Pulse Pressure Ratio Research Articles

Brachial artery hyperaemic blood flow velocity in relation to established indices of vascular function and global atherosclerosis

Systolic to diastolic blood flow velocity (SDFV) ratio in the brachial artery recently proved to be related to cardiovascular risk and carotid atherosclerosis. We hypothesized that the SDFV ratio was related to established markers of vascular function and global atherosclerosis. Established markers of endothelial function in forearm resistance vessels, flow-mediated vasodilation and arterial stiffness were assessed in the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study including 1016 individuals aged 70. Whole-body magnetic resonance angiography was performed in a random 306 of the participants. Atherosclerotic lesions were summarized in a total atherosclerotic score (TAS). Before and during hyperaemia of the brachial artery, systolic and diastolic blood flow velocities were measured by Doppler. The SDFV ratio was positively related to endothelium-independent vasodilatation, while inverse relations were found to flow-mediated dilation, common carotid artery distensibility and the stroke volume to pulse pressure ratio. Endothelium-dependent vasodilatation and total peripheral resistance index were not significantly related to the SDFV ratio. The SDFV ratio (P = 0·015) and the blood flow increase (BFI) during hyperaemia (P = 0·020) were both significantly related to TAS after gender adjustment. When adjusted for the Framingham risk score, both the SDFV ratio (P = 0·057) and BFI (P = 0·078) lost somewhat in significance. The SDFV ratio was related to established markers of both vasodilation and arterial compliance, and to global atherosclerosis. Future larger studies have to evaluate whether the SDFV ratio is related to global atherosclerosis independently of traditional risk factors.

Thermoplastic–lignocellulose composites enhanced by chemically treated Alcell lignin as compatibilizer

In this study, chemically treated Alcell lignin was used as a compatibilizer in the preparation of polypropylene–oil palm empty fruit bunch (PP-EFB) composites. Basically, this study was divided into two stages. In the first stage, glycidyl methacrylate (GMA) and allyl glycidyl ether (AGE) were used to treat Alcell lignin in different ratios (1:1, 1:2 and 1:3) based on equivalent weight. Then, the treated lignin was used as a compatibilizer at different percentages (1%, 3% and 5%, based on the weight of EFB filler) in the preparation of lignocellulosic–thermoplastic composites. The size of the EFB filler used for this study was 53–180 µm and the ratio of PP to EFB filler was fixed at 40%:60% (based on weight). The results showed that the incorporation of GMA- and AGE-treated lignin had enhanced the mechanical properties and increased the hydrophobicity of lignocellulosic–thermoplastic composites. By comparison, those with the GMA-treated lignin exhibited better enhancement in mechanical properties as compared to those with AGE-treated lignin.

The effect of 4 weeks of aerobic exercise on vascular and baroreflex function of young men with a family history of hypertension

The effect of short-term aerobic exercise on vascular function of young individuals with a family history of hypertension was investigated. Thirty young men with a family history of hypertension were randomly assigned to either an exercise (n=15) or control (n=15) group. Exercise subjects performed 30 min of supervised cycle training at 65% of their maximal oxygen uptake (VO(2max)), three times per week for 4 weeks. Control subjects were asked to maintain their normal levels of physical activity. Peak leg and forearm blood flow were assessed using plethysmography and was determined as the highest blood flow following 5 min of reactive hyperemia. Cardiopulmonary baroreceptor (CPBR) sensitivity was measured using lower body negative pressure (LBNP) for 5 min at -20 mm Hg. CPBR was determined by calculating change of stroke volume and forearm vascular resistance at baseline and during LBNP. Carotid baroreceptor (CBR) sensitivity was assessed using neck suction at -20, -40, -60 and -80 mm Hg pressures, and was determined from RR interval divided by systolic blood pressure. Augmentation index (AIx), a measure of arterial stiffness, was assessed using applanation tonometry and was calculated as the ratio of augmented pressure and pulse pressure. The major findings were that the exercise group showed increase in leg vasodilation, reduction in AIx and increase in VO(2max) compared with the control group (P<0.05). However, there was no significant change for CPBR and CBR. A short-term moderate-intensity aerobic exercise intervention in young men with a family history of hypertension significantly reduced arterial stiffness and increased aerobic fitness.

