Measurement Of Aortic Pressure Research Articles

COMPARISON OF COMPONENTS OF CENTRAL AORTIC AND PERIPHERAL BLOOD PRESSURE FOR PREDICTION OF CARDIOVASCULAR EVENTS IN A 2-YEAR AND 14-YEAR FOLLOW-UP OF A HYPERTENSIVE COHORT

Objective: The aim of this study was to assess components of central aortic pressure, brachial blood pressure and indices of arterial stiffness for prediction of cardiovascular events in a hypertensive cohort. Design and method: Noninvasive measurements of central aortic blood pressure (SphygmoCor), brachial pressure, central augmentation index (cAIx), augmented pressure (cAP) and carotid intima-media thickness (IMT) were obtained in 681 hypertensive patients (age 61 ± 9 years, 425 males). The primary endpoints were defined as cardiovascular disease (CVD) events or death from CVD. An initial analysis was conducted at mean 2-year follow-up and a second analysis is currently being conducted at mean 14-year follow-up. Results: Total events were 59 (8.7%) for the 2-year follow-up and 265 (38.9%) for the 14-year follow-up. Major cardiovascular events were 49 (83.1%) and 178 (67.2%) respectively. The analysis of the 2-year follow-up suggested that central systolic (cSBP) and pulse pressure (cPP) showed higher hazard ratios (HR/10 mmHg) for cardiovascular events compared to peripheral pressure indices (pSBP, pPP) at age >60 years (cSBP: HR = 1.18, pSBP: HR = 1.17, p = 0.034; cPP: HR = 1.28, pPP: HR = 1.2, p = 0.019). Each SD increase in IMT and in cAP was associated with 1.4 times higher risk of increased total events in elderly patients (age >60 years). Males showed that each SD increase in cAP was associated with significantly higher risk of increased total events than females. The complete data for the 14-year follow-up analysis has only recently become available and the analysis will be completed for the conference presentation. Conclusions: Preliminary analysis in a short-term (2-year) follow-up study of a large hypertensive cohort has shown that central aortic pressure and its components can improve prediction of CVD compared to peripheral pressure. The final analysis of the long-term (14-year) follow-up will determine which components are robust predictors and will provide important information on the clinical and epidemiological relevance of central aortic pressure.

Hemodynamic performance of self-expandable transcatheter aortic valve replacement systems during valve deployment.

Little is known about valve hemodynamic performance during the Evolut and Neo deployment course. We aimed to evaluate transvalvular mean and peak-to-peak gradients over several intraprocedural timepoints during TAVR with Evolut PRO+ (Medtronic) and Neo (Boston Scientific) systems. This was single-center pilot sub-study from the SavvyWire EFficacy and SafEty in Transcatheter Aortic Valve Implantation Procedures (SAFE-TAVI) trial. Participants received either the Evolut PRO+ or Neo for native valve severe aortic stenosis and the SavvyWire (OpSens Medical) was used for device delivery, pacing, and continuous left ventricular and aortic pressure measurements. For the Evolut, evaluation was done for baseline, two-thirds of valve deployment (still recapturable), 90% of valve deployment (no longer recapturable), and post-deployment hemodynamics. For the Neo, analysis was done at baseline, after the first step (top-crown deployment), and at final status. Nineteen patients were included (Evolut = 15; Neo = 4). There were no statistically significant changes in peak-to-peak gradients (44 mm Hg [IQR:33-69] vs 43 mm Hg [IQR:26-62], P = .41) between baseline and two-thirds of valve deployment in the Evolut patients. There was a significant decrease in mean (40 mm Hg [IQR:32-54] vs 14 mm Hg [IQR:10-18], P less than .001) and peak-to-peak (43 mmHg [IQRS:26-62] vs 9 mm Hg [IQR:8-13], P less than .001) transvalvular gradients between two-thirds and 90% of valve deployment for Evolut. Neo patients exhibited a decrease in transvalvular gradients after top-crown deployment (42.5 mm Hg baseline vs 13 mm Hg). Transvalvular gradients did not vary between the point of "no-recapture" compared to baseline values in patients receiving the Evolut, whereas a significant reduction in transvalvular gradients was observed when the valve was deployed at 90% and fully deployed. The Neo valve was slightly obstructive after the first step of deployment.

