Abnormal Wave Reflections and Left Ventricular Hypertrophy Late After Coarctation of the Aorta Repair

Clinical features, hemodynamics, and outcomes of pulmonary hypertension in adults with coarctation of aorta

BACKGROUND

Pulmonary hypertension (pH) and secondary right ventricle dysfunction is present in 20 % of adults with coarctation of aorta (COA) based on echocardiographic studies. There are limited data about invasive hemodynamic characterization of PH in COA. The purpose of this study was to delineate the clinical features, hemodynamics, and outcomes of PH in COA.

METHOD

Retrospective cohort study of adults with repaired COA that underwent right heart catheterization (RHC). PH was defined as pulmonary artery (PA) mean pressure > 20 mmHg, and PH was classified as isolated precapillary PH and combined pre/postcapillary PH.

RESULTS

Of 99 COA patients that underwent RHC, 57 (58 %) had PH. Of the patients with PH, 14 (25 %) had isolated precapillary PH while 43 (75 %) had postcapillary PH with or without precapillary disease. The correlates of PH were PA compliance (adjusted OR 0.79, 95 % CI 0.71-0.86 per 1 ml/mmHg), left atrial reservoir strain (adjusted OR 0.95, 95 % CI 0921-0.98 per 1 %), and atrial fibrillation (adjusted OR 2.18, 95 % CI 1.20-13.5). Higher PA mean pressure was associated with risk of cardiovascular events (adjusted HR 1.04, 95 % CI 1.02-1.06 per 1 mmHg) and all-cause mortality (adjusted HR 1.05, 95 % CI 1.02-1.08 per 1 mmHg).

CONCLUSIONS

PH was present in over half of adults with COA referred for RHC, and one-quarter of the patients with PH presented with isolated precapillary PH suggesting an underlying PA vascular dysfunction as a contributing mechanism. Further studies are required to determine optimal therapies and strategies for prevention and treatment of PH in this population.

CLINICAL SUMMARY

Of 99 adults with repaired coarctation of aorta (COA) that underwent right heart catheterization, 57 % had pulmonary hypertension (pH). Of the patients with PH, 25 % had isolated precapillary PH while 75 % had combined pre/postcapillary PH. The correlates of PH were pulmonary artery (PA) compliance, left atrial reservoir strain and atrial fibrillation. PH was associated with cardiovascular events and all-cause mortality. These data suggest PA vascular dysfunction in addition to left-sided heart disease as potential etiologies for PH in this population. Further studies are required to determine optimal therapies and strategies for prevention and treatment of PH in this population.

A study on the correlation between lung injury severity and cardiac function through a closed-loop model

OBJECTIVE

Numerous clinical and pathological studies have confirmed that lung injury can cause cardiovascular disease, but there is no explanation for the mechanism by which the degree of lung injury affects cardiac function. We attempt to reveal this mechanism of influence by simulating a cyclic model.

METHOD

This study established a closed-loop cardiovascular model with a series of electrical parameters. Including the heart, lungs, arteries, veins, etc., each part of the cardiovascular system is modeled using centralized parameters. Adjusting these lung resistances to alter the degree of lung injury is aimed at reflecting the impact of different degrees of lung injury on cardiac function. Finally, analyze and compare the changes in blood pressure, aortic flow, atrioventricular volume, and atrioventricular pressure among different lung injuries to obtain the changes in cardiac function.

RESULTS

In this model, the peak aortic flow decreased, the earlier the trough appeared, and the total aortic flow decreased. Left atrial blood pressure decreased from 6.5 mmHg to around 5.5 mmHg, left ventricular blood pressure decreased from 100 mmHg to around 50 mmHg, and aortic blood pressure also decreased from 100 mmHg to around 50 mmHg. The blood pressure in the pulmonary artery, right atrium, and right ventricle increases. The right ventricular blood pressure decreased from 20 mmHg to around 40 mmHg, while the right atrial blood pressure slightly increased. It can be seen that the increase in impedance has a greater impact on ventricular blood pressure than on atrium. Pulmonary arterial pressure significantly increases, rising from 20 mmHg to around 50 mmHg, forming pulmonary hypertension. The left ventricular end-systolic potential energy, filling energy, stroke work, stroke output, left ventricular filling period, maximum blood pressure during ventricular ejection period, and stroke energy efficiency decrease.

CONCLUSION

We established a closed-loop cardiovascular model that reveals that the more severe lung injury, the higher blood pressure in the pulmonary artery, right atrium, and right ventricle, while the lower blood pressure in the left atrium, left ventricle, and aorta. The increase in pulmonary impedance leads to abnormalities in myocardial contraction, diastolic function, and cardiac reserve capacity, leading to a decrease in cardiac function. This closed-loop model provides a method for pre assessment of cardiovascular disease after lung injury.

Clinical features, haemodynamics, and outcomes of heart failure with preserved ejection fraction in coarctation of aorta

AIMS

There are similarities in the pathogenesis of cardiac remodelling and dysfunction in heart failure with preserved ejection fraction (HFpEF) and coarctation of aorta (COA). We hypothesized that clinical HFpEF would be highly prevalent in adults with COA, and that the presence of HFpEF would increase the risk of mortality in this population. The aim of this study was to define the clinical features, haemodynamics, and prognostic implications of HFpEF in COA.

METHODS AND RESULTS

Consecutive adults with repaired COA that underwent right heart catheterization were identified retrospectively. HFpEF was defined as heart failure symptoms (exertional dyspnoea or fatigue), preserved left ventricular ejection fraction ≥50%, and pulmonary artery wedge pressure at rest >15 mmHg. Of 99 COA patients, 32 (32%) had HFpEF. The correlates of HFpEF were obesity (adjusted odds ratio [OR] 4.15, 95% confidence interval [CI] 1.31-13.2), atrial fibrillation (adjusted OR 3.13, 95% CI 1.00-10.7), total arterial compliance index (adjusted OR 0.12, 95% CI 0.06-0.41 per 1 ml/mmHg*m2), and pulmonary artery compliance index (adjusted OR 0.36, 95% CI 0.15-0.56 per 1 ml/mmHg*m2). Of 99 patients, 24 (24%) died and 5 (5%) underwent heart transplant. The 10-year cumulative incidence of death/transplant was higher in COA patients with HFpEF compared with patients without HFpEF (39% vs. 12%, p = 0.001). The presence of HFpEF was associated with increased risk of death/transplant (adjusted hazard ratio 1.68, 95% CI 1.16-3.11).

CONCLUSIONS

Heart failure with preserved ejection fraction is common in adults with COA and is associated with greater risk of death/transplant, emphasizing a pressing need for interventions to prevent and treat HFpEF in COA.

Clinical impact of novel CMR technology on patients with congenital heart disease. A scientific statement of the Association for European Pediatric and Congenital Cardiology (AEPC) and the European Association of Cardiovascular Imaging (EACVI) of the ESC

Cardiovascular magnetic resonance (CMR) imaging is recommended in patients with congenital heart disease (CHD) in clinical practice guidelines as the imaging standard for a large variety of diseases. As CMR is evolving, novel techniques are becoming available. Some of them are already used clinically, whereas others still need further evaluation. In this statement the authors give an overview of relevant new CMR techniques for the assessment of CHD. Studies with reference values for these new techniques are listed in the supplement.

Coarctation of Aorta With Tricuspid Aortic Valve Is Not Associated With Ascending Aortic Aneurysm

BACKGROUND

Aortic aneurysm is common in patients with coarctation of aorta (COA), but it is unclear whether the risk of aortic aneurysms is due to COA or related to the presence of other risk factors such as bicuspid aortic valve (BAV) and hypertension.

OBJECTIVES

The purpose of this study was to assess the relationship among COA, BAV, and thoracic aortic aneurysms.

METHODS

A total of 867 patients with COA (COA group) were matched 1:1:1 to 867 patients with isolated BAV (BAV group) and 867 patients without structural heart disease (SHD) (no-SHD group). The COA group was further subdivided into a COA+BAV subgroup (n = 304 [35%]), and COA with tricuspid aortic valve (TAV) (COA+TAV subgroup [n = 563 (65%)]). Aortic dimensions were assessed at baseline and at 3, 5, and 7 years.

RESULTS

Compared with the no-SHD group, the COA+BAV subgroup had larger aortic root diameter (37 mm [Q1-Q3: 30-43 mm] vs 32 mm [Q1-Q3: 27-35 mm]; P < 0.001) and mid ascending aorta dimeter (34 mm [Q1-Q3: 29-40 mm] vs 28 mm [Q1-Q3: 24-31 mm]; P = 0.008). Similarly, the BAV group had larger aortic root diameter (37 mm [Q1-Q3: 30-42 mm] vs 32 mm [Q1-Q3: 27-35 mm]; P < 0.001), and mid ascending aorta dimeter (35 mm [Q1-Q3: 30-40 mm] vs 28 mm [Q1-Q3: 24-31 mm]; P < 0.001). Compared with the COA+TAV subgroup, the COA+BAV subgroup and BAV group were associated with larger aortic root and mid ascending aorta diameter at baseline and follow-up. The risk of acute aortic complications was low in all groups.

