and WG was significantly different from the respective AIx response of the control group. No difference was observed in the reduction of AIx between sessions, but a significantly earlier peak decrease in AIx, as well as a more prolonged decreasing effect, was observed after RG and RO consumption compared to WO and WG. Central systolic and diastolic pressures were diminished after all four combinations of wine and olive oil (P < 0.05).

CONCLUSIONS

Combined consumption of wine and olive oil provided beneficial postprandial effects on haemodynamics. These findings reveal an additional favourable effect of components of the Mediterranean diet on haemodynamics in the postprandial state.

Association between wasted pressure effort and left ventricular hypertrophy in hypertension: influence of arterial wave reflection

BACKGROUND

Wave reflection during the systole increases left ventricular (LV) pressure, tension-time index (TTI) and myocardial oxygen requirement. The purpose of this study was to extract that component of extra myocardial oxygen requirement that is due to early systolic wave reflection, define it as wasted effort (DeltaE(w)), and examine its relationship to LV hypertrophy (LVH).

METHODS

Radial artery pressure waveforms were recorded using applanation tonometry and central aortic waveforms generated in 98 patients with untreated hypertension. Aortic augmentation index (AI(a)), wave reflection amplitude (i.e., aortic augmented pressure (AG)) and systolic duration (ED-Tr), ejection duration (ED) and round-trip travel time of the pressure wave (Tr) were calculated from the aortic waveform, and DeltaE(w) estimated as 2.09 AG (ED-Tr). Carotid-femoral pulse wave velocity (PWV(e)) was also measured and LV mass index (LVMI) determined by echocardiography.

RESULTS

DeltaE(w) was significantly correlated with age, body height, and LVMI. Women had greater DeltaE(w) than men. The correlation between DeltaE(w) and LVMI was independent of age, gender and body height (P = 0.003). Patients with LVH (LVH (+) group) showed greater DeltaE(w) than patients without LVH (LVH (-) group) (P = 0.003), and this difference remained significant when adjusted for confounding factors. Also, AI(a) and AG were higher in the LVH (+) than in the LVH (-) group (both P < 0.01). In contrast, PWV(e) was not different between the groups, and Tr showed only a marginal difference (P = 0.07).

CONCLUSIONS

DeltaE(w) appears to be directly and positively associated with LVH in untreated hypertensive patients. The amplitude and duration of the reflected wave, rather than its travel time, are probably responsible for this association.

Association of premature ventricular complexes with central aortic pressure indices and pulse wave velocity

BACKGROUND

Although premature ventricular complex (PVC) occurs frequently, its predisposing factors have rarely been studied. We examined the connection between PVC and aortic stiffness.

METHODS

We recruited 200 consecutive patients (< 50 years, 95 men, mean age 36 +/- 10 years) who received a 24-hour ambulatory electrocardiography examination for palpitation and PVC loads. Muscular artery pulse wave velocity (PWVm) and 4 main aortic pressure indices-augmented pressure, augmentation index (AI(x)), AI(x) corrected for a steady heart rate of 75 beat/min, and the extra workload-were measured, and atherosclerosis risk was evaluated.

RESULTS

Eighty-three (42%) patients had no PVC loads; 58 (29%) patients had low loads (< 24 beat/d), and 59 (29%) had high loads (> or = 24 beat/d). Only age and hyperlipidemia were significantly associated with PVC loads. Using a multivariate logistic regression model adjusted for potential confounders, we found that AI(x) (odds ratio [OR] 1.88, 95% CI 1.20-2.91, P = .005); augmented pressure (OR 1.57, 95% CI 1.02-2.43, P = .042); AI(x) corrected for a steady heart rate of 75 beat/min (OR 1.82, 95% CI 1.18-2.82, P = .007); and PWVm (OR 1.53, 95% CI 1.07-2.19, P = .021) were independent factors for PVC loads.

CONCLUSION

Increased central aortic pressure indices as well as PWVm were associated with increased PVC loads in young patients undergoing 24-hour ambulatory electrocardiography. Central aortic properties probably contributed to the occurrence of PVC.

