Aortic Systolic Pressure Research Articles

Design and intelligent control of mock circulation system to reproduce patient-specific physiological indexes

Mock circulatory system (MCS) is a practicable solution to the cardiovascular device evaluation and pathological study prior to in vivo testing. In order to enhance the patient-specific imitative ability of the MCS in vitro tests, a personalized MCS that simulates aortic pressure and mean flow for a patient-specific condition is developed. The designed MCS can be fully controlled automatically, which is consisted of left ventricle, aortic compliance chamber, systemic vascular resistance and reservoir. A soft actor-critic based intelligent control method for personalized in vitro simulation is proposed, which is strongly robust to the MCS complexity and uncertainty. The designed MCS with the proposed control method can simulate aortic pressure and flow of a personalized patient with high accuracy and fast adjusting speed. The MCS control experiments are conducted with several groups of typical cardiovascular patients’ physiological indexes. The results show that the maximum deviations of aortic systolic and diastolic pressures from the target values are less than 2 mmHg, and the maximum deviation of aortic flow is less than 0.2 L/min. Therefore, the developed MCS is potential to the personalized in vitro evaluation of cardiovascular devices such as ventricular assist devices and heart valves.

Arterial Wave Reflection and Aortic Valve Stenosis: Diagnostic Challenges and Prognostic Significance.

IntroductionArterial wave reflection is an important component of the left ventricular afterload, affecting both pressure and flow to the aorta. The aim of the present study was to evaluate the impact of wave reflection on transvalvular pressure gradients (TPG), a key parameter for the evaluation of aortic valve stenosis (AS), as well as its prognostic significance in patients with AS undergoing a transcatheter aortic valve replacement (TAVR).Materials and MethodsThe study population consisted of 351 patients with AS (mean age 84 ± 6 years, 43% males) who underwent a complete hemodynamic evaluation before the TAVR. The baseline assessment included right and left heart catheterization, transthoracic echocardiography, and a thorough evaluation of the left ventricular afterload by means of wave separation analysis. The cohort was divided into quartiles according to the transit time of the backward pressure wave (BWTT). Primary endpoint was all-cause mortality at 1 year.ResultsEarly arrival of the backward pressure wave was related to lower cardiac output (Q1: 3.7 ± 0.9 lt/min vs Q4: 4.4 ± 1.0 lt/min, p < 0.001) and higher aortic systolic blood pressure (Q1: 132 ± 26 mmHg vs Q4: 117 ± 26 mmHg, p < 0.001). TPG was significantly related to the BWTT, patients in the arrival group exhibiting the lowest TPG (mean TPG, Q1: 37.6 ± 12.7 mmHg vs Q4: 44.8 ± 14.7 mmHg, p = 0.005) for the same aortic valve area (AVA) (Q1: 0.58 ± 0.35 cm2 vs 0.61 ± 0.22 cm2, p = 0.303). In multivariate analysis, BWTT remained an independent determinant of mean TPG (beta 0.3, p = 0.002). Moreover, the prevalence of low-flow, low-gradient AS with preserved ejection fraction was higher in patients with early arterial reflection arrival (Q1: 33.3% vs Q4: 14.9%, p = 0.033). Finally, patients with early arrival of the reflected wave (Q1) exhibited higher all-cause mortality at 1 year after the TAVR (unadjusted HR: 2.33, 95% CI: 1.17–4.65, p = 0.016).ConclusionEarly reflected wave arrival to the aortic root is associated with poor prognosis and significant aortic hemodynamic alterations in patients undergoing a TAVR for AS. This is related to a significant decrease in TPG for a given AVA, leading to a possible underestimation of the AS severity.

First in-human modified atrial septostomy combining radiofrequency ablation and balloon dilation

ObjectivePreclinical research suggests that the combined use of radiofrequency ablation and balloon dilation (CURB) could create stable interatrial communications without device implantation. This study examined the first in-human use of...

