Long-term follow-up after aortic coarctation repair: The unsolved issue of exercise-induced hypertension

Coarctation of the Aorta: Modern Paradigms Across the Lifespan

While coarctation of the aorta varies greatly in both severity and age at presentation, all patients are at increased risk of hypertension both before and after repair. Despite advances in knowledge about genetic etiologies, pathophysiologic mechanisms, and optimal repair strategies, patients with repaired coarctation of the aorta remain at increased risk of acquired cardiovascular disease. The aims of this review are to describe the management of coarctation of the aorta at all ages before and after repair, highlight pathophysiologic mechanisms of hypertension, and review long-term follow-up considerations.

Hypertensive response to exercise in adult patients with repaired aortic coarctation

OBJECTIVE

The clinical and prognostic implications of a hypertensive response to exercise after repair of coarctation of the aorta (CoA) remain controversial. We aimed to determine the prevalence of a hypertensive response to exercise, identify factors associated with peak exercise systolic blood pressure (SBP) and explore the association of peak exercise SBP with resting blood pressure and cardiovascular events during follow-up.

METHODS

From the Dutch national CONgenital CORvitia (CONCOR) registry, adults with repaired CoA who underwent exercise stress testing were included. A hypertensive response to exercise was defined as a peak exercise SBP ≥210 mm Hg in men and ≥190 mm Hg in women. Cardiovascular events consisted of coronary artery disease, stroke, aortic complications and cardiovascular death.

RESULTS

Of the original cohort of 920 adults with repaired CoA, 675 patients (median age 24 years (range 16-72 years)) underwent exercise stress testing. Of these, 299 patients (44%) had a hypertensive response to exercise. Mean follow-up duration was 10.1 years. Male sex, absence of a bicuspid aortic valve and elevated resting SBP were independently associated with increased peak exercise SBP. Peak exercise SBP was positively predictive of office SBP (β=0.11, p<0.001) and 24-hour SBP (β=0.05, p=0.03) at follow-up, despite correction for baseline SBP. During follow-up, 100 patients (15%) developed at least 1 cardiovascular event. Peak exercise SBP was not significantly associated with the occurrence of cardiovascular events (HR 0.994 (95% CI 0.987 to 1.001), p=0.11).

CONCLUSIONS

A hypertensive response to exercise was present in nearly half of the patients in this large, prospective cohort of adults with repaired CoA. Risk factors for increased peak exercise SBP were male sex, absence of a bicuspid aortic valve and elevated resting SBP. Increased peak exercise SBP independently predicted hypertension at follow-up. These results support close follow-up of patients with a hypertensive response to exercise to ensure timely diagnosis and treatment of future hypertension.

Isolated Coarctation of the Aorta: Current Concepts and Perspectives

Current management of isolated CoA, localized narrowing of the aortic arch in the absence of other congenital heart disease, is a success story with improved prenatal diagnosis, high survival and improved understanding of long-term complication. Isolated CoA has heterogenous presentations, complex etiologic mechanisms, and progressive pathophysiologic changes that influence outcome. End-to-end or extended end-to-end anastomosis are the favored surgical approaches for isolated CoA in infants and transcatheter intervention is favored for children and adults. Primary stent placement is the procedure of choice in larger children and adults. Most adults with treated isolated CoA thrive, have normal daily activities, and undergo successful childbirth. Fetal echocardiography is the cornerstone of prenatal counseling and genetic testing is recommended. Advanced 3D imaging identifies aortic complications and myocardial dysfunction and guides individualized therapies including re-intervention. Adult CHD program enrollment is recommended. Longer follow-up data are needed to determine the frequency and severity of aneurysm formation, myocardial dysfunction, and whether childhood lifestyle modifications reduce late-onset complications.

The clinical presentation and outcome of aortic coarctation associated with left ventricular inflow and outflow tract lesion in adult patients: Shone syndrome and beyond

BACKGROUND

Aortic coarctation (AoCoa) is a congenital stenosis of aorta, which often co-exists with other congenital heart defects. Many studies have shown the importance of regular follow-up in these patients however there is scarcity of knowledge relating to the impact of left ventricle inflow lesions (LVIT) and left ventricle outflow track lesions (LVOT). The aim of this study is to evaluate the impact of isolated AoCoa with LVIT and/or LVOT on haemodynamic, morbidity and mortality.