Direct monitoring pressure overload predicts cardiac hypertrophy in mice

Pressure overload (POL) is a classical model for studying cardiac hypertrophy, but there has been no direct measure of hemodynamics in a conscious ambulatory mouse model of POL. We used abdominal aortic constriction to produce POL and radiotelemetry to measure the blood pressure and heart rate for three weeks. The cardiac size correlated with the systolic pressure in the last week is better than other hemodynamic parameters. Cardiac fibrosis was more correlated to the cardiac size than to the systolic pressure. The expression of the cardiac genes that are typically associated with cardiac hypertrophy was correlated with both cardiac size and systolic pressure. In conclusion, the systolic pressure is the major determinant of cardiac hypertrophy in the murine POL model. In contrast, cardiac fibrosis shows the influence of other factors besides systolic pressure. The combination of the POL model with continuous direct measurements of hemodynamics represents a significant technological advance and will lead to an extended usefulness of POL methodologically.

Effects of angiotensin-converting enzyme gene polymorphism and serum vitamin D levels on ambulatory blood pressure measurement and left ventricular mass in Turkish hypertensive population

INTRODUCTION

Regulation of angiotensin converting enzyme (ACE) and angiotensin II (ang-II) levels is under genetic control. 1,25(OH)2 vitamin D3 treatment has been shown to reduce the ang-II level, reduce myocardial hypertrophy and to decrease blood pressure. This study was designed to examine the effect of ACE gene polymorphisms on 24-h ambulatory blood pressure measurement (24 h) values, vitamin D levels and target organ damage in hypertensive patients.

METHODS

This study was carried on 118 patients with essential hypertension (female/male: 70/48, mean age: 49.1+/-7.6 years, hypertension duration: 56+/-40.5 months). All patients were assessed for target organ damage; the eye by retinal examination, the heart with echocardiography and the kidney with blood and 24-h urine analysis. 24-h ambulatory blood pressure measurement was performed in all patients. PCR amplification was employed to detect ACE genotypes.

RESULTS

ACE genotypes were as follows: DD (n=49) 41.5%; ID (n=37) 31.4% and II (n=32) 27.1%. No difference was present between groups of ACE polymorphism when 24-h ambulatory blood pressure measurement values, retinal vascular changes and microalbuminuria were taken into account. Statistically significant left ventricular mass index levels were obtained in the DD group when compared with the non-DD (ID+II) group (P : 0.009). Positive correlations have been noted between left ventricular mass index and day/night and early morning systolic pressures. A negative correlation exists between serum 25 (OH) vitamin D levels and 24-h ambulatory blood pressure measurement values (P<0.05).

CONCLUSIONS

The presence of the D allele is linked with a higher risk for left ventricular mass index in the Turkish hypertensive population.

Arterial haemodynamics on ventricular hypertrophy in rats with simulated aortic stiffness

Aortic stiffness (AS) exerts significant impact on the cardiovascular risks. We developed a new model to produce AS. The purposes were to evaluate the haemodynamic consequence and to correlate the haemodynamic parameters with the extent of ventricular hypertrophy (VH). We applied silicon gel for embedding of the abdominal and/or thoracic aorta. After 1-4 weeks of AS, the left ventricular weight (LVW), LVW to body weight (BW) ratio (LVW/BW), and the morphological changes in cardiomyotes were quantified for VH. We determined the aortic pressure (AP), stroke volume, cardiac output, total peripheral resistance (TPR), characteristic impedance (Zc), pulse wave reflection (P(b)) and pulse wave velocity (PWV). Aortic embedding (AE) increased LVW, LVW/BW, systolic and pulse pressure (PP), Zc, P(b) and PWV accompanied by decreases in diastolic pressure and arterial compliance. The magnitude of these haemodynamic and cardiac changes were in an order of combined, thoracic and abdominal AE. Correlation analysis revealed that the VH was well correlated with pulsatile haemodynamics such as Zc, PP, P(b) and PWV, while less with steady components (Mean AP and TPR). Our results indicate that pulsatile haemodynamic parameters are significantly elevated after AS. The alterations in pulsatile haemodynamics are the major causes leading to VH.