VASCULAR STIFFNESS AS AN TARGET OF OPTIMAL ANTIHYPERTENSIVE THERAPY

Objective: To evaluate the 24-hour blood pressure (BP) control and the effect of the triple fixed combination (TFC) amlodipine / indapamide / perindopril on the arterial stiffness parameters according to 24-hour blood pressure monitoring (ABPM) data in patients with uncontrolled hypertension (HTN). Design and method: The study involved 78 patients with insufficient BP control, against the background of previous combination therapy. All patients received TFC amlodipine / indapamide / perindopril. The patient’s condition was assessed during 4 observation visits: visit 1- inclusion, visit 2 - 4 weeks, visit 3 -12 weeks, visit 4 - 24 weeks observation. At each visit, the achievement of the target BP level &lt; 130/80 mm Hg was assessed, as well as the effect of therapy on the parameters of arterial stiffness (pulse wave velocity (PWVao), pulse pressure (PP), agumentation index (Aix), arterial stiffness index (ASI)) and central aortic pressure parameters (systolic aortic pressure (SBPao), diastolic pressure in the aorta (DBPao), central pulse pressure (PPao)) according to ABPM Results: In subjects with HTN with ineffective antihypertensive therapythe initial office BP was 160.8 ± 10.3 / 91.5 ± 8.1 mm Hg. After 24 weeks of therapy with a TFC there was a significant decrease in blood pressure to 121.3 ± 3.5 / 73.6 ± 4.2 mm Hg (p &lt; 0.001). According to ABPM data, mean values of daily BP significantly (p &lt; 0.001) decreased from 153.9 ± 9.04 / 8.38 ± 9.18 to 120.3 ± 4.7 / 73.4 ± 4.7 mm Hg. Data analysis showed a decrease PWVao (11.39 ± 1.32 m/s vs 9.98 ± 0.91 m/s, p &lt; 0,05) as well as ASI (174 (138, 253) vs 139 (107.196) mmHg; p &lt; 0.001) and Aix -29,9 (-41,12) vs - 33,7 (-53, 9) p &lt; 0,05. There was a statistically significant decrease in the parameters the central pressure in the aorta (Fig.1) Conclusions: In patients with HTN and previous uneffective antihypertensive therapy the FTC amlodipine / indapamide / perindopril provided high antihypertensive effectiveness. Parameters of vascular stiffness can serve as criteria for quality control of blood pressure and can be used to assess the effectiveness of antihypertensive therapy.

INCREASE ARTERIAL STIFFNESS IN MOYAMOYA DISEASE PRESENTING WITH HYPERTENSION AND STROKE: A NOVEL FINDING IN A VERY RARE CASE IN SINGAPORE

Objective: Arterial stiffness in Moyamoya disease (MMD) has not been described before in literature. We describe a young 42 year-old lady who initially presented as hypertensive urgency and recurrent stroke and was later diagnosed with MMD. We would like to highlight increased arterial stiffness as a cause of hypertension in patients with MMD. Design and method: This is a case report of a 42 year old lady 42 year Singaporean lady presented in 2015 with headache and transient ischemic attack(TIA) and systolic blood pressure was 200mmHg. She was diagnosed with hypertension at the age 28 years and started on telmisartan 40 mg OD. There was no end organ damage and secondary hypertension work up was negative. She has recurrent TIAs and was started on T. atorvastatin 40 mg ON and T clopidogrel 75 mg OD in Feb 2017. She presented with stroke in March 2019, and MRI revealed left posterior temporal-parietal infarct, MRA revealed severe stenosis of left terminal internal carotid artery(ICA). She presented with recurrent stroke in April 2019 and MRI/MRA revealed scattered acute infarcts in left MCA and ACA territories and severe steno-occlusive disease involving left ICA. She underwent left external carotid –internal carotid bypass in June 2019. In light of these findings, MMD was diagnosed. Results: She was started on T spironolactone and her blood pressure was kept in stable range of 130–150/80–95mmHg. An arterial stiffness study by SphygmoCor in June 2020 showed markedly increased arterial stiffness with markedly increased augmentation index, aortic augmentation pressure, aortic systolic pressure and aortic pulse pressure for the patient’s age. Conclusions: We present an interesting and rare case of hypertension in a young patient with MMD associated with increased arterial stiffness, with no renovascular disease. This is one of the first cases reported in MMD with increased arterial stiffness. We also highlighted genetic studies and case reports that have suggested that the histopathological process underlying Moyamoya vessels may also affect systemic vessels. We hope that this article will inspire more research on the relationship between MMD and hypertension, particularly in terms of how systemic vasculature is affected.

AORTIC CALCIFICATION INCREASES CENTRAL BLOOD PRESSURE RELATIVE TO BRACHIAL BLOOD PRESSURE IN CKD PATIENTS – A STUDY IN PATIENTS UNDERGOING ELECTIVE CORONARY ANGIOGRAPHY

Objective: Chronic kidney disease (CKD) and arterial stiffness are associated with increased central (aortic) systolic blood pressure (cSBP) relative to brachial systolic blood pressure (bSBP). This study examined the impact of aortic calcification on cSBP relative to bSBP in patients with CKD. Design and method: Patients with or without CKD undergoing elective coronary angiography (CAG) at Aarhus University Hospital were considered for inclusion in this cross-sectional study. During CAG, cSBP was measured in the ascending aorta with a fluid-filled catheter while bSBP was measured simultaneously with an oscillometric device using a cuff. Furthermore, patients underwent a non-contrast computed tomography (CT) scan of the entire aorta with subsequent blinded Agatston-scoring of the aorta from (but excluding) the aortic valve to the aortic bifurcation. Carotid-femoral pulse wave velocity was measured in duplicate using a Sphygmocor device. Data are presented as mean ± standard deviation unless stated otherwise. Statistical comparisons were made using Wilcoxon rank sum test for differences between 2 groups and Bonferroni-adjusted Kruskal-Wallis test when testing for differences between &gt; 2 groups. Results: 149 patients were included in the study. Of these, 134 patients had a CT-scan of sufficient quality to allow analysis. Patient characteristics and measurements of BP and pulse wave velocity are presented in Table 1. Agatston-score was higher in CKD patients as compared to patients with normal kidney function (table 1, P &lt; 0.001). bSBP was 6.5 ± 13.1 mmHg higher than cSBP in patients categorized into the first tertile of Agatston-scores. This difference was reduced to 3.3 ± 11.0 mmHg in the second tertile (p = 0.31, compared to first tertile) and -2.6 ± 16.8 mmHg in the third tertile (p &lt; 0.01, compared to first tertile). Conclusions: Patients with CKD have a higher degree of aortic calcification. Furthermore, patients with a high degree of aortic calcification have a higher invasively measured cSBP as compared to the bSBP measured with an ordinary oscillometric BP device.

