Aortic Stenosis Left ventricular systolic dysfunction Symptoms of heart failure, syncope, exertional dyspnea, or angina Asymptomatic with mean Doppler-derived gradient >60 mm Hg by echocardiography Asymptomatic with progressively reduced exercise capacity on cardiopulmonary exercise testing Asymptomatic with high-risk exercise stress test demonstrating symptoms of angina, ischemic electrocardiographic changes, or hypotension during exertion In adults with severe aortic stenosis, the guidelines published by the American College of Cardiology and American Heart Association recommend aortic valve intervention if there is associated (1) left ventricular systolic dysfunction, defined as ejection fraction less than 50%, and/or (2) symptoms of heart failure, syncope, exertional dyspnea, angina, or presyncope by history or on exercise testing.58 However, pediatric patients are generally lower surgical risk than adult patients In addition, with a longer life expectancy, there may be advantage in earlier intervention to preserve left ventricular systolic function before maladaptive myocardial remodeling becomes irreversible These factors may justify earlier intervention in children with severe aortic valve stenosis even prior to the onset of symptoms or ventricular dysfunction A mean pressure gradient of 60 mm Hg or greater across the aortic valve by echocardiography has been recommended as an indication for intervention in asymptomatic young patients.58 Exercise testing can be useful to determine need for early intervention in asymptomatic children with severe aortic stenosis and preserved left ventricular systolic function by (1) demonstrating objective reductions in measures of exercise capacity, (2) eliciting exertional symptoms in more sedentary individuals, (3) measuring a fall in blood pressure with exercise, or (4) inducing ischemic or repolarization changes on electrocardiogram during exercise, all of which are high-risk clinical features that indicate need for aortic valve intervention Catheter Intervention The technique for transcatheter balloon aortic valvuloplasty is similar to that for neonates Balloon valuvuloplasty may be considered in young adults with congenital aortic stenosis; however, it is typically not successful in older adults due to significant calcification of the cusps and suboptimal results Compared with surgical valvotomy, the advantages of balloon aortic valvuloplasty include avoidance of cardiopulmonary bypass and sternotomy, shorter hospital stay, and lower costs Long-term survival is similar in both groups with a 10-year survival of 90% in the surgical group versus 87% in the balloon group.105 There is a greater risk for aortic valve regurgitation after balloon intervention relative to surgery Freedom from moderate to severe aortic regurgitation is approximately 60% at 10 years.82 In a comparative metaanalysis, the 10-year freedom from reintervention was lower following balloon intervention at 46% compared with 73% following surgical intervention.105 However, the freedom from aortic valve replacement was similar between both groups Another single-center study also reported lower freedom from reintervention of 27% after balloon valvuloplasty, versus 65% after surgical valvotomy at 5 years of follow-up, as well as a higher need for aortic valve replacement in the balloon group.90 Surgical Intervention Open surgical valvotomy for noncritical stenosis can be performed with very low mortality (2% to 3%) However, there remains a relatively high rate of reoperation of approximately 30% to 40% at 15 to 20 years.106 Bicuspidalization of the unicuspid valve in young adults works well.107 Conversion of congenitally bicuspid aortic valves to tricuspid arrangement might confer better outcomes, probably due to reduction in cusps stress load and improved flow patterns, by providing optimal effective orifice area Reconstruction is safe, with early mortality approaching zero and with a 5-year freedom from valve replacement up to 75%.108–112 In general, early valve function after reconstruction is excellent; however, long-term durability of repair is unknown Aortic valve replacement is performed when repair is not feasible Options for valve replacement include mechanical prosthetic valve, pulmonary autograft (Ross procedure), or bioprosthetic valve The advantages and disadvantages of the various options of valve replacement are discussed later in the section on surgical management for aortic regurgitation Long-Term Outcomes Patients with congenital valvar aortic stenosis require life-long follow-up for progressive aortic valve dysfunction, both before and after intervention Aortic valve intervention, whether it consists of balloon valvuloplasty or surgical repair/replacement, should be considered palliative, and subsequent monitoring is required to evaluate for need for reintervention overtime For patients with bicuspid aortic valve, surveillance of the ascending aorta is also required due to the risk for progressive aortic dilation and dissection