Is cardioplegia system pressure the optimal measure of coronary perfusion during antegrade cardioplegia delivery? A critical review of pressure measurements for optimal antegrade delivery.

Antegrade cardioplegia is routinely given during cardiac surgery. The delivery of antegrade cardioplegia from the cardiopulmonary bypass machine has many variables. Many perfusionists rely exclusively on cardioplegia system pressure to ensure safe antegrade delivery. Our group reviewed antegrade cardioplegia delivery in 50 patients undergoing coronary artery bypass graft. The data collected included the cardioplegia system pressure and the patient's direct aortic root pressure. The analysis of the data found weak correlation between the two pressures with a large mean difference and a wide standard deviation. The results suggest the direct measurement of aortic root pressure as guidance to antegrade cardioplegia instead of relying solely on cardioplegia system pressure.

A study on transfer function to estimate the central aortic blood pressure waveform

Noninvasive measurement of the central aortic blood pressure has become an important technique that has generated a lot of interest around the medicine industry because it can estimate the central aortic blood pressure waveform without inserting a pressure-sensing catheter into the ascending aorta. The accuracy of noninvasive estimation of aortic hemodynamics and cardiac contractility is still debatable in noninvasive measurement of the central aortic blood methods. The objective of this project is to investigate the transfer functions available for converting radial blood pressure waveforms to central aortic blood pressure waveforms. In this project, three different transfer functions will be investigated which are The Generalized Transfer Function, N-Point Moving Average and Adaptive Transfer Function in order to recommend the effective method in terms of accuracy. The study methodology will be conducted through the software MATLAB R2021b. The investigation of these three methods will be conducted with data collected from virtual subjects from the HaeMod database. The Generalized transfer function, N-Point Moving Average and Adaptive Transfer Function will be coded, evaluated, and analyzed as part of the methodology. The determination of the most effective method among the three transfer functions will be attributed according to output comparison of Systolic peak differences, the RMSE and the MAPE between the estimated central aortic blood pressure and the measured central aortic blood pressure.

Non-invasive central aortic pressure measurement: what limits its application in clinical practice?

The following article highlights the need for methodological transparency and consensus for an accurate and non-invasive assessment of central aortic blood pressure (aoBP), which would contribute to increasing its validity and value in both clinical and physiological research settings. The recording method and site, the mathematical model used to quantify aoBP, and mainly the method applied to calibrate pulse waveforms are essential when estimating aoBP and should be considered when analyzing and/or comparing data from different works, populations and/or obtained with different approaches. Up to now, many questions remain concerning the incremental predictive ability of aoBP over peripheral blood pressure and the possible role of aoBP-guided therapy in everyday practice. In this article, we focus on "putting it on the table" and discussing the main aspects analyzed in the literature as potential determinants of the lack of consensus on the non-invasive measurement of aoBP.

Role of atrial natriuretic peptide in the dissociation between flow relations with ventricular mass and function in a community with volume-dependent hypertension.