SHORT-TERM HIGH SALT INTAKE ADVERSELY AFFECTS PARAMETERS DERIVED FROM RESERVOIR-EXCESS PRESSURE ANALYSIS AND CENTRAL ARTERY HAEMODYNAMICS IN OVERWEIGHT/OBESE ADULTS

Objective: The association between high salt intake and blood pressure is well-recognised. In overweight/obese individuals, obesity-associated hyperinsulinaemia augments renal sodium reabsorption and in combination with high salt intake this may alter blood pressure and arterial haemodynamics. We determined whether short-term high salt intake altered reservoir-excess pressure and central artery haemodynamic parameters in overweight/obese individuals. Design and method: We studied 15 middle-aged and older adults (59.3 ± 6.4 yrs, 5F) who were overweight/obese with elevated systolic blood pressure (130 &lt; SBP &lt; 159 mmHg). In a double-blind cross-over design, they were randomly assigned to seven days of low salt diet (LSD: 50 mmol/day) or high salt intake (HIS: LSD with 200 mmol/day of sodium tablets) separated by a two-week washout period. The parameters derived from reservoir-excess pressure analysis including reservoir pressure integral, peak reservoir pressure (MAXPR), excess pressure integral (INTXSP), peak excess pressure (MAXXSP), systolic rate constant and diastolic rate constant (DRC) were obtained by radial artery tonometry. Additionally central artery haemodynamic parameters including aortic systolic pressure (aSBP), diastolic pressure (aDBP), pulse pressure (aPP) and subendocardial viability index (SVI) were derived from ensemble-averaged radial pulse waveform using generalised transfer function. Aortic pulse wave velocity (aPWV) was estimated as proposed by Hughes et al (Front Physiol. 2020). Results: MAXPR (111.0 ± 10.9 vs 105.4 ± 10.4 mmHg), MAXXSP (41.7 ± 12.0 vs 36.6 ± 5.7 mmHg) and DRC (2.0 ± 0.4 vs 1.8 ± 0.3 s-1) were higher following HIS compared to LSD (p &lt; 0.05). There was no convincing evidence that INTXSP was greater following HIS than LSD (6.9 ± 3.2 vs 5.8 ± 1.6 mmHg s, p = 0.055). aSBP (126.3 ± 15.4 vs 117.6 ± 10.1 mmHg), aDBP (76.3 ± 6.2 vs 73.1 ± 6.3 mmHg) and aPP (50.0 ± 17.4 vs 44.5 ± 10.8 mmHg) were also higher following HIS compared to LSD (p &lt; 0.05). SVI was similar between HIS and LSD (162.7 ± 29.6 vs 171.6 ± 25.0 %, p = 0.143). A greater aPWV was observed following HIS compared to LSD (5.6 ± 1.6 vs 4.9 ± 0.8 m/s, p = 0.034). Conclusions: Short-term HIS adversely alters reservoir function and central artery haemodynamics in overweight/obese adults. These observations suggest a potential mechanism that may increase cardiovascular disease risk associated with HIS in this population.

A novel nonlinear afterload for ex vivo heart evaluation: Porcine experimental results.

BackgroundExisting working heart models for ex vivo functional evaluation of donor hearts often use cardiac afterloads made up of discrete resistive and compliant elements. This approach limits the practicality of independently controlling systolic and diastolic aortic pressure to safely test the heart under multiple loading conditions. We present and investigate a novel afterload concept designed to enable such control.MethodsSix ∼70 kg pig hearts were evaluated in vivo, then ex vivo in left‐ventricular working mode using the presented afterload. Both in vivo and ex vivo, the hearts were evaluated at two exertion levels: at rest and following a 20 μg adrenaline bolus, while measuring aortic pressure and flow, left ventricular pressure and volume, and left atrial pressure.ResultsThe afterload gave aortic pressure waveforms that matched the general shape of the in vivo measurements. A wide range of physiological systolic pressures (93 to 160 mm Hg) and diastolic pressures (73 to 113 mm Hg) were generated by the afterload.ConclusionsWith the presented afterload concept, multiple physiological loading conditions could be tested ex vivo, and compared with the corresponding in vivo data. An additional control loop from the set pressure limits to the measured systolic and diastolic aortic pressure is proposed to address discrepancies observed between the set limits and the measured pressures.

