Maternal vascular indices at 36 weeks' gestation in pregnancy with small or growth-restricted fetus.

OBJECTIVE: To compare maternal vascular indices and hemodynamic parameters at 35-37 weeks' gestation in pregnancies complicated by delivery of a small-for-gestational-age (SGA) or growth-restricted (FGR) neonate. METHODS: This was a prospective observational study of women with a singleton pregnancy attending for a routine hospital visit at 35 + 0 to 36 + 6 weeks' gestation. The visit included recording of maternal demographic characteristics, medical history, vascular indices and hemodynamic parameters, which were obtained using a non-invasive operator-independent device and included pulse-wave velocity, augmentation index, cardiac output, stroke volume, central systolic and diastolic blood pressure, total peripheral resistance and heart rate. Women with hypertensive disorders of pregnancy were excluded. SGA was diagnosed if birth weight was < 10th percentile. FGR was diagnosed if, in addition to birth weight < 10th percentile, at the 35-37-week scan, uterine artery or umbilical artery pulsatility index (PI) was > 95th percentile or fetal middle cerebral artery PI was < 5th percentile. RESULTS: Among the 6413 women included in the study, there were 605 (9.4%) cases of SGA, 133 (2.1%) cases of FGR and 5675 (88.5%) cases that were unaffected by SGA or FGR. Women with SGA or FGR, compared to unaffected pregnancies, had increased peripheral vascular resistance and reduced cardiac output. Central systolic and diastolic blood pressure were increased in the FGR group compared with the unaffected group. Aortic stiffness, as assessed by pulse-wave velocity, and augmentation index did not differ between affected and unaffected pregnancies. In the FGR group, compared with the SGA group, central systolic and diastolic blood pressure were higher, whereas heart rate was lower. CONCLUSIONS: SGA and FGR pregnancies exhibit deranged maternal hemodynamic responses compared with unaffected pregnancies. Pregnancies with FGR have higher central blood pressure compared to those with SGA, but it remains unclear whether these differences are driven by the size of the fetus or pathological fetal growth. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Maternal vascular indices and hemodynamic parameters at 36 weeks' gestation in gestational and pre-existing diabetes mellitus.

OBJECTIVE: To compare maternal vascular indices and hemodynamic parameters at 35-37 weeks' gestation in pregnancies complicated by gestational diabetes mellitus (GDM), those with pre-existing diabetes mellitus (DM) and those without GDM or pre-existing DM. METHODS: This was a prospective observational study in women with a singleton pregnancy attending for a routine hospital visit at 35 + 0 to 36 + 6 weeks' gestation. The visit included recording of maternal demographic characteristics and medical history, and measurement of vascular indices and hemodynamic parameters using a non-invasive operator-independent device. These included carotid-to-femoral pulse-wave velocity, augmentation index, cardiac output, stroke volume, central systolic and diastolic blood pressure, total peripheral resistance and heart rate. The values in the GDM and pre-existing DM groups were compared to those in the unaffected group. RESULTS: We examined 6746 women, of whom 396 were excluded because they had chronic hypertension or developed pre-eclampsia or gestational hypertension. The study population of 6350 pregnancies contained 99 (1.6%) with pre-existing Type-I or Type-II DM and 617 (9.7%) that developed GDM, including 261 (42.3%) that were treated with diet alone, 239 (38.7%) treated with metformin alone and 117 (19.0%) treated with insulin with or without metformin. Among women with GDM and those with pre-existing DM, compared to those without GDM or pre-existing DM, there was a higher median cardiac output and heart rate, central systolic and diastolic blood pressure and pulse-wave velocity, but there was no significant difference in stroke volume or total peripheral resistance. There were no significant differences within the GDM group according to treatment type, except for higher heart rate in women treated with metformin alone compared to the group treated with diet alone. CONCLUSION: Women with GDM and those with pre-existing DM have evidence of early vascular disease in the third trimester, and this may contribute to their increased long-term cardiovascular risk. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Association of central blood pressure with an exaggerated blood pressure response to exercise among elite athletes.

