The American College of Cardiology and American Heart Association recently released the 2020 ACC/AHA guideline for the management of patients with valvular heart disease. This part includes suggestions on aortic stenosis (AS), aortic regurgitation (AR), or bicuspid aortic valve (BAV).

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The 2020 ACC/AHA guideline for the management of patients with valvular heart disease was updated to incorporate new evidence about treatments for heart valve disease. The new guideline replaces the 2014 guideline and 2017 focused update. The following are the main suggestions on aortic stenosis (AS), aortic regurgitation (AR), or bicuspid aortic valve (BAV).

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Use of disease stages

The guideline recommends using disease stages to stratify patients with valvular heart disease. Valve anatomy, the severity of valve dysfunction, the ventricular and pulmonary circulation response to valve dysfunction and symptoms are the criteria to be considered during disease staging.

• Stage A- At risk
• Stage B- Progressive
• Stage C- Asymptomatic severe
  • Stage C1- With ventricular compensation
  • Stage C2- With ventricular decompensation
• Stage D- Symptomatic severe

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Use of anticoagulation

A non–vitamin K oral anticoagulant (NOAC) can be used instead of vitamin K antagonist (VKA) in patients with atrial fibrillation and native heart valve disease other than rheumatic mitral stenosis, or among patients with atrial fibrillation and a bioprosthesis >3 months after valve replacement. NOAC or VKA should be used based on the CHA2DS2-VASc score.

In patients with atrial fibrillation and rheumatic mitral stenosis, anticoagulation with a VKA is recommended. An NOAC should be avoided in cases with a mechanical prosthesis without or with atrial fibrillation.

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Multidisciplinary heart valve team

The management of patients with severe valvular heart disease (being considered for valve intervention) should be done under the supervision of a multidisciplinary heart valve team. Consultation with or referral to a primary valve centre or a comprehensive valve centre can be considered in the following cases:

• Discussion of treatment options in the setting of asymptomatic patients with severe valve disease
• Patients who might benefit from valve repair rather than valve replacement
• Among patients with multiple comorbidities

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Stages of valvular aortic stenosis

Efficient management of patients with valvular aortic stenosis depends on the accurate diagnosis of the cause and stage of the disease process. Severe symptomatic (Stage D) aortic stenosis is subcategorised based on the gradient, flow, and left ventricular ejection fraction (LVEF).

• Stage D1 reflects patients with high-gradient symptomatic aortic stenosis (Vmax ≥4.0 m/s, mean gradient ≥40 mmHg, aortic valve area [AVA] ≤1.0 cm²)
• Stage D2 reflects low-flow, low-gradient severe aortic stenosis with reduced LVEF (AVA ≤1.0 cm², Vmax <4.0 m/s or mean gradient <40 mmHg, LVEF <50%)
• Stage D3 reflects low-flow, low-gradient severe aortic stenosis with normal LVEF (“paradoxical low-flow severe AS”; LVEF ≥50%, stroke volume index <35 ml/m²)

Assessment of aortic valve haemodynamics should be carried out accurately with Doppler echocardiography or cardiac catheterisation. It’s important to take into account the inherent variability of the measurements and calculations during clinical decision-making.

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Timing of intervention for severe aortic stenosis

Intervention for severe aortic stenosis predominantly is based on the presence of symptoms or LV systolic dysfunction. In symptomatic patients with severe high-gradient aortic stenosis, ample evidence demonstrates the beneficial effects of aortic valve replacement (AVR) on survival, symptoms, and LV systolic function. Clinical vigilance is essential to identify the most common initial symptom of aortic stenosis (exertional dyspnoea or decreased exercise tolerance) and proceed promptly to aortic valve replacement.

