Enhanced Aortic Pressure Wave Reflection in Patients After Repair of Aortic Coarctation

Vascular Health in Congenital Heart Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Congenital heart disease (CHD) affects 1% of live births and is a risk factor for cardiovascular disease and reduced life expectancy. Previous studies have suggested CHD is associated with impaired vascular health, but this has not been established. Therefore, the objective of this study was to examine the effect of CHD on vascular health.

METHODS

Eight electronic databases were searched through April 12, 2024. Studies of all designs (except case studies and reviews) that reported on the population (individuals with CHD of any age), comparator (individuals without CHD), and outcomes of interest: endothelial dependent (flow-mediated vasodilation, reactive hyperemia index) and independent (nitroglycerin-mediated dilation) vascular function, arterial stiffness (pulse wave velocity, stiffness index, augmentation index, distensibility, and compliance), and carotid intima-media thickness were included. Results are presented as standardized mean difference (SMD) with 95% confidence interval (CI) and as effect size.

RESULTS

We included 138 studies (N = 16,115) in the meta-analysis. Individuals with CHD exhibited decreased vascular function compared with those without including decreased low-mediated vasodilation (SMD, -0.96 [95% CI, -1.22 to -0.70]; I2 = 85%; large effect size), reactive hyperemia index using ultrasound (SMD, -2.88 [95% CI, -4.85 to -0.90]; I2 = 96%; large effect size), and nitroglycerin-mediated dilation (SMD, -0.98 [95% CI, -1.35 to -0.61]; I2 = 87%; large effect size). Various CHD subtypes including coarctation of the aorta, transposition of the great arteries, and tetralogy of Fallot, after the Fontan procedure showed significant vascular dysfunction. Shunt lesions did not show significant vascular dysfunction.

CONCLUSIONS

CHD is associated with vascular dysfunction, increased arterial stiffness, and greater carotid intima-media thickness in pediatric and adult patients.

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.

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.

An experimental evaluation of a concept to improve conventional aortic prostheses

Conventionally used textile prosthesis for traditional open surgical repair (OSR) of aortic aneurysms have a lower compliance than the native aortic tissue. Graft placements lead to an acute drop in compliance which effects cardiovascular risk and the development of graft related complications. A custom-made spring casing was applied to a Dacron graft segment under physiological pressure conditions within a five-element biventricular mock circulation loop, to investigate experimentally a concept to improve the compliance of a conventional aortic prosthesis by changing the transverse graft cross-section. Two different prosthesis locations, proximal and distal of compliant silicone tubing were used to study uniaxial graft compression with an elastic device. To characterise the devices' performance by means of pulse pressure (PP), diastolic pressure (P_dia) and pulse wave velocity(PWV), fluid pressures and flow were recorded. In a proximal graft setting (ascending aorta repair) elastic uniaxial compression with a custom-made spring casing (2 cm width) could significantly reduce PP by 10-14% (p < .001) and slowed PWV from 6.7 to 5.2 m/s (22%, p = .002). Applied to a graft in a distal position, the spring casing demonstrated less impact on PP (2-10%), but significantly reduced PWV in this mock aorta segment from 13.7 to 5.5 m/s (60%, p = .004). In conclusion, a newly conceptualised spring casing applied to the external wall of synthetic aortic grafts can reduce PP and slow PWV. By restoring elastic aortic recoil in stiff textile aortic prostheses, the presented concept is a potential solution to improve long-term aortic prosthesis related complications.

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.

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.

Low Peak dP/dt in the Descending Aorta in Patients After Successful Aortic Arch Repair