PURPOSE: The systolic blood pressure/workload (SBP/MET) slope was recently reported to be a reliable parameter to identify an exaggerated blood pressure response (eBPR) in the normal population and in athletes. However, it is unclear whether an eBPR correlates with central blood pressure (CBP) and vascular function in elite athletes. METHODS: We examined 618 healthy male elite athletes (age 25.8 ± 5.1 years) of mixed sports with a standardized maximum exercise test. CBP and vascular function were measured non-invasively with a validated oscillometric device. The SBP/MET slope was calculated and the threshold for an eBPR was set at > 6.2 mmHg/MET. Two groups were defined according to ≤ 6.2 and > 6.2 mmHg/MET, and associations of CBP and vascular function with the SBP/MET slope were compared for each group. RESULTS: Athletes with an eBPR (n = 180, 29%) displayed a significantly higher systolic CBP (102.9 ± 7.5 vs. 100 ± 7.7 mmHg, p = 0.001) but a lower absolute (295 ± 58 vs. 384 ± 68 W, p < 0.001) and relative workload (3.14 ± 0.54 vs. 4.27 ± 1.1 W/kg, p < 0.001) compared with athletes with a normal SBP/MET slope (n = 438, 71%). Systolic CBP was positively associated with the SBP/MET slope (r = 0.243, p < 0.001). In multiple logistic regression analyses, systolic CBP (odds ratio [OR] 1.099, 95% confidence interval [CI] 1.045-1.155, p < 0.001) and left atrial volume index (LAVI) (OR 1.282, CI 1.095-1.501, p = 0.002) were independent predictors of an eBPR. CONCLUSION: Systolic CBP and LAVI were independent predictors of an eBPR. An eBPR was further associated with a lower performance level, highlighting the influence of vascular function on the BPR and performance of male elite athletes.

Aortic blood pressure and pulse wave indices responses to exercise in peripheral artery disease.

Peripheral artery disease (PAD) refers to obstructed blood flow in peripheral arteries typically due to atherosclerotic plaques. How PAD alters aortic blood pressure and pressure wave propagation during exercise is unclear. Thus, this study examined central blood pressure responses to plantar flexion exercise by investigating aortic pulse wave properties in PAD. Thirteen subjects with PAD and 13 healthy [age-, sex-, body mass index (BMI) matched] subjects performed rhythmic plantar flexion for 14 min or until fatigue (20 contractions/min; started at 2 kg with 1 kg/min increment up to 12 kg). Brachial (oscillometric cuff) and radial (SphygmoCor) blood pressure and derived-aortic waveforms were analyzed during supine rest and plantar flexion exercise. At rest, baseline augmentation index (P = 0.0263) and cardiac wasted energy (P = 0.0321) were greater in PAD due to earlier arrival of the reflected wave (P = 0.0289). During exercise, aortic blood pressure (aMAP) and aortic pulse pressure showed significant interaction effects (P = 0.0041 and P = 0.0109, respectively). In particular, PAD had a greater aMAP increase at peak exercise (P = 0.0147). Moreover, the tension time index was greater during exercise in PAD (P = 0.0173), especially at peak exercise (P = 0.0173), whereas the diastolic time index (P = 0.0685) was not different between the two groups. Hence, during exercise, the subendocardial viability ratio was lower in PAD (P = 0.0164), especially at peak exercise (P = 0.0164). The results suggest that in PAD, the aortic blood pressure responses and myocardial oxygen demand during exercise are increased compared with healthy controls.

Association Between Aortic Stiffness and Exercise Tolerance in Patients at the Risk Stage of Heart Failure.

BACKGROUND: The number of patients with heart failure (HF) has increased, and it is crucial to prevent the development of HF in patients at risk of HF. The present study aimed to risk stratify patients in Stage A and B HF based on associations between exercise-induced changes in aortic stiffness and exercise tolerance.Methods and Results: Patients in Stage A and B HF who performed a cardiopulmonary exercise test were enrolled in the study (n=106; median age 65.0 years [interquartile range 52.8-73.0 years]). Exercise tolerance was examined by the percentage of predicted peak oxygen consumption (%V̇O2peak). The ascending aortic pressure waveform was estimated non-invasively. Aortic stiffness was assessed using the augmentation index (AIx) and reflection magnitude (RM). Multivariable regression analysis showed that AIx measured both before and after exercise was significantly associated with %V̇O2peak (ß=-0.221 [P=0.049] and ß=-0.342 [P=0.003], respectively). When participants were divided into %V̇O2peak subgroups using a cut-off value of 60%, RM decreased immediately after exercise and remained lower 5 min after exercise in the group with preserved exercise tolerance, but recovered to baseline levels 5 min after exercise in the group with reduced exercise tolerance. CONCLUSIONS: Exercise-induced increases in aortic stiffness were associated with exercise tolerance in patients at risk of HF, suggesting that exercise-induced changes in aortic stiffness may be useful to stratify high-risk patients.

Comparison between central and automated peripheral blood pressure measurement for early detection of kidney dysfunction in hypertensive patients.