CONCLUSIONS

These findings suggest that BAV (and not COA) was associated with ascending thoracic aorta dimensions, and that patients with COA+TAV were not at a greater risk of developing ascending aortic aneurysms as compared with patients without SHD.

Impact of left ventricular hemodynamic forces in adult patients with treated aortic coarctation and preserved left ventricular systolic function

BACKGROUND

The LV myocardial strain and hemodynamic forces (HDFs) are innovative markers of LV function. Aortic coarctation is safely repaired in infancy; however, mortality and morbidity remain increased in later life. The study investigated the role of left ventricular myocardial deformation and HDFs in asymptomatic patients who underwent successful aortic coarctation repair.

METHODS

Clinical and echocardiographic data were analyzed from 42 repaired CoA, 32 ± 20 years after surgery, 2D echocardiographic global longitudinal strain (GLS), circumferential strain (GCS) and HDFs were determined. CoA patients were compared with 42 patients affected by blood hypertension and 84 healthy controls; all matched for age and gender.

RESULTS

All groups had normal LV ejection fraction (LVEF), dimensions, and volumes. CoA patients showed a significantly higher rate of LV mass indexed (p < .001) and left atrial volumes indexed (p < .001). LV myocardial and endocardial global longitudinal and circumferential strain were decreased in CoA patients (p < .001, p < .001; p = .032 and p < .001, respectively). HDF parameters such as LV longitudinal force, LV systolic longitudinal force and LV impulse (LVim) were uniformly reduced (p = .006, p = .001, and p = .001, respectively). LV myocardial strain and HDF parameter values were independently associated with hospitalization for heart failure on univariable Cox regression analysis.

CONCLUSION

Despite preserved LVEF, patients with CoA had lower LV myocardial strain and HDF parameters values, independently associated with hospitalization for heart failure.

Aortic growth after arch reconstruction with patch augmentation: a 2-decade experience

OBJECTIVES

Optimal aortic sizing during aortic arch reconstruction remains unknown. Negative effects of arch under- or oversizing are well-published. We aimed to characterize longitudinal aortic growth after patch-augmented arch reconstruction to identify the initial reconstructed arch size that results in normal mid-term arch dimensions.

METHODS

Single-centre, retrospective review of infants undergoing Damus-Kaye-Stansel (DKS) or non-DKS patch-augmented aortic arch reconstruction between 2000 and 2021. Ascending aorta, proximal and distal transverse arch, aortic isthmus (AIsth) and descending aorta dimensions were measured in postoperative echocardiograms (<3 months from index operation) and cross-sectional imaging (>12 months). Longitudinal changes to aortic dimensions and z-scores were analysed. Secondary outcomes included reintervention, valve and ventricular function, mortality and transplantation.

RESULTS

Fifty-four patients (16 DKS, 38 non-DKS) were included. At 6.3 [2.2, 12.0]-year follow-up, all aortic segments grew significantly in both groups, while z-scores remained unchanged except for non-DKS proximal and distal transverse arch z-scores, which significantly increased (P < 0.05 each). When stratified by initial postoperative z-score (z < -1, -1 ≤ z ≤ 1, z > 1), non-DKS patients with initial AIsth z-score <-1 had a final z-score significantly smaller than both the targeted z-score zero (P = 0.014) and final z-score in a group with initial postoperative z-score ±1 (P = 0.009). Valve and ventricular function remained stable. Eighteen patients required reintervention, 1 died and 1 underwent transplant.

CONCLUSIONS

Over mid-term follow-up, aortic growth after arch reconstruction with patch augmentation was proportional when repaired to normal z-score dimensions, aside from proximal transverse arch, which disproportionately dilated. AIsth undersizing prevailed mid-term and trended towards a higher reintervention rate. Initial reconstruction between z-score 0 and +1 resulted in maintenance of that z-score size at mid-term follow-up. Overall, it is crucial to achieve targeted aortic sizing at index operation to maintain appropriate aortic dimensions over time and reduce reintervention risk with specific focus on the AIsth.

Validation of a laser projection platform for the preparation of surgical patches used in paediatric cardiac surgery

OBJECTIVES

Reconstruction of cardiovascular anatomy with patch material is integral to the repair of congenital heart disease. We present validation of a laser projection platform for the preparation of surgical patches as a proof-of-concept for intraoperative use in patient-specific planning of paediatric cardiac surgery reconstructions.

METHODS

The MicroLASERGUIDE, a compact laser projection system that displays computer-aided designs onto 2D/3D surfaces, serves as an alternative to physical templates. A non-inferiority comparison of dimensional measurements was conducted between laser projection ('laser') and OZAKI AVNeo Template ('template') methods in creation of 51 (each group) size 13 valve leaflets from unfixed bovine pericardium. A digital version of the OZAKI AVNeo Template dimensions served as control. Feasibility testing was performed with other common patch materials (fixed bovine pericardium, PTFE and porcine main pulmonary artery as a substitute for pulmonary homograft) and sizes (13, 23) (n = 3 each group).

RESULTS

Compared to control (height 21.5, length 21.0 mm), template height and length were smaller (height and length differences of -0.3 [-0.5 to 0.0] and -0.4 [-0.8 to -0.1] mm, P < 0.01 each); whereas, both laser height and length were relatively similar (height and length differences of height 0.0 [-0.2 to 0.2], P = 0.804, and 0.2 [-0.1 to 0.4] mm, P = 0.029). Template percent error for height and length was -1.5 (-2.3 to 0.0)% and -1.9 (-3.7 to -0.6)% vs 0.2 (-1.0 to 1.1)% and 1.0 (-0.5 to 1.8)% for the laser. Similar results were found with other materials and sizes. Overall, laser sample dimensions differed by a maximum of 5% (∼1 mm) from the control.

CONCLUSIONS

The laser projection platform has demonstrated promise as an alternative methodology for the preparation of surgical patches for use in cardiac surgery. This technology has potential to revolutionize preoperative surgical planning for numerous congenital anomalies that require patient-specific patch-augmented repair.

Aortic shape variation after frozen elephant trunk procedure predicts aortic events: Principal component analysis study

Objective

The frozen elephant trunk procedure is a well-established technique for the repair of type A ascending aortic dissection and complex aortic arch pathology. The ultimate shape created by the repair may have consequences in long-term complications. The purpose of this study was to apply a machine learning technique to comprehensively describe 3-dimensional aortic shape variations after the frozen elephant trunk procedure and associate these variations with aortic events.

Methods

Computed tomography angiography acquired before discharge of patients (n = 93) who underwent the frozen elephant trunk procedure for type A ascending aortic dissection or ascending aortic arch aneurysm was preprocessed to yield patient-specific aortic models and centerlines. Aortic centerlines were subjected to principal component analysis to describe principal components and aortic shape modulators. Patient-specific shape scores were correlated with outcomes defined by composite aortic event, including aortic rupture, aortic root dissection or pseudoaneurysm, new type B dissection, new thoracic or thoracoabdominal pathologies, residual descending aortic dissection with residual false lumen flow, or thoracic endovascular aortic repair complications.

Results

The first 3 principal components accounted for 36.4%, 26.4%, and 11.6% of aortic shape variance, respectively, and cumulatively for 74.5% of the total shape variation in all patients. The first principal component described variation in arch height-to-length ratio, the second principal component described angle at the isthmus, and the third principal component described variation in anterior-to-posterior arch tilt. Twenty-one aortic events (22.6%) were encountered. The degree of aortic angle at the isthmus described by the second principal component was associated with aortic events in logistic regression (hazard ratio, 0.98; 95% confidence interval, 0.97-0.99; P = .046).

Conclusions

The second principal component, describing angulation at the region of the aortic isthmus, was associated with adverse aortic events. Observed shape variation should be evaluated in the context of aortic biomechanical properties and flow hemodynamics.

The contribution of upper and lower body arterial vessels to the aortic root reflections: A one-dimensional computational study

BACKGROUND AND OBJECTIVES

Reflections measured at the aortic root are of physiological and clinical interest and thought to be composed of the superimposed reflections arriving from the upper and lower parts of the circulatory system. However, the specific contribution of each region to the overall reflection measurement has not been thoroughly examined. This study aims to elucidate the relative contribution of reflected waves arising from the upper and lower human body vasculature to those observed at the aortic root.

METHODS

We utilised a one-dimensional (1D) computational model of wave propagation to study reflections in an arterial model that included 37 largest arteries. A narrow Gaussian-shaped pulse was introduced to the arterial model from five distal locations: carotid, brachial, radial, renal, and anterior tibial. The propagation of each pulse towards the ascending aorta was computationally tracked. We calculated the reflected pressure and wave intensity at the ascending aorta in each case. The results are presented as a ratio of the initial pulse.

RESULTS

The findings of this study indicates that pressure pulses originated at the lower body can hardly be observed, while those originated from the upper body account for the largest portion of reflected waves seen at the ascending aorta.

