para>The condition is more commonly diagnosed in infants than in adults.
Neonatal coarctations are often missed secondary to a patent ductus arteriosus (PDA), allowing pulmonary artery blood to bypass shunt to the distal aortic arch to a site distal to the segment of narrowing.
A greater risk of complications is possible if surgical correction is delayed beyond early childhood.
Pregnancy Considerations
Uncorrected coarctation or restenosis carries a high risk of aortic rupture or dissection and cerebral hemorrhage.
Even with correction, there is a higher incidence of miscarriage and preeclampsia during pregnancy.
EPIDEMIOLOGY
Incidence
- More common in fall and winter births
- Predominant age: infants and children
- 4 in 10,000 live births
Prevalence
- 4-6% of all congenital heart defects
- Sixth most common cause of congenital heart disease
- Sex predilection: male > female (2 to 5:1)
- Mostly sporadic, with rare familial occurrences
ETIOLOGY AND PATHOPHYSIOLOGY
- Two theories include hemodynamic alterations in intrauterine blood flow causing altered flow through the aortic arch and decreased isthmic flow potentiating coarctation versus migration of ductus arteriosus tissue into the lumen of the aorta resulting in obstruction.
- As PDA progressively closes, gradient across the coarctation increases leading to an increase in left ventricular pressure load and to the evolution of collateral blood flow.
- Histologic findings
- Medial thickening, cystic medial necrosis, and intimal hyperplasia at the coarctation site
Genetics
No specific inheritance pattern but increased familial risk for congenital left ventricular outflow tract obstruction anomalies, 3-10% incidence with Turner syndrome
RISK FACTORS
- Male gender
- Family history of left ventricular outflow tract obstruction
- Turner syndrome
COMMONLY ASSOCIATED CONDITIONS
- Bicuspid aortic valve: 85%
- Patent ductus arteriosus: 65%
- Ventricular septal defect: 30-35%
- Mitral valve abnormalities
- Turner syndrome
- Transposition of the great vessels or double outlet right ventricle
- Aneurysm of circle of Willis
- Neurofibromatosis I
- Intercostal aneurysms
- PHACE syndrome, Williams syndrome-rare conditions
GENERAL PREVENTION
- If prenatal screening level II US reveals polyhydramnios or cardiac defect, fetal echocardiography is indicated given the increased risk of congenital heart defect including CoA (1)[B].
- Generally, prenatal diagnosis is challenging because small percent of cardiac output flows through defect.
- Presence of other cardiac findings/defects improves detection.
DIAGNOSIS
HISTORY
- Headaches
- Lower limb claudication, presyncope or syncope
- Chest pain or dyspnea on exertion
- Decreased exercise tolerance
- Rarely cyanosis or epistaxis
- Irritability, poor feeding, failure to thrive, diaphoresis, dyspnea in infants
- Rapid deterioration in an initially asymptomatic newborn occurs after acute ductal closure.
PHYSICAL EXAM
- Pulse delay and decreased amplitude in lower versus upper limb arteries during simultaneous palpation of the brachial or radial artery and femoral artery ("brachial-femoral delay" or "radiofemoral delay")
- Upper extremity hypertension (HTN) and a differential ≥20 mm Hg systolic pressure compared with lower extremity (2)
- Prominent neck pulsations
- Prominent left ventricular impulse, systolic ejection click, aortic stenosis, or regurgitation murmur if bicuspid aortic valve is present. Other murmur of concomitant congenital heart disease such as PDA, ventricular septal defect, or rarely mitral valve disease (3)
- Bruit and palpable pulsations in the intercostal spaces (coarctation, collaterals, patent ductus arteriosus)
- Corkscrew tortuosity of retinal arterioles on funduscopy (3)
- Left arm diameter may be smaller than the right if site of coarctation is proximal to left subclavian artery.
- In older children and adults, underdevelopment of lower extremities may be observed.
- Tachypnea, prominent right ventricular impulse, hepatomegaly, pale, cyanotic skin in infants
DIFFERENTIAL DIAGNOSIS
- Takayasu arteritis
- Atheromatous narrowing of the aorta
- Complications related to umbilical artery catheterization and aortic instrumentation
DIAGNOSTIC TESTS & INTERPRETATION
Age at the time of diagnosis is influenced by the severity of the coarctation
- Chest radiograph (CXR) with rib notching, "figure 3 sign" related to a notch or indent of the aorta at the site of coarctation or cardiomegaly
- ECG may show right ventricular hypertrophy in neonates but left ventricular hypertrophy in older patients.