Whether differential effects of volume load on left ventricular mass (LVM) and function occur in sustained volume-dependent primary hypertension, and the impact of atrial natriuretic peptide (ANP) on these effects, is unknown. From aortic pressure, velocity and diameter measurements and echocardiography, we determined in an African community (n = 772), the impact of systemic flow-induced increases in central pulse pressure (PPc) and circulating ANP (ELISA) on LVM and indexes of function. Stroke volume (SV), but not aortic flow (Q), was associated with LVM and mean wall thickness (MWT) beyond stroke work and confounders (p < 0.0001). Adjustments for SV markedly decreased the relationships between PPc and LVMI or MWT. However, neither SV, nor Q were independently associated with either myocardial s', e', or E/e' (p > 0.14) and adjustments for neither SV nor Q modified relationships between PPc and s', e' or E/e' (p < 0.005 to <0.0001). SV was nevertheless strongly and independently associated with ANP (p < 0.0001) and ANP was similarly strikingly associated with s' (p < 0.0001) and e' (p < 0.0005), but not E/e', independent of confounders and several determinants of afterload. Importantly, ANP concentrations were inversely rather than positively associated with LV diastolic dysfunction (DD) (p < 0.005) and lower rather than higher ANP concentrations contributed markedly to the ability to detect DD in those with, but not without LV hypertrophy. In populations with sustained volume-dependent hypertension, flow (SV)-related increases in PP have a major impact on LV structure, but not on function, an effect attributed to parallel striking beneficial actions of ANP on myocardial function.

The effect of successful lower extremity revascularization on aortic stiffness in patients with peripheral arterial disease.

Peripheral arterial disease (PAD) is a global health problem and associated with poor outcomes. It causes increased arterial stiffness. The association of PAD with aortic arterial stiffness was investigated in previous studies. However, there is limited data regarding the effect of peripheral revascularization on arterial stiffness. The aim of our study is to investigate the effect of peripheral revascularization on aortic stiffness parameters in patients with symptomatic PAD. A total of 48 patients with PAD who underwent peripheral revascularization were included in the study. Echocardiography was performed before and after the procedure, and aortic stiffness parameters were obtained by using aortic diameters and arterial blood pressure measurements. Post-procedural aortic strain (5.1 [1.3-14] vs. 6.3 [2.8-6.3], p = 0.009) and aortic distensibility (0.2 [0.0-0.9] vs. 0.3 [0.1-1.1], p = 0.001) measurements were significantly increased compared to pre-procedural values. Patients were also compared according to the lesion laterality, site and treatment methods. It was found that the change in aortic strain (p = 0.031) and distensibility (p = 0.043) were significantly higher in unilateral lesion compared to bilateral lesion. Also, the change in aortic strain (p = 0.042) and distensibility (p = 0.033) were significantly higher in iliac site lesion compared to superficial femoral artery (SFA) site lesion. Moreover, the change in aortic strain was significantly higher (p = 0.013) in patients treated with stent compared to only balloon angioplasty. Our study showed that successful percutaneous revascularization significantly reduced aortic stiffness in PAD. The change in aortic stiffness was significantly higher in unilateral lesions, iliac site lesions and stent-treated lesions.

Orthostatic blood pressure adaptations, aortic stiffness, and central hemodynamics in the general population: insights from the Malmö Offspring Study (MOS)

PurposeArterial stiffness is independently associated with orthostatic hypotension in older individuals. The relationship between orthostatic blood pressure adaptation and aortic stiffness has not been thoroughly examined in a younger population. We investigated the relationship between orthostatic blood pressure adaptations, central aortic hemodynamics, and aortic stiffness in a cohort of predominantly younger and middle-aged adults.MethodsWe analyzed an observational, population-based study of 5259 individuals living in Malmö, Sweden. We related aortic stiffness and central hemodynamics assessed by carotid–femoral pulse wave velocity and pulse wave analysis at the arteria radialis using Sphygmocor to orthostatic blood pressure adaptation after 3 min standing.ResultsThe mean age of the population was 41.9 ± 14.5 years, and 52.1% were women. We observed the highest aortic stiffness and central aortic blood pressure measurements in the lowest and highest quartiles of orthostatic systolic blood pressure differences (p < 0.001). Aortic stiffness and central aortic blood pressure gradually decreased across increasing quartiles of orthostatic diastolic blood pressure difference (p < 0.001). After full adjustment, orthostatic diastolic blood pressure remained significantly associated with aortic stiffness (p = 0.001) and central aortic blood pressure (p < 0.001), whereas orthostatic systolic blood pressure was significantly associated only with central aortic systolic blood pressure (p = 0.009). No significant associations were found between subclinical orthostatic hypotension, aortic stiffness, and central hemodynamics.ConclusionsOur findings demonstrate that altered blood pressure responses to orthostatic challenges, both blood pressure reductions and blood pressure increases, are independently and inversely associated with markers of aortic stiffness (vascular aging) in a predominantly young to middle-aged population.