The association of pulse pressure and urinary albumin creatinine ratio with arterial stiffness in elderly hypertensive patients

Objective: Our study is to explore the association of pulse pressure and urinary albumin creatinine ratio (UACR) with arterial stiffness in elderly hypertensive patients. Methods: We randomly recruited 354 elderly isolated systolic hypertension individuals (mean age, 74.41±8.48years). Blood and urinary samples were collected to determine biochemical indicators and UACR. Carotid–femoral PWV was determined in order to assess arterial stiffness. We analyzed PWV in different groups according to pulse pressure (≤60mmHg, >60mmHg) and in each tertile of UACR (<10.34mg/g, 10.34~25.60mg/g, >25.60mg/g).

The Glashow resonance at IceCube: signatures, event rates and pp vs. pγ interactions

We revisit the signatures of the Glashow resonance process ν̄ee → W in thehigh-energy astrophysical neutrino observatory IceCube. We note that in addition to the standard hadronic and electromagnetic showers produced by an incoming neutrino at the resonance energy of Eν ≈ 6.3 PeV, there are two clear signals of the process: the ``pure muon" from ν̄ee → ν̄μμ and the ``contained lollipop"from ν̄ee → ν̄ττ. The event rate and the signal-to-background ratio (the ratio of the resonant to concurrent non-resonant processes) are calculated for each type of interaction, based on current flux limits on the diffuse neutrino flux.Because of the low background in the neighborhood of the resonance, the observation of only one pure muon or contained lollipop event essentially signals discovery of the resonance, even if the expected event numbers are small.We also evaluate the total event rates of the Glashow resonance from the extra-galactic diffuse neutrino flux and emphasize its utility as a discovery tool to enable first observations of such a flux. We find that one can expect 3.6 (0.65) events per year for a pure pp (pγ) source, along with an added contribution of 0.51 (0.21) from non-resonant events. We also give results as a function of the ratio of pp vs pγ sources.

Pulse Wave Analysis

See related article, pp 1108–1116 Applanation tonometry, a simple noninvasive technique for recording a high-fidelity waveform from an accessible pulse, has facilitated pulse wave analysis in large population studies. Most interest has focused on estimating an aortic or “central” waveform by the application of a filter or generalized transfer function applied to a radial waveform.1 Systolic pressure and pulse pressure differ between central and peripheral arteries as a result of peripheral amplification. By contrast, there is little regional variation in mean and diastolic pressures within large arteries and conduit arteries. A synthesized aortic waveform can, thus, be calibrated on the assumption of equality of mean and diastolic pressures at central and peripheral sites and used to estimate central systolic and pulse pressures. The main limitation of this approach, at least for the estimation of central systolic blood pressure, is the accuracy of the peripheral blood pressure measurements used to calibrate the waveform.2 Most studies and a recent meta-analysis suggest that central pressures provide a better prediction of cardiovascular risk than peripheral pressures,3 a finding intuitively rationalized in terms of the load on the left ventricle and coronary and carotid arteries. In addition to central blood pressure, a variety of indices can be obtained relating to inflection points or shoulders in the arterial waveform. Central augmentation pressure (AP) is the height above the first systolic shoulder of the aortic waveform and central augmentation index (AI; cAI) the ratio of AP to central pulse pressure (Figure). AP is thought to relate to pressure wave reflection from the periphery of the circulation and cAI to be an index of pressure wave reflection. However, this interpretation has been challenged, and it has been suggested …

Utility of Noninvasive Aneurysm Sac Pressure Measurement During and After Endovascular Abdominal Aortic Aneurysm Repair