Statins: a perspective for left ventricular hypertrophy treatment

Left ventricular hypertrophy (LVH), despite its adaptive nature, is associated with an increased risk of cardiovascular morbidity and mortality. Achievement of LVH regression is thus considered a principal therapeutic aim. However, regression of LVH induced by various therapeutic means may exhibit differing patterns, with variable biological implications. Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase (statins) have been shown to induce prevention or regression of LVH in different models of pathological myocardial growth. In addition to reduction of LV mass, statins were shown to reduce myocardial fibrosis, increase capillary density network and attenuate electrical instability of the hypertrophied heart. Most importantly, statins improved systolic and diastolic LV function and even decreased mortality. The inhibition of hypertrophic growth was only partly achieved by reduction of haemodynamic overload. Direct mechanisms, such as inhibition of neurohumoral activation in the myocardial tissue, attenuated production of growth factors and markers of inflammation and reduction of oxidative stress also seem to participate. The protective effect of statins was associated with the inhibition of expression and activation of small guanosintriphosphate-binding proteins such as Ras and Rho, which control the intensity of oxidative stress, the production and availability of nitric oxide, and the expression of genes involved in myocardial growth. In addition to reduction of LV mass, statins may also improve the prognosis of LVH independently of their lipid-lowering effect.

Hour-to-hour and week-to-week variability and reproducibility of wave reflection indices derived by aortic pulse wave analysis: implications for studies with repeated measurements

BACKGROUND

Wave reflections are implicated increasingly in clinical research.

AIMS

The purpose of the present study was to investigate whether wave reflection indices are reproducible when measured repeatedly (more than twice) at longer time intervals, namely hour-to-hour and week-to-week, in healthy subjects; something that has not yet been examined.

METHODS

Bland-Altman plots, the interclass correlation coefficients (ICC) and coefficient of variation were used for this purpose. Two series, with measurements repeated in triplicate, were performed in 22 healthy subjects: the first at intervals of 1 h and the second at 1-week time intervals. Augmentation index (AIx), heart rate-corrected AIx (AI@75) and arrival time of reflected waves at the central aorta (tr) were calculated by aortic pulse wave analysis.

RESULTS

AIx and AI@75 presented very good to excellent reproducibility (ICC = 0.86) for hour-to-hour repeated measurements, while tr was also highly reproducible (ICC = 0.79). AIx, AI@75 and tr were substantially reproducible when measured repeatedly with 1-week intervals, providing ICCs greater than 0.70. Bland-Altman plots confirmed these results, indicating that more than 90% of AIx, AI@75 and tr measurements fell within two standard deviations of the mean difference.

CONCLUSIONS

Wave reflections are substantially reproducible even when measurements repeated in triplicate are performed at longer time intervals (hours and weeks). A quantifiable amount of variation was reported, which should be taken carefully into consideration in interventional studies with repeated measurements and in observational studies investigating differences or correlations of these indices.

Analyzing the radial pulse waveform: narrowing the gap between blood pressure and outcomes

PURPOSE OF REVIEW

The use of peripheral pressure wave recording devices to estimate central vessel pressure profiles has grown over the past decade. This review will briefly recount the history behind this technology and discuss where it fits into the measurement of vascular properties that may predict outcomes such as death, heart attack, stroke or kidney disease progression.

RECENT FINDINGS

Recent cross-sectional studies involving both children with chronic kidney disease and adult patients with cardiovascular disease are reviewed. Importantly there are now at least three prospective series that indicate pulse wave analysis technology may be useful both for endpoint prediction (complementing blood pressure and other standard vascular risk factors) and for informing mechanisms of benefit when clinical trials with similar blood pressure control have discordant outcomes depending on the drug assignment.