Aneurysm Sac Pressure during Branched Endovascular Aneurysm Repair versus Multilayer Flow Modulator Implantation in Patients with Thoracoabdominal Aortic Aneurysm.

Open thoracoabdominal repair is the gold standard in the TAAA treatment. However, there are endovascular techniques, that sometimes may be an alternative, such as branched endovascular aneurysm repair (BEVAR) or implantation of the multilayer flow modulator (MFM). In this study, we aimed to assess differences in the aneurysm sac pressure (ASP) between patients undergoing BEVAR and MFM implantation. The study included 22 patients with TAAA (14 patients underwent BEVAR, while eight MFM implantation). The pressure sensor wire was placed inside the aneurysm. A measurement of ASP and aortic pressure (AP) was performed during the procedure. The systolic pressure index (SPI), diastolic pressure index (DPI), and pulse pressure index (PPI) were calculated as a quotient of the ASP and AP values. After the procedure, SPI and PPI were lower in the BEVAR group than in the MFM group. During a procedure, a drop in SPI and PPI was noted in patients undergoing BEVAR, while no changes were revealed in the MFM group. This indicates that BEVAR, but not MFM, is associated with a reduction in systolic and pulse pressure in the aneurysm sac in patients with TAAA.

Evaluating the Effectiveness of Stenting for Aortic Coarctation

Coarctation of the aorta (CoA) is a congenital cardiovascular malformation involving narrowing of the thoracic aorta just distal to the left subclavian artery. The aim of our study was to evaluate the hemodynamic effects of endovascular treatment for CoA by using invasive aortic catheterization. All patients with CoA who underwent treatment by aortic stent implantation between September 1, 2003, and February 1, 2019, at the "Onassis Cardiac Surgery Center," in Athens, Greece, were evaluated. Patients were treated with either bare (uncovered) Cheatham-Platinum (bCP) or covered Cheatham-Platinum (cCP) stent implantations. Invasive aortic pressure measurements were recorded before and after the endovascular intervention. A total of 48, eight zig CP stents, comprising 24 bCP and 24 cCP stents were implanted in 47 patients. The mean aortic diameter (mm) at the CoA lesion increased from 9.7 ± 3.3 to 19.2 ± 2.9 mm (p <0.01) after the endovascular procedure. The invasive mean blood pressure (BP; mm Hg) from catheterization in the descending aorta increased (before = 114.2 ± 12.8 vs. after = 135.5 ± 28.1; p <0.01), while the invasive mean BP (mm Hg) from catheterization in the ascending aorta was decreased (before = 156.8 ± 25.0 vs. after = 138.4 ± 27.5; p <0.01) after the intervention. The mean aortic BP gradient decreased in both types of stents after intervention (BP gradient among patients with cCP stents = 30.9 +/- 23.6 mmHg and BP gradient among patients with bCP stents = 38.0 +/-23.1 mmHg). However, there was no statistically significant difference between the two types of stents; p = 0.36. Invasive aortic catheterization provided evidence that endovascular stenting with either bare or covered stents is efficient in treating patients with CoA.

Science, Medicine, and the Anesthesiologist

Science, Medicine, and the Anesthesiologist

Noninvasive Measurement of Aortic Pressure and Evaluation of Arterial Stiffness in Patients with Hypertension: An Observational Study.