Purpose The utility of noninvasive pressure sensors in the intra- and postoperative settings is not entirely clear. The objectives of this study were to determine intraoperative pressure criteria in the setting of technically successful endovascular aneurysm repair (EVAR) and to evaluate pressure changes during follow-up. Materials and Methods A total of 55 patients (42 men) underwent attempted noninvasive sensor monitor placement within the aneurysm sac. Pressures were recorded before and after EVAR. Recordings were repeated at 1 day, 2 weeks, 3 months, and 1 year. Clinical data, pressure recordings, and computed tomography were retrospectively assessed. Results Noninvasive pressure sensors were successfully placed in 51 patients. The mean intraoperative decreases in pulse pressure (PP) and PP ratio (PPR) in the setting of technical success were statistically different versus (i) baseline recordings and (ii) pressures obtained in the setting of type I endoleak (74.2% vs 41.5% and 76.2% vs 46.5%, respectively). At follow-up, there were continued decreases in PP and PPR, with a decrease in mean pressure resuming at the 3-month interval. Four of 14 type II endoleaks were treated because of relatively increased pressure with stable or increased aneurysm size. Conclusions An intraoperative decrease in PP and PPR in the range of approximately 70% after EVAR was associated with successful aneurysm exclusion. Noninvasive sensors can provide useful ancillary information in confirming technical success intraoperatively. During follow-up, an increase in sensor pressure recordings may be suggestive of clinically significant endoleak; however, further research is necessary.

The relation of non-invasively and invasively assessed aortic pulsatile indices to the presence and severity of coronary artery disease

Objectives. The aim of the study was to assess the relationship between non-invasively (NIA) and invasively assessed (IA) aortic pulsatile indices and the presence and severity of coronary artery disease (CAD). Subjects and Methods. The study group consisted of 58 patients who were admitted to our institute for elective coronary angiography (CAG). We measured the aortic systolic, diastolic and mean blood pressure (BP) using non-invasive and invasive techniques. We assessed the pulsatile indices of the aortic pressure waveform (APW) including pulse pressure (PP), fractional PP (FPP, the ratio of PP to mean BP) and pulsatility index (PI, the ratio of PP to diastolic BP). The severity of CAD was assessed by Gensini score. Results. IA aortic PP, FPP and PI were significantly higher in patients with CAD than without CAD, but NIA indices did not show significant differences between two groups. After multivariate stepwise adjustment, the odds ratio (OR) and confidence interval (CI) of having significant CAD was: PP per 10 mmHg, OR = 2.51 (95% CI 1.12–5.63); FPP per 0.1, OR = 3.30 (95% CI 1.25–8.72); and PI per 0.1, OR = 1.88 (95% CI 1.09–3.23). In linear regression analysis, IA aortic systolic BP (SBP), PP, FPP and PI were significantly correlated with Gensini score, but NIA indices were not correlated. The NIA aortic PP was lower than IA aortic PP (mean difference: 6.1 ± 15.8 mmHg). Conclusion. IA aortic PP, FPP and PI were related to the presence and severity of CAD, but NIA assessed indices of APW were not related. NIA aortic PP underestimated IA aortic PP.

Pulse pressure and systolic night–day ratio interact in prediction of macrovascular disease in patients with type 2 diabetes mellitus

Patients with type 2 diabetes mellitus are at increased risk of cardiovascular disease (CVD). We examined the predictive ability of 24-hour ambulatory pulse pressure (24-h PP), ambulatory arterial stiffness index (AASI) and diurnal blood pressure (BP) parameters for fatal and non-fatal CVD in patients with type 2 diabetes mellitus. A total of 108 patients with type 2 diabetes mellitus (mean duration 6.6 years) were followed for 9.5 (0.5-14.5) years. At baseline, all patients underwent ambulatory BP monitoring. During follow-up, 45 patients had cardiovascular (CV) events (35 non-fatal and 10 fatal). In bivariate analysis, events during follow-up were predicted by 24-h PP (P<0.01), AASI, 24-h systolic BP and systolic and diastolic night-day BP ratio (P<0.05 for all). In Cox regression analysis adjusted for established risk markers, only 24-h PP and systolic night-day BP ratio predicted CV events, P<0.05 for both. A significant interaction between the two parameters was found, P<0.05; thus, the higher the systolic night-day ratio, the greater the increase in hazard ratio (HR) per mmHg increase in 24-h PP and vice versa. A combined 10 mmHg increase in 24-h PP and 10%-point increase in systolic night-day ratio from the 25th percentile increased the adjusted HR (95% confidence interval) for CV events with 1.29 (0.53; 3.12), whereas a similar increase from the 75th percentile increased the HR with 4.2 (1.54; 11,51). Our study showed that 24-h PP and systolic night-day ratio interact as predictors of CV events in type 2 diabetes patients, and should be considered in conjunction when evaluating the risk of CVD.