One of the most important problems in patients with aortic coarctation or interruption of the aortic arch after successful aortic arch repair is developing cardiovascular disease in the future. It has been reported that the repaired site is stiff and generates a new pressure wave reflection, which could lead to cardiovascular disease. The purpose of this study was to clarify the influence of the repaired portion's stiffness on the pressure waveform in patients. Fifteen patients (age: 7.4 ± 3.2 years) who had successful aortic arch repair were enrolled. Their peak dP/dt in the ascending aorta (AAo) and the descending aorta (DAo) were compared with those of age-matched controls with a normal aortic arch. The ascending and descending aortic systolic blood pressures in aortic arch repair patients were higher than those in age-matched controls (AAo: 103.1 ± 13.3 vs. 91.9 ± 9.2 mmHg, p = 0.012 and DAo: 108.7 ± 16.4 vs. 96.5 ± 9.9 mmHg, p = 0.020). Although no difference existed in the peak dP/dt in the AAo between the aortic arch repair patients and the controls (572.1 ± 100.1 vs. 543.3 ± 110.2 mmHg/s, p = 0.460), the peak dP/dt in the DAo in the aortic arch repair patients was significantly lower than that in the controls (489.3 ± 75.2 vs. 579.4 ± 106.0 mmHg/s, p = 0.013). The peak dP/dt in the DAo in aortic arch repair patients is low. The stiff repaired site may attenuate pulsation.

Preserved Cardiac Blood Supply-Workload Balance in Pediatric Patients After Aortic Arch Repair

One of the most important problems in patients with aortic coarctation after aortic arch repair is future cardiovascular disease. We have previously reported that the enhancement of aortic pressure wave reflection in patients could be one of the causes of future cardiovascular diseases, because it results in an increase of the left ventricular workload and is disadvantageous for coronary circulation. Seventeen patients who had undergone aortic arch repair without pressure gradient in their aortic arch were enrolled. An ascending aortic pressure waveform was recorded by a pressure-sensor-mounted catheter, and a subendocardial viability ratio, which measures cardiac blood supply-workload balance, was calculated. The values were compared with those in age-matched controls. The patients' mean age was 6.8 ± 2.8 years. The mean ascending aortic systolic pressure was higher (100.4 ± 12.9 vs. 90.2 ± 8.9 mmHg, p = 0.0011) and the pulse pressure was wider (38.1 ± 7.1 vs. 32.5 ± 5.4 mmHg, p = 0.0072) in patients than in control subjects. There was no difference in the mean subendocardial viability ratio (1.01 ± 0.25 vs. 1.01 ± 0.24, ns), while the mean tension time index (27.4 ± 5.6 vs. 23.0 ± 3.3, p = 0.0001) and diastolic pressure time index (28.4 ± 11.1 vs. 23.6 ± 8.0, p = 0.0082) were higher in patients than in controls. The cardiac blood supply-workload balance was preserved in patients after aortic arch repair, despite an increase in their cardiac workload.

Primary-care management of patients with coarctation of the aorta

Coarctation of the aorta is a congenital cardiac defect that results in a variable degree of obstruction to the left side of the heart. It can present with either acute shock in the neonatal period as a critical lesion or it can appear more insidiously with hypertension or other findings later in life. This article summarises aspects of outpatient care of patients with this lesion, including clinical history and physical examination, ancillary testing, and issues associated with long-term follow-up and management. Increasing knowledge and experience with this group of patients have allowed for a higher level of evidence-based care over the long term.

Persistent reduced myocardial deformation in neonates after CoA repair

INTRODUCTION

Surgical repair of coarctation of the aorta (CoA) is a safe procedure in children, however the condition is known for its potential recurrence and other related complications. The available evidence shows abnormal intrinsic properties of the aorta in CoA, thus suggesting additional effect, even after CoA repair, on left ventricular (LV) function. Accordingly, we sought to obtain a better understanding of LV myocardial mechanics in very early-corrected CoA using two-dimensional STE.

METHODS AND RESULTS

We retrospectively studied 21 patients with corrected CoA at a median age of 9 (2-53) days at three time points: 1) just before intervention, 2) at short-term follow-up and 3) at medium-term follow-up after intervention and compared them with normal values. Speckle tracking analysis was conducted via vendor independent software, Tomtec. After intervention, LV function significantly improved (from -12.8±3.9 to -16.7±1.7; p<0.001), however normal values were not reached even at medium term follow-up (-18.3±1.7 vs. -20±1.6; p=0.002). Medium term longitudinal strain correlated with pre intervention EF (r=0.58, p=0.006). Moreover, medium term subnormal values were more frequently associated with bicuspid aortic valve (33.3% vs. 66.6%; p<0.05).