BACKGROUND: There is a close relationship between blood pressure levels and the risk of cardiovascular events, strokes, and kidney disease. For many years, the gold standard instrument for blood pressure measurement was a mercury sphygmomanometer and a stethoscope, but this century-old technique of Riva-Rocci/Korotkov is being progressively removed from clinical practice. Central blood pressure is considered better than peripheral blood pressure in predicting cardiovascular events, as it assesses wave reflections and viscoelastic properties of the arterial wall which make systolic and pulse pressures vary from central to peripheral arteries, but mean blood pressure is constant in the conduit arteries. METHODS: The study included 201 patients with primary hypertension (108 patients with chronic kidney disease and 93 patients without kidney disease). All patients underwent blood pressure measurement by OMRON M2 and Mobil-O-Graph devices, kidney function assessment and abdominal ultrasonography. RESULTS: Patients with chronic kidney disease were significantly older (60.02 ± 9.1 vs. 55.33 ± 8.5; P < 0.001), with longer duration of hypertension (7.56 ± 5.9 vs. 6.05 ± 5.8; P = 0.020) in comparison to those without chronic kidney disease. Automated peripheral measurement of systolic blood pressure, diastolic blood pressure and pulse pressure were significantly higher in comparison to central blood pressure. Patients with chronic kidney disease had significantly higher augmentation index (24.06 ± 12.6 vs. 19.02 ± 10.8; P < 0.001) and pulsed wave velocity (8.66 ± 1.5 vs. 8.69 ± 6.8; P = 0.004) in comparison to those without chronic kidney disease. Augmentation index had positive correlation with pulse wave velocity (r = 0.183, P = 0.005). There was negative correlation between both pulse wave velocity and augmentation index and estimated glomerular filtration rate (r = -0.318, P < 0.001), and (r = -0.236, P < 0.001), respectively. Hence, arterial stiffness parameters are good positive test for prediction of chronic kidney disease. CONCLUSION: There is a strong agreement between non-invasive centrally and automated peripherally measured blood pressure in diagnosis of hypertension. But non-invasive central measurements are preferred over automated measurements for early prediction and detection of renal impairment.

Central diastolic blood pressure, plasma aldosterone and uric acid are associated with microalbuminuria in essential hypertension: a case-control study.

OBJECTIVE: To study the development of microalbuminuria (MAU) in essential hypertension (EHT), we investigated the association of MAU with central blood pressure (CBP), direct renin concentration (DRC), plasma aldosterone (PA), and uric acid (UA). METHOD: We determined 24 h-urinary albumin excretion (24 h-UAE) in patients with EHT who were hospitalized at TEDA International Cardiovascular Hospital from June 2020 to May 2022. We defined MAU as 24 h-UAE in the range of 30 mg/24 h to 300 mg/24 h. Univariate and multivariate analyses were conducted to determine the associations of MAU with CBP, DRC, PA, and UA in EHT, considering demographic and clinical information. We also plotted receiver operating characteristic curves (ROCs) for predicting MAU using these results. RESULTS: More than a quarter of patients (26.5%, 107/404, 95% CI: 22.2-31.1%) were diagnosed with MAU in EHT. A higher body mass index (BMI), longer duration of hypertension, and higher severity were associated with MAU. Also, nearly 10% more creatinine levels were recorded in the MAU group than in the control group (69.5 ± 18.7 µmol/L vs. 64.8 ± 12.5 µmol/L, P = 0.004). The increase was also observed for PA (15.5, 9.7-20.6 ng/dL vs. 12.3, 9.0-17.3 ng/dL, P = 0.024) and UA (419.8 ± 105.6 µmol/L vs. 375.1 ± 89.5 µmol/L, P < 0.001) in the MAU group compared to that in the control group. Several variables were associated with MAU, including central diastolic blood pressure (CDBP) (OR = 1.017, 95% CI: 1.002-1.032, P = 0.027), PA (OR = 1.043, 95% CI: 1.009-1.078, P = 0.012) and UA (OR = 1.005, 95% CI: 1.002-1.008, P < 0.001). For MAU prediction, the area under the curve (AUC) was 0.709 (95% CI: 0.662-0.753; P < 0.001) when CDBP, PA, and UA were used in combination, and the optimal probability of the cut-off value was 0.337. CONCLUSION: We found that CDBP, PA, and UA, used for MAU prediction, might be associated with its development during EHT.

The significance of central blood pressure for cardiovascular target organ damage in children and adolescents after kidney transplantation.

