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

Is the burden of late hypertension and cardiovascular target organ damage in children and adolescents with coarctation of the aorta after early successful repair different to healthy controls?

OBJECTIVE

Cardiovascular morbidity is high in patients with coarctation of aorta even after successful repair. This study aimed to assess the frequency of late hypertension and the relationship between ambulatory hypertension and cardiovascular target organ damage in children and adolescents after early and successful repair of coarctation of the aorta.

METHODS

Twenty-five children and adolescents (mean age 13.5 ± 3.43 years) with repaired coarctation of the aorta (median age at repair 4 months, arm-leg gradient <20 mmHg) and 16 healthy controls were included. Office and ambulatory blood pressure, pulse wave velocity, and left ventricular mass index were assessed.

RESULTS

Both day- and night-time systolic blood pressure standard deviation score and left ventricular mass index were significantly higher in patients compared to controls (p ≤ 0.001 for all), whereas pulse wave velocity did not differ. The prevalence of masked hypertension, isolated nocturnal hypertension, and left ventricular hypertrophy were 40, 28, and 24%, respectively. Left ventricular mass index was higher in patients with sustained hypertension, masked hypertension, and normotension compared to controls (p < 0.05). In multivariate analysis, higher night-time systolic blood pressure standard deviation score was the only independent predictor of left ventricular mass index.

CONCLUSION

The present study reveals a high prevalence of masked hypertension, isolated nocturnal hypertension, and left ventricular hypertrophy in children and adolescents with coarctation of the aorta even after early and successful repair. Ambulatory blood pressure monitoring should be considered to diagnose hypertension. All coarctation of aorta patients should be followed up lifelong and encouraged to establish a healthy lifestyle starting from childhood.

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.

Aortic stenting in the growing sheep causes aortic endothelial dysfunction but not hypertension: Clinical implications for coarctation repair

BACKGROUND

Stent implantation is the treatment of choice for adolescents and adults with aortic coarctation (CoAo). Despite excellent short-term results, 20%-40% of the patients develop arterial hypertension later in life, which was attributed to inappropriate response of the aortic baroreceptors to increased stiffness of the ascending aorta (ASAO), either congenital or induced by CoAo repair. In particular, it has been hypothesized that stent itself may cause or sustain hypertension. Therefore, we aimed to study the hemodynamic and structural impact following stent implantation in the normal aorta of a growing animal.

METHODS

Eight female sheep completed the study and a stent was implanted in four. Every 3 mo we measured blood pressure of the anterior and posterior limbs and left ventricular function by echocardiography. Twelve months later invasive pressure was measured under baseline and simulated stress conditions. Expression of genes indicating oxidative stress (OS), endothelial dysfunction (ED) and stiffness, as well as pathological examination were performed in ascending (ASAO) and descending aorta (DSAO).

RESULTS

SOD1 and MMP9 gene expression were higher in ASAO of the stented animals, compared to DSAO and controls, while NOS3 was decreased. No differences were found in blood pressure and echocardiographic parameters. No histological differences were found in the aorta of the two groups of animals.

CONCLUSIONS

Stent does not affect central and peripheral hemodynamics, cardiac structure and function even in the long term. However, the finding of markers of OS and increased stiffness of ASAO, proximal to the stent, points to molecular mechanisms for increased cardiovascular risk of patients with stented CoAo.

Late hypertension in patients with repaired aortic coarctation

Coarctation of the aorta represents more than a simple obstructive lesion, as there is often evidence of hypertension and vascular dysfunction despite successful surgery at an early age. There are ample data showing that a large proportion of patients develop arterial hypertension, and this appears to increase with age. Our understanding of the pathogenesis of late hypertension is incomplete, and there is limited information on which drugs are most appropriate. Increased arterial rigidity is now well described in this patient group, although it is not known how this should influence therapy. The increase in afterload associated with this increased rigidity has been found to have an impact on the left ventricle at an early stage, and the interaction between the vascular dysfunction and the ventricle is an area of interest and active research. This article reviews some recent studies and highlights areas where research questions remain.

Aortic surgery is one of the risk factors for enhancement of pressure wave reflection in adult patients with congenital heart disease

BACKGROUND

Excessive aortic pressure wave reflection is one of the risk factors of cardiovascular diseases. In some clinical course of congenital heart diseases, the elevated pressure wave reflection has been reported. The purpose of this study is to elucidate the risk factors of the enhanced pressure wave reflection in adult patients with congenital heart disease.

METHODS

We enrolled 99 adult (≥20 years) patients with congenital heart disease. We measured their radial pressure augmentation index and examined the relationship between it and various clinical variables.

RESULTS

The radial pressure augmentation index was 77.1 ± 19.1% and it had a significant correlation with the history of aorto-pulmonary shunt (t=4.194; p<0.0001), age (t=4.091; p<0.0001), height (t=-3.580; p=0.001) and the history of direct aortic surgery (t=2.253; p=0.027). Forty-four patients (44.4%) demonstrated high radial augmentation index (>1SD of age- and gender matched control) and the determinants of the elevated radial augmentation index were the history of aorto-pulmonary shunt (odds ratio, 21.32; 95% confidence interval, 5.47-83.14; p<0.0001) and the direct aortic surgery (4.18; 1.38-12.72; p=0.012).

CONCLUSIONS

The history of aortic surgeries enhances aortic pressure wave reflection in adult patients with congenital heart disease. The enhanced aortic pressure wave reflection is one of the risk factors for cardiovascular diseases. Therefore, the adult patients with congenital heart disease after aortic surgeries should be carefully observed and tightly controlled concerning the risk factors for cardiovascular diseases.