SUMMARY

Pulse wave analysis is an interesting technology with the plausible benefit of estimating central vascular pressures. Since the principal target organs we seek to protect with our treatments are all connected to the aorta, it may be that a better understanding of target organ risk from an aortic as opposed to a brachial standpoint will help move forward our interventions to reduce vascular disease.

Arterial Ultrasonography and Tonometry as Adjuncts to Cardiovascular Risk Stratification

Myocardial infarction and stroke often occur without prior warning in asymptomatic individuals. Identifying individuals at risk is important for cost-effective use of preventive therapies. Algorithms based on risk factors statistically associated with cardiovascular events classify individuals into high-risk, intermediate-risk, or low-risk categories. However, more than one-third of adults in the U.S. are in the intermediate-risk category, and decisions regarding therapy are challenging in this subset. Testing for alterations in arterial function and structure that predate cardiovascular events may help refine cardiovascular risk assessment in the intermediate-risk group and identify candidates for aggressive therapy. Vascular ultrasonography and tonometry are promising test modalities for assessment of arterial function and structure in asymptomatic subjects. Several prospective studies have shown that measures of arterial function and structure provide prognostic information incremental to conventional risk factors. Standardization of methodology and establishment of quality control standards in the performance of these tests could facilitate their integration into clinical practice as adjuncts to existing cardiovascular risk stratification algorithms.

Central blood pressures: do we need them in the management of cardiovascular disease? Is it a feasible therapeutic target?

It is well established that in young and healthy individuals central (aortic or carotid) systolic and pulse pressures are different from peripheral (brachial) corresponding pressures as a consequence of progressive changes in arterial stiffness and pressure wave reflections along the arterial tree. There is evidence indicating that in interventions with pharmaceutical and non-pharmaceutical agents, central pressures are subjected to greater changes than peripheral pressures, and they are more closely related to the pathophysiology of end-organ damage or cardiovascular risk. Therefore central blood pressures may be of higher clinical importance than peripheral pressures. The present review aims to provide an insight into the (patho)physiology of central blood pressures, to present the most accurate techniques for their estimation, and to discuss the available experimental and epidemiological data that support the emerging need for the evaluation of central blood pressures in clinical practice.

Aortic augmentation index is associated with the ankle-brachial index: a community-based study

BACKGROUND

Increased arterial stiffness has been associated with greater risk of cardiovascular events. We investigated whether aortic augmentation index (AIx), a measure of arterial stiffness and wave reflection, was associated with the ankle-brachial index (ABI), a measure of peripheral arterial disease (PAD).

METHOD

AIx and ABI were measured in a community-based sample of 475 adults without prior history of heart attack or stroke (mean age 59.3 years, 46.5% men). Radial artery pulse waveforms were obtained by applanation tonometry and an ascending aortic pressure waveform derived by a transfer function. AIx is the difference between the first and second systolic peak of the ascending aortic pressure waveform indexed to the central pulse pressure. ABI was measured using a standard protocol, and subjects with non-compressible vessels (ABI >1.5) were excluded from the analyses. Multivariable linear and logistic generalized estimating equations (GEE) analyses were used to assess whether AIx was associated with ABI and ABI <1.00, respectively, independent of conventional risk factors.

RESULTS

Mean (+/-S.D.) values were: AIx, 29.3+/-11.6%; ABI, 1.12+/-0.13; 59 (12.4%) participants had an ABI <1.00. Variables associated with a lower ABI (and ABI <1.00) included older age, shorter height, female sex, higher total cholesterol, hypertension medication use, history of smoking, and higher AIx. After adjustment for mean arterial pressure and the above variables, higher AIx remained associated with a lower ABI (P=0.015) and ABI <1.00 (P=0.002). A significant interaction (P=0.007) was present between AIx and age in the prediction of ABI; the (inverse) association of AIx with ABI was stronger in older subjects (>65 years).

CONCLUSION

AIx, a measure of arterial stiffness and wave reflection, was independently associated with a lower ABI in asymptomatic subjects from the community, and this association was modified by age.

