Coarctation of aorta

CoA is a congenital heart defect characterized by a discrete narrowing of the thoracic aorta, typically distal to the left subclavian artery.

The pathogenesis of coarctation is not fully understood, but two main theories exist. The hemodynamic hypothesis suggests that reduced in utero blood flow across the aortic isthmus leads to abnormal aortic development. The ectopic ductal tissue hypothesis proposes that ductal tissue extends into the aorta, thickening its walls, and as the ductus arteriosus closes, this creates the coarctation. Coarctation of the aorta results in elevated afterload on the left ventricle, leading to LVH and hypertension, and may induce the development of collateral circulation.

CoA is the sixth most common congenital heart disease, occurring in up to 1 in 3,000 to 4,000 live births.

Risk factors for coarctation of the aorta include genetic conditions such as Turner's syndrome, bicuspid aortic valve, elongation of the transverse aorta, and hypertension.

Clinically, CoA is often asymptomatic, but can present with severe hypertension leading to headache, epistaxis, HF and/or aortic dissection. Other symptoms may include exertional intolerance, dizziness, lower extremity claudication, abdominal angina and ICH. CoA can be complicated by the development of aortic aneurysms, particularly in the ascending aorta.

The prognosis of CoA largely depends on the timing of diagnosis and intervention. Early detection and intervention, such as open or endovascular repair, can lead to good outcomes, including better BP control. The 15-year survival rate after CoA repair in patients aged < 21 years is reported to be 92%.