Changes of the non-invasive myocardial work in patient undergoing transcatheter aortic valve replacement: the influence of left bundle branch block

Abstract Funding Acknowledgements Type of funding sources: None. Patients with left bundle branch block (LBBB) are known to have substantially increased afterload sensitivity. It gains particular importance in subjects with aortic stenosis: patients with pre-existing LBBB may benefit more from interventions such as transcatheter aortic valve replacement (TAVR) by an effective and rapid reduction of the left ventricular (LV) pressures. Accordingly, our aim was to investigate the changes of LV myocardial work indices in patients undergoing TAVR by the presence of preoperative LBBB. Non-invasive myocardial work indices are novel echocardiographic parameters which adjust LV deformation to the instantaneous LV pressure, overcoming the the load-sensitivity of the traditional LV functional measures. Thirty patients undergoing TAVR were enrolled (37% female; age: 78±6 years; aortic valve area [AVA]: 0.7±0.3 cm2). Fourteen patients (47%; LBBB group) showed LBBB pattern on ECG, by demonstrating native LBBB (n=6; 20%) or having ventricular pacing dependency (n=8; 27%), while 16 patients had narrow QRS (53%; non-LBBB group). Prior to the procedure, subjects underwent a detailed echocardiographic investigation. Speckle-tracking analysis was performed and global longitudinal strain (GLS) was measured. LV pressure curve was estimated by adding the mean aortic valve gradient to the aortic systolic pressure. Using these measures, LV global constructive work index (CMWI) and global work efficiency (GWE). were quantified by commercially available software. A 6 months follow-up examination was also performed and at that time point we determined the aforementioned parameters. As expected, AVA significantly improved after the procedure in the pooled study group (1.8±0.4 cm2; p&amp;lt;0.001). GLS also significantly increased (-13.2±4.2 vs. -15.2±3.9 %; p&amp;lt;0.01), while CMWI only showed a tendential decrease (2422±788 vs. 2166±640 mmHg%; p=NS) at the follow-up. GLS (-10.6±3.7 vs. -15.5±3.4%; p&amp;lt;0.001), CMWI (1877±679 vs. 2898±529 mmHg%; p&amp;lt;0.001), and also GWE (82±9 vs. 91±4%; p&amp;lt;0.01) was significantly lower in the LBBB-group compared to the non-LBBB patients. At the follow-up, GLS was still significantly lower in the LBBB patients (-13.2±4.6 vs. -16.9±2.1%; p&amp;lt;0.01), however, CMWI was comparable between the two groups (1956±776 vs. 2350±439 mmHg%, p=NS). Pressure overload of the LV may affect patients with LBBB substantially more than subjects without it. TAVR causes an immediate and significant decrease in the LV afterload, which results in a more pronounced improvement in the LBBB group compared to those with no LBBB.

Comparison of a pulsatile and a continuous flow left ventricular assist device in high-risk PCI

BackgroundMechanical circulatory support devices are able to generate additional cardiac output or maintain sufficient circulation during high-risk PCI. We prospectively compared the hemodynamic and clinical performance of the new iVAC2L® device with the Impella 2.5® device during high-risk PCI. Materials and methodsIn 40 patients [10 female, age 75 ± 8 years, left ventricular ejection fraction (LVEF) 44 ± 11%] high-risk PCIs were performed under iVAC (n = 20) or Impella (n = 20) support. Hemodynamic parameters were collected before and after device placement as well as immediately after PCI. Blood parameters of hemolysis were analyzed before and after support. ResultsCorrect device placement was achieved in 17 patients (85%) under iVAC use and in 19 patients (95%) under Impella use. PCI success was 98%. Under iVAC2L® support, systolic, diastolic and mean aortic blood pressure increased significantly with increasing support time. In contrast, aortic pressure increased directly under Impella support, but the increase was comparable between both devices. Impella support generated a significantly higher additional blood flow, as compared to iVAC support (2.07 ± 0.09 l/min vs. 1.25 ± 0.05 l/min, p < 0.001). Five patients (iVAC n = 3) suffered from critical events during high-risk PCI, but both devices were able to maintain stable hemodynamic conditions. After PCI, one severe bleeding occurred in each group. After Impella support, haptoglobin was significantly decreased, indicating potential hemolysis. ConclusionsHigh-risk PCIs under support by both devices are feasible and safe and ensure stable hemodynamic conditions also if complications occur. Aortic pressure increases significantly with both devices, but later under iVAC use. Potential hemolysis occurs more frequent under Impella support.

