CHAPTER 3: THE ADULT WITH COARCTATION OF THE AORTA

PATIENT STORY

A 23-year-old man was seen for difficult-to-control hypertension. On initial presentation he had a blood pressure (BP) of 160/90 mm Hg. Despite initiation of multiple antihypertensive medications including hydrochlorothiazide and lisinopril, the patient remained hypertensive with systolic BP of greater than 140 mm Hg. The patient was asymptomatic but reported a lifelong murmur. Physical examination revealed a right upper extremity BP of 146/82 mm Hg. Cardiovascular examination was significant for a grade II/VI systolic ejection murmur and a posterior systolic murmur in the left infrascapular region. Lower extremity pulses were diminished. A transthoracic echocardiogram demonstrated a bicuspid aortic valve, mild aortic dilation, and flow acceleration across the aortic isthmus.

CASE EXPLANATION

• This patient has coarctation of the aorta (CoA) and its most common manifestation is systemic arterial hypertension.

• Patients with CoA often present in infancy with congestive heart failure.¹ However, those who escape diagnosis in childhood most commonly present with difficult-to-control hypertension later in life.

• This patient also had a bicuspid aortic valve (BAV) which is present in approximately 50% to 60% of patients with CoA.

• Aortic dilation along with a BAV can also be seen in such patients.

EPIDEMIOLOGY

• The incidence of CoA is approximately 0.3 per 1000 live births^{2, 3} and accounts for approximately 5% to 8% of congenital heart disease making it the eighth most common congenital heart defect.^{4, 5}

• CoA, like other forms of left-sided heart obstruction, is more common in males than females.⁴

• While CoA can be isolated, it often coexists with other forms of heart disease: Of patients with simple CoA, 42% have a patent ductus arteriosus. Approximately 50% to 60% of patients with CoA have bicommissural aortic valve (BAV). Approximately 10% have an intracranial aneurysm.^{6, 7}

• CoA often coexists with other forms of left heart obstruction including mitral stenosis, subaortic stenosis, and aortic stenosis. In addition, CoA is associated with atrial septal defects, ventricular septal defects, and complex congenital heart disease (eg, hypoplastic left heart syndrome, atrioventricular canal defect, transposition of the great arteries).³

• Women with Turner syndrome (gonadal dysgenesis with 45,X karyotype) have an increased risk (12%-35%) of CoA.^{8, 9, 10}

ETIOLOGY

• The etiology of CoA is multifactorial and incompletely understood.

• There is a compelling evidence for a genetic contribution to CoA.^{11, 12, 13, 14} CoA is more common in the children of women with CoA.¹⁵ The genetics is not simple, however, while NOTCH1 mutations have been described in patients with CoA, this mutation is absent in most patients.¹⁶ Linkage analysis has identified multiple candidate genes¹⁷ although progress has been hindered by the relative rarity of the disorder and phenotypic variability. As CoA often coexists with other forms of left heart obstruction, as described above, some have speculated whether ...