METHODS

We have retrospectively analysed clinical data of all adult AoCoa patients who underwent echocardiography between 2010-2018 in our centre. Outcome measures included death, number of hospitalisations for cardiac causes, development of cardiac arrhythmia, new prescription of HF medication.

RESULTS

A total of 406 AoCoa patients were included and were followed for a median 4.2 years. At baseline, 38% patients had AoCoa alone, 54% patients had LVOT, 3% patients had LVIT, and 5% patients had mixed LVIT and LVOT, including patients with Shone syndrome. Patients with mixed LVIT and LVOT had the highest mortality of the four groups and the highest heart failure-related morbidity. Moreover, they were the most prone to have a higher indexed LA volume compared to patients with no LVOT (p=0.0001). During follow-up, 13 patients died, of which 21% patients were from the mixed LVIT and LVOT group.

CONCLUSIONS

AoCoa patients with a combination of LVIT and LVOT including Shone complex are associated with a significantly higher morbidity and mortality compared to AoCoa alone.

Long-term observation of adults after successful repair of aortic coarctation

Introduction

Despite successful repair of aortic coarctation, cardiovascular complications occur.

Aim

To analyse type and frequency of late complications and their impact on exercise capacity in adults after aortic coarctation repair.

Material and methods

Fifty-eight adults after aortic coarctation repair, 36 male, median age 27.46 ±10.57, were compared to 30 healthy volunteers. Physical examination, transthoracic echocardiography, carotid intima-media thickness measurement, cardiopulmonary exercise test and 24-hour ambulatory blood pressure monitoring were performed.

Results

The main complications were: arterial hypertension 48.3%, myocardial hypertrophy in echocardiography 29.34%, recoarctation 25.86%, aortic dilation 13.79% and coronary artery disease 6.89%. Exercise tolerance was reduced in the cardiopulmonary exercise test. The VO₂/kg peak was lower, 29.01 ±8.79 vs. 49.16 ±7.38 ml/kg/min, p < 0.001, VE/VCO₂ peak higher 28.18 ±4.69 vs. 26.78 ±3.13, p = 0.017. The peak heart rate was reduced, 157.28 ±22.22 vs. 177.93 ±23.08 bpm, p < 0.001, peak systolic blood pressure was higher, 174.79 ±17.62 vs. 153.33 ±4.79 mm Hg, p < 0.001. Systolic blood pressure in 24-hour ambulatory monitoring correlated with left ventricle mass index, r = 0.29, p = 0.025, wall thickness, r = 0.31, p = 0.039. Age at operation was related to left ventricle wall thickness, r = 0.27, p = 0.041, and carotid intima-media thickness, r = 0.26, p = 0.046. There was no association of any cardio-pulmonary parameters with time from surgery, type of operation or echocardiography results.

Conclusions

Adults after aortic coarctation repair suffer from arterial hypertension, recurrent aortic stenosis, aortic aneurysms, and coronary artery disease. Reduced exercise capacity in cardio-pulmonary exercise test is related to hypertensive reaction and chronotropic incompetence.

Mild Coarctation of Aorta is an Independent Risk Factor for Exercise-Induced Hypertension

Exercise-induced hypertension is a predictor of cardiovascular events in patients with coarctation of aorta (COA). However, it is unclear whether mild COA diagnosis is an independent risk factor of exercise-induced hypertension. We hypothesized that for every unit increase in exercise, patients with COA (without hemodynamically significant coarctation) will have a higher rise in systolic blood pressure (SBP) compared with matched controls. One hundred forty-nine patients with COA (aortic coarctation peak velocity <2 m/s) who underwent exercise testing were matched 1:1 to controls using propensity score method based on age, sex, body mass index, hypertension diagnosis, and SBP at rest. We compared exercise-induced change in SBP between patients with COA and controls and also assessed the correlation between Doppler-derived aortic vascular function indices (effective arterial elastance index and total arterial compliance index) and exercise-induced changes in SBP. Compared with controls, patients with COA had a greater change in SBP per unit metabolic equivalent (β=2.86; 95% CI, 1.96–4.77 versus 1.07, 95% CI, −0.15 to 1.75; P =0.018) and per unit oxygen pulse (β=4.57; 95% CI, 2.97–7.12 versus 1.45, 95% CI, −0.79 to 2.09, P <0.001). There was a correlation between SBP peak −SBP rest and elastance index ( r =0.38, P =0.032) and between SBP peak −SBP rest and total arterial compliance index ( r =−0.51, P =0.001), suggesting an association between vascular dysfunction and exercise-induced BP changes. Patients with COA, without significant obstruction, had higher exercise-induced changes in SBP after adjustment for other risk factors for hypertension. Considering the already known prognostic importance of exercise-induced hypertension, the current study highlights the potential role of exercise testing for risk stratification of patients with mild COA.