Arterial stiffness, a major marker of vascular impedance, has been identified as a predictor of adverse cardiac outcomes. The present study determined the relationship between blood pressure (BP) and arterial stiffness measured noninvasively using a periscope in hypertensive patients. It has also evaluated the usefulness of indices of arterial stiffness in cardiovascular (CV) risk stratification and the necessity to implement these aortic pressure parameters in clinical practice. The prospective, observational study involved patients with hypertension between the age of 18 and 80 years. The demographic and anthropometric measurements of all the participants were recorded and various central and peripheral (brachial) arterial pressure parameters were measured using a periscope. The clinical variables were compared separately for different CV risk grades and arterial stiffness index (ASI) using Kruskal-Wallis test for non-normal data and chi-square test for count data. The correlation of different parameters with CV risk grade and ASI were evaluated using Spearmen's correlation method. The agreement of different ASI indices with CV risk grades was assessed using Kappa method. The study recruited a total of 3,032 patients with hypertension. Classification of the subjects for CV risk grades had demonstrated that major proportion of the patients (n = 713) had moderate and severe CV risks (n = 708). The classification of hypertensive patients for arterial stiffness had shown that 1,037 subjects had severe arterial stiffness. Classification of arterial stiffness based on BP levels had demonstrated that 623 patients with severe arterial stiffness and 315 with borderline arterial stiffness had stage II hypertension, and 480 patients with normal BP had no arterial stiffness. Brachial ASI had a strong correlation with systolic BP (SBP). A very good agreement with K value 0.871 was noted for Kappa agreement of arterial stiffness indices with CV risk. The present study corroborates the use of central BP parameters as indicators of arterial stiffness in hypertensive subjects. Noninvasive measurement of these indices has wider implications in personalized risk assessment of CV risk in subjects with hypertension.

Rationale and design of SAVI-AoS: A physiologic study of patients with symptomatic moderate aortic valve stenosis and preserved left ventricular ejection fraction.

BackgroundModerate aortic valve stenosis occurs twice as often as severe aortic stenosis (AS) and carries a similarly poor prognosis. Current European and American guidelines offer limited insight into moderate AS (MAS) patients with unexplained symptoms. Measuring valve physiology at rest while most patients experience symptoms during exertion might represent a conceptual limitation in the current grading of AS severity. The stress aortic valve index (SAVI) may delineate hemodynamically significant AS among patients with MAS.ObjectivesTo investigate the diagnostic value of SAVI in symptomatic MAS patients with normal left ventricular ejection fraction (LVEF ≥ 50%): aortic valve area (AVA) > 1 cm2 plus either mean valve gradient (MG) 15–39 mmHg or maximal aortic valve velocity (AOV max) 2.5–3.9 m/s. Short-term objectives include associations with symptom burden, functional capacity, and cardiac biomarkers. Long-term objectives include clinical outcomes.Methods and resultsMulticenter, non-blinded, observational cohort. AS severity will be graded invasively (aortic valve pressure measurements with dobutamine stress testing for SAVI) and non-invasively (echocardiography during dobutamine and exercise stress). Computed tomography (CT) of the aortic valve will be scored for calcium, and hemodynamics simulated using computational fluid dynamics. Cardiac biomarkers and functional parameters will be serially monitored. The primary objective is to see how SAVI and conventional measures (MG, AVA and Vmax) correlate with clinical parameters (quality of life survey, 6-minute walk test [6MWT], and biomarkers).ConclusionsThe SAVI-AoS study will extensively evaluate patients with unexplained, symptomatic MAS to determine any added value of SAVI versus traditional, resting valve parameters.