Sex Differences in Vascular Endothelial Function After Liver Transplant

INTRODUCTIONLiver transplant (LT) recipients have an increased risk of developing cardiovascular disease (CVD) after transplant. Sex differences may be a significant determinant in the pathophysiology of CVD. However, sex‐differences in vascular dysfunction, an established precursor to CVD, have not been explored in LT recipients. The purpose of this study was to investigate the sex differences in vascular function and cardiometabolic risk‐factors to CVD among LT patients.METHODSConduit artery endothelial function was measured via flow‐mediated dilation of the brachial artery (FMDBA) with duplex ultrasound in 23 age‐matched LT patients (11 Male, 12 Female; Mean ± SEM: Age 55 ± 2 years). Aortic pressure waves were synthesized from radial artery waveforms acquired by applanation tonometry and the use of a generalized transfer function. Novel plasma based cardiometabolic risk factors were assessed with nuclear magnetic resonance spectroscopy. Lipoprotein insulin resistance index (LPIR) was calculated as a weighted combination of concentrations and particle sizes of very low‐density, low‐density, and high‐density lipoproteins. Diabetes risk index (DRI) factors LPIR and branched‐chain amino acid levels to predict the risk of type 2 diabetes. Metabolic inflammation index (INFX) combines concentrations of the inflammation biomarker GlycA and high‐density lipoprotein particle subspecies.RESULTSMales had lower FMDBA than females (3.98 ± 0.63 vs 6.27 ± 0.43%, p &lt; 0.01). There were no sex differences in aortic systolic pressure (Male vs Female; 129 ± 3 vs 118 ± 5 mmHg, p = 0.09), body mass index (38 ± 2 vs 36 ± 2 kg/m2, p = 0.61), LPIR (57 ± 7 vs 55 ± 7, p = 0.89), DRI (53 ± 7 vs 44 ± 6, p = 0.38), or INFX (47 ± 2 vs 54 ± 3, p = 0.13).CONCLUSIONSMales had poorer vascular endothelial function compared to females following LT, suggesting that males may be more susceptible to the development of CVD after LT. However, this increased risk cannot be explained by differences in traditional cardiometabolic risk factors. Future research should identify non‐traditional CVD risk factors that contribute to sex differences in vascular function towards implementing precision medicine for the prevention and management of CVD in LT patients.

Individualized Estrogen Dosing in Women Undergoing Premenopausal Bilateral Oophorectomy

Early menopause (prior to age 46 years) due to bilateral oophorectomy results in an abrupt loss of estrogen and other ovarian hormones and an increased risk of cardiovascular disease (CVD). Administration of estrogen partially mitigates this increased CVD risk; however, optimal dosing strategies for lowering CVD risk have not been studied. Current standard care is to use a dose of estrogen higher than that used for vasomotor symptom treatment in women after natural menopause in order to approximate the physiologic estradiol levels in premenopausal women (standard care); however, estradiol levels are not generally measured. An individualized approach that titrates estradiol levels to premenopausal hormone levels (individualized dosing) may be better for CVD risk mitigation in this younger population.The goal of this study was to compare the effect of estradiol dosing strategies (standard care vs. individualized dosing) on subclinical predictors of CVD in women with early menopause due to bilateral oophorectomy.We studied a total of 18 women at baseline and 6 months following surgical and medical intervention: 6 women underwent bilateral oophorectomy and were treated with standard care (age 41±2 years), 7 women underwent bilateral oophorectomy followed by estrogen therapy dosage based on individualized dosing (39±2 years), and 5 women served as time controls (did not undergo bilateral oophorectomy and were studied during the early‐follicular phase of the menstrual cycle at both visits; 34±3 years). At each time point, we assessed parameters of subclinical CVD including resting aortic blood pressure, carotid‐femoral pulse wave velocity, and blood pressure changes during a handgrip test and a cold pressor test.At baseline, serum estradiol levels were similar amongst groups (p&gt;0.05). After 6 months, women who received individualized dosing of estrogen therapy had higher serum estradiol levels (179±23 pg/ml) than women who received standard care (53±25 pg/ml, p=0.01) and women in the control group (78±27 pg/ml, p=0.03). Systolic and diastolic aortic blood pressures did not change between baseline and 6 months, nor did they differ amongst groups at any time point (p&gt;0.05 for all). There were no group or time differences in the change in mean blood pressure during the handgrip exercise or cold pressor test across 6 months (p&gt;0.05 for all).Over a 6‐month follow‐up, despite differences in serum estradiol levels following two different estradiol dosing strategies after bilateral oophorectomy, there were no group differences or detrimental changes in subclinical CVD parameters across time. It is yet to be seen if differences in these parameters will be apparent following a longer duration after bilateral oophorectomy.