CONCLUSION

LV myocardial function in neonates with CoA can be feasibly evaluated and followed up by speckle tracking echocardiography. LV subendocardial dysfunction however, remains in early infancy coarctation long after repair. Long-term follow-up through adulthood using myocardial deformation measurements should shed light on the natural history and consequences of this anomaly.

Serum concentration of procollagen type III amino-terminal peptide is increased in patients with successfully repaired coarctation of the aorta with left ventricular hypertrophy

Pathological left ventricular hypertrophy (LVH) with myocardial fibrosis is an independent risk factor for cardiovascular mortality. Previous studies indicated that patients with coarctation of the aorta (CoA) have increased left ventricular mass (LVM) including LVH, even after successful CoA repair. It is unclear whether the increased LVM is pathological one with cardiac fibrosis. Group A consisted of 17 patients with successfully repaired CoA. Group B consisted of 17 postoperative subjects who matched the age and postoperative periods of group A. Group C comprised 28 subjects for the geometric standard of the left ventricle. The LVM index (LVMI) and the relative wall thickness (RWT) of group A and B were compared with the values of 17 age-matched subjects from group C. The serum concentration of procollagen type III amino-terminal peptide (P-III-P), a biomarker for myocardial fibrosis, in group A was compared with the concentration in group B. The correlations between the serum P-III-P concentration and LVMI and RWT were studied in group A and non-A group. In group A, RWT and LVMI were significantly higher than those in group C (0.37 ± 0.05 vs. 0.31 ± 0.02, p < 0.01; 44.8 ± 11.2 vs. 36.5 ± 7.6, p = 0.04, respectively), and the serum P-III-P concentration was significantly higher than that in group B (1.59 ± 0.74 vs. 1.07 ± 0.33, p = 0.04). Serum P-III-P concentrations were well correlated with RWT and LVMI (r = 0.89, p < 0.01; r = 0.63, p < 0.01, respectively) in group A. LVH in patients with successfully repaired CoA may have an abnormal pathogenesis associated with myocardial fibrosis.

Fluid dynamics of coarctation of the aorta and effect of bicuspid aortic valve

Up to 80% of patients with coarctation of the aorta (COA) have a bicuspid aortic valve (BAV). Patients with COA and BAV have elevated risks of aortic complications despite successful surgical repair. The development of such complications involves the interplay between the mechanical forces applied on the artery and the biological processes occurring at the cellular level. The focus of this study is on hemodynamic modifications induced in the aorta in the presence of a COA and a BAV. For this purpose, numerical investigations and magnetic resonance imaging measurements were conducted with different configurations: (1) normal: normal aorta and normal aortic valve; (2) isolated COA: aorta with COA (75% reduction by area) and normal aortic valve; (3) complex COA: aorta with the same severity of COA (75% reduction by area) and BAV. The results show that the coexistence of COA and BAV significantly alters blood flow in the aorta with a significant increase in the maximal velocity, secondary flow, pressure loss, time-averaged wall shear stress and oscillatory shear index downstream of the COA. These findings can contribute to a better understanding of why patients with complex COA have adverse outcome even following a successful surgery.

Aortic pressure wave reflection in patients after successful aortic arch repair in early infancy

Despite the apparently successful surgical repair of aortic coarctation, subsequent cardiovascular complications have sometimes been encountered. Aortic pressure wave reflection is one of the risk factors for developing cardiovascular diseases, and an enhancement of the pressure wave reflection has been reported in patients after aortic arch repair. To clarify this issue, the increase in pressure wave reflection was evaluated in patients <15 years old who underwent aortic arch repair. This study enrolled 35 patients after aortic arch repair in early infancy. All patients underwent cardiac catheterization, and in 20 patients, there was no pressure difference within the repaired aortic arch. The aortic pressure waveforms in patients after successful aortic arch repair were recorded using a pressure sensor-mounted catheter, and the augmentation index in the ascending aorta was calculated. The augmentation index in patients after an aortic arch repair was increased compared with control subjects, although there was no pressure difference between the ascending and descending aorta (P<0.0001). The increase in the augmentation index was correlated with the patient's age (r=0.8932, P<0.0001) and with the left ventricular posterior wall thickness (r=0.4075, P=0.0373). In patients who undergo aortic arch repair, the pressure wave reflection is accelerated, even when the aortic arch repair is 'successful'. This increase is one of the possible causes of left ventricular hypertrophy.