A systematic review and meta-analysis of exercise and exercise hypertension in patients with aortic coarctation

Exercise hypertension is a common occurrence among individuals with aortic coarctation. Although exercise is known to be beneficial among the general population, the risks and benefits of exercise among those with aortic coarctation are less clear. This systematic review evaluates the benefits and risks of exercise for persons with aortic coarctation. Electronic databases were systematically searched (that is, MEDLINE and EMBASE) and key reviews cross-referenced to identify articles for inclusion. Original research articles reporting exercise among individuals with aortic coarctation were included. From 2608 individual citations, 68 eligible articles were identified. Aerobic exercise stress tests were found to be useful for determining exercise hypertension experiences post-surgical repair (N=5), and other long-term secondary findings (N=3). Experiences of exercise hypertension were associated with abnormal cardiac and/or aortic geometry and cardiac function (N=7). Exercise capacity was generally found to be similar to non-aortic coarctation controls post surgery (N=6). Exercise hypertension was experienced by 27% of participants, including 10% of adults and 43% of children/youth. Individuals who experience exercise hypertension experience greater increases in systolic blood pressure with exercise. No investigations identified evaluated forms of exercise other than aerobic stress tests and no exercise training programs have been conducted to date. Exercise stress tests can be valuable in this population for determining exercise hypertension, especially in the year post-surgical repair. Additional research is urgently needed to accurately assess the benefits and risks of exercise and exercise hypertension, and applicability of exercise restrictions for this population.

Balloon Dilatation and Stenting for Aortic Coarctation: A Systematic Review and Meta-Analysis

BACKGROUND

There is no systematic assessment of available evidence on effectiveness and comparative effectiveness of balloon dilatation and stenting for aortic coarctation.

METHODS AND RESULTS

We systematically searched 4 online databases to identify and select relevant studies of balloon dilatation and stenting for aortic coarctation based on a priori criteria (PROSPERO 2014:CRD42014014418). We quantitatively synthesized results for each intervention from single-arm studies and obtained pooled estimates for relative effectiveness from pairwise and network meta-analysis of comparative studies. Our primary analysis included 15 stenting (423 participants) and 12 balloon dilatation studies (361 participants), including patients ≥10 years of age. Post-treatment blood pressure gradient reduction to ≤20 and ≤10 mm Hg was achieved in 89.5% (95% confidence interval, 83.7-95.3) and 66.5% (44.1-88.9%) of patients undergoing balloon dilatation, and in 99.5% (97.5-100.0%) and 93.8% (88.5-99.1%) of patients undergoing stenting, respectively. Odds of achieving ≤20 mm Hg were lower with balloon dilatation as compared with stenting (odds ratio, 0.105 [0.010-0.886]). Thirty-day survival rates were comparable. Numerically more patients undergoing balloon dilatation experienced severe complications during admission (6.4% [2.6-10.2%]) compared with stenting (2.6% [0.5-4.7%]). This was supported by meta-analysis of head-to-head studies (odds ratio, 9.617 [2.654-34.845]) and network meta-analysis (odds ratio, 16.23, 95% credible interval: 4.27-62.77) in a secondary analysis in patients ≥1 month of age, including 57 stenting (3397 participants) and 62 balloon dilatation studies (4331 participants).

CONCLUSIONS

Despite the limitations of the evidence base consisting predominantly of single-arm studies, our review indicates that stenting achieves superior immediate relief of a relevant pressure gradient compared with balloon dilatation.

Avoidable costs of stenting for aortic coarctation in the United Kingdom: an economic model

BACKGROUND

Undesirable outcomes in health care are associated with patient harm and substantial excess costs. Coarctation of the aorta (CoA), one of the most common congenital heart diseases, can be repaired with stenting but requires monitoring and subsequent interventions to detect and treat disease recurrence and aortic wall injuries. Avoidable costs associated with stenting in patients with CoA are unknown.