Differences in central systolic blood pressure and aortic stiffness between aerobically trained and sedentary individuals

The purpose of this study was to evaluate central (carotid) artery blood pressure (BP) in endurance athletes. Carotid-femoral (= aortic) pulse wave velocity (PWV) together with radial and carotid tonometry and pulse wave analysis were performed at rest in 30 endurance athletes and 30 sedentary controls, all males matched for age, height, brachial systolic BP (SBP), and diastolic BP. Whereas brachial BP was similar in the two groups, carotid SBP and pulse pressure (PP) were higher in endurance athletes than in controls irrespective of age (123.1 ± 2.17 vs. 110.2 ± 1.29 mm Hg, and 50.9 ± 1.95 vs. 34.1 ± 1.01 mm Hg; P < .0001 for both). PP amplification evaluated from the brachial/carotid PP ratio was lower in athletes than in controls (1.05 ± 0.04 vs. 1.40 ± 0.02; P < .0001). When compared with controls, athletes had lower PWV (7.81 ± 0.17 vs. 9.8 ± 0.23 m/second; P < .0001), higher reflected wave transit time/left ventricular ejection time ratio ( P = .02), and lower heart rate (52.03 ± 1.54 vs. 68.9 ± 1.72 beats/minute; P < .0001). When matched for brachial BP, central SBP and PP were higher in endurance athletes than in sedentary controls. The possible negative pathophysiological impact of increased central BP on the overall favorable effects of training deserves further study.

A clinical pilot study to evaluate the correlation between pulse wave velocity and cardiac output during elective surgery

Pulse wave velocity (PWV) is defined as the speed of conduction of a pressure wave generated by cardiac systole through the arterial tree. It may be non-invasively estimated from the pulse transit time that is measured as the interval between the R wave on an electrocardiogram and first inflexion point of the paired plethysmographic wave recorded from a finger pulse oximeter [1]. Within a simple two-component Windkessel model of the arterial system, PWV is proportional to the square root of arterial elastance [2]. Elastance is defined as the ratio of pulse pressure (PP) to stroke volume (SV). PWV might therefore provide a non-invasive estimate of cardiac output.

Midterm results with thoracic endovascular aortic repair for chronic type B aortic dissection with associated aneurysm