Assessment of vascular wall shear stress and implications for atherosclerotic disease

Mechanical characteristics of circulation and vasculature, such as blood flow in combination with geometrical features, participate in the generation of several pathophysiological processes, such as development of blood vessel structure, chronic vessel tone regulation, atherosclerosis and others. We aim to briefly describe the basic mechanical and haemodynamic phenomena related to the forces applied to arterial walls, especially shear stresses and the shear-induced physiologic and pathophysiologic processes focusing on those related to atherosclerotic disease.

The heart in renovascular disease—An association demanding further investigation

A close relationship exists between cardiovascular and renal disease; they often occur concomitantly, and abnormalities in either system are pathophysiologically important in both causing disease and determining clinical outcome in the other. Whilst the main focus of the article relates to the adverse association between atherosclerotic renovascular disease (ARVD) and the cardiovascular system, it is important to briefly review relevant epidemiology.

Transmission of calibration errors (input) by generalized transfer functions to the aortic pressures (output) at different hemodynamic states

BACKGROUND

Aortic pressure waveforms are calculated non-invasively by applying generalized transfer functions (GTF) to tonometric radial pressure waveforms. Input errors mainly during acquisition and calibration of tonometric pressures are "transferred" to aortic pressure calculation. The present study aimed to quantify the proportion of specific input errors which is "transferred" by the GTFs in a wide range of hemodynamic conditions and for different error combinations in brachial systolic (SBP) and diastolic (DBP) blood pressure measurements.

METHODS

Aortic pulse wave analysis was performed in 103 subjects (52 normotensive and 51 untreated hypertensive) by the SphygmoCor System. Each pressure waveform was initially calibrated by sphygmomanometrical brachial pressures. Isolated, parallel and reverse errors in brachial SBP/DBP from -10 to +10 mmHg were simulated, by recalibration of the recorded radial pressure waveforms, inducing specific "errors" of GTF-input values. For every recalculated aortic SBP and DBP, the difference from the initial estimated value was considered to represent the "transferred error" to the aortic pressure estimation.

RESULTS

Parallel errors by +/-5 mmHg in both SBP and DBP resulted to an identical change in GTF-derived aortic pressures, as expected. When an overestimation in SBP by 5 mmHg and an underestimation in DBP by -5 mmHg occurred (reverse errors), almost 56% of this error (approximately 2.8 mmHg) was transferred. An isolated error in brachial SBP by +/-5 mmHg was transmitted by 76% ( approximately 3.8 mmHg) to GTF-derived aortic SBP. In subjects with mean blood pressure>117 mmHg or with heart rates<74 bpm, a greater percent of the calibration error was transferred to GTF-derived blood pressures.

CONCLUSIONS

Input errors in brachial pressure values result in a quantifiable effect on transfer function output (aortic pressures). The percent of the "error transfer" by the GTFs depends on heart rate and BP levels, which should be taken into account when applying GTFs at populations with different hemodynamic conditions.

Arterial stiffness assessed by pulse wave analysis in essential hypertension: relation to 24-h blood pressure profile

BACKGROUND

Arterial stiffness is a risk factor for cardiovascular morbidity and mortality and appears to be increased in arterial hypertension. The purpose of the present study was to relate systemic arterial stiffness assessed by pulse wave analysis to variables of 24-h ambulatory blood pressure monitoring (ABPM) in patients with essential hypertension.

METHODS

Seventy-two subjects with untreated mild to moderate arterial hypertension underwent evaluation with 24-h ambulatory blood pressure monitoring. In the same subjects, applanation tonometry and pulse wave analysis was performed for evaluation of systemic arterial stiffness expressed as augmentation index and estimated aortic pulse wave velocity.

RESULTS

Clinic systolic blood pressure, mean heart rate during 24-h blood pressure monitoring and height were independent predictors of augmentation index and estimated aortic pulse wave velocity. The 41 patients with blunted reduction in nighttime blood pressure (nondippers) showed higher mean systolic blood pressure (p=0.02), lower systolic and diastolic blood pressure variability (p<0.001), higher pulse pressure during 24-h monitoring (p=0.05) and higher estimated aortic pulse wave velocity (p=0.03), indicating stiffer arteries in this group.