CONCLUSIONS

Our study validates the findings of earlier studies, which demonstrated that human arterial bifurcations have a significantly lower reflection coefficient in the forward direction as compared to the backward direction. The results of this study underscore the need for further in-vivo investigations to provide a deeper understanding of the nature and characteristics of reflections observed in the ascending aorta, which can inform the development of effective strategies for the management of arterial diseases.

Is There a Role for Imaging Youth at Risk of Atherosclerosis?

PURPOSE OF REVIEW

Cardiovascular (CV) risk factors such as dyslipidemia, hypertension, diabetes, and obesity are associated with an increased risk for CV events in adults. Noninvasive measures of vascular health are associated with these CV events and can potentially help risk stratify children with CV risk factors. The purpose of this review is to summarize recent literature regarding vascular health in children with cardiovascular risk factors.

RECENT FINDINGS

Adverse changes in pulse wave velocity, pulse wave analysis, arterial distensibility, and carotid intima-media thickness are seen in children with CV risk factors supporting potential utility in risk stratification. Assessing vascular health in children can be challenging due to growth-related changes in vasculature, multiple assessment modalities, and differences in normative data. Vascular health assessment in children with cardiovascular risk factors can be a valuable tool for risk stratification and help identify opportunities for early intervention. Future areas of research include increasing normative data, improving conversion of data between different modalities, and increasing longitudinal studies in children linking childhood risk factors to adult CV outcomes.

Bromocriptine Improves Central Aortic Stiffness in Adolescents With Type 1 Diabetes: Arterial Health Results From the BCQR-T1D Study

BACKGROUND

The presence of vascular dysfunction is a well-recognized feature in youth with type 1 diabetes (T1D), accentuating their lifetime risk of cardiovascular events. Therapeutic strategies to mitigate vascular dysfunction are a high clinical priority. In the bromocriptine quick release T1D study (BCQR-T1D), we tested the hypothesis that BCQR would improve vascular health in youth with T1D.

METHODS

BCQR-T1D was a placebo-controlled, random-order, double-blinded, cross-over study investigating the cardiovascular and metabolic impact of BCQR in T1D. Adolescents in the BCQR-T1D study were randomized 1:1 to phase-1: 4 weeks of BCQR or placebo after which blood pressure and central aortic stiffness measurements by pulse wave velocity, relative area change, and distensibility from phase-contrast magnetic resonance imaging were performed. Following a 4-week washout period, phase 2 was performed in identical fashion with the alternate treatment.

RESULTS

Thirty-four adolescents (mean age 15.9±2.6 years, hemoglobin A1c 8.6±1.1%, body mass index percentile 71.4±26.1, median T1D duration 5.8 years) with T1D were enrolled and had magnetic resonance imaging data available. Compared with placebo, BCQR therapy decreased systolic (∆=-5 mmHg [95% CI, -3 to -7]; P<0.001) and diastolic blood pressure (∆=-2 mmHg [95% CI, -4 to 0]; P=0.039). BCQR reduced ascending aortic pulse wave velocity (∆=-0.4 m/s; P=0.018) and increased relative area change (∆=-2.6%, P=0.083) and distensibility (∆=0.08%/mmHg; P=0.017). In the thoraco-abdominal aorta, BCQR decreased pulse wave velocity (∆=-0.2 m/s; P=0.007) and increased distensibility (∆=0.05 %/mmHg; P=0.013).

CONCLUSIONS

BCQR improved blood pressure and central and peripheral aortic stiffness and pressure hemodynamics in adolescents with T1D over 4 weeks versus placebo. BCQR may improve aortic stiffness in youth with T1D, supporting future longer-term studies.

On-treatment blood pressure and cardiovascular mortality in adults with repaired coarctation of aorta

BACKGROUND

Although, hypertension is common in adults with repaired coarctation of aorta (COA), there are no data about on-treatment blood pressure (BP), and its relationship to outcomes in this population. The purpose of this study was to determine the relationship between on-treatment BP and cardiovascular mortality in adults with repaired COA.

METHODS

Retrospective study of adults with repaired COA on antihypertensive therapy (n = 461, age 39 ± 11). All BP measurements obtained within the first 3 years were averaged to determine the on-treatment BP, and the patients were stratified into BP quartiles using the cut-off points from the guidelines.

RESULTS

Being in the upper systolic BP (SBP) quartiles (SBP 120-129, 130-139 and ≥140) was associated with higher risk of cardiovascular mortality (HR 1.05, 95%CI 1.01-1.07, HR 1.12, 95%CI 1.04 to 1.15 and HR 1.39, 95%CI 1.13 to 1.59), as compared to being the lowest SBP quartile. We observed a 7% increase in the risk of cardiovascular mortality for every 5 mmHg increase in SBP, and a 4% increase in risk of cardiovascular mortality for every 5 mmHg increase in DBP.

CONCLUSIONS

Collectively, these data suggest that even s less severe form of hypertension SBP (120-129 mmHg) was not benign, and perhaps should be considered for antihypertensive therapy. A randomized controlled clinical trial is required to determine whether this group of patients (SBP 120 to 129 mmHg) would benefit from antihypertensive therapy, and to determine the optimal type and intensity of antihypertensive therapy in this population.

Effect of lower extremity amputation on cardiovascular hemodynamic environment: An in vitro study

Lower extremity amputation (LEA) was associated with a greater risk of cardiovascular disease, but its hemodynamic mechanisms have not been fully studied. Therefore, to clarify the interrelationship between them, and figure out the potential pathogenesis, the exploration of the hemodynamic environment change of patients after LEA was premeditatedly executed. A near-physiological mock circulatory system (MCS) was employed in the present work to replicate the cardiovascular circulation after LEA in a short time and the unsteady-state numerical simulation was utilized as an auxiliary method to observe the changes of the hemodynamic environment inside the blood vessel. Higher severity of LEA leads to higher peripheral vascular impedance, higher blood pressure, and more obvious redistribution of blood perfusion volume. In addition, higher severity of LEA leads to lower wall shear stress (WSS), higher oscillatory shear index (OSI), and higher relative residence time (RRT) appeared in the infrarenal abdominal aorta and the iliac artery, while these changes are closely related to the higher probability of cardiovascular diseases. Results showed that different degrees of LEA (varying heights, unilateral/bilateral) have diverse effects on the patient's hemodynamic environment. This study explained the potential pathogenesis of cardiovascular diseases after LEA from a hemodynamic perspective and provided a certain reference value for the improvement of the cardiovascular hemodynamic environment and the prevention of cardiovascular diseases in lower extremity amputees.

Prognostic Value of the H2FPEF Score in Adults With Repaired Coarctation of Aorta

Background

Risk stratification is challenging in adults with repaired coarctation of aorta (COA) because of the complex interaction of multiple hemodynamic factors and differences in left ventricular adaptation to these factors. The H2FPEF score was originally developed for differentiating between heart failure with preserved ejection fraction and noncardiac dyspnea, but it has been shown to be useful for prognostication in other cardiovascular pathologies.

Objectives

The purpose of this study was to assess the prognostic role of the H2FPEF score in adults with repaired COA.

Methods

This is a retrospective cohort study of adults with repaired COA at the Mayo Clinic (2003-2019). The H2FPEF score was calculated at baseline and at 5-year follow-up. Cardiovascular events (heart failure hospitalization, transplant, or cardiovascular death) were ascertained from medical records.

Results

We identified 712 patients (age 33 years [range 21-45 years]; 419 [59%] males). The baseline H2FPEF score was 2.2 ± 1.4. There was a temporal increase in the H2FPEF score at 5 years (ΔH2FPEF score 0.34 ± 0.11) due to the increase in the prevalence of hypertension, obesity, and high filling pressures. The H2FPEF score correlated with left atrial volume (r = 0.73, P < 0.001), right atrial volume (r = 0.41, P < 0.001), right ventricular fractional area change (r = -0.46, P < 0.001), and left ventricular e' (r = -0.52, P < 0.001). Both the baseline H2FPEF score and ΔH2FPEF score were independently associated with cardiovascular events.

Conclusions

These results suggest that the H2FPEF score can be used for prognostication in patients with COA. The temporal increase in the H2FPEF score was due to factors such as hypertension, obesity, and high filling pressures, and hence, it provides potential therapeutic targets to improve outcomes in this population.

Vascular aging in adult congenital heart disease-a narrative review

Background and Objective

Many studies about the high prevalence of cardiovascular disease in adults with congenital heart disease (CHD) have been published in response to the growing number of adult patients with CHD. The aging process leads to hypertension and cardiovascular disease, which is caused by a degenerative change in the systemic arterial system characterized by the stiffening of elastic arteries (known as arteriosclerosis) and the enlargement of aorta. In patients with CHD, aortic dilatation (so-called aortopathy) is one of the most frequent complications. It is well known the anatomical and histological changes in aortopathy are similar to those in aging process. The increase of pulse wave velocity (PWV) enhances pressure wave reflection, and it augments left ventricular afterload and impairs the coronary supply-workload balance in aging. This article reviews the aortic function in patients with CHD, aiming to provide a new direction for the management of their cardiovascular aging process.