- Elevated B-type natriuretic peptide (BNP)
- Echocardiography (transthoracic or transesophageal) may directly image the site of coarctation and measure the velocity of blood flow across the site of coarctation (although velocity and gradient may be decreased in the presence of well-formed collaterals). Also, can evaluate for coexisting congenital anomalies
- MRI/MRA of the chest and multislice computed tomography (MSCT) can directly image the entire aorta and site of coarctation, as well as collateral vessels. Cardiac catheterization and invasive aortic angiography are not commonly required for the diagnosis and may be performed at the time of a percutaneous intervention such as angioplasty or stent placement.
TREATMENT
Treatment options and timing depend on age of diagnosis and severity of narrowing.
MEDICATION
- Alprostadil (prostaglandin E1) to maintain patency of ductus arteriosus in infancy: Continuous IV or intra-arterial infusion, start infusion at 0.05 to 0.1 Ī¼g/kg/min, continue infusion until CoA repair is complete.
- Supportive measures and inotropes for acute decompensated heart failure
- Short-term postoperative antihypertensives may be needed, including esmolol or nitroprusside.
- Long-term antihypertensives include β-blockers and ACE inhibitors.
- Management of heart failure if present
- Antibiotic prophylaxis if indicated (for dental or invasive procedures)
SURGERY/OTHER PROCEDURES
- Repair indicated in neonates with critical CoA depends on PDA patency and infants, children, and adults with peak-to-peak gradient >20 mm Hg or <20 mm Hg with radiologic evidence of significant coarctation and collateral flow. There is insufficient evidence to determine the best mode of repair for coarctation.
- Surgical correction is the treatment of choice for native aortic coarctation in the neonate.
- Surgical correction or balloon angioplasty can be done in infancy if urgently indicated, with best results achieved when performed in patients aged 1 to 2 years (4)[A].
- Surgical approach is based on patient's aortic arch anatomy. Most commonly repaired via left lateral thoracotomy which is associated with lower rates of morbidity, mortality, and reintervention; however, median sternotomy may be required (2)[C]. Aortic arch obstruction should be completely relieved at the time of surgical intervention to minimize the risk of long-term recoarctation.
- Common operative procedures:
- Resection with end-to-end anastomosis
- Aortic arch advancement (resection with end to side anastomosis) (5)[B]
- Patch aortoplasty (Dacron or PTFE patch)
- Subclavian flap aortoplasty
- Bypass grafting
- Percutaneous stent placement (either bare metal or covered) is an option for adults and children >30 kg.
- Balloon angioplasty is the treatment of choice in children with recoarctation but is associated with higher rates of recoarctation and aneurysm formation compared with surgical repair (6)[B]
ONGOING CARE
FOLLOW-UP RECOMMENDATIONS
- Exercise may exacerbate HTN, but normal activity is nonetheless recommended after correction.
- Isometric activities such as heavy lifting should be avoided.
- Consider exercise stress test to gauge BP response to exercise, particularly for athletes.
- Endocarditis prophylaxis is only required when repair involved implantation of a conduit or during the first 6 months after repair if prosthetic material or stenting was used.
- Close observation, including echocardiography, CT, or MRI at least every 5 years is important for detection of long-term complications such as aneurysm formation and recoarctation.
- Imaging to evaluate intracranial vessels
- Precautions:
- Lowering BP may cause hypoperfusion of sites distal to coarctation (such as abdominal organs and lower extremities).
- Lowering BP is not advised in pregnancy unless mandated by emergency, as it may decrease blood flow to the fetus.
Patient Monitoring
- Frequent postoperative follow-up for evidence of restenosis and late complications
- Clinical evaluation combined with MRI has been shown to be cost-effective and safe screening strategy (1)[C].
- Need for antihypertensives may decrease with time.
DIET
Heart-healthy and low-sodium diet is recommended.
PATIENT EDUCATION
- Discuss postrepair complications with patient.
- Patients should be encouraged to lead normal lives and pursue usual activities after coarctation correction.
PROGNOSIS
- Depends on age of repair and presence of other cardiac abnormalities with higher survival rates for younger patients at the time of repair.