BACKGROUND: Cardiovascular (CV) complications are important causes of morbidity and mortality in children after kidney transplantation (KTx). In adults, central blood pressure (cBP) is an accepted predictor of CV sequelae. We aimed to assess the prognostic value of cBP over peripheral blood pressure (pBP) for existing CV damage. METHODS: We measured cBP and pBP in 48 pediatric KTx recipients (mean age: 13.5 ± 4.2 years). Assessment of left ventricular mass index (LVMI) and aortic pulse wave velocity (PWV) allowed detection of CV target organ damage. LVMI and PWV were used as endpoints in multivariable linear regression models, in which cBP and pBP were compared for their predictive value. RESULTS: Using cBP z-scores, we identified a larger number of patients with uncontrolled or untreated hypertension compared to pBP (36% vs. 7%). Central systolic blood pressure (cSBP) was a significant independent predictor of LVMI, while peripheral systolic blood pressure (pSBP) was not. Comparing central (cDBP) and peripheral (pDBP) diastolic blood pressure for their predictive value on PWV revealed a greater estimate for cDBP (0.035 vs. 0.026 for pDBP) along with a slightly better model fit for cDBP. CONCLUSIONS: Our data in a small group of patients provide first evidence that cBP measurements in pediatric KTx recipients might be helpful in identifying patients at risk for the development of CV sequelae. Investigating a larger patient number, ideally repeatedly, is needed to create further evidence supporting our findings. In light of available devices measuring cBP noninvasively, the implementation of such clinical studies post-KTx care should be feasible. A higher resolution version of the Graphical abstract is available as Supplementary information.

Study of central aortic blood pressure in hypertensive patients & its relation with blood pressure-lowering drugs.

Background & objectives: In clinical settings, peripheral blood pressure (PBP) is measured routinely. It is thought that central blood pressure (CBP) which reflects aortic BP, may be more predictive of outcomes in specific populations. Hence, this study was carried out to measure CBP in patients with hypertension and to see the effect of antihypertensive drugs on CBP. Methods: This cross-sectional study was conducted on 134 hypertensive patients and 134 normotensive healthy individuals as controls. Peripheral BPs and CBPs were measured of all patients and controls. The data were correlated and the effect of antihypertensive drugs on CBP was also evaluated. Results: Of the 134 hypertensive patients, 44 (32.84%) were newly diagnosed and the rest 90 (67.16%) had a history of hypertension and were on treatment. Of these 90 patients on treatment, 37 (41.11%) had uncontrolled peripheral BP and 53 (58.89%) had normal peripheral BP. Of the 134 hypertensive patients, 45 (33.58%) had controlled CBP. In 90 patients, who were on antihypertensive treatment, 45 (50%) had controlled CBP and 45 (50%) had uncontrolled CBP. Patients on calcium channel blockers (CCBs) had better control of CBP. Interpretation & conclusions: Hypertension is diagnosed mainly by measuring peripheral BP. CBP, which correlates better with the incidence of cardiovascular events, is not routinely measured. Patients with a history of hypertension and on treatment had normal office peripheral BP, but a few of them had high CBP and may require modification in treatment for control of CBP. Control of CBP was better in patients taking CCB.

24-hour central blood pressure and immune system activation in adolescents with primary hypertension - a preliminary study.

Introduction: Adult and pediatric data suggest a positive relationship between the extent of subclinical inflammation, blood pressure, and hypertension-mediated organ damage (HMOD) in primary hypertension (PH). 24-hour (24-h) ambulatory blood pressure (ABPM) and central blood pressure (CBP) are strong predictors of HMOD. Our study aimed to analyze the relationship between 24-h central ABPM, subclinical inflammation, and clinical data in adolescents with PH. Material and methods: In 28 untreated adolescents with PH (14.50 ±2.27 years) and 25 healthy peers (14.76 ±2.83 years), we analyzed 24-h peripheral and central ABPM, markers of subclinical inflammation (neutrophil-to-lymphocyte ratio - NLR, platelet-to-lymphocyte ratio - PLR, mean platelet volume - MPV), and clinical and biochemical data. Results: Patients with PH had higher 24-h peripheral and central blood pressure than healthy peers. In all 53 patients, we found significant (p < 0.05) positive correlations between NLR, PLR and 24-h central systolic, diastolic, and mean blood pressure (24-h cSBP, 24-h cDBP, 24-h cMAP), between 24-h central augmentation index corrected for heart rate 75 (24-h cAIx75HR) and platelet count. In 28 patients with PH, 24-h cAIx75HR correlated with low-density lipoprotein (LDL) cholesterol (R = 0.442), and ambulatory arterial stiffness index with body mass index (BMI) (R = 0.487), uric acid (R = 0.430), and high-density lipoprotein (HDL) cholesterol (R = -0.428). Conclusions: Increased central 24-h blood pressure may be associated with immune system activation in adolescents with primary hypertension. In adolescents with primary hypertension, dyslipidemia and hyperuricemia are risk factors for increased arterial stiffness. Further studies on central and peripheral blood pressure in terms of their relationship with inflammation in these patients are needed.

Personalized physiologic flow waveforms improve wave reflection estimates compared to triangular flow waveforms in adults.

