• aortic coarctation
• pregnancy
• hypertension
• aortic diseases

Coarctation of the aorta (figure 1A and B) accounts for around 5% of congenital heart defects1 and is frequently associated with a generalised arteriopathy. The natural course of the disease is varied and depends on coarctation severity as well as associated comorbidities and cardiac defects, which are common. Coarctation-related cardiovascular complications may include, inter alia, systemic hypertension, left heart diastolic dysfunction(figure 1C), intracranial haemorrhage (from an associated berry aneurysm), aortic rupture/dissection, premature coronary and cerebral artery disease. In recent decades, surgical and percutaneous interventions for coarctation of the aorta have been established with good long-term results.2 The morbidity after surgical repair and interventional balloon dilatation or stenting remains largely related to aortic complications and long-standing hypertension.

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Figure 1

Risk factors for women with coarctation considering pregnancy beyond heart failure. CW, continuous wave; LA, left atrium; LV, left ventricle; RA, right atrium; RV, right ventricle.

Pregnancy is associated with increased haemodynamic demands, hormone-related connective tissue changes as well as other neurohormonal alternations that may adversely affect women with aortic pathology and/or other congenital heart defects. The outcome of pregnancy in women with coarctation of the aorta has been reported in a small number of case reports and case series. Population-based data from the USA have suggested that pregnancy in women with coarctation of the aorta is associated with higher rates of cardiovascular morbidity and caesarean section, longer inpatient stays and higher inpatient costs.3 Women with an arm-to-leg blood pressure difference of <20 mmHg after coarctation repair are considered to have mild degree of pressure afterload and in them, pregnancy has been reported to be well tolerated.4 Overall, hypertension has usually been reported to be a major cause of morbidity during pregnancy and is commonly associated with a haemodynamically significant gradient at the site of coarctation for both unrepaired or repaired patients.3–5 Hypertension is a contributing factor for aortic root dilatation, cerebral bleeding and obstetric complications during pregnancy.

In view of the underlying aortopathy in patients with coarctation of the aorta, even after repair, the risk for aneurysm formation and the development of systemic hypertension remain.6 In women with coarctation and associated bicuspid aortic valve, aortic root dilatation (figure 1D) is an especially common finding. While patients with Dacron patch repair of the coarctation are at particular risk of repair site aneurysms (figure 1E), those with interposition grafts are at a risk of re-coarctation (figure 1F) and false aneurysm formation. Late aortic complications may be easily missed with transthoracic echocardiography and thus patients require serial cardiovascular MRI or CT scan of the aorta. Aortic aneurysms are associated with an increased risk of maternofetal complications including aortic dissection and rupture.7 Data are lacking with regard to the risk for dissection related to pregnancy in women with a dilated aorta. According to the 2018 European Society of Cardiology guidelines for the management of cardiovascular disease during pregnancy, women should be counselled against pregnancy when the aortic diameter is >50 mm because of the risk for catastrophic aortic complications.7

Patients with aortic coarctation in combination with other cardiac anomalies carry a significantly higher risk compared with those without. Coexisting valve disease such as mitral or aortic valve dysfunction is common in the adult coarctation population. More severe obstructive left heart lesions in series may also occur (Shone syndrome; supramitral ring, parachute mitral valve, aortic stenosis, hypoplastic aortic arch and coarctation of the aorta) and increase the risk for maternofetal adverse effects. Ventricular diastolic dysfunction in women with long-standing systemic hypertension, left ventricular outflow obstruction or late coarctation repair is an important consideration and women with ventricular systolic dysfunction or symptoms of heart failure before pregnancy are at especially high risk.8

In the current issue of the journal, Ramlakhan and Tobler8 report the maternofetal clinical outcomes of pregnancy in women who have coarctation of the aorta from the worldwide prospective Registry of Pregnancy and Cardiac Disease (ROPAC). These data are one of the largest series to date (n=303) and suggest that pregnancy is well tolerated and that the rate of cardiac events including hypertension-related complications is acceptable—in fact, the authors point out that the rate of hypertensive disorders of pregnancy in their cohort (5%) is comparable to reported rates in the general population and much lower than the rate reported in the largest coarctation pregnancy series to date (20%–25%).3 5 As expected, prepregnancy signs of heart failure, left ventricular ejection fraction (LVEF) <40%, New York Heart Association (NYHA) class >I and cardiac medication use were predictive of major adverse cardiac events.

In the series reported by Ramlakhan and Tobler,8 42% of women were already on cardiac medications prior to pregnancy, predominantly antihypertensive treatment, which reflects the high rate of systemic hypertension, even in the absence of aortic obstruction that occurs in the setting of repaired coarctation of the aorta.2 A remarkable 138 centres in 53 countries contributed data and, importantly, 21% of women were from emerging countries. Ninety-eight per cent of women were NYHA class I or II prior to conception and only 2% had an LVEF less than 40%. Only 4% of the cohort had an aortic dimension >40 mm, encouragingly suggesting that women are generally being counselled and managed according to current guidelines. However, there are no data8 describing the degree of residual aortic obstruction, and as stated in the limitations the authors were unable to report what spectrum of coarctation phenotypes with varying residual lesions and postrepair complications was represented. This deficiency is an understandable inherent limitation of an impressive international registry but needs to be considered before we relax our current recommendations. Currently, repaired coarctation is considered WHO II–III depending on the individual risk factor profile.7 The data reported in this issue of Heart8 certainly support a WHO risk level II (estimated maternal cardiac event rate of 5%–10%) for women included in their specific cohort but higher risk women may not have been well represented.

In the current era, prepregnancy assessment remains strongly recommended for women with repaired or unrepaired coarctation of the aorta to help establish the level of risk and optimise any treatable issues.7 The low rate of hypertensive disorders of pregnancy in the ROPAC series8 contrasts significantly with earlier reports from Nationwide Inpatient Sample data in the USA3 and the population-based Dutch CONCOR registry data.5 One possible explanation for this discrepancy is the selection bias associated with women managed by centres ‘engaged’ enough to contribute to the ROPAC data set who are likely to be cared for by physicians with more interest, resources and expertise in maternal cardiology—the high rates of prepregnancy medication and low rates of high-risk women suggest that on the whole, the women in this new report8 were well managed.

International registries such as ROPAC are crucial to help us better understand and improve our patient outcomes and are especially important in the setting of relatively rare conditions such as coarctation of the aorta, but are limited by the amount of datapoints that can realistically be collected. Based on the ROPAC coarctation data, it seems reasonable to conclude (in accordance with current guidelines) that a woman with coarctation but no major comorbidities and an aorta with minimal obstruction and diameter <40 mm, good functional class and LVEF >40% is at low risk for maternofetal complications, but these new data are not sufficient for us to let our guard down in women with high-risk features.