Thoracic endovascular aortic repair for chronic type B aortic dissection with associated descending thoracic aneurysm remains controversial. Concerns include potential ischemic complications due to branch vessel origin from the chronic false lumen and continued retrograde false lumen/aneurysm sac pressurization via fenestrations distal to implanted endografts. The present study examines midterm results with thoracic endovascular aortic repair for chronic (>2 weeks) type B aortic dissection with associated aneurysm to better understand the potential role of thoracic endovascular aortic repair for this condition. Between March 2005 and December 2009, 51 thoracic endovascular aortic repair procedures were performed at a single institution for management of chronic type B dissection. The indication for thoracic endovascular aortic repair was aneurysm in all cases. A subset of 7 patients (14%) underwent placement of the EndoSure wireless pressure measurement system (CardioMEMS, Inc, Atlanta, Ga) in the false lumen adjacent to the primary tear for monitoring aneurysm sac/false lumen pulse pressure after thoracic endovascular aortic repair. Mean patient age was 57±12 years (range, 30-82 years); 14 patients (28%) were female. Mean aortic diameter was 6.2±1.4 cm. There were no in-hospital/30-day deaths, strokes, or permanent paraplegia/paresis. There were no complications related to compromise of downstream branch vessels arising from the false lumen. Two patients (3.9%) who had preexisting ascending aortic dilation had retrograde acute type A aortic dissection; both were repaired successfully. Median postoperative length of stay was 4 days. Mean follow-up is 27.0±16.5 months (range, 2-60 months). Actuarial overall survival is 77.7% at 60 months with an actuarial aorta-specific survival of 98% over this same time period. Actuarial freedom from reintervention is 77.3% at 60 months. All patients with the EndoSure wireless pressure measurement system exhibited a decrease in aneurysm sac/false lumen pulse pressure indicating a depressurized false lumen. The aneurysm sac/false lumen pulse pressure ratio decreased from 52%±27% at the predischarge measurement to 14%±5% at the latest follow-up reading (P=.029). Thoracic endovascular aortic repair for chronic type B dissection with associated aneurysm is safe and effective at midterm follow-up. Aneurysm sac/false lumen pulse pressure measurements demonstrate a significant reduction in false lumen endotension, thus ruling out clinically significant persistent retrograde false lumen perfusion and provide proof of concept for a thoracic endovascular aortic repair-based approach. Longer-term follow-up is needed to determine the durability of thoracic endovascular aortic repair for this aortic pathology.

Tensor Correlations Measured inHe3(e,e′pp)n

We have measured the He3(e,e′pp)n reaction at an incident energy of 4.7 GeV over a wide kinematic range. We identified spectator correlated pp and pn nucleon pairs by using kinematic cuts and measured their relative and total momentum distributions. This is the first measurement of the ratio of pp to pn pairs as a function of pair total momentum ptot. For pair relative momenta between 0.3 and 0.5 GeV/c, the ratio is very small at low ptot and rises to approximately 0.5 at large ptot. This shows the dominance of tensor over central correlations at this relative momentum.Received 17 August 2010DOI:https://doi.org/10.1103/PhysRevLett.105.222501© 2010 The American Physical Society

Arterial stiffness, but not endothelium-dependent vasodilation, is related to a low Ankle-Brachial index

Arterial compliance and endothelium-dependent vasodilation are two characteristics of the vessel wall. In the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study we studied the relationships between arterial compliance and endothelium-dependent vasodilation versus the Ankle-Brachial index (ABI), a clinically used index of peripheral artery disease. In the population-based PIVUS study (all aged 70), arterial compliance was determined by ultrasound as the distensibility of the carotid artery and the stroke volume to pulse pressure (SV/PP) ratio by echocardiography, while endothelium-dependent vasodilation was assessed by the invasive forearm technique with acetylcholine (EDV) and brachial artery ultrasound (FMD) in 519 subjects in whom the Ankle-Brachial index was investigated. After adjustments for gender and Framingham risk score, distensibility in the carotid artery and the SV/PP ratio were significantly reduced in subjects with a reduced ABI (< 0.9) in both legs (n=15, P = 0.0006 and P = 0.0003, respectively). Endothelium-dependent vasodilation was not significantly related to a reduced ABI. A reduced arterial compliance, but not endothelium-dependent vasodilation, was related to a low ABI in both legs after adjustment for major risk factors, suggesting that atherosclerosis in the leg arteries is associated with arterial compliance also in other parts of the vasculature.

Acute effect of a single bout of aerobic exercise on vascular and baroreflex function of young males with a family history of hypertension