On inlet pressure boundary conditions for CT-based computation of fractional flow reserve: clinical measurement of aortic pressure

Background and objectives A quick calculation approach of steady-state fractional flow reserve (FFRss) based on computed tomography angiography (CTA) images is a reliable non-invasive way of calculate FFR, the assumptions used in the research should be study further to increase forecast accuracy. The effect of inlet and outlet boundary conditions on FFRss was investigated. Methods 15 patients who had been diagnosed with coronary artery disease were enrolled in this study. We investigated the sensitivity of calculating FFR to boundary circumstances, using invasive FFR as a benchmark. There are two types of inlet: (1) aortic pressure based on clinically measured. (2) mean pressure calculated based on physiological formula; we further studied the outlet changes of FFRss under different coronary vasodilation responses (24%, 48%, 72%). Results According to the calculate FFR results of all patients, FFRSST (based on the clinical experiment) and FFRSSM (based on the physiological formula) {r = 0.99, [95% confidence interval (CI):0.0.94 to 1.14] (p < 0.001)}. Although the pressure difference between the two pressure boundary conditions is 15 mmHg, the calculated FFR result does not change significantly. The microcirculation resistance of the outlet gradually rose as the vasodilation state changed, and the computed FFR increased. Conclusions A numerical analysis of the effects of proximal and distal boundary constraints of computational models on computed CT-FFR is presented. The findings revealed that distal boundary circumstances (hyperemic vasodilation response of coronary micro-vessels) have a significant impact on FFR, providing evidence to guide the development and application of a computational model for estimating FFR.

Significant venous flow alterations following brain arteriovenous malformation Surgery: Assessment by transcranial colour duplex

Brain arteriovenous malformation (bAVM) resection imposes several post-operative clinical challenges including intracranial haemorrhage (ICH). Daily non-invasive monitoring of haemodynamic measurements may be useful in predicting post-operative ICH.This prospective study used transcranial colour duplex (TCCD) and central aortic pressure (CAP) measurements to evaluate 15 bAVM patients pre-operatively and daily ≤ 14 days post-operatively.TCCD measurements of middle cerebral artery and veins included peak systolic (PSV), end diastolic (EDV), and pulsatility indices (PI). Parameters were compared with 7 craniotomy patients (non-bAVM craniotomy/surgical group). Normal reference values included 20 healthy volunteers.Significant middle cerebral vein MCV changes in bAVM patients occurred;Maximal PSV was significantly higher (median 47 cm/s) compared to non-bAVM craniotomy/surgical controls (median 17 cm/s, p = 0.0123); maximal PI was significantly higher (median 0.99, p = 0.005) compared to the non-bAVM craniotomy/surgical controls (median 0.49).In 8 of 15 patients, increased MCV velocity and pulsatility “stabilised” within 14 days post-operatively. Mean number of days for the 8 patients to reach stable state was 5.9 days, (range 0–9 days).To our knowledge, this is the first imaging study demonstrating significant venous changes post bAVM resection. Significant increased venous flow occurs in pial veins bilaterally. Increased pressure of venous flow is evidenced by a significant increase in diameter and pulsatility. Subsequently, haemorrhagic complications may be due distal constriction of the pial veins causing venous hypertension. The cause of the dilated vascular bed is unknown.

Comparing Central Aortic Pressures Obtained Using a SphygmoCor Device to Pressures Obtained Using a Pressure Catheter.

This study compared aortic pressures estimated using a SphygmoCor XCEL PWA device (ATCOR, Naperville, IL) noninvasively with aortic pressures obtained using pressure catheters during catheterization procedures and analyzed the impact of a linear-fit function on the estimated pressure values. One hundred and thirty-six patients scheduled for cardiac catheterization procedure were enrolled in IRB approved studies. Catheterization procedures were performed according to standard-of-care to acquire aortic pressure measurements. Immediately after the catheterization procedure with the pressure catheters removed, while the patients were still in the catheterization laboratory, central aortic pressures were estimated with the SphygmoCor device (using its inbuilt transfer function). The error between measured and estimated aortic pressures was evaluated using Bland-Altman analysis (n = 93). A linear-fit was performed between the measured and estimated pressures, and using the linear equation the error measurements were repeated. A bootstrap analysis was performed to test the generalizability of the linear-fit function. In a subset of cases (n = 13), central aortic pressure values were also obtained using solid-state high-fidelity catheters (Millar, Houston, TX), and the error measurements were repeated. The magnitude of errors between the measured and estimated aortic pressures (mean errors >6.4 mm Hg; mean errors >8.0 mm Hg in the subset) were reduced to less than 1 mm Hg after using the linear-fit function derived in this study. For the population examined in this study, the SphygmoCor data must be used with the linear-fit function to obtain aortic pressures that are comparable to the measurements obtained using pressure catheters. Trial Numbers NCT03243942 and NCT03245255.