Isoproterenol stress test during catheterization of patients with coarctation of the aorta

BACKGROUND

The exercise test is considered useful in selecting high-risk patients with repaired coarctation of the aorta (CoA), but it is difficult to obtain the cooperation of pediatric patients. The present study determines the feasibility of the isoproterenol stress test (IST) among pediatric patients with CoA.

METHODS

Thirteen patients with repaired or mild preoperative CoA aged 1-207 (median 13) months underwent 16 IST during cardiac catheterization. Peak-to-peak pressure gradients (PG) over the coarctation site were measured at baseline and at IST. Balloon angioplasty (BAP) was applied to patients with significant stenosis on angiography.

RESULTS

The PG between the ascending and the descending aorta was significantly higher at IST than at baseline (20.5 ± 11.5 vs 5.6 ± 3.9 mmHg, P < 0.0001). Heart rate, the systolic blood pressure measured at the ascending aorta, and pulse pressure were all significantly higher at IST than at baseline. The PG at IST decreased >10 mmHg in three of six patients after BAP.

CONCLUSIONS

Significant pressure gradients over the coarctation site develop at IST in pediatric patients with repaired CoA or in preoperative patients with mild coarctation.

Left ventricular and ascending aortic function after stenting of native coarctation of aorta

Patients with surgically corrected aortic coarctation have increased proximal aortic stiffness that might contribute to the known worse cardiovascular outcomes. We examined the effect of stenting on the mid-term ascending aortic elastic properties and its relation to cardiac structure and function in adults with native coarctation of the aorta. A total of 20 consecutive patients (13 men, age at stenting 30 + or - 8 years) were prospectively studied before and 14 + or - 2 months after coarctation stenting. The aortic stiffness index was calculated using the ascending aortic diameters and right arm blood pressure values. The ventricular long-axis function was assessed using pulsed-wave tissue Doppler imaging at the septal site. The results were compared to those from 31 normal controls. Statistically significant improvement was found in aortic narrowing (catheter-derived gradient 32 + or - 11 vs 10 + or - 6 mm Hg), left ventricular mass index (132.8 + or - 50.1 vs 114.7 + or - 47.7 g/m(2)), long-axis function, and left atrial volume index (26.5 + or - 5.3 vs 23.7 + or - 5.6 mm(3)/m(2)). The patients continued to have a thicker left ventricle, reduced long-axis function, and larger left atrium after intervention than did the controls. They also had impaired proximal aortic function with respect to the controls that remained unchanged after stenting (aortic stiffness index 10.7 + or - 4.5 to 10.1 + or - 3.0). The poststenting aortic stiffness index correlated modestly with the left ventricular mass index and reduced long-axis velocity. In conclusion, aortic stenting resulted in partial mid-term improvement in cardiac structure and function in adults with coarctation of aorta but the ascending aortic elastic properties remained abnormal. Such a degree of impairment was related to residual left ventricular hypertrophy and dysfunction. Early identification of such patients and optimum management might avoid these irreversible ventriculoaortic disturbances and their known consequences.

A meta-analysis of the mechanism of blood pressure change with aging

OBJECTIVES

We undertook a meta-analysis to determine whether changes in wave reflection substantiate the consensus explanation of why blood pressure (BP) changes with aging.

BACKGROUND

Consensus documents attribute the aging changes in BP to wave reflection moving progressively from diastole into systole. However, the extensive quantitative data on this phenomenon have never been systematically reviewed. Individual studies have been small, and limited to a narrow age range.

METHODS

Using PubMed, Cochrane, and Web of Science databases, we identified 64 studies (including 13,770 subjects, age range 4 to 91 years) reporting the timing of wave reflection, defined as the time from the onset (foot) of the pressure waveform to the shoulder point (anachrotic notch).