Methods

Papers on vascular physiology in CHD were retrieved. I searched all original papers and reviews about the vascular physiology in CHD using PubMed, published from January 1, 1973 to June 30, 2022, in English.

Key Content and Findings

Enhancement of pressure wave reflection has been reported in many CHDs. Although PWV in whole aorta is not necessarily elevated, the abnormal arterial stiffness gradient is common in patients with CHD.

Conclusions

Many reports concerning functional abnormalities of the aorta have been reported. The abnormalities can result in cardiovascular disease and organ damage. The practitioners should carefully treat patients with CHD while paying attention to their aging process.

Unlocking the Non-invasive Assessment of Conduit and Reservoir Function in the Aorta

Aortic surgeries in congenital conditions, such as hypoplastic left heart syndrome (HLHS), aim to restore and maintain the conduit and reservoir functions of the aorta. We proposed a method to assess these two functions based on 4D flow MRI, and we applied it to study the aorta in pre-Fontan HLHS. Ten pre-Fontan HLHS patients and six age-matched controls were studied to derive the advective pressure difference and viscous dissipation for conduit function, and pulse wave velocity and elastic modulus for reservoir function. The reconstructed neo-aorta in HLHS subjects achieved a good conduit function at a cost of an impaired reservoir function (69.7% increase of elastic modulus). The native descending HLHS aorta displayed enhanced reservoir (elastic modulus being 18.4% smaller) but impaired conduit function (three-fold increase in peak advection). A non-invasive and comprehensive assessment of aortic conduit and reservoir functions is feasible and has potentially clinical relevance in congenital vascular conditions.

Hypertension after coarctation repair-a systematic review

BACKGROUND

Coarctation of the Aorta (CoA) leads to increased morbidity and mortality later in life despite early surgical or percutaneous treatment. Many long-term complications are related to hypertension (HT) which is a common finding late after coarctation repair.

METHODS

A systematic Review was performed including articles published between February 2012 to December 2020. Systematic searches were conducted on PubMed and the Cochrane Controlled Trials Register to look for studies on HT after aortic CoA-repair. PRISMA guidelines were used.

RESULTS

In this systematic review on HT after CoA Repair the mean prevalence of HT was 47.3% (20-70%). A progressive character was of the HT was found, furthermore if only studies are included with 24 h blood pressure (BP) recording in addition to standard BP measurements, the incidence of HT rose to 57.8%.

DISCUSSION

Most clinical studies look at complications, mortality rate and residual pressure gradient rather than correlating hemodynamic indices with long-term outcome. Although HT is commonly based in measurement of peripheral BP, it has been shown that peripheral BP in CoA patients has a poor correlation with central aortic pressure. Central aortic hemodynamics are significantly altered in patients with repaired CoA, which can now adequately be investigated non-invasively. At the present time there are no studies linking long-term outcome with abnormal central hemodynamics.

Relation between Oscillometric Measurement of Central Hemodynamics and Left Ventricular Hypertrophy in Hypertensive Patients

Introduction

The augmentation index (AIx) or central systolic blood pressure (SBP), measured by radial applanation tonometry, has been reported to be independently associated with left ventricular hypertrophy (LVH) in Japanese hypertensive patients. Cuff-based oscillometric measurement of the AIx using Mobil-O-Graph® showed a low or moderate agreement with the AIx measurement with other devices.

Methods

The AIx measured using the Mobil-O-Graph was validated against the tonometric measurements of the radial AIx measured using HEM-9000AI in 110 normotensive healthy individuals (age, 21-76 years; 50 men). We investigated the relationship between the central hemodynamics assessed using the Mobil-O-Graph and LVH in 100 hypertensive patients (age, 54-75 years; 48 men), presenting a wall thickness of ≥11 mm and ≥10 mm in men and women, respectively.

Results

Although the Mobil-O-Graph-measured central AIx showed no negative values, it correlated moderately with the HEM-9000AI-measured radial AIx (r = 0.602, p < 0.001) in the normotensive individuals. The hypertensive patients did not show a significant difference in the central SBP between the sexes, but the central AIx was lower in men than in women. The independent determinants influencing left ventricle (LV) mass index (LVMI) (R² = 0.362; adjusted R² = 0.329, p < 0.001) were heart rate (β = -0.568 ± 0.149, p < 0.001), central SBP (β = 0.290 ± 0.100, p = 0.005), and aortic root diameter (β = 1.355 ± 0.344, p = 0.001). Age (β = -0.025 ± 0.124, p = 0.841) and the central AIx (β = 0.120 ± 0.131, p = 0.361) were not independently associated with the LVMI. The area under the receiver operator characteristic curve to evaluate the diagnostic performance of the central AIx for the presence of LVH (LVMI >118 g/m² in men or >108 g/m² in women) was statistically significant in men (0.875, p < 0.001) but not in women (0.622, p = 0.132). In men, a central AIx of 28.06% had a sensitivity of 83.3% and specificity of 80.0% for detecting LVH.

Conclusions

AIx measurement in men provided useful prognostic information for the presence of LVH. Pulse-wave analysis assessed using the Mobil-O-Graph may be a valuable tool for detecting LVH in hypertensive patients.

Cardiovascular Morbidity and Mortality in Adult Patients With Repaired Aortic Coarctation

Background The long-term burden of cardiovascular disease after repair of coarctation of the aorta (CoA) has not been elucidated. We aimed to determine the incidence of and risk factors for cardiovascular events in adult patients with repaired CoA. Additionally, mortality rates were compared between adults with repaired CoA and the general population. Methods and Results Using the Dutch Congenital Corvitia (CONCOR) registry, patients aged ≥16 years with previous surgical or transcatheter CoA repair from 5 tertiary referral centers were included. Cardiovascular events were recorded, comprising coronary artery disease, stroke/transient ischemic attack, aortic complications, arrhythmias, heart failure hospitalizations, endocarditis, and cardiovascular death. In total, 920 patients (median age, 24 years [range 16-74 years]) were included. After a mean follow-up of 9.3±5.1 years, 191 patients (21%) experienced at least 1 cardiovascular event. A total of 270 cardiovascular events occurred, of which aortic complications and arrhythmias were most frequent. Older age at initial CoA repair (hazard ratio [HR], 1.017; 95% CI, 1.000-1.033 [P=0.048]) and elevated left ventricular mass index (HR, 1.009; 95% CI, 1.005-1.013 [P<0.001]) were independently associated with an increased risk of cardiovascular events. The mortality rate was 3.3 times higher than expected based on an age- and sex-matched cohort from the Dutch general population (standardized mortality ratio, 3.3; 95% CI, 2.3-4.4 [P<0.001]). Conclusions This large, prospective cohort of adults with repaired CoA showed a high burden of cardiovascular events, particularly aortic complications and arrhythmias, during long-term follow-up. Older age at initial CoA repair and elevated left ventricular mass index were independent risk factors for the occurrence of cardiovascular events. Mortality was 3.3-fold higher compared with the general population. These results advocate stringent follow-up after CoA repair and emphasize the need for improved preventive strategies.

Coarctation of aorta is associated with left ventricular stiffness, left atrial dysfunction and pulmonary hypertension

BACKGROUND

Brachial systolic blood pressure (BP) is the most commonly used metric for monitoring hypertension. However, recent studies suggest that brachial systolic BP underestimates left ventricle (LV) systolic load in patients with coarctation of aorta (COA). Since brachial systolic BP is used as a surrogate of arterial afterload in clinical practice, it is important to determine how well it correlates with LV remodeling and stiffness in patients with COA as compared to patients with idiopathic hypertension.

METHODS

This is cross-sectional study of COA patients with hypertension (COA group) and adults with idiopathic hypertension (control group). Both groups were matched 1:1 based on age, sex, BMI and systolic BP. We hypothesized that the COA group will have higher LV systolic and diastolic stiffness, and more advanced left atrial remodeling and pulmonary hypertension. We assessed LV systolic stiffness using end-systolic elastance, and diastolic stiffness using LV stiffness constant and chamber capacitance (LV-end-diastolic volume at an end-diastolic pressure of 20mm Hg) RESULTS: There were 112 patients in each group. Although both groups had similar systolic BP, the COA group had a higher end-systolic elastance (2.37 ± 0.74 vs 2.11 ± 0.54 mm Hg/mL, P= .008), higher LV stiffness constant (6.91 ± 0.81 vs 5.93 ± 0.79, P= .006) and lower LV-end-diastolic volume at an end-diastolic pressure of 20mm Hg (58 ± 9 vs 67 ± 11 mL/m2, P< .001). Additionally, the COA group had more advanced left atrial remodeling and higher pulmonary artery pressures which is corroborating evidence of high LV filling pressure.

CONCLUSIONS

COA patients have more LV stiffness and abnormal hemodynamics compared to non-COA patients with similar systolic BP, suggesting that systolic BP may underestimate LV systolic load in this population. Further studies are required to determine whether the observed LV stiffness and dysfunction translates to more cardiovascular events during follow-up, and whether adopting a stricter systolic BP target in clinical practice or changing threshold for COA intervention will lead to less LV stiffness and better clinical outcomes.