The effect of one single bout of aerobic exercise on the vascular and baroreceptor function of individuals with a family history of hypertension was investigated. Forty young males, mean age 21 years, comprising offspring with (FH(+); n=20) and without (FH(-); n=20) a family history of hypertension participated in this study. Acute exercise was performed on a stationary bike for 20 min at 60% of maximal oxygen uptake. Peak forearm blood flow (FBF) was assessed using plethysmography and was determined as the highest blood flow after 5 min of reactive hyperaemia. Cardiopulmonary baroreceptor (CPBR) sensitivity was measured using lower-body negative pressure (LBNP) for 5 min at -20 mm Hg. CPBR was determined by calculating change of stroke volume and forearm vascular resistance (FVR) at baseline and during LBNP. Carotid baroreceptor (CBR) sensitivity was assessed using neck suction at -20, -40, -60 and -80 mm Hg pressures and was determined from RR interval divided by systolic blood pressure. Augmentation index (AIx), a measure of wave reflection, was assessed using applanation tonometry, and was calculated as the ratio of augmented pressure and pulse pressure. The peak FBF at pre-exercise was lower in FH(+) than in FH(-) subjects. Twenty minutes of acute cycle exercise resulted in significantly increased peak FBF by 22% in FH(+) and by 11% in FH(-) subjects, whereas peak FVR of both groups decreased by 17% and 11%, respectively. No change occurred in CPBR, CBR or AIx. It is concluded that 20 min of acute cycle exercise normalised baseline FBF and forearm vasodilation during hyperaemia in FH(+) subjects.

Aortic wave reflection in women and men

Augmentation index (AIx), a marker of the number of aortic wave reflections (AWRs), is influenced not only by the magnitude of incident and reflected pressure waves but also by the time of return. A new triangulation method has been developed, enabling us to better quantify AWRs and to determine their sex differences, which may relate to body size or pulse pressure (PP) amplification, measured from the brachial PP-to-carotid PP (B/C) ratio. With the use of pulse wave analysis, AWRs were evaluated in 51 women and 72 men treated for hypertension and studied in relationship to age, blood pressure, and pulse wave velocity. When women were compared with men, AIx (expressed in %PP and adjusted to heart rate) was significantly higher, together with a significant decrease of the B/C ratio and an increase of the reflection magnitude and of the amplitude (but not the timing) of the backward pressure wave. The significance of the amplitude difference between men and women was enhanced after an adjustment to heart rate or pulse wave velocity but was abolished after an adjustment to body height or the B/C ratio. In the overall population, AIx and the reflection magnitude index were positively (r(2) = 0.39) and independently associated, after excluding confounding factors such as drug treatment. In conclusion, when compared with men, women treated for hypertension have increased AIx, related to the increased amplitude, and not timing, of backward pressure waves. This finding relates to sex differences in body size and mostly brachial-carotid PP amplification, a parameter highly related to the sex difference of cardiovascular risk.

Vascular and baroreceptor abnormalities in young males with a family history of hypertension

Vascular and baroreceptor abnormalities in 44 young males, mean age 21 years, comprising of offspring with (FH(+); n = 22) and without (FH(-); n = 22) hypertensive parents, were investigated. Peak forearm blood flow (FBF), which was defined as the highest blood flow obtained following reactive hyperaemia, was assessed using strain gauge plethysmography following 5 min of ischemia. Cardiopulmonary baroreceptor sensitivity was assessed using lower body negative pressure for 5 min at -20 mmHg and was determined by calculating change of stroke volume and forearm vascular resistance (FVR) to lower body negative pressure. Carotid baroreceptor sensitivity was assessed using neck suction at -20, -40, -60, and -80 mmHg and was calculated by dividing RR interval by systolic blood pressure. Augmentation index, a measure of wave reflection, was assessed using applanation tonometry and was calculated as the ratio of augmented pressure and pulse pressure. Peak FBF of FH(+) was 19% lower than the FH(-) (p = 0.02). Also FH(+) had 17% higher peak FVR compared to FH(-) (p = 0.04). However, there were no significant differences between groups for cardiopulmonary, carotid baroreceptor sensitivity, and augmentation index. These results suggest that peripheral vascular dysfunction appears earlier than abnormal baroreceptor sensitivity in young males with a family history of hypertension.