RESULTS

In subjects of all ages, reflection times were well within systole. There was a small tendency for younger subjects to have later reflection, but this was only 0.7 ms per year, whereas the weighted mean reflection time was 136 ms (99% confidence interval: 130 to 141 ms) and the mean duration of systole was 328 ms (99% confidence interval: 310 to 347 ms). At this rate of change with age, arrival of wave reflection would only be construed to be in diastole at an extrapolated age of -221 years.

CONCLUSIONS

These findings challenge the current consensus view that a shift in timing of wave reflection significantly contributes to the changes in the BP waveform with aging. We should re-evaluate the mechanisms of BP elevation in aging.

Surveillance of cardiovascular risk in the normotensive patient with repaired aortic coarctation

Background

Repaired coarctation of the aorta is associated with premature atherosclerosis and an increased risk of cardiovascular events even in normotensive subjects. To date clinical risk stratification has focused on brachial blood pressures ignoring the complex pulsatility of the aortic wave form. The aim of this study was to assess components of this pulsatility in a clinical setting and to suggest possible techniques to improve risk stratification.

Methods

This was a prospective study recruiting patients from a tertiary referral centre. Pulse wave morphology was assessed using applanation tonometry. B-mode ultrasound and cardiac magnetic resonance were used to assess carotid intimal–medial thickness and left ventricular mass.

Results

Forty-six subjects with repaired coarctation of the aorta (range 16–62 years; mean 31 years) and 20 matched controls were studied. Baseline brachial systolic and diastolic blood pressures were not statistically different between the 2 groups. Peripheral (62.5 mmHg (11.3) vs. 50.6 mmHg (15.0), p = 0.0008) and central (34.5 mmHg (7.7) vs. 28.7 mmHg (4.7), p = 0.005) pulse pressures were elevated in the coarctation patients compared to controls. The reflected pressure wave returned to the ascending aorta earlier in the coarctation group (p = 0.007) and the tension time index (TTI) was increased (p = 0.03). The sub-endocardial viability index (SVI) was reduced in the coarctation subjects (159 (33) vs. 186 (31)%; p = 0.009) but there was no differences in central augmentation index (p = 0.35).

Conclusions

This study demonstrates that there are patients with repaired coarctation who have an excellent mid-term outcome free from ventricular hypertrophy, carotid intima medial thickening and with relatively preserved vascular reactivity. However even in this “best outcome” cohort there were abnormal vascular characteristics that may predispose to increased cardiovascular risk. Simple non-invasive investigations can more extensively characterise these sub-clinical abnormalities and by utilised in long-term surveillance.

Angular (Gothic) aortic arch leads to enhanced systolic wave reflection, central aortic stiffness, and increased left ventricular mass late after aortic coarctation repair: evaluation with magnetic resonance flow mapping

OBJECTIVE

We sought to investigate the mechanism whereby a particular deformity of the aortic arch, an angulated Gothic shape, might lead to hypertension late after anatomically successful repair of aortic coarctation.

METHODS

Fifty-five normotensive patients with anatomically successful repair of aortic coarctation and either a Gothic (angulated) or a Romanesque (smooth and rounded) arch were studied with magnetic resonance angiography and flow mapping in both the ascending and descending aortas. Systolic waveforms, central aortic stiffness, and pulse velocity were measured. We hypothesized that arch angulation would result in enhanced systolic wave reflection with loss of energy across the aortic arch, as well as increased central aortic stiffness.

RESULTS

Twenty patients were found to have a Gothic, and 35 a Romanesque, arch. Patients with a Gothic arch showed markedly augmented systolic wave reflection (12 +/- 6 vs 5 +/- 0.3 mL, P < .001) and greater loss of systolic wave height in the distal aorta (30% +/- 16% vs 22% +/- 12%, P < .01) compared with that of subjects with a Romanesque arch. Pulse wave velocity was also increased with a Gothic arch (5.6 +/- 1.1 vs 4.1 +/- 1 m/s, P < .0001), as well as left ventricular mass index (85 +/- 15 vs 77 +/- 20 g/m2). Patients with a Romanesque arch had increased aortic stiffness compared with that of control subjects (stiffness beta-index, 3.9 +/- 0.9 vs 2.9 +/- 1; P = .03).

