Coarctation of the Aorta: Diagnosis and Management

Definition and Anatomic Features

Coarctation of the aorta is a congenital narrowing of the aorta, typically occurring just distal to the left subclavian artery at the ligamentum arteriosum, causing upper extremity hypertension and lower extremity hypoperfusion that requires lifelong surveillance even after successful repair 1, 2.
The American Heart Association recommends that coarctation consists of short-segment narrowing in the region of the ligamentum arteriosum adjacent to the origin of the left subclavian artery 1.
The European Society of Cardiology notes that in some cases, narrowing extends to the aortic arch or isthmus 1.
The lesion manifests as either a discrete stenosis or a hypoplastic segment, with more distal locations termed mid-aortic syndrome requiring different management 3.
An intrinsic abnormality in the aortic wall predisposes to dissection or rupture in the ascending aorta or at the coarctation site itself 1.
Extensive collateral vessels may develop proximal to the obstruction, which can reduce the measured gradient and mask the true severity of obstruction 1.

Bicuspid aortic valve occurs in 50-85% of coarctation patients and requires concurrent surveillance 3, 2.
The European Heart Journal recommends that additional associated conditions include subaortic stenosis 4, and circle of Willis cerebral artery aneurysms (10% prevalence) 3.
Ascending aortic aneurysms are also associated with coarctation 3.
Coarctation may be associated with Turner syndrome, occurring in 7-18% of Turner syndrome patients, with up to 12.6% of females with coarctation having Turner syndrome 3.

The pathognomonic finding is brachial-femoral pulse delay with decreased amplitude or absent femoral pulses compared to brachial pulses 1, 4.
Hypertension is present in the right arm relative to the lower extremities, unless anomalous origin of the right subclavian artery is present 1.
Blood pressure findings include supine bilateral arm (brachial artery) pressures and prone right or left supine leg (popliteal artery) pressures 1, 5.
A pressure differential >20 mmHg between upper and lower extremities suggests significant coarctation 6.

Every patient with systemic arterial hypertension should have brachial and femoral pulses palpated simultaneously to assess for brachial-femoral delay, which is a Class I recommendation with Level of Evidence C 1, 4.
Blood pressure measurements at both arms and one lower extremity are mandatory in all coarctation patients 3, 2, 6.
Initial imaging and hemodynamic evaluation by transthoracic echocardiography (TTE) is the first-line diagnostic tool 1, 4.
The American College of Cardiology recommends that every patient with coarctation (repaired or not) should have at least one cardiovascular MRI or CT scan for complete evaluation of the thoracic aorta and intracranial vessels, which is a Class I recommendation with Level of Evidence B 1, 4.

Intervention is indicated in patients with hypertension and an increased non-invasive gradient between upper and lower limbs confirmed with invasive peak-to-peak measurement >20 mmHg 3, 2, 6.
The European Heart Journal recommends that endovascular treatment should be considered in hypertensive patients with >50% narrowing relative to aortic diameter at the diaphragm, even if invasive peak-to-peak gradient is <20 mmHg, when technically feasible 3, 6.
For older children (>25 kg) and adults, covered stenting is the first-choice treatment for native coarctation and re-coarctation 3, 2, 6.

Hypertension should be controlled with beta-blockers, ACE inhibitors, or angiotensin-receptor blockers as first-line medications 4.
The European Society of Cardiology recommends that hypertension in coarctation patients should be treated according to standard ESC or ACC/AHA hypertension guidelines 3, 2, 7.

Hypertension remains an important complication even after successful treatment and is more common when initial repair is performed in adulthood 3, 2.
Right arm 24-hour ambulatory blood pressure measurement or exercise tests better detect hypertension than office measurements alone 3, 7, 6.
Imaging of the aorta with CMR or cardiac CT every 3-5 years is required, adjusted to previous imaging findings, clinical status, and type of intervention 3, 2, 7, 6.
Surveillance for bicuspid aortic valve dysfunction and ascending aortic dilation is required in coarctation patients 6.