Sex differences in aortic hemodynamics and associations with white matter hyperintensities in middle‐aged and older adults

Elevated blood pressure (BP) in midlife increases the risk of developing white matter hyperintensities (WMH) in the brain. WMH are associated with increased risk of cognitive decline and dementia. Structural changes of the large central arteries occur prior to changes in brachial BP. We have previously reported positive associations between aortic hemodynamics and WMH in normotensive postmenopausal women. The purpose of this study was to evaluate sex differences in aortic hemodynamics and associations with WMH burden in middle‐aged and older adults. Ninety‐nine participants (age = 63 ± 4y), including n = 35 men and n = 64 postmenopausal women participated in this study. Aortic hemodynamics were derived from radial artery pressure waveforms measured using applanation tonometry. Aortic systolic blood pressure (aSBP), aortic diastolic blood pressure (aDBP), augmented pressure (AP), aortic augmentation index (AIx), and aortic transit time were calculated. WMH lesion volume and intracranial volume (ICV) were measured using a FLAIR and T1 scan on a 3T MRI scanner, respectively. WMH fraction was calculated as (WMH lesion volume/ICV)*100 and cubic root transformed to reduce skewness. Age‐adjusted multiple linear regressions were used to determine the influence of aortic hemodynamics on WMH fraction. There were no sex differences in aSBP or aDBP. AP was greater in women compared with men (16 ± 5 mmHg vs. 11 ± 5 mmHg; P &lt; 0.001). AIx was also greater in women compared with men (28 ± 6 % vs. 18 ± 9 %; P &lt; 0.001). Aortic transit time was lower in women compared with men (140 ± 11 ms vs. 151 ± 12 ms; P &lt; 0.001). There were no sex differences in WMH fraction. There was a positive association between aSBP and WMH fraction in both men (r = 0.37, P = 0.015) and women (r = 0.36, P = 0.017). In addition, aDBP was positively associated with WMH fraction in men (r = 0.47, P = 0.003) and women (r = 0.36, P = 0.017). AP was positively associated with WMH fraction in men (r = 0.34, P = 0.027), but not women (r = 0.24, P = 0.296). AIx was positively associated with WMH fraction in men (r = 0.46, P = 0.004), but not women (r = 0.22, P = 0.570). There were no significant associations between aortic transit time and WMH fraction. In conclusion, AP and AIx were greater in women compared with men. The positive associations between AP and WMH fraction and AIx and WMH fraction were only apparent in men. These findings suggest a sex‐specific association between augmented pressure and augmentation index and WMH burden in middle‐aged and older adults.

Effect of Aquatic Exercise Training on Left Ventricular Afterload in in Middle‐aged and Older Normotensives: Evaluation by Polar coordinate description

Regular aerobic physical activity has been recommended to prevent the age‐related increase in cardiovascular disease risks. However, the effect of in‐water aerobic exercise training (e.g., swimming, head‐out aquatic exercise) on the aortic augmentation index (AIx), an index of left ventricular afterload, is inconsistent. Recently, there has been a gaining recognition about the limitations of dimensionless ratio‐based metrics, including AIx (=augmentation pressure [AP]/pulse pressure [PP]). The single‐use of ratio would provide incomplete information relative to the “content” of the two components: since AP is a component of PP, the training‐induced change in AP might be masked by the corresponding change in PP. Accordingly, using the newly proposed companion metrics of AIx by polar coordinate description, we determined the effect of head‐out aquatic exercise training on left ventricular afterload in middle‐aged and older adults. We evaluated aortic hemodynamics in 15 normotensives (62±10 y.o., four men) before and after a 15‐week aquatic exercise course. Aortic hemodynamics were estimated from brachial arterial pressure waveforms via the general transfer function method. Companion metrics of AIx (AIxC=√{AP2+PP2}) were calculated as measures of arterial load. The participation rate in the training course was 86 %. Aortic systolic blood pressure (SBP) decreased after the training course (from 112±8 to 108±11 mmHg, P=0.02). AIxC also decreased (from 45±7 to 42±7 mmHg2, P=0.01). In contrast, AIx remained unchanged (from 47±10 to 45±11 %, P=0.148) presumably due to parallel changes in AP (from 19±5 to 17±5 mmHg, P=0.002) and PP (from 41±6 to 39±6 mmHg, P=0.01). These findings suggest that head‐out aquatic exercise training might lower the left ventricular afterload in middle‐aged and older normotensives. The newly introduced companion metric may provide better insight into underlying physiology.