Central aortic pressure waveforms contain valuable prognostic information in addition to central systolic pressure. Using pressure-flow relations, wave separation analysis can be used to decompose aortic pressure waveforms into forward- (Pf) and backward-traveling (Pb) components. Reflection magnitude, the ratio of pressure amplitudes (RM = Pb/Pf), is a predictor of heart failure and all-cause mortality. Aortic flow can be measured via Doppler echocardiography or estimated using a triangular flow waveform; however, the latter may underestimate the flow waveform convexity and overestimate Pb and RM. We sought to determine the accuracy of a personalized synthetic physiologic flow waveform, compared with triangular and measured flow waveforms, for estimating wave reflection indices in 49 healthy young (27 ± 6 yr) and 29 older adults [66 ± 6 yr; 20 healthy, 9 chronic kidney disease (CKD)]. Aortic pressure and measured flow waveforms were acquired via radial tonometry and echocardiography, respectively. Triangular and physiologic flow waveforms were constructed from aortic pressure waveforms. Compared with the measured flow waveform, the triangular waveform underestimated Pf in older, but not young, adults and overestimated Pb and RM in both groups. The physiologic waveform was equivalent to measured flow in deriving all wave reflection indices and yielded smaller mean absolute biases than the triangular waveform in all instances (P < 0.05). Lastly, central pulse pressure was associated with triangular, but not physiologic, mean biases for Pb and RM independent of age or central arterial stiffness (P < 0.05). These findings support the use of personalized physiologic flow waveforms as a more robust alternative to triangular flow waveforms when true flow cannot be measured.NEW & NOTEWORTHY We demonstrate that triangular flow waveforms overestimate wave reflection indices, particularly at higher central pulse pressures independent of age or carotid-femoral pulse wave velocity. In contrast, personalized physiologic flow waveforms provide equivalent wave reflection estimates as measured flow waveforms, thereby offering a more robust alternative to triangulation when aortic flow cannot be measured.

Estimating central blood pressure from aortic flow: development and assessment of algorithms.

Central blood pressure (cBP) is a highly prognostic cardiovascular (CV) risk factor whose accurate, invasive assessment is costly and carries risks to patients. We developed and assessed novel algorithms for estimating cBP from noninvasive aortic hemodynamic data and a peripheral blood pressure measurement. These algorithms were created using three blood flow models: the two- and three-element Windkessel (0-D) models and a one-dimensional (1-D) model of the thoracic aorta. We tested new and existing methods for estimating CV parameters (left ventricular ejection time, outflow BP, arterial resistance and compliance, pulse wave velocity, and characteristic impedance) required for the cBP algorithms, using virtual (simulated) subjects (n = 19,646) for which reference CV parameters were known exactly. We then tested the cBP algorithms using virtual subjects (n = 4,064), for which reference cBP were available free of measurement error, and clinical datasets containing invasive (n = 10) and noninvasive (n = 171) reference cBP waves across a wide range of CV conditions. The 1-D algorithm outperformed the 0-D algorithms when the aortic vascular geometry was available, achieving central systolic blood pressure (cSBP) errors ≤ 2.1 ± 9.7 mmHg and root-mean-square errors (RMSEs) ≤ 6.4 ± 2.8 mmHg against invasive reference cBP waves (n = 10). When the aortic geometry was unavailable, the three-element 0-D algorithm achieved cSBP errors ≤ 6.0 ± 4.7 mmHg and RMSEs ≤ 5.9 ± 2.4 mmHg against noninvasive reference cBP waves (n = 171), outperforming the two-element 0-D algorithm. All CV parameters were estimated with mean percentage errors ≤ 8.2%, except for the aortic characteristic impedance (≤13.4%), which affected the three-element 0-D algorithm's performance. The freely available algorithms developed in this work enable fast and accurate calculation of the cBP wave and CV parameters in datasets containing noninvasive ultrasound or magnetic resonance imaging data.NEW & NOTEWORTHY First, our proposed methods for CV parameter estimation and a comprehensive set of methods from the literature were tested using in silico and clinical datasets. Second, optimized algorithms for estimating cBP from aortic flow were developed and tested for a wide range of cBP morphologies, including catheter cBP data. Third, a dataset of simulated cBP waves was created using a three-element Windkessel model. Fourth, the Windkessel model dataset and optimized algorithms are freely available.

Feasibility of non-invasive measurement of central blood pressure and arterial stiffness in shock.