Atherosclerosis measured by whole body magnetic resonance angiography and carotid artery ultrasound is related to arterial compliance, but not to endothelium‐dependent vasodilation – the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study

Arterial compliance and endothelium-dependent vasodilation are two characteristics of the vessel wall. In the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study, we studied the relationships between arterial compliance and endothelium-dependent vasodilation versus atherosclerosis as measured with two imaging modalities. In the population-based PIVUS study (1016 subjects aged 70), arterial compliance was determined by ultrasound in the carotid artery and the stroke volume to pulse pressure ratio by echocardiography, while endothelium-dependent vasodilation was assessed by the invasive forearm technique with acetylcholine and brachial artery ultrasound. Intima-media thickness was evaluated by ultrasound in the carotid artery (n = 954). Stenosis in the carotid, aorta, renal, upper and lower leg arteries were determined by magnetic resonance angiography in a random subsample of 306 subjects. After adjustments for gender, Framingham risk score, obesity, myocardial infarction and stroke, distensibility in the carotid artery and the stroke volume to pulse pressure ratio were both significantly related to a weighted index of stenosis in the five arterial territories evaluated by magnetic resonance angiography (p<0.02 for both). Distensibility in the carotid artery (P = 0.021), but not the stroke volume to pulse pressure ratio (P = 0.08), was also significantly related to intima-media thickness. In the elderly population, atherosclerosis is mainly related to arterial compliance, but not to endothelium-dependent vasodilation in peripheral conduit or resistance vessels.

Impact of the metabolic syndrome on aortic pulse pressure and ascending aortic pulsatility in patients with angiographically normal coronary arteries

Large artery stiffness is a major determinant of pulse pressure (PP), and PP at baseline has been associated with future coronary events. To evaluate the impact of the metabolic syndrome on aortic PP and ascending aortic pulsatility (AP) in patients with angiographically normal coronary arteries. Forty-two patients with the metabolic syndrome and 40 age matched control subjects without the metabolic syndrome were included in the study. All subjects had normal coronary arteries. Diagnosis of the metabolic syndrome was based on the International Diabetes Federation guidelines published in 2005. Ascending AP was estimated as the ratio of aortic PP to mean blood pressure. Aortic PP (59+/-12 mmHg versus 43+/-10 mmHg; P<0.001) and ascending AP (0.54+/-0.10 versus 0.48+/-0.10; P<0.001) were significantly higher in the metabolic syndrome group. Multiple regression analysis revealed statistically independent relationships between ascending AP and fasting blood glucose, waist circumference and systolic blood pressure (model R2=0.408; P<0.001). The metabolic syndrome, as a whole, was also independently associated with both ascending AP (P<0.01) and aortic PP (P<0.01). The data showed that the metabolic syndrome is independently associated with increased aortic PP and ascending AP in patients with normal coronary arteries, suggesting aortic stiffness as one of the possible mechanisms underlying the excess cardiovascular risk associated with the metabolic syndrome.

I019 Influence of endurance exercice on central systolic blood pressure and aortic distensibility

Objectives To evaluate central (carotid) artery blood pressure (BP) in endurance athletes. Methods Derived ascending aortic pressure and direct carotid pressure waveforms were recorded using radial and carotid tonometry at rest in 30 endurance athletes and 30 sedentary controls, all males matched for age, height, brachial systolic BP (SBP) and diastolic BP. Results Whereas brachial BP was similar in the two groups, carotid SBP and pulse pressure (PP) were higher in endurance athletes than in controls irrespective of age (123.1±2.17 vs. 110.2±1.29 mmHg, and 50.9±1.95 vs. 34.1±1.01 mmHg, respectively; p<0.0001 for both). PP amplification evaluated from the brachial/carotid PP ratio was lower in athletes than in sedentary controls (1.057±0.037 vs. 1.40±0.002, respectively; p<0.0001) at each given value of heart rate. When compared to controls, athletes had lower PWV (7.81±0.17 vs. 9.8±0.23 m/s; p<0.0001), higher reflected wave transit time/left ventricular ejection time ratio (p=0.02) and lower heart rate (52.03±1.54 vs. 68.9±1.72 beats/min ; p<0.0001). Conclusion Central, and not brachial, SBP and PP are significantly higher in endurance athletes when compared to matched controls. A long-term follow-up is needed to investigate this finding, which is associated with reduced heart rate and disappearance of PP amplification Figure options Download full-size image Download as PowerPoint slide .