Other conditions in which aortic valve replacement is suggested include:

1. Asymptomatic patients
   1. At low surgical risk with decreasing exercise tolerance or exercise-associated decrease ≥10 mm Hg in systolic blood pressure
   2. Very severe AS (Vmax ≥5.0 m/s)
   3. Serum B-type natriuretic peptide (BNP) >3 times normal
   4. Progression of Vmax ≥0.3 m/s per year
2. Asymptomatic patients with severe high-gradient aortic stenosis and a progressive decrease in LVEF to <60% on ≥3 serial imaging studies

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Choice of intervention for patients for whom a bioprosthetic AVR is appropriate

In patients for whom a bioprosthetic AVR is appropriate, factors to be considered while selecting between surgical aortic valve replacement (SAVR) and transcatheter aortic valve implantation (TAVI) include:

• Presence of symptoms
• Patient age and anticipated life expectancy
• The indication for intervention
• Predicted surgical risk
• Anatomy or other factors referable to transfemoral (TF) TAVI feasibility

The panel recommends the following:

1. For symptomatic and asymptomatic patients with severe AS and any indication for AVR who are <65 years of age or have a life expectancy >20 years, SAVR is recommended.
2. For symptomatic patients with severe AS who are 65 to 80 years of age and have no anatomic contraindication to transfemoral TAVI, either SAVR or transfemoral TAVI is recommended after shared decision-making about the balance between expected patient longevity and valve durability.
3. For symptomatic patients with severe AS who are >80 years of age or for younger patients with a life expectancy <10 years and no anatomic contraindication to transfemoral TAVI, transfemoral TAVI is recommended in preference to SAVR.
4. For patients with an indication for AVR for whom a bioprosthetic valve is preferred but valve or vascular anatomy or other factors are not suitable for transfemoral TAVI, SAVR is recommended.
5. For symptomatic patients of any age with severe AS and a high or prohibitive surgical risk, TAVI is recommended if predicted post-TAVI survival is >12 months with an acceptable quality of life.

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Categorising patients with asymptomatic severe aortic regurgitation

In patients with asymptomatic severe aortic regurgitation (AR), the disease is subcategorized based on LVEF and LV end-systolic diameter (LVESD).

1. Stage C1 reflects normal LVEF (≥55%; previously ≥50% in the 2014 AHA/ACC guidelines) and mild to moderate LV dilation (LVESD <50 mm).
2. Stage C2 reflects abnormal LV systolic function (LVEF <55%; previously <50%) or severe LV dilation (LVESD 50 mm or indexed LVESD >25 mm/m2; unchanged from previous).

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Intervention for severe aortic regurgitation

Intervention for severe AR depends on:

• The presence of symptoms or LV systolic dysfunction (LVEF ≤55%; both Class 1); or
• The presence of severe LV dilation (LVESD >50 mm or indexed LVESD >25 mm/m²; Class 2a)

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Bicuspid aortic valve - Diagnostic testing

Patients with bicuspid aortic valve require careful evaluation of both the aortic valve and the aorta throughout their lifetimes.

1. In patients with bicuspid aortic valve, transthoracic echocardiography (TTE) is recommended to assess valve morphology, assess aortic stenosis and aortic regurgitation, assess the aortic root and ascending aorta, and evaluate for the presence of aortic coarctation. TTE helps evaluate aortic valve anatomy and hemodynamics; it also provides improved 2D and 3D images when required.
2. If the aortic sinuses, sinotubular junction, and ascending aorta cannot be accurately or fully assessed on echocardiography, then cardiac magnetic resonance angiography or computed tomography angiography is indicated.
3. Lifelong serial imaging is indicated if the aorta diameter is ≥4.0 cm. As progression of valve disease and growth of the aorta can occur in the absence of symptoms, diagnostic imaging plays an integral role in the surveillance process.

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Interventions for patients with bicuspid aortic valve

In patients with bicuspid aortic valve, replacement of the aorta is indicated in the following cases:

• Aortic diameter >5.5 cm
• Aortic diameter 5.0-5.5 cm plus an additional risk factor for dissection (family history of dissection, aortic growth >0.5 cm per year, aortic coarctation)
• Aortic diameter ≥4.5 cm with an indication for SAVR