Persistent Hypertension and Left Ventricular Hypertrophy After Repair of Native Coarctation of Aorta in Adults

[Figure: see text].

Arterial Stiffness in Congenital Heart Disease

Transposition of the great arteries (TGA), coarctation of the aorta (CoA), single ventricle (SV) and tetralogy of Fallot (ToF) are forms of congenital heart disease (CHD). Despite advances in treatment, cardiovascular and cerebrovascular complications in patients with repaired CHD occur earlier in life compared to healthy subjects. A factor that may contribute to this increased risk is elevated arterial stiffness. This systematic review provides a critical assessment of current evidence on central arterial stiffness in patients with CHD compared to healthy controls. In July 2020, Medline OVID, EMBASE and Scopus were searched using keywords and MeSH terms. Articles were included if they reported indices of aortic or carotid artery stiffness in patients with TGA, CoA, SV or ToF, and compared these to controls. Additional studies were screened from the reference lists of included articles. Of 1,033 studies identified, 43 were included in the final review. Most studies identified at least one index of central arterial stiffness, commonly in the aortic root or ascending aorta, that was higher in patients with CHD compared to controls. The commonly reported surrogate markers of stiffness were pulse wave velocity, aortic distensibility and the β stiffness index. There was a relatively small number of original studies, and synthesis of data was limited by methodological heterogeneity, highlighting the need for further studies with standardised methods. However, there was consistent evidence of early and/or accelerated arterial stiffening in CHD patients, which may contribute to the increased risk of adverse cardiovascular and cerebrovascular events in this population.

Impact of Obesity on Measures of Cardiovascular and Kidney Health in Youth With Type 1 Diabetes as Compared With Youth With Type 2 Diabetes

OBJECTIVE

Insulin resistance and obesity are independently associated with type 1 diabetes (T1D) and are known risk factors for cardiovascular and kidney diseases, the leading causes of death in T1D. We evaluated the effect of BMI on cardiovascular and kidney outcomes in youth with T1D versus control youth with normal weight or obesity and youth with type 2 diabetes (T2D).

RESEARCH DESIGN AND METHODS

Pubertal youth (n = 284) aged 12-21 years underwent assessments of resting heart rate (RHR), systolic blood pressure (SBP) and diastolic blood pressure (DBP), leptin, hs-CRP, adiponectin, ratio of urine albumin to creatinine, and estimated glomerular filtration rate. Participants with T1D underwent bicycle ergometry for VO₂peak, monitoring for peripheral brachial artery distensibility (BAD), endothelial function testing for reactive hyperemic index, and aortic MRI for central arterial stiffness or shear.

RESULTS

In adolescents with T1D, RHR, SBP, DBP, mean arterial pressure, leptin, hs-CRP, and hypertension prevalence were significantly higher, and BAD, descending aorta pulse wave velocity, and VO₂peak lower with an obese versus normal BMI. Although hypertension prevalence and RHR were highest in obese adolescents with T1D and adiponectin lowest in youth with T2D, other measures were similar between obese adolescents with T1D and those with T2D.

CONCLUSIONS

Obesity, now increasingly prevalent in people with T1D, correlates with a less favorable cardiovascular and kidney risk profile, nearly approximating the phenotype of youth with T2D. Focused lifestyle management in youth-onset T1D is critically needed to reduce cardiovascular risk.

Wave Reflection and Ventriculo-Arterial Coupling in Bicuspid Aortic Valve Patients With Repaired Aortic Coarctation

BACKGROUND

Ventriculo-arterial (VA) coupling in bicuspid aortic valve (BAV) patients can be affected by the global aortopathy characterizing BAV disease and the presence of concomitant congenital lesions such as aortic coarctation (COA). This study aimed to isolate the COA variable and use cardiovascular magnetic resonance (CMR) imaging to perform wave intensity analysis non-invasively to shed light on VA coupling changes in BAV. The primary hypothesis was that BAV patients with COA exhibit unfavorable VA coupling, and the secondary hypothesis was that BAV patients with COA exhibit increased wave speed as a marker of reduced aortic distensibility despite successful surgical correction.

METHODS

Patients were retrospectively identified from a CMR database and divided into two groups: isolated BAV and BAV associated with repaired COA. Aortic and ventricular dimensions, global longitudinal strain (GLS), and ascending aortic flow data and area were collected and used to derive wave intensity from CMR data. The main variables for the analysis included all wave magnitudes (forward compression/expansion waves, FCW and FEW, respectively, and reflected backward compression wave, BCW) and wave speed.

RESULTS

In the comparison of patients with isolated BAV and those with BAV associated with repaired COA (n = 25 in each group), no differences were observed in left ventricular ejection fraction, GLS, or ventricular volumes, whilst significant increases in FCW and FEW magnitude were noted in the BAV and repaired COA group. The FCW inversely correlated with age and aortic size. Whilst the BCW was not significantly different compared with that in patients with/without COA, its magnitude tends to increase with a lower COA index. Patients with repaired COA exhibited higher wave speed velocity. Aortic wave speed (inversely related to distensibility) was not significantly different between the two groups.

CONCLUSION

In the absence of a significant restenosis, VA coupling in patients with BAV and COA is not negatively affected compared to patients with isolated BAV. A reduction in the magnitude of the early systolic FCW was observed in patients who were older and with larger aortic diameters.

Multimodal assessment of vascular and ventricular function in children and adults with repaired aortic coarctation

BACKGROUND

Coarctation of the Aorta (CoA) is associated with increased aortic stiffness and diastolic left ventricular dysfunction. The mechanisms involved and impact of age remain unclear. It was the aim of this study to characterize arterial and cardiac function, their correlation, and the effect of age in children and adults with repaired CoA.

METHODS

Multimodal cardiovascular assessment from the ascending aorta to microcirculation and endothelial function was performed prospectively. Statistical analyses included multivariable linear regression and correlation of vascular parameters with age and diastolic function.

RESULTS

Fifty-seven patients with well-repaired CoA and 77 healthy controls were included (age 8-59). There was no significant difference in age, gender, body surface area and BMI between the groups. Ascending aortic distensibility was decreased while common carotid intima media thickness, central augmentation index corrected to a heart rate of 75/min [Aix75], peripheral Aix75 and aging index were increased in the CoA group. Interestingly, in a subgroup analysis of CoA patients with tricuspid vs. bicuspid aortic valves (BAV), only the latter had increased Aix75. Carotid-femoral pulse wave velocity [cfPWV], reactive hyperemia index and microcirculation were not significantly different between CoA and control patients. Diastolic function was impaired in the CoA group relative to controls. Both diastolic function and age correlated moderate-strongly with arterial parameters.

CONCLUSIONS

Patients with well repaired CoA have increased proximal arterial stiffness which correlates with diastolic function and age. Increased Aix75 may be attributed to a high prevalence of associated BAV. Neither cfPWV nor peripheral endothelial or microcirculatory function are impaired.

Patients with Fontan circulation have abnormal aortic wave propagation patterns: A wave intensity analysis study

BACKGROUND

Elevated systemic afterload in patients with Fontan circulation may lead to impaired single ventricular function. Wave intensity analysis (WIA) enables evaluation of compression and expansion waves traveling through vasculature. We aimed to investigate the unfavorable wave propagation causing excessive afterload may be an important contributor to the overall single ventricle function and to the limited functional capacity in this patient population.

METHODS

Patients with hypoplastic left heart syndrome (HLHS) (n = 25), single left ventricle (SLV) (n = 24), and normal controls (n = 10) underwent phase-contrast MRI based WIA analysis evaluated in the ascending aorta. Forward compression wave (FCW) representing dP/dt, backward compression wave (BCW) reflecting vascular stiffness, and forward decompression wave (FDW) representing LV relaxation were recorded and indexed to each other.

RESULTS

FCW was lowest in HLHS patients (1098 mm⁵/s), and higher in the SLV group (1457 mm5/s), and controls (6457 mm5/s) (P < 0.001). BCW/FCW was increased in HLHS (0.22) and SLV (0.14) groups compared to controls (0.08) (P = 0.003). Peak VO2 correlated with FCW (R = 0.50, P = 0.015), stroke volume (R = 0.72, P < 0.001), and cardiac output (R = 0.44, P = 0.034).

CONCLUSIONS

Patients with HLHS and SLV have unfavorable aortic WIA patterns with increased BCW/FCW ratio indicating increased systemic afterload due to retrograde compression waves. Reduced FCW and systolic MRI indices correlated with peak VO2 suggesting that abnormal systolic wave propagation may play a role in exercise intolerance for Fontan patients.

Increased prevalence of left ventricular diastolic dysfunction in adults with repaired coarctation of aorta

Background

Left ventricular (LV) pressure overload and coronary artery disease are common in patients with coarctation of aorta (COA), and they are risk factors for LV diastolic dysfunction. Patients with COA may have aortic vasculopathy that can result in LV pressure overload even in the absence of hemodynamically significant COA. We therefore hypothesized that patients with mild COA (without hemodynamically significant COA) will have more LV diastolic dysfunction compared to controls.