Progression of type B intramural hematoma in patients with obstructive sleep apnea

ObjectiveIn the present study, we estimated the influence of obstructive sleep apnea (OSA) on the progression of type B intramural hematoma (IMHB). MethodsA total of 127 patients had undergone sleep evaluations and esophageal pressure measurements. The variables associated with aorta-related adverse events and mortality were summarized by logistic regression analysis and Cox proportional hazard models. A competing risk analysis of death was used to estimate aorta- and non–aorta-related mortality. ResultsThe OSA group had a greater aorta-related adverse events rate (46% vs 4%; P < .001). The mean nighttime systolic pressure (odds ratio [OR], 1.24; 95% confidence interval [CI], 1.11-1.38; P < .001) was associated with aorta-related adverse events during the acute phase. Thoracic endovascular aortic repair (hazard ratio [HR], 16.2; 95% CI, 7.68-34.22, P < .001) and mean morning systolic pressure (HR, 1.43; 95% CI, 1.22-1.68; P < .001) were associated with a higher rate of aorta-related adverse events. OSA (HR, 3.19; 95% CI, 2.57-12.15; P < .001) and mean morning systolic pressure (HR, 1.59; 95% CI, 1.27-2.01; P = .002) were significantly associated with aorta-related mortality. Competing risk analysis revealed significantly higher aorta-related mortality in the OSA group (11.8% vs 2.0%; P = .0412). A neutrophil/lymphocyte ratio >3.52 (specificity, 90.2%; sensitivity, 89.5%) and mean platelet volume/platelet ratio >0.049 (specificity, 98.0%; sensitivity, 98.7%) had diagnostic value for detecting OSA in patients with IMHB. ConclusionsThe presence of OSA led to a higher aorta-related adverse event rate and mortality in patients with IMHB. The variables associated with these outcomes included thoracic endovascular aortic repair, mean morning and nighttime systolic pressure, and OSA. The neutrophil/lymphocyte ratio and platelet volume/platelet ratio are valuable for detecting OSA in patients with IMHB.

L-Citrulline supplementation attenuates aortic pulse pressure and wave reflection responses to cold stress in older adults

Augmented aortic systolic blood pressure (SBP) and wave reflection via sympathetic-mediated vasoconstriction elevates the risk for adverse cardiovascular events in older adults. L-citrulline (L-CIT) supplementation has shown to reduce aortic SBP and pulse pressure (PP) responses to cold pressor test (CPT) induced sympathoactivation in young men. The aim of this study was to elucidate the efficacy of L-CIT supplementation to attenuate aortic hemodynamic responses to CPT in older adults. Sixteen older adults were randomly assigned to placebo or L-CIT (6g/day) for 14-days in a crossover, double-blind, placebo-controlled design. Brachial SBP and aortic SBP, PP, augmented pressure (AP), augmentation index standardized at 75bpm (AIx@75), and pressure of the forward (Pf) and reflected (Pb) waves were evaluated at rest and during CPT pre- and post-intervention. Although no hemodynamic changes at rest, brachial SBP (Δ-12±18 vs. Δ4±14mmHg; P=0.008) and aortic SBP (Δ-10±14 vs. Δ4±12mmHg; P=0.005), PP (Δ-10±12 vs. Δ4±11mmHg; P=0.002), AP (Δ-4±4 vs. Δ2±7mmHg; P=0.004), AIx@75 (Δ-3.2±7.2 vs. Δ2.2±6.9%; P=0.038), Pf (Δ-6±10 vs. Δ3±9mmHg; P=0.019), and Pb (Δ-4±6 vs. Δ2±6mmHg; P=0.008) responses to the CPT were significantly attenuated following L-CIT supplementation vs. placebo. L-CIT supplementation attenuated aortic pulsatile pressure and pressure wave reflection responses to CPT in older adults, providing possible cardioprotection during cold-induced sympathoactivation in older adults.

Glucose Metabolic Disorders Enhance Vascular Dysfunction Triggered by Particulate Air Pollution: a Panel Study.

Vascular dysfunction is a biological pathway whereby particulate matter (PM) exerts deleterious cardiovascular effects. The effects of ambient PM on vascular function in prediabetic individuals are unclear. A panel study recruited 112 Beijing residents with and without prediabetes. Multiple vascular function indices were measured up to 7 times. The associations between vascular function indices and short-term exposure to ambient PM, including fine particulate matter (PM2.5), ultrafine particles, accumulation mode particles, and black carbon, and the modification of these associations by glucose metabolic status were examined using linear mixed-effects models. Increases in brachial artery pulse pressure, central aortic pulse pressure, and ejection duration, and decreases in subendocardial viability ratio and reactive hyperemia index were significantly associated with at least one PM pollutant in all participants, indicating increased vascular dysfunction. For example, for an interquartile range increment in 5-day moving average ultrafine particles, brachial artery pulse pressure, and central aortic pulse pressure increased 5.4% (0.8%-10.4%) and 6.2% (1.2%-11.5%), respectively. Additionally, PM-associated changes in vascular function differed according to glucose metabolic status. Among participants with high fasting blood glucose levels (≥6.1 mmol/L), PM exposure was significantly associated with increased brachial artery systolic blood pressure, central aortic systolic blood pressure, brachial artery pulse pressure, central aortic pulse pressure, and augmentation pressure normalized to a heart rate of 75 bpm and decreased subendocardial viability ratio and reactive hyperemia index. Weaker or null associations were observed in the low-fasting blood glucose group. Glucose metabolic disorders may exacerbate vascular dysfunction associated with short-term ambient PM exposure.