BACKGROUND: Patients in haemodynamic shock are in need for an intensive care treatment. Invasive haemodynamic monitoring is state of the art for these patients. However, evolved, non-invasive blood pressure monitoring devices offer advanced functions like the assessment of central blood pressure and arterial stiffness. We analysed the feasibility of two oscillometric blood pressure devices in patients with shock. METHODS: We performed a monocentre prospective study, enrolling 57 patients admitted to the intensive care unit (ICU), due to septic and/or cardiogenic shock. We assessed invasive and non-invasive peripheral and central blood pressure <24 hours and 48 hours after admission on the ICU. Additional haemodynamic parameters such as pulse wave velocity (PWV), augmentation pressure and augmentation index were obtained through Mobil-o-Graph PWA (IEM) and SphygmoCor XCEL (AtCor Medical). RESULTS: A complete haemodynamic assessment was successful in all patients (48) with the Mobil-o-Graph 24 hours PWA and in 29 patients with the SphygmoCor XCEL (P = .001), when cases of death or device malfunction were excluded. Reasons for failure were severe peripheral artery disease, haemodynamic instability, oedema and agitation. Invasive blood pressure showed a sufficient correlation with both devices; however, large differences between invasive and non-invasive techniques were recorded in Bland-Altmann analysis (P < .05 for all parameters). PWV differed between the two devices. CONCLUSION: Non-invasive peripheral blood pressure measurement remains a rescue technique. However, non-invasive assessment of arterial stiffness and central blood pressure is possible in patients with septic or cardiogenic shock. Further studies are required to assess their clinical significance for patients in shock.

Alcohol Exerts a Shifted U-Shaped Effect on Central Blood Pressure in Young Adults.

BACKGROUND: Consumption of 1-2 alcoholic beverages daily has been associated with a lower risk of cardiovascular disease and all-cause mortality in middle-aged and older adults. Central blood pressure has emerged as a better predictor of cardiovascular risk than peripheral blood pressure. However, the effects of habitual alcohol consumption on central blood pressure particularly in young adults, who are among the largest consumers of alcohol in North America, have yet to be investigated. OBJECTIVE: We aimed to study the effect of alcohol consumption on central and peripheral blood pressure, and arterial stiffness in young adults. DESIGN: Cross-sectional observational study. MAIN MEASURES: Using a standardized questionnaire, alcohol consumption (drinks/week) was queried; participants were classified as non- (< 2), light (2-6), moderate (women 7-9, men 7-14), and heavy drinkers (women > 9, men > 14). Central blood pressure and arterial stiffness were measured using applanation tonometry. KEY RESULTS: We recruited 153 healthy, non-smoking, non-obese individuals. We found a U-shaped effect of alcohol consumption on blood pressure. Light drinkers had significantly lower central systolic and mean arterial blood pressure, but not peripheral blood pressure when compared to non- and moderate/heavy drinkers (P < 0.05). No significant associations with arterial stiffness parameters were noted. CONCLUSIONS: A U-shaped relationship was found between alcohol consumption and central and mean arterial blood pressure in young individuals, which importantly, was shifted towards lower levels of alcohol consumption than currently suggested. This is the first study, to our knowledge, that examines the effect of alcohol consumption on central blood pressure and arterial stiffness exclusively in young individuals. Prospective studies are needed to confirm the relationships observed herein.

Lower-body dynamic exercise reduces wave reflection in healthy young adults.

NEW FINDINGS: What is the central question of this study? There is a paradoxical reduction in augmentation index during lower-body dynamic (LBD) exercise in the face of an increase in central pressure. To determine causality, the amplitudes of forward and backward pressure waves were assessed separately using wave separation analysis. What is the main finding and its importance? Reflection magnitude decreased during LBD exercise in healthy young adults and was attributable to an increased forward pressure wave amplitude and decreased backward pressure wave amplitude. This vasoactive response might limit the adverse effects of wave reflection during LBD exercise, optimizing ventricular-arterial interactions. ABSTRACT: Acute lower-body dynamic (LBD) exercise decreases surrogate measures of wave reflection, such as the augmentation index. However, the augmentation index is influenced by the combined effects of wave reflection timing, magnitude and other confounding factors external to wave reflection, which make it difficult to discern the origin of changes in surrogate measures. The relative contributions of forward (Pf) and backward (Pb) pressure wave amplitudes to central pressure can be determined by wave separation analysis. Reflection magnitude (RM = Pb/Pf) and the timing of apparent wave reflection return can also be determined. We tested the hypothesis that acute LBD exercise decreases RM and reflected wave transit time (RWTT). Applanation tonometry was used to record radial artery pressure waveforms in 25 adults (24 ± 4 years of age) at baseline and during light-, moderate- and vigorous-intensity exercise. Wave separation analysis was conducted offline using a personalized physiological flow wave to determine Pf, Pb, RM and RWTT. The RM decreased during all intensities of exercise compared with baseline (all P < 0.001; baseline, 43 ± 5%; light, 33 ± 6%; moderate, 23 ± 7%; vigorous, 17 ± 5%). The reduction in RM was attributable to the combined effect of increased Pf and decreased Pb during exercise. The RWTT decreased during all intensities of exercise compared with baseline (all P < 0.04; baseline, 156 ± 17 ms; light, 144 ± 15 ms; moderate, 129 ± 16 ms; vigorous, 121 ± 17 ms). Lastly, in a stepwise multilinear regression, Pf, but not Pb and RWTT, contributed to increased central pulse pressure during LBD exercise. These data show that wave reflection decreased and that central pulse pressure is most influenced by Pf during LBD exercise.