- Survival after operative repair: 90% by 10 years, 85% by 20 years, and 70% by 30 years
- 90% mortality by age of 50 years if left uncorrected
- Surgical repair of CoA between ages 1 and 5 years associated with increased long-term survival
COMPLICATIONS
Most common with late or no correction:
- Rupture or dissection of aortic aneurysm
- Residual or restenosis
- Systemic HTN
- Heart failure
- Accelerated coronary artery disease
- Aneurysm of circle of Willis and stroke
- Endarteritis or endocarditis
- Aortic valve disease (stenosis or insufficiency)
- Postcoarctectomy syndrome: recurrence, HTN, atherosclerotic heart disease, aneurysm at site of coarctectomy, progressive aortic stenosis, and/or regurgitation
- Postrepair myocardial perfusion defects in the absence of coronary artery disease
- Fistula formation between aorta and airways leading to hemoptysis
- Complications following repair
- Aneurysm formation (more common with Dacron patch aortoplasty) (7)[C]
- Recoarctation (more common with PTFE) (7)[C]
- Pseudoaneurysm formation
- Aortic dissection, related to stent grafts
- Stent migration
REFERENCES
11 Sharony R, Fejgin MD, Biron-Shental T, et al. Who should be offered fetal echocardiography? One center's experience with 3965 cases. Isr Med Assoc J. 2009;11(9):542-545.22 Cardoso G, Abecasis M, Anjos R, et al. Aortic coarctation repair in the adult. J Card Surg. 2014;29(4):512-518.33 Rosenthal E. Coarctation of the aorta from fetus to adult: curable condition or life long disease process? Heart. 2005;91(11):1495-1502.44 Mery CM, Guzm ”n-Pruneda FA, Carberry KE, et al. Aortic arch advancement for aortic coarctation and hypoplastic aortic arch in neonates and infants. Ann Thorac Surg. 2014;98(2):625-633.55 P ”dua LM, Garcia LC, Rubira CJ, et al. Stent placement versus surgery for coarctation of the thoracic aorta. Cochrane Database Syst Rev. 2012;(5):CD008204.66 Harris KC, Du W, Cowley CG, et al. A prospective observational multicenter study of balloon angioplasty for the treatment of native and recurrent coarctation of the aorta. Catheter Cardiovasc Interv. 2014;83(7):1116-1123.77 Gali ±anes EL, Krajcer Z. Endovascular treatment of coarctation and related aneurysms [published online ahead of print June 11, 2014]. J Cardiovasc Surg (Torino).
ADDITIONAL READING
- Alcibar J, Blanco R, Fernandez L, et al. Elective implantation of covered stents for coarctation and recoartation in adolescents and adults. Rev Esp Cardiol (Engl Ed). 2013;66(6):443-449.
- Mery CM, Guzm ”n-Pruneda FA, Trost JGJr, et al. Contemporary results of aortic coarctation repair through left thoracotomy. Ann Thorac Surg. 2015;100(3):1039-1046. doi:10.1016/j.athoracsur.2015.04.129.
- O'Brien P, Marshall AC. Coarctation of the aorta. Circulation. 2015;131(9):e363-e365.
- For patient education materials, contact the American Heart Association, 7320 Greenville Avenue, Dallas, TX 75231, 214-373-6300, http://www.americanheart.org.
- Warnes CA, Williams RG, Bashore TM, et al. ACC/AHA 2008 guidelines for the management of adults with congenital heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (writing committee to develop guidelines on the management of adults with congenital heart disease). Circulation. 2008;118(23):e714-e833.
CODES
ICD10
Q25.1 Coarctation of aorta
ICD9
747.10 Coarctation of aorta (preductal) (postductal)
SNOMED
Coarctation of aorta (disorder)
CLINICAL PEARLS
- This congenital abnormality may become clinically apparent at any age and is strongly associated with bicuspid aortic valve.
- Screening for delayed and weak femoral pulse compared to brachial or radial pulse ("brachial-femoral delay") by simultaneous palpation is important to evaluate for coarctation in patients with hypertension or in whom coarctation is otherwise suspected.
- Imaging tests such as echocardiography, chest CT, or MRI/MRA of the chest are required to establish the diagnosis.
- Early diagnosis and surgical or percutaneous correction are crucial for improved prognosis. Without treatment, mortality rates increase up to 90% by age 50 years related to heart failure, aortic dissection, and intracranial hemorrhage.
- Pregnancy should be carefully discussed before conception given maternal and fetal risks.