CONCLUSIONS

Angulated Gothic aortic arch is associated with increased systolic wave reflection, as well as increased central aortic stiffness and left ventricular mass index. These findings explain (at least in part) the association between this pattern of arch geometry and late hypertension at rest and on exercise in subjects after coarctation repair.

Effect of endovascular stenting of aortic coarctation on biventricular function in adults

OBJECTIVE

To investigate the effect of endovascular stenting of aortic coarctation on biventricular function in adults during intermediate-term follow-up.

METHODS

21 patients (age 34 (10) years) were studied prospectively before and 14 (2) months after coarctation stenting from year 2002 to 2005. Biventricular function and blood pressure measurements were made. The post-stenting results were compared with pre-stenting values (group 1), with 22 age- and sex-matched post-surgical repair patients (group 2) and 30 normal controls (group 3).

RESULTS

The peak systolic gradient across the coarctation site fell (55 (15) mm Hg to 18 (8) mm Hg, p<0.001). Systolic, mean blood pressure and left ventricular (LV) mass dropped after stenting (p<0.05 for all). LV long-axis function improved at intermediate-term follow-up (tissue Doppler imaging lateral and septal systolic and diastolic velocities and E/Em ratios: LSm, 6.5 (1.4) cm/s to 7.9 (1.7) cm/s; SSm, 5.8 (1.2) cm/s to 7.3 (1.6) cm/s; LEm, 8.1 (1.3) to 9.4 (2.3) cm/s; SEm, 6.7 (1.5) cm/s to 7.8 (1.9) cm/s; LE/Em, 11.2 (2.7) to 9.8 (2.8); SE/Em, 14.8 (5.3) to 11.8 (3.9); p<0.05 for all). No significant difference in LV ejection fraction, conventional LV diastolic measurements (E, A, E/A ratio, IVRT and DT) was found after stenting. No significant deterioration of right ventricular function was seen in stented patients. Both post-stenting and post-surgical repair patients had poorer LV long-axis function than controls (p<0.01 for all).

CONCLUSIONS

Endovascular stenting of aortic coarctation resulted in medium-term LV mass regression and long-axis function improvement that may provide insight into long-term outcome of the stented patients. The results support aortic stenting in patients with anatomically suitable defects, given the additional benefit of avoiding cardiopulmonary bypass. The clinical significance of subclinical myocardial dysfunction in patients with stented or repaired coarctation warrants further studies.

Evidence suggests rigid aortic grafts increase systolic blood pressure: results of a preliminary study

Abdominal aortic aneurysm (AAA) is a serious complication of the aorta and is treated using vascular bypass grafts. Two main classes of graft are available to treat AAA; grafts implanted by open surgery and stent-grafts implanted using minimally invasive endovascular techniques. Both classes of graft consist of an aortic section which bifurcates into two iliac sections. It has been hypothesized that implantation of aortic grafts and stent-grafts serve to significantly increase abdominal aortic pressures. In this study, an open-loop computer-controlled pumping system was built to produce physiologically realistic pressure and flow-rates. Models of a compliant abdominal aortic aneurysm, a compliant walled graft and a tapered graft were manufactured using an injection moulding technique and fused deposition modelling was used to create a rigid walled graft. A specific transient flow-rate waveform was then applied at the inlet of each model and the resulting pressure waveforms 30 mm upstream from the bifurcation was recorded. Peak pressure measurements were recorded over the course of the pulse for each model. The compliant aneurysm model was found to have a systolic pressure of 107 mmHg while the complaint graft model was 153 mmHg. The rigid graft model had a peak systolic pressure of 199 mmHg. In the tapered graft, the peak pressure dropped to 142 mmHg. The data suggests that implanting a graft model in place of an aneurysm model in an in vitro flow circuit can increase the pressures recorded upstream from the iliac bifurcation and that tapered grafts may alleviate this problem.