Changes in Noninvasive Arterial Stiffness and Central Blood Pressure After Endovascular Abdominal Aneurysm Repair.

PURPOSE: To evaluate the impact of elective endovascular aneurysm repair (EVAR) on the carotid-femoral pulse wave velocity (cfPWV) and central pressure waveform, through 1-year follow-up. MATERIALS AND METHODS: A tonometric device was used to measure cfPWV and estimate the central pressure waveform in 20 patients with an infrarenal abdominal aortic aneurysm scheduled for elective EVAR. The evaluated central hemodynamic parameters included the central pressures, the augmentation index (AIx), and the subendocardial viability ratio (SEVR). AIx quantifies the contribution of reflected wave to the central systolic pressure, whereas SEVR describes the myocardial perfusion relative to the cardiac workload. Measurements were performed before EVAR, at discharge, and 6 weeks and 1 year after EVAR. RESULTS: CfPWV was increased at discharge (12.4±0.4 vs 11.3±0.5 m/s at baseline; p=0.005) and remained elevated over the course of 1-year follow-up (6 weeks: cfPWV = 12.2±0.5 m/s; 1 year: cfPWV = 12.2±0.7 m/s, p<0.05). After an initial drop in systolic central pressure at discharge, all the central pressures increased thereafter up to 1 year, without significant differences compared with baseline. The same was observed for the AIx and SEVR. CONCLUSION: Endovascular aortic aneurysm repair caused an increase in pulse wave velocity compared with baseline, which remained elevated through 1 year follow-up, which may be related to an increased cardiovascular risk. However, no differences in central pressure, augmentation index, and subendocardial viability ration were observed during follow-up.

Examining the relationship between arterial stiffness and swim-training volume in elite aquatic athletes.

PURPOSE: Factors such as prone body position, hydrostatic pressure, and intermittent breath-holding subject aquatic athletes to unique physical and environmental stressors during swimming exercise. The relationship between exposure to aquatic exercise and both arterial stiffness and wave reflection properties is not well-understood. This study assessed central artery stiffness and wave reflection properties in elite pool-swimmers (SW), long-distance open-water swimmers (OW), and water polo players (WP) to examine the relationship between these variables and aquatic exercise. METHODS: Athletes competing in SW, OW and WP events at the FINA World Championships were recruited. Carotid-femoral pulse wave velocity, and pulse wave analysis were used to quantify arterial stiffness, and central wave reflection properties. RESULTS: Athletes undertook differing amounts of weekly swimming distance in training according to their discipline (SW: 40.2 ± 21.1 km, OW: 59.7 ± 28.4 km, WP: 11.4 ± 6.3 km; all p < 0.05). Pulse wave velocity (Males [SW: 6.0 ± 0.6 m/s, OW: 6.5 ± 0.8 m/s, WP: 6.7 ± 0.9 m/s], Females [SW: 5.4 ± 0.6 m/s, OW: 5.3 ± 0.5 m/s, WP: 5.2 ± 0.8 m/s; p = 0.4]) was similar across disciplines for females but was greater in male WP compared to male SW (p = 0.005). Augmentation index (Males [SW: - 3.4 ± 11%, OW: - 9.6 ± 6.4%, WP: 1.7 ± 10.9%], Females [SW: 3.5 ± 13.5%, OW: - 13.2 ± 10.7%, WP: - 2.8 ± 10.7%]) was lower in male OW compared to WP (p = 0.03), and higher in female SW compared to OW (p = 0.002). Augmentation index normalized to a heart rate of 75 bpm was inversely related to weekly swim distance in training (r = - 0.27, p = 0.004). CONCLUSIONS: This study provides evidence that the central vasculature of elite aquatic athletes differs by discipline, and this is associated with training load.

Age-specific association between invasively measured central blood pressure and left ventricular mass index.