Posture-Related Differences in Cardiovascular Function Between Young Men and Women: Study of Noninvasive Hemodynamics in Rural Malawi.

BackgroundCardiovascular risk is higher in men than in women, but little information exists about sex‐related differences in cardiovascular function from low‐income countries. We compared hemodynamics between sexes in rural Malawi in a cohort followed up since their birth.Methods and ResultsSupine, seated, and standing hemodynamics were recorded from 251 women and 168 men (mean age, 21 years; body mass index, 21 kg/m2) using oscillometric brachial waveform analyses (Mobil‐O‐Graph). The results were adjusted for estimated glomerular filtration rate, and plasma potassium, lipids, and glucose. Men had higher brachial and aortic systolic blood pressure and stroke index regardless of posture (P<0.001), and higher upright but similar supine diastolic blood pressure than women. Regardless of posture, heart rate was lower in men (P<0.001), whereas cardiac index did not differ between sexes. Women presented with lower supine and standing systemic vascular resistance index (P<0.001), whereas supine‐to‐standing increase in vascular resistance (P=0.012) and decrease in cardiac index (P=0.010) were higher in women. Supine left cardiac work index was similar in both sexes, whereas standing and seated left cardiac work index was higher in men than in women (P<0.001).ConclusionsIn young Malawian adults, men had higher systolic blood pressure, systemic vascular resistance, and upright cardiac workload, whereas women presented with higher posture‐related changes in systemic vascular resistance and cardiac output. These findings show systematic sex‐related differences in cardiovascular function in a cohort from a low‐income country with high exposure to prenatal and postnatal malnutrition and infectious diseases.

Patient-Specific Modelling and Parameter Optimisation to Simulate Dilated Cardiomyopathy in Children

PurposeLumped parameter modelling has been widely used to simulate cardiac function and physiological scenarios in cardiovascular research. Whereas several patient-specific lumped parameter models have been reported for adults, there is a limited number of studies aiming to simulate cardiac function in children. The aim of this study is to simulate patient-specific cardiovascular dynamics in children diagnosed with dilated cardiomyopathy, using a lumped parameter model.MethodsPatient data including age, gender, heart rate, left and right ventricular end-systolic and end-diastolic volumes, cardiac output, systolic and diastolic aortic pressures were collected from 3 patients at Great Ormond Street Hospital for Children, London, UK. Ventricular geometrical data were additionally retrieved from cardiovascular magnetic resonance images. 23 parameters in the lumped parameter model were optimised to simulate systolic and diastolic pressures, end-systolic and end-diastolic volumes, cardiac output and left and right ventricular diameters in the patients using a direct search optimisation method.ResultsDifference between the haemodynamic parameters in the optimised cardiovascular system models and clinical data was less than 10%.ConclusionThe simulation results show the potential of patient-specific lumped parameter modelling to simulate clinical cases. Modelling patient specific cardiac function and blood flow in the paediatric patients would allow us to evaluate a variety of physiological scenarios and treatment options.

Color-coded summation images for the evaluation of blood flow in endovascular aortic dissection fenestration

BackgroundTo analyze the benefit of color-coded summation images in the assessment of target lumen perfusion in patients with aortic dissection and malperfusion syndrome before and after fluoroscopy-guided aortic fenestration.MethodsBetween December 2011 and April 2020 25 patients with Stanford type A (n = 13) or type B dissection (n = 12) and malperfusion syndromes were treated with fluoroscopy-guided fenestration of the dissection flap using a re-entry catheter. The procedure was technically successful in 100% of the cases and included additional iliofemoral stent implantation in four patients. Intraprocedural systolic blood pressure measurements for gradient evaluation were performed in 19 cases. Post-processed color-coded DSA images were obtained from all DSA series before and following fenestration. Differences in time to peak (dTTP) values in the compromised aortic lumen and transluminal systolic blood pressure gradients were analyzed retrospectively. Correlation analysis between dTTP and changes in blood pressure gradients was performed.ResultsMean TTP prior to dissection flap fenestration was 6.85 ± 1.35 s. After fenestration, mean TTP decreased significantly to 4.96 ± 0.94 s (p < 0.001). Available systolic blood pressure gradients between the true and the false lumen were reduced by a median of 4.0 mmHg following fenestration (p = 0.031), with significant reductions in Stanford type B dissections (p = 0.013) and minor reductions in type A dissections (p = 0.530). A moderate correlation with no statistical significance was found between dTTP and the difference in systolic blood pressure (r = 0.226; p = 0.351).ConclusionsHemodynamic parameters obtained from color-coded DSA confirmed a significant reduction of TTP values in the aortic target lumen in terms of an improved perfusion in the compromised aortic region. Color-coded DSA might thus be a suitable complementary tool in the assessment of complex vascular patterns prevailing in aortic dissections, especially when blood pressure measurements are not conclusive or feasible.