Methods

Adult patients with mild COA (Doppler peak velocity < 2.5 m/s) were matched 1:1 to patients without structural heart disease using propensity score method based on age, sex, body mass index, hypertension and blood pressure. The objective was to compare LV diastolic dysfunction (defined as E/e′ > 2 standard deviations above age-specific normative values) between adults with repaired COA and controls.

Results

Of 204 COA and 204 control patients (age 35 ± 12 years), patients with COA had higher septal and lateral E/e′ ratio (12 ± 4 vs 9 ± 4, p = 0.009) and (10 ± 3 vs 7 ± 3, p < 0.001), respectively. Compared to controls, the prevalence of LV diastolic dysfunction was higher in patients with COA for every age group: <40 years (63% vs 13%, p < 0.001); 41–60 years (87% vs 33%, p < 0.001); age > 60 years (82% vs 56%, p = 0.076). Left ventricular mass index (LVMI) was the strongest determinant of E/e′ (β = 2.71 per 10 g/m², standard error = 1.25, p < 0.001).

Conclusion

LV diastolic dysfunction was common in patients with COA, and the association with LVMI suggests that patients with COA may have ongoing LV pressure overload in the absence of hemodynamically significant re-coarctation.

Prediction of post-stenting biomechanics in coarcted aortas: A pilot finite element study

Endovascular stenting has recently become a standard treatment for native coarctation of the aorta (CoA) in children and young adults, given the efficacy in relieving vessel obstruction with a low incidence of adverse events. Yet, despite the short-term success of the technique, late hypertension remains an endemic risk. To assess the impact of the percutaneous procedure on the aortic wall biomechanics, we designed a novel finite element (FE) protocol for the simulation of endovascular stenting in three patient-specific CoA anatomies, developing a remeshing procedure that allows for coping with different CoA severities. Our FE protocol was able to yield numerical results on stent distortions and stresses, as well as on changes in aortic wall stresses and distensibility. These results were consistent with intraprocedural in-vivo evidences and with previous findings from the literature, and they suggest that our numerical approach could be used to understand the role of patient specific anatomical features (CoA severity and arch type) on the post-stenting aortic biomechanics. If soundly validated on a vast cohort of patients, our approach could support patient selection for the procedure.

The modified arterial reservoir: An update with consideration of asymptotic pressure (P∞) and zero-flow pressure (Pzf)

This article describes the modified arterial reservoir in detail. The modified arterial reservoir makes explicit the wave nature of both reservoir (P_res) and excess pressure (P_xs). The mathematical derivation and methods for estimating P_res in the absence of flow velocity data are described. There is also discussion of zero-flow pressure (P_zf), the pressure at which flow through the circulation ceases; its relationship to asymptotic pressure (P_∞) estimated by the reservoir model; and the physiological interpretation of P_zf . A systematic review and meta-analysis provides evidence that P_zf differs from mean circulatory filling pressure.

Pulsatile arterial haemodynamics in heart failure

Due to the cyclic function of the human heart, pressure and flow in the circulation are pulsatile rather than continuous. Addressing pulsatile haemodynamics starts with the most convenient measurement, brachial pulse pressure, which is widely available, related to development and treatment of heart failure (HF), but often confounded in patients with established HF. The next level of analysis consists of central (rather than brachial) pressures and, more importantly, of wave reflections. The latter are closely related to left ventricular late systolic afterload, ventricular remodelling, diastolic dysfunction, exercise capacity, and, in the long-term, the risk of new-onset HF. Wave reflection may also represent a suitable therapeutic target. Treatments for HF with preserved and reduced ejection fraction, based on a reduction of wave reflection, are emerging. A full understanding of ventricular-arterial coupling, however, requires dedicated analysis of time-resolved pressure and flow signals, which can be readily accomplished with contemporary non-invasive imaging and modelling techniques. This review provides a summary of our current understanding of pulsatile haemodynamics in HF.

Metformin Improves Insulin Sensitivity and Vascular Health in Youth With Type 1 Diabetes Mellitus

BACKGROUND

Cardiovascular disease is the leading cause of mortality in type 1 diabetes mellitus (T1DM) and relates strongly to insulin resistance (IR). Lean and obese adolescents with T1DM have marked IR. Metformin improves surrogate markers of IR in T1DM, but its effect on directly measured IR and vascular health in youth with T1DM is unclear. We hypothesized that adolescents with T1DM have impaired vascular function and that metformin improves this IR and vascular dysfunction.

METHODS

Adolescents with T1DM and control participants underwent magnetic resonance imaging of the ascending (AA) and descending aorta to assess pulse wave velocity, relative area change, and maximal (WSS_MAX) and time-averaged (WSS_TA) wall shear stress. Participants with T1DM also underwent assessment of carotid intima-media thickness by ultrasound, brachial distensibility by DynaPulse, fat and lean mass by dual-energy x-ray absorptiometry, fasting laboratories after overnight glycemic control, and insulin sensitivity by hyperinsulinemic-euglycemic clamp (glucose infusion rate/insulin). Adolescents with T1DM were randomized 1:1 to 3 months of 2000 mg metformin or placebo daily, after which baseline measures were repeated.

RESULTS

Forty-eight adolescents with T1DM who were 12 to 21 years of age (40% body mass index [BMI] ≥90th percentile; 56% female) and 24 nondiabetic control participants of similar age, BMI, and sex distribution were enrolled. Adolescents with T1DM demonstrated impaired aortic health compared with control participants, including elevated AA and descending aorta pulse wave velocity, reduced AA and descending aorta relative area change, and elevated AA and descending aorta WSS_MAX and WSS_TA. Adolescents with T1DM in the metformin versus placebo group had improved glucose infusion rate/insulin (12.2±3.2 [mg·kg^-1·min^-1]/μIU/μL versus -2.4±3.6 [mg·kg^-1·min^-1]/μIU/μL, P=0.005; 18.6±4.8 [mg·lean kg^-1·min^-1]/μIU/μL versus -3.4±5.6 [mg·lean kg^-1·min^-1]/μIU/μL, P=0.005) and reduced weight (-0.5±0.5 kg versus 1.6±0.5 kg; P=0.004), BMI (-0.2±0.15 kg/m² versus 0.4±0.15 kg/m²; P=0.005), and fat mass (-0.7±0.3 kg versus 0.6±0.4 kg; P=0.01). Glucose infusion rate/insulin also improved in normal-weight participants (11.8±4.4 [mg·kg^-1·min^-1]/μIU/μL versus -4.5±4.4 [mg·kg^-1·min^-1]/μIU/μL, P=0.02; 17.6±6.7 [mg·lean kg^-1·min^-1]/μIU/μL versus -7.0±6.7 [mg·lean kg^-1·min^-1]/μIU/μL, P=0.02). The metformin group had reduced AA WSS_MAX (-0.3±0.4 dyne/cm² versus 1.5±0.5 dyne/cm²; P=0.03), AA pulse wave velocity (-1.1±1.20 m/s versus 4.1±1.6 m/s; P=0.04), and far-wall diastolic carotid intima-media thickness (-0.04±0.01 mm versus -0.00±0.01 mm; P=0.049) versus placebo.

CONCLUSIONS

Adolescents with T1DM demonstrate IR and impaired vascular health compared with control participants. Metformin improves IR, regardless of baseline BMI, and BMI, weight, fat mass, insulin dose, and aortic and carotid health in adolescents with T1DM. Metformin may hold promise as a cardioprotective intervention in T1DM.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov . Unique identifier: NCT01808690.

Large vessels as a tree of transmission lines incorporated in the CircAdapt whole-heart model: A computational tool to examine heart-vessel interaction

We developed a whole-circulation computational model by integrating a transmission line (TL) model describing vascular wave transmission into the established CircAdapt platform of whole-heart mechanics. In the present paper, we verify the numerical framework of our TL model by benchmark comparison to a previously validated pulse wave propagation (PWP) model. Additionally, we showcase the integrated CircAdapt-TL model, which now includes the heart as well as extensive arterial and venous trees with terminal impedances. We present CircAdapt-TL haemodynamics simulations of: 1) a systemic normotensive situation and 2) a systemic hypertensive situation. In the TL-PWP benchmark comparison we found good agreement regarding pressure and flow waveforms (relative errors ≤ 2.9% for pressure, and ≤ 5.6% for flow). CircAdapt-TL simulations reproduced the typically observed haemodynamic changes with hypertension, expressed by increases in mean and pulsatile blood pressures, and increased arterial pulse wave velocity. We observed a change in the timing of pressure augmentation (defined as a late-systolic boost in aortic pressure) from occurring after time of peak systolic pressure in the normotensive situation, to occurring prior to time of peak pressure in the hypertensive situation. The pressure augmentation could not be observed when the systemic circulation was lumped into a (non-linear) three-element windkessel model, instead of using our TL model. Wave intensity analysis at the carotid artery indicated earlier arrival of reflected waves with hypertension as compared to normotension, in good qualitative agreement with findings in patients. In conclusion, we successfully embedded a TL model as a vascular module into the CircAdapt platform. The integrated CircAdapt-TL model allows detailed studies on mechanistic studies on heart-vessel interaction.