Background: The impact of age on the association between central aortic hemodynamics and left ventricular (LV) remodeling has not been well elucidated. We compared the relationship between measurements of central blood pressure (CBP) and LV mass index (LVMI) according to their ages (<50 years versus ≥50 years). Methods: A total of 305 consecutive subjects (64.4 ± 10.9 years, 60.7% males) who underwent invasive coronary angiography (ICA) for the evaluation of coronary artery disease were prospectively enrolled. Just before ICA, CBP was measured at the aortic root using a pig-tail catheter, and CBP indices, including aortic systolic blood pressure (aSBP), aortic pulse pressure (aPP), aortic fractional pulse pressure (=aPP/mean aortic pressure), and aortic pulsatility index (=aPP/diastolic aortic pressure), were recorded. All subjects underwent transthoracic echocardiography, and LVMI was measured on the same day of ICA. Results: In simple linear correlation analyses, LVMI was associated with all CBP indices in subjects aged <50 years (n = 29) (P < .05 for each), but not in those aged ≥50 years (n = 276) (P > .05 for each). In the younger age group (≤50 years), multivariable analysis showed that aSBP (ß = 0.457, P= .021) and aPP (ß = 0.610, P= .006) had a significant association with LVMI after adjusting for possible confounding factors. The results remained consistent even when analyzed in a 1:1 propensity score-matched cohort. In conclusion, invasively measured aPP showed the closest association with LVMI in subjects aged <50 years, but not those aged ≥50 years. Conclusion: Aortic pulsatile hemodynamic status appears to have a greater effect on LV remodeling in younger people than in older people.

Ambulatory hemodynamic patterns, obesity, and pulse wave velocity in children and adolescents.

BACKGROUND: In recent years, pulse wave velocity (PWV) has emerged as a surrogate marker of cardiovascular disease in children with cardiovascular risk factors. The aims of the present study were to identify determinants of PWV in children according to their weight status and to investigate the role of peripheral blood pressure and central hemodynamic parameters in the association between PWV and obesity. METHODS: We included in the study healthy children and adolescents randomly selected from a school-based blood pressure screening study. All participants underwent ambulatory blood pressure monitoring and 24-h pulse wave analysis. RESULTS: Overweight and obese children had higher 24-h PWV, 24-h peripheral and central systolic blood pressure (SBP), and cardiac output than normal weight ones. Children with both overweight and hypertension presented the highest 24-h PWV values (p < 0.001). Peripheral and central SBP, body mass index (BMI), and hemodynamic parameters, including stroke volume, cardiac output, total peripheral resistance, and cardiac index, were all associated with 24-h PWV. However, in stepwise regression analysis, 24-h peripheral and central SBP and cardiac index, but not BMI, were independent predictors of 24-h PWV. There were statistically significant differences in 24-h blood pressure and hemodynamic parameters among those on the lower and highest 24-h PWV quartile, but there were no significant differences in BMI among 24-h PWV quartile groups. CONCLUSIONS: Arterial stiffness is higher in overweight and obese children in the co-presence of hypertension. Peripheral and central SBP are the main determinants of 24-h PWV independent of weight status. Graphical abstract.

Central hemodynamics in relation to low-level environmental lead exposure.

Purpose: Arterial stiffness predicts cardiovascular complications. The association between arterial stiffness and blood lead (BL) remains poorly documented. We aimed to assess the association of central hemodynamic measurements, including pulse wave velocity (aPWV), with blood lead in a Flemish population.Materials and Methods: In this Flemish population study (mean age, 37.0 years; 48.3% women), 267 participants had their whole BL and 24-h urinary cadmium (UCd) measured by electrothermal atomic absorption spectrometry in 1985-2005. After 9.4 years (median), they underwent applanation tonometry to estimate central pulse pressure (cPP), the augmentation index (AI), pressure amplification (PA), and aPWV. The amplitudes of the forward (Pf) and backward (Pb) pulse waves and reflection index (RI) were derived by a pressure-based wave separation algorithm.Results: BL averaged 2.93 µg/dL (interquartile range, 1.80-4.70) and UCd 4.79 µg (2.91-7.85). Mean values were 45.0 ± 15.2 mm Hg for cPP, 24.4 ± 12.4% for AI, 1.34 ± 0.21 for PA, 7.65 ± 1.74 m/s for aPWV, 32.7 ± 9.9 mm Hg for Pf, 21.8 ± 8.4 mm Hg for Pb, and 66.9 ± 18.4% for RI. The multivariable-adjusted association sizes for a 2-fold higher BL were: +3.03% (95% confidence interval, 1.56, 4.50) for AI; -0.06 (-0.08, -0.04) for PA; 1.02 mm Hg (0.02, 2.02) for Pb; and 3.98% (1.71, 6.24) for RI (p ≤ .045). In 206 participants never on antihypertensive drug treatment, association sizes were +2.59 mm Hg (0.39, 4.79) for cPP and +0.26 m/s (0.03, 0.50) for aPWV. Analyses adjusted for co-exposure to cadmium were consistent.Conclusion: In conclusion, low-level environmental lead exposure possibly contributes to arterial stiffening and wave reflection from peripheral sites.