Reduced life expectancy of patients with untreated CoA is due to systemic hypertension, accelerated coronary artery disease, stroke, heart failure, aortic rupture/dissection, cerebral hemorrhage, infective endarteritis/endocarditis, concomitant aortic valve disease (usually involving a BAV), and sudden cardiac death of presumed arrhythmogenic etiology.4 Even adults whose CoA has been detected early and managed with catheter-based and surgical interventions continue to face lifelong complications, including recoarctation, aneurysm formation, premature coronary artery disease, and cerebrovascular disease—mostly resulting from residual hypertension.3
Persistent hypertension has been reported in 68% of patients with repaired CoA at long-term follow-up. Hypertension may result in recurrence of CoA (incidence ranges from 5% to 50%), a residual CoA, or an idiopathic condition.7
The role of primary care providers is crucial in early detection and prompt referral to specialists in ACHD. For clinicians who manage these patients, increased morbidity and mortality from the associated cardiovascular sequelae pose an ongoing challenge.8
Presentation
Patients with hemodynamically stable coarctation in adolescence or adulthood are usually asymptomatic. Occasionally, a patient may be diagnosed with CoA based on its typical appearance on CXR or may come to medical attention because of an incidental murmur or management of hypertension.4 Symptoms vary in intensity and include headache, epistaxis, claudication, exertional fatigue, heart failure, aortic rupture, or dissection.7 Based on the Seventh Report of the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7), and the 2008 American College of Cardiology/American Heart Association (ACC/AHA) guidelines for adults with congenital heart disease, patients with hypertension and/or a history of CoA repair should be evaluated periodically for coarctation.8
Physical Examination
Physical assessment should include simultaneous palpation of the brachial and femoral pulses to assess amplitude and timing, looking for diminished arterial pulses and brachial-femoral delay. Additionally, measurement of supine bilateral arm (brachial artery) BP and right or left supine leg BP is recommended to detect differing pressures.8
The following physical findings may be suggestive of CoA or recoarctation:
• Systolic BP in the right arm higher than in the lower extremities, unless the origin of the right subclavian artery is anomalous and thus is not reliable; the left arm BP may not always be reliable because of the origin of the left subclavian artery, which may vary and may or may not be hypertensive
• Hyperdynamic carotid pulsations
• A pulse delay between the right arm and the femoral or popliteal arteries
• A murmur or bruit heard in the left interscapular position; a systolic ejection click of moderate intensity heard along the left sternal border
• In cases of BAV, an early diastolic decrescendo murmur of aortic regurgitation
Diagnostic Workup
The diagnosis of CoA is usually confirmed by echocardiography or radiographic imaging, including cardiac MRI or CT angiography.8
The initial diagnostic workup should include echocardiography, which may demonstrate left ventricular hypertrophy and secondary ST-T wave abnormalities, and a two-dimensional Doppler echocardiogram, which can establish the diagnosis and severity of the CoA, with possible associated cardiac defects.9 Also recommended is a CXR, which may occasionally reveal rib notching (caused by erosion of the inferior border of the posterior ribs by enlarged intercostal arteries), also known as the 3 sign. Finally, cardiac MRI is used to delineate the coarctation anatomy and to determine whether collateral arteries and/or associated vascular anomalies and flow abnormalities exist.9 If MRI is not possible, CT angiography can be an alternate approach. Subsequently, invasive angiography is required for better assessment of the coarctation gradient and hemodynamic measurement.9
Treatment
Management of CoA requires treatment of hypertension with β-blockers, ACE inhibitors, and/or ARBs as first-line medications. Aortic root size, the presence of aortic regurgitation, or both may influence the choice of antihypertensive agents.3
Intervention is recommended if the peak-to-peak coarctation gradient is ≥ 20 mm Hg, or the peak-to-peak coarctation gradient is < 20 mm Hg, with evidence of significant coarctation and collateral flow on radiologic imaging.8 The choice of treatment (stenting or surgery) should be decided by a team of ACHD cardiologists, interventionalists, and surgeons at an ACHD center.
Surgical intervention via a lateral left thoracotomy approach was first performed in 1944. The most common surgical repair is resection with end-to-end anastomosis, which yields a low mortality and recoarctation rate. Other techniques such as resection with replacement by a tube graft, patch aortoplasty, and bypass graft are used less frequently.10-12 Postsurgical morbidity most commonly includes recoarctation and residual hypertension.
Thoracotomy was the only surgical treatment until 1982, when balloon angioplasty became available as an alternative.13 However, recoarctation, aneurysm formation, and aortic dissection are major disadvantages to balloon angioplasty.13
In the early 1990s, endovascular stents were introduced and have become an alternative approach to surgical repair.14 Aneurysms remain a significant complication in 4% to 7% of patients who undergo stent placement for CoA.14