CONCLUSIONS

These results suggest that blood pressure change from day- to nighttime is an important determinant of arterial stiffness assessed by pulse wave analysis; this association could contribute to the higher cardiovascular risk in nondippers.

An updated clinical primer on large artery mechanics: implications of pulse waveform analysis and arterial tonometry

PURPOSE OF REVIEW

The use of pulse wave analysis with arterial tonometry has accelerated over the last year. Despite approval from the US Food and Drug Administration in 2001 on the use of generalized transfer function to generate the central (aortic) pressure wave from the radial waveform, this technique is still questioned. This review summarizes major findings on (a) value of arterial tonometry in determining indices of cardiovascular function, (b) use of these indices in outcome and drug studies, (c) relevance to major trials on blood pressure reduction.

RECENT FINDINGS

Pulse pressure has emerged as a better predictor of cardiac ischemic events than systolic, diastolic, and mean brachial pressure. Central systolic and pulse pressure and augmentation index have shown an even better relation with cardiovascular events and with outcomes. The claim by specific angiotensin-converting enzyme inhibitor and angiotensin receptor blocker drugs of their benefits "beyond blood pressure lowering" has been challenged on the basis of greater reduction in central and aortic pressure compared with brachial pressure measured by cuff sphygmomanometer, as shown by the pREterax in regression of Arterial Stiffness in a contrOlled double-bliNd study. Augmentation index is higher in hypertension, is inversely related to body height, and can be reduced by exercise. Augmentation index shows a linear relation with age up to 60 years. Regrettably, recent major trials such as the Comparison of Amlodipine versus Enalapril to Limit Occurrences of Thrombosis, Prevention of Events with Angiotensin Converting Enzyme Inhibition, and Valsartan Antihypertensive Long-term Use Evaluation studies have not included pulse wave analysis to distinguish the relative benefit of different drugs.

SUMMARY

Pulse wave analysis will assist in a better understanding of hypertension as well as in establishing the extent of cardiovascular disease and for monitoring therapy.

Acute effects of caffeine on blood pressure and wave reflections in healthy subjects: should we consider monitoring central blood pressure?

BACKGROUND

Data concerning blood pressure changes, acutely induced by caffeine consumption, are conflicting. Furthermore, limited data exist regarding central hemodynamic response to caffeine ingestion by healthy young subjects. We investigated the acute effect of coffee (80 mg of caffeine) and decaffeinated coffee on peripheral and central hemodynamics, as well as on wave reflections.

SUBJECTS

For this purpose, 16 healthy volunteers (eight females and eight males, mean age 29+/-3.2 years) were investigated.

METHODS

Repeated measurements were performed at baseline and 30, 60, 90 and 120 min after oral administration of each beverage in a double-blind crossover design. Aortic blood pressures, augmentation index (AI) and pressure (AP) and timing of reflected waves were evaluated by using applanation tonometry and pulse wave analysis.

RESULTS

Regular coffee increased central systolic (SBP) and diastolic pressure (DBP) from 96.2+/-9.9 to 101.1+/-10.1 mmHg, p=0.011 and from 72.6+/-9.4 to 76.5+/-9.0 mmHg, p=0.027, respectively, but no change was observed following consumption of decaffeinated coffee. Peripheral systolic blood pressure did not change significantly after the administration of either coffee. Augmentation index increased significantly following regular coffee consumption. The change in AI was significantly higher following regular compared to decaffeinated coffee consumption as shown by analysis of variance (ANOVA) for repeated measures (p=0.001).

CONCLUSIONS

These caffeine effects reveal an unfavourable effect on wave reflections and therefore on left ventricular (LV) pulsatile afterload. It also revealed a significant acute effect of caffeine consumption on central hemodynamics which is not observed at peripheral pressures.