METHODS

We developed an economic model to calculate potentially avoidable costs in stenting treatment of CoA in the United Kingdom over 5 years. We calculated baseline costs for the intervention and potentially avoidable complications and follow-up interventions and compared these to the costs in hypothetical scenarios with improved treatment effectiveness and complication rates.

RESULTS

Baseline costs were £16 688 ($25 182) per patient. Avoidable costs ranged from £137 ($207) per patient in a scenario assuming a 10% reduction in aortic wall injuries and reinterventions at follow-up, to £1627 ($2455) in a Best-case scenario with 100% treatment success and no complications. Overall costs in the Best-case scenario were 90.2% of overall costs at Baseline. Reintervention rate at follow-up was identified as most influential lever for overall costs. Probabilistic sensitivity analysis showed a considerable degree of uncertainty for avoidable costs with widely overlapping 95% confidence intervals.

CONCLUSIONS

Significant improvements in the treatment effectiveness and reductions in complication rates are required to realize discernible cost savings. Up to 10% of total baseline costs could be avoided in the best-case scenario. This highlights the need to pursue patient-specific treatment approaches which promise optimal outcomes.

Beyond Pressure Gradients: The Effects of Intervention on Heart Power in Aortic Coarctation

BACKGROUND

In aortic coarctation, current guidelines recommend reducing pressure gradients that exceed given thresholds. From a physiological standpoint this should ideally improve the energy expenditure of the heart and thus prevent long term organ damage.

OBJECTIVES

The aim was to assess the effects of interventional treatment on external and internal heart power (EHP, IHP) in patients with aortic coarctation and to explore the correlation of these parameters to pressure gradients obtained from heart catheterization.

METHODS

In a collective of 52 patients with aortic coarctation 25 patients received stenting and/or balloon angioplasty, and 20 patients underwent MRI before and after an interventional treatment procedure. EHP and IHP were computed based on catheterization and MRI measurements. Along with the power efficiency these were combined in a cardiac energy profile.

RESULTS

By intervention, the catheter gradient was significantly reduced from 21.8±9.4 to 6.2±6.1mmHg (p<0.001). IHP was significantly reduced after intervention, from 8.03±5.2 to 4.37±2.13W (p < 0.001). EHP was 1.1±0.3 W before and 1.0±0.3W after intervention, p = 0.044. In patients initially presenting with IHP above 5W intervention resulted in a significant reduction in IHP from 10.99±4.74 W to 4.94±2.45W (p<0.001), and a subsequent increase in power efficiency from 14 to 26% (p = 0.005). No significant changes in IHP, EHP or power efficiency were observed in patients initially presenting with IHP < 5W.

CONCLUSION

It was demonstrated that interventional treatment of coarctation resulted in a decrease in IHP. Pressure gradients, as the most widespread clinical parameters in coarctation, did not show any correlation to changes in EHP or IHP. This raises the question of whether they should be the main focus in coarctation interventions. Only patients with high IHP of above 5W showed improvement in IHP and power efficiency after the treatment procedure.

TRIAL REGISTRATION

clinicaltrials.gov NCT02591940.

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.

Emerging Research Directions in Adult Congenital Heart Disease: A Report From an NHLBI/ACHA Working Group

Congenital heart disease (CHD) is the most common birth defect, affecting about 0.8% of live births. Advances in recent decades have allowed >85% of children with CHD to survive to adulthood, creating a growing population of adults with CHD. Little information exists regarding survival, demographics, late outcomes, and comorbidities in this emerging group, and multiple barriers impede research in adult CHD. The National Heart, Lung, and Blood Institute and the Adult Congenital Heart Association convened a multidisciplinary working group to identify high-impact research questions in adult CHD. This report summarizes the meeting discussions in the broad areas of CHD-related heart failure, vascular disease, and multisystem complications. High-priority subtopics identified included heart failure in tetralogy of Fallot, mechanical circulatory support/transplantation, sudden cardiac death, vascular outcomes in coarctation of the aorta, late outcomes in single-ventricle disease, cognitive and psychiatric issues, and pregnancy.