Abstract 9538: Comparison of Central Aortic Pressures Obtained Using an Invasive Pressure Catheter and the Noninvasive Sphygmocor Device

Introduction: The SphygmoCor (ATCOR, Naperville, IL) device utilizes a generalized transfer function based on patient’s age and gender to derive the aortic pressure pulse from the brachial-cuff based pressure measurements. This study compared aortic pressures obtained using SphygmoCor with aortic pressures obtained during cardiac catheterization. Hypothesis: Mean differences in aortic pressures obtained using SphygmoCor and pressure catheters will be less than 5 mmHg. Methods: After IRB approval, 136 patients were enrolled. During standard-of-care catheterization procedure, aortic pressure measurements were obtained using fluid-filled catheters. In a subset of patients (n = 13) the aortic pressure values were also obtained using solid-state high-fidelity Millar catheters. Immediately after the catheterization procedure, while the patients were still in the catheterization laboratory (on the procedure table), central aortic pressures were estimated with the SphygmoCor device. The measured and estimated aortic pressures were compared using linear regression and Bland-Altman analysis. A linear fit was performed to derive an additional transfer function to convert SphygmoCor pressure values to catheter-based aortic pressures, and the resulting differences in pressure values were compared. A bootstrap analysis was performed to test the generalizability of this transfer function. Results: Mean differences in systolic, diastolic and pulse aortic pressures obtained using the two techniques ranged from 6.5 to 18.0 mmHg (p &lt; 0.001). In the subset with high-fidelity catheters, the differences ranged from 8.0 to 18.9 mmHg. With the linear-fit transfer function, the differences in systolic, diastolic and pulse aortic pressures were low (&lt; 1 mmHg) corresponding to a reduction in bias noted with Bland-Altman analysis. The bootstrap analysis of the transfer function (100 iterations) achieved a coefficient of variation for the root mean square error &lt; 8.4% for systolic, diastolic and pulse aortic pressures. Conclusions: The magnitude of the differences between the SphygmoCor-estimated and catheter-based systolic, diastolic and pulse aortic pressures reduced considerably after using the linear-fit transfer function derived in this study.