The effects of age at correction of aortic coarctation and recurrent obstruction on adolescent patients: MRI evaluation of wall shear stress and pulse wave velocity

Background

Coarctation patients before curative reconstruction are exposed to abnormal flow patterns which potentially could cause wall deterioration. This study evaluated the effect of age at correction on the pulse wave velocity (PWV) and peak wall shear stress (WSS) in adolescent patients with corrected coarctation. Effects of valve morphology and presence of reobstruction were also evaluated.

Methods

Twenty-one patients aged 13.7 ± 2.6 years (mean ± standard deviation) were included (bicuspid aortic valve, n = 14; reobstruction, n = 9). Mean age at correction was 1.0 ± 1.8 years. PWV was determined from two high-temporal through-plane phase-contrast magnetic resonance imaging (MRI) acquisitions, for two segments: ascending aorta plus aortic arch and descending aorta. WSS was determined from four-dimensional flow MRI. Peak WSS over five systolic phases was determined for ascending aorta, aortic arch, and descending aorta.

Results

Patients with tricuspid aortic valve showed a significant correlation between the age at correction and descending aorta PWV (r_s = 0.80, p = 0.010). Significant differences were found between patients without and with reobstruction for peak WSS in the aortic arch (3.9 ± 1.3 Pa versus 6.5 ± 2.2 Pa, respectively; p = 0.003) and descending aorta (5.0 ± 1.3 Pa versus 6.7 ± 1.1 Pa, respectively; p = 0.005).

Conclusions

A prolonged period of abnormal haemodynamic exposure may result in increased aortic wall stiffening. The increased peak WSS as results of a reobstruction possibly promotes different disease progression, which endorse longitudinal follow-up examination of corrected coarctation patients.

Aortic stiffness in adolescent Turner and Marfan syndrome patients

OBJECTIVES

Turner syndrome (TS) and Marfan syndrome (MFS) are partially characterized by aortopathies with a risk of developing severe aortic dilation, stiffness and consequent dissection and aneurysm formation. The incidence of a bicuspid aortic valve (BAV) is also increased in TS. We investigated aortic stiffness in teenage TS and MFS patients and evaluated to what degree stiffness in TS patients is augmented by the presence of a BAV.

METHODS

Fifty-seven patients with TS (n = 37) and MFS (n = 20), as well as 22 controls with similar age and size distribution underwent evaluation of thoracic aortic stiffness using phase-contrast magnetic resonance imaging. Calculated stiffness indices including pulse wave velocity (PWV), distensibility and relative area change (RAC) were collected to characterize the ascending aorta and descending aorta. PWV was also determined to evaluate global aortic arch stiffness.

RESULTS

Patients with TS had reduced distensibility (0.43 vs 0.58%/mmHg, P < 0.05) and RAC (21 vs 29%, P < 0.01) in the ascending aorta when compared with normal controls. Similarly, patients with MFS had reduced ascending aortic distensibility (0.39 vs 0.58%/mmHg, P < 0.05) and RAC (22 vs 29%, P < 0.05). There were no differences in measured PWV in the ascending aorta. Patients with TS had significantly elevated PWV measured in the aortic arch when compared with controls (2.7 vs 1.9 m/s, P < 0.05). Patients with MFS had more prominent elevation in aortic arch PWV (4.2 vs 1.9 m/s, P < 0.01). The descending aortas had decreased distensibility (0.36 vs 0.55%/mmHg, P < 0.05) and RAC (18 vs 25%, P < 0.01) only in MFS patients. Additionally, 18 TS patients with a BAV were compared with 19 TS patients with a trileaflet aortic valve, without significant differences observed in any of the considered stiffness indices.

CONCLUSIONS

TS and MFS teenage patients display evidence of increased aortic stiffness. In TS patients, this is focused in the ascending aorta and is independent of the presence of a BAV. MFS patients display a generalized reduction in compliance of the entire aorta.

Proximal pulmonary vascular stiffness as a prognostic factor in children with pulmonary arterial hypertension

Aims

Main pulmonary artery (MPA) stiffness and abnormal flow haemodynamics in pulmonary arterial hypertension (PAH) are strongly associated with elevated right ventricular (RV) afterload and associated with disease severity and poor clinical outcomes in adults with PAH. However, the long-term effects of MPA stiffness on RV function in children with PAH remain poorly understood. This study is the first comprehensive evaluation of MPA stiffness in children with PAH, delineating the mechanistic relationship between flow haemodynamics and MPA stiffness as well as the prognostic ability of these measures regarding clinical outcomes.

Methods and results

Fifty-six children diagnosed with PAH underwent baseline cardiac magnetic resonance (CMR) acquisition and were compared with 23 control subjects. MPA stiffness and wall shear stress (WSS) were evaluated using phase contrast CMR and were evaluated for prognostic potential along with standard RV volumetric and functional indices. Pulse wave velocity (PWV) was significantly increased (2.8 m/s vs. 1.4 m/s, P < 0.0001) and relative area change (RAC) was decreased (25% vs. 37%, P < 0.0001) in the PAH group, correlating with metrics of RV performance. Decreased WSS was associated with a decrease in RAC over time (r = 0.679, P < 0.001). For each unit increase in PWV, there was approximately a 3.2-fold increase in having a moderate clinical event.

Conclusion

MPA stiffness assessed by non-invasive CMR was increased in children with PAH and correlated with RV performance, suggesting that MPA stiffness is a major contribution to RV dysfunction. PWV is predictive of moderate clinical outcomes, and may be a useful prognostic marker of disease activity in children with PAH.

The aorta after coarctation repair - effects of calibre and curvature on arterial haemodynamics

BACKGROUND

Aortic shape has been proposed as an important determinant of adverse haemodynamics following coarctation repair. However, previous studies have not demonstrated a consistent relationship between shape and vascular load. In this study, 3D aortic shape was evaluated using principal component analysis (PCA), allowing investigation of the relationship between 3D shape and haemodynamics.

METHODS

Sixty subjects (38 male, 25.0 ± 7.8 years) with repaired coarctation were recruited. Central aortic haemodynamics including wave intensity analysis were measured noninvasively using a combination of blood pressure and phase contrast cardiovascular magnetic resonance (CMR). 3D curvature and radius data were derived from CMR angiograms. PCA was separately performed on 3D radius and curvature data to assess the role of arch geometry on haemodynamics. Clinical findings were corroborated using 1D vascular models.

RESULTS

There were no independent associations between 3D curvature and any hemodynamic parameters. However, the magnitude of the backwards compression wave was related to the 1st (r = - 0.36, p = 0.005), 3rd (r = 0.27, p = 0.036) and 4th (r = - 0.31, p = 0.017) principle components of radius. The 4th principle componentof radius also correlated with central aortic systolic pressure. These aortas had larger aortic roots, more transverse arch hypoplasia and narrower aortic isthmuses.

CONCLUSIONS

There are major modes of variation in 3D aortic shape after coarctation repair witha modest association between variation in aortic radius and pathological wave reflections, but not with 3D curvature. Taken together, these data suggest that shape is not the major determinant of vascular load following coarctation repair, and calibre is more important than curvature.

Reduced Aortic Distensibility is Associated With Higher Aorto-Carotid Wave Transmission and Central Aortic Systolic Pressure in Young Adults After Coarctation Repair

Background The long-term prognosis of patients with repaired aortic coarctation is characterized by high rates of cardiovascular and cerebrovascular disease related to hypertension, the basis of which remains unclear. To define potential underlying mechanisms, we investigated aortic and carotid arterial biomechanics and wave dynamics, and determinants of aortic systolic blood pressure, in young adults after coarctation repair. Methods and Results Aortic arch and carotid biomechanics, wave intensity and wave power, and central aortic blood pressure, were derived from echocardiography and brachial blood pressure in 43 young adults after coarctation repair and 42 controls. Coarctation subjects had higher brachial and central systolic blood pressure ( P=0.04), while aortic compliance was lower and characteristic impedance (Zc) higher. Although carotid intima-media thickness was higher ( P<0.001), carotid biomechanics were no different. Carotid forward compression wave power was higher and was negatively correlated with aortic compliance ( R2=0.42, P<0.001) and distensibility ( R2=0.37, P=0.001) in coarctation subjects. Aortic wave power and wave reflection indices were no different in control and coarctation patients, but coarctation patients with elevated aortic Zc had greater aorto-carotid transmission of forward compression wave power ( P=0.006). Aortic distensibility was the only independent predictor of central aortic systolic blood pressure on multivariable analysis. Conclusions Young adults following coarctation repair had a less compliant aorta, but no change in carotid biomechanics. Reduced aortic distensibility was related to greater transmission of aortic forward wave energy into the carotid artery and higher central aortic systolic blood pressure. These findings suggest that reduced aortic distensibility may contribute to later cardiovascular and cerebrovascular disease after coarctation repair.