Myocardial Perfusion in Hypoplastic Left Heart Syndrome

The status of the systemic right ventricular coronary microcirculation in hypoplastic left heart syndrome (HLHS) is largely unknown. It is presumed that the systemic right ventricle's coronary microcirculation exhibits unique pathophysiological characteristics of HLHS in Fontan circulation. The present study sought to quantify myocardial blood flow by cardiac magnetic resonance imaging and evaluate the determinants of microvascular coronary dysfunction and myocardial ischemia in HLHS. One hundred nineteen HLHS patients (median age, 4.80 years) and 34 healthy volunteers (median age, 5.50 years) underwent follow-up cardiac magnetic resonance imaging ≈1.8 years after total cavopulmonary connection. Right ventricle volumes and function, myocardial perfusion, diffuse fibrosis, and late gadolinium enhancement were assessed in 4 anatomic HLHS subtypes. Myocardial blood flow (MBF) was quantified at rest and during adenosine-induced hyperemia. Coronary conductance was estimated from MBF at rest and catheter-based measurements of mean aortic pressure (n=99). Hyperemic MBF in the systemic ventricle was lower in HLHS compared with controls (1.89±0.57 versus 2.70±0.84 mL/g per min; P<0.001), while MBF at rest normalized by the rate-pressure product, was similar (1.25±0.36 versus 1.19±0.33; P=0.446). Independent risk factors for a reduced hyperemic MBF were an HLHS subtype with mitral stenosis and aortic atresia (P=0.017), late gadolinium enhancement (P=0.042), right ventricular diastolic dysfunction (P=0.005), and increasing age at total cavopulmonary connection (P=0.022). The coronary conductance correlated negatively with systemic blood oxygen saturation (r, -0.29; P=0.02). The frequency of late gadolinium enhancement increased with age at total cavopulmonary connection (P=0.014). The coronary microcirculation of the systemic ventricle in young HLHS patients shows significant differences compared with controls. These hypothesis-generating findings on HLHS-specific risk factors for microvascular dysfunction suggest a potential benefit from early relief of frank cyanosis by total cavopulmonary connection.

Arterial Stiffness and Vascular Aging: Effects of Hypertension

This review highlights the relationship of age and arterial hypertension observed in the aging process. The main structural and functional changes underlying the increase in vascular stiffness are analyzed. The similarity of vascular changes in aging and arterial hypertension was noted. The negative effect of increased central blood pressure on target organs is considered. Attention is paid to the analysis of arterial stiffness as a marker of vascular aging. The parameters of the carotid-femoral pulse wave propagation velocity, the cardio-ankle vascular index (CAVI), the ankle-brachial index, the finger-brachial index, and the augmentation index were examined separately. The prognostic and clinical value of the parameters of vascular stiffness is considered. In particular, the clinical guidelines for arterial hypertension report the need to use arterial stiffness indicators to improve the accuracy of cardiovascular risk stratification, especially in medium-risk patients. Measurement of vascular stiffness and central aortic pressure should be recommended as one of the methods for stratifying cardiovascular risk in patients with intermediate SCORE risk, as well as in those whose target organ damage was not detected by routine methods. The article also notes the independent diagnostic and prognostic value of the CAVI.

Ageing, hypertension and aortic valve stenosis – Understanding the series circuit using cardiac magnetic resonance and applanation tonometry

BackgroundAortic stenosis (AS) is no longer considered to be a disease of fixed left ventricular (LV) afterload, but rather, functions as a series circuit, with important contributions from both the valve and vasculature. Patients with AS are typically elderly, with hypertension and a markedly remodelled aorta. The arterial component is sizeable, and yet, quantifying this to-date has been difficult to determine. We compared measurement of aortic pressure, flow and global LV load using a cardiac magnetic resonance (CMR)/applanation tonometry (AT) technique to uncouple ventriculo-arterial (VA) interactions. Methods20 healthy elderly patients and 20 with AS underwent a CMR/AT protocol. CMR provided LV volume and aortic flow simultaneously with AT pressure acquisition. Aortic pressure was derived by transformation of the AT waveform. Systemic vascular resistance (SVR) and global LV load were determined as the relationship of pressure to flow in the frequency domain. Values from both cohorts were compared. ResultsAS patients were older (p ​< ​0.01) albeit with no significant difference in brachial or central aortic pressure. SVR (14228 vs 19906 ​dyne ​s.cm−3; p ​= ​0.02) and load (740 vs 946 ​dyne ​s.cm−3; p ​= ​0.02) were higher in patients with AS, whilst aortic peak flow velocity was lower (38 vs 58 ​cm/s; p ​< ​0.01). ConclusionsQuantification of aortic pressure, flow velocity and global LV load using a simultaneous CMR/AT technique is able to demonstrate the progressive effects of hypertension and aortic stiffening with advanced age and valvular stenosis. This technique may help to better identify future patients at risk of VA coupling mismatch after correction of AS.