Comparison of invasive and non-invasive aortic wave intensity and wave power analyses in sheep

OBJECTIVE

Wave intensity (WI) and wave power (WP) analyses are powerful approaches for assessing ventricular-vascular interactions and arterial dynamics using invasive and non-invasive methods. However, in vivo comparison of these methods for large arteries is lacking. This study assessed agreement, correlation and relative changes in wave size in invasive and non-invasive aortic WI/WP analyses, and associated sources of error.

APPROACH

The proximal descending thoracic aorta (DTA) of nine wethers was instrumented with a micromanometer and perivascular transit-time flow probe to measure high-fidelity blood pressure (P) and flow (Q) for invasive WI/WP analyses at baseline and during haemodynamic perturbations produced by cardiac pacing, distal DTA constriction and dobutamine-induced inotropic stimulation. In 212 experimental runs, concurrent echocardiographic DTA diameter and velocity (U) data were acquired for non-invasive WI/WP analyses, with measurement of forward compression wave (FCW), backward compression wave (BCW) and forward decompression wave (FDW) cumulative intensity (CI), cumulative power (CP) and wave-related pressure changes (ΔP).

MAIN RESULTS

Although agreement between invasive and non-invasive FCW, BCW and FDW CI/CP measures was variable (bias  -84% to  +7%), correlation was good (R  =  0.66-0.84), with lower bias and higher correlation for ΔP variables and similar relative changes in FCW and BCW CI/ΔP during haemodynamic perturbations. Main error sources were overestimation of invasive U due to assumed fixed vessel diameter, inaccuracies in non-invasive Q, and non-invasive underestimation of peak P/U and Q rates of change.

SIGNIFICANCE

Despite variable agreement, non-invasive CI/CP indices correlate well with invasive measurements, and detect relative changes in major waves induced by haemodynamic perturbations.

Impaired aortic distensibility and elevated central blood pressure in Turner Syndrome: a cardiovascular magnetic resonance study

BACKGROUND

Women with Turner Syndrome have an increased risk for aortic dissection. Arterial stiffening is a risk factor for aortic dilatation and dissection. Here we investigate if arterial stiffening can be observed in Turner Syndrome patients and is an initial step in the development of aortic dilatation and subsequent dissection.

METHODS

Fifty-seven women with Turner Syndrome (48 years [29-66]) and thirty-six age- and sex-matched controls (49 years [26-68]) were included. Distensibility, blood pressure, carotid-femoral pulse wave velocity (PWV), the augmentation index (Aix) and central blood pressure were determined using cardiovascular magnetic resonance, a 24-h blood pressure measurement and applanation tonometry. Aortic distensibility was determined at three locations: ascending aorta, transverse aortic arch, and descending aorta.

RESULTS

Mean aortic distensibility in the descending aorta was significantly lower in Turner Syndrome compared to healthy controls (P = 0.02), however, this was due to a much lower distensibility among Turner Syndrome with coarctation, while Turner Syndrome without coarctation had similar distensibility as controls. Both the mean heart rate adjusted Aix (31.4% vs. 24.4%; P = 0.02) and central diastolic blood pressure (78.8 mmHg vs. 73.7 mmHg; P = 0.02) were higher in Turner Syndrome compared to controls, and these indices correlated significantly with ambulatory night-time diastolic blood pressure. The presence of aortic coarctation (r = - 0.44, P = 0.005) and a higher central systolic blood pressure (r = - 0.34, P = 0.03), age and presence of diabetes were inversely correlated with aortic distensibility in TS.

CONCLUSION

Aortic wall function in the descending aorta is impaired in Turner Syndrome with lower distensibility among those with coarctation of the aorta, and among all Turner Syndrome higher Aix, and elevated central diastolic blood pressure when compared to sex- and age-matched controls.

TRIAL REGISTRATION

The study was registered at ClinicalTrials.gov ( #NCT01678274 ) on September 3, 2012.

Noninvasive wave intensity analysis predicts functional worsening in children with pulmonary arterial hypertension

The purpose of the present study was to characterize pulmonary vascular stiffness using wave intensity analysis (WIA) in children with pulmonary arterial hypertension (PAH), compare the WIA indexes with catheterization- and MRI-derived hemodynamics, and assess the prognostic ability of WIA-derived biomarkers to predict the functional worsening. WIA was performed in children with PAH ( n = 40) and healthy control subjects ( n = 15) from phase-contrast MRI-derived flow and area waveforms in the main pulmonary artery (MPA). From comprehensive WIA spectra, we collected and compared with healthy control subjects forward compression waves (FCW), backward compression waves (BCW), forward decompression waves (FDW), and wave propagation speed ( c-MPA). There was no difference in the magnitude of FCW between PAH and control groups (88 vs. 108 mm⁵·s^-1·ml^-1, P = 0.239). The magnitude of BCW was increased in patients with PAH (32 vs. 5 mm⁵·s^-1·ml^-1, P < 0.001). There was no difference in magnitude of indexed FDW (32 vs. 28 mm⁵·s^-1·ml^-1, P = 0.856). c-MPA was increased in patients with PAH (3.2 vs. 1.6 m/s, P < 0.001). BCW and FCW correlated with mean pulmonary arterial pressure, right ventricular volumes, and ejection fraction. Elevated indexed BCW [heart rate (HR) = 2.91, confidence interval (CI): 1.18-7.55, P = 0.019], reduced indexed FDW (HR = 0.34, CI: 0.11-0.90, P = 0.030), and increased c-MPA (HR = 3.67, CI: 1.47-10.20, P = 0.004) were strongly associated with functional worsening of disease severity. Our results suggest that noninvasively derived biomarkers of pulmonary vascular resistance and stiffness may be helpful for determining prognosis and monitoring disease progression in children with PAH. NEW & NOTEWORTHY Wave intensity analysis (WIA) studies are lacking in children with pulmonary arterial hypertension (PAH) partially because WIA, which is necessary to assess vascular stiffness, requires an invasive pressure-derived waveform along with simultaneous flow measurements. We analyzed vascular stiffness using WIA in children with PAH who underwent phase-contrast MRI and observed significant differences in WIA indexes between patients with PAH and control subjects. Furthermore, WIA indexes were predictive of functional worsening and were associated with standard catheterization measures.

Arterioventricular interaction after coarctation repair

BACKGROUND

Hypertension is common in patients with coarctation of the aorta (CoA), even after successful repair. Increased aortic stiffness has been implicated in the pathology of CoA-associated hypertension. This study aimed to investigate aortic vascular function and its relationship with hypertension in well-repaired CoA-patients at long-term follow-up. Furthermore, we assessed the additive effect of hypertension to adverse arterioventricular coupling associated with increased aortic stiffness.

METHODS

Twenty-two CoA-patients (age 30 ± 10.6 years) with successful surgical repair (n = 12) or balloon angioplasty (BA) (n = 10) between 3 months and 16 years of age with a follow-up of >10 years and 22 healthy controls underwent cardiac magnetic resonance imaging (CMR), at mean follow-up of 29.3 years, to study aortic pulse wave velocity (PWV), aortic distensibility, global left ventricular (LV) function, LV dimensions, and LV myocardial deformation.

RESULTS

CoA-patients had significantly increased aortic arch PWV (5.6 ± 1.9 m/s vs. 4.5 ± 1.0 m/s, P = .02) and decreased distensibility (4.5 ± 1.8 × 10-3 mmHg^-1 vs. 5.8 ± 1.8 × 10-3 mmHg^-1, P = .04) compared to controls. Significant differences in aortic arch PWV were found between hypertensive patients, normotensive patients and controls (6.1 ± 1.8 m/s vs. 4.9 ± 1.9 m/s and 4.5 ± 1.0 m/s, respectively, P = .03). Aortic arch PWV and distensibility were correlated with systolic blood pressure (R = 0.37 and R = -0.37, respectively, P = .03 for both). Global LV function, LV mass, LV dimensions and myocardial deformation were similar in CoA-patients when compared to controls.

CONCLUSIONS

Central aortic stiffness is significantly increased in well-repaired CoA-patients long-term after repair, and is associated with hypertension. Global LV function, myocardial deformation indices and LV dimensions are however preserved.

Enhanced Aortic Pressure Wave Reflection in Patients with Aortic Coarctation after Aortic Arch Repair

Background

In patients with aortic coarctation after successful aortic arch repair, it is well known that early-onset cardiovascular diseases can develop.

Summary

We studied the pressure waveform in patients after aortic arch repair focusing on a pressure wave reflection. In patients after aortic arch repair, the repaired portion generates a new reflected pressure wave. As a result, the newly generated pressure wave causes aortic pressure augmentation, loss of pressure amplification, and left ventricular hypertrophy with fibrosis. Balloon dilatation of the aortic arch may also generate a new pressure wave reflection.

Key Messages

In patients with aortic coarctation after aortic arch repair, the reconstructed site generates a new pressure wave reflection. This could be one of the causes of their future cardiovascular diseases.