What is the appropriate management of aortic valve stenosis?

Management of Aortic Stenosis

All symptomatic patients with severe aortic stenosis require aortic valve replacement (surgical or transcatheter) because medical therapy alone results in approximately 50% mortality within 2-3 years. 1, 2, 3

Initial Assessment and Risk Stratification

Define Severity

• Severe aortic stenosis is defined by aortic valve area ≤1.0 cm², peak velocity ≥4 m/s, or mean gradient ≥40 mmHg 2, 3
• Classify patients based on: symptom status, left ventricular ejection fraction, flow status (stroke volume index), and transvalvular gradient 1, 2

Assess Symptom Status

• The three hallmark symptoms mandating urgent intervention are: angina, syncope (or near-syncope), and heart failure-related dyspnea 2
• Critical pitfall: Symptoms can be difficult to determine in elderly patients with comorbidities or reduced mobility; exercise stress testing can unmask latent symptoms in apparently asymptomatic patients 2, 3, 4

Management Algorithm by Clinical Scenario

Symptomatic Severe Aortic Stenosis

Intervention is appropriate regardless of surgical risk 1, 2, 3

Choose intervention type based on surgical risk:

• Prohibitive surgical risk (≥50% predicted 30-day mortality, frailty, porcelain aorta, hostile chest, prior chest radiation, severe hepatic/pulmonary disease): TAVR is recommended 2, 3

• High surgical risk (STS-PROM ≥8%): TAVR is preferred 1, 2, 3

• Intermediate surgical risk (STS-PROM 4-8%): Both TAVR and SAVR are appropriate; decision by multidisciplinary Heart Team 1, 2, 3

• Low surgical risk (STS-PROM <4%): SAVR is strongly preferred, especially in younger patients (<65 years) for durability 5, 2, 3

Exception to intervention: Medical management is appropriate only when life expectancy is <1 year from non-cardiac causes or when comorbidities (not the aortic stenosis) dominate the patient's health status 1, 3

Asymptomatic Severe Aortic Stenosis

Immediate intervention is indicated for:

• Left ventricular ejection fraction <50% (regardless of surgical risk) 5, 2, 3
• Undergoing other cardiac surgery (CABG, aortic repair, other valve procedures) 2, 3
• Abnormal exercise stress test: systolic blood pressure fall ≥10-20 mmHg, development of symptoms, or markedly reduced exercise tolerance 2, 3

Strong consideration for intervention (Class IIa):

• Very severe AS: peak velocity ≥5.0-5.5 m/s or mean gradient ≥60 mmHg 2, 3
• Rapid progression: increase in jet velocity ≥0.3 m/s per year with severe valve calcification 2, 3
• Markedly elevated BNP (>3× age- and sex-adjusted normal) 2

Watchful waiting with surveillance is appropriate for truly asymptomatic patients with normal LV function and none of the above features 2, 3, 4

Special Scenario: Low-Flow, Low-Gradient Severe AS with Reduced EF

This requires dobutamine stress echocardiography to distinguish true-severe from pseudo-severe stenosis 1, 5, 2

• If contractile reserve is present (flow increases with dobutamine) and confirms truly severe AS: AVR is appropriate regardless of surgical risk 5, 2

• If no contractile reserve but valve is heavily calcified on echo/CT confirming truly severe AS: AVR is still appropriate with high or intermediate surgical risk, though operative mortality is higher 5, 2, 6, 7

• If stress testing suggests pseudo-severe stenosis: medical management is appropriate 1

Concomitant Disease Management

Coronary Artery Disease

• Coronary angiography should be performed in all patients considered for intervention, as 40-75% have CAD 3
• SAVR plus CABG is appropriate for patients with severe AS and significant coronary disease requiring revascularization 1, 3
• For intermediate/high surgical risk with less complex CAD (lower SYNTAX score), catheter-based approaches may be appropriate 1

Concomitant Valvular Disease

• Primary mitral regurgitation: Will not improve with AS correction alone; requires concomitant or staged procedure 1
• Secondary mitral regurgitation: May improve with isolated AS treatment depending on degree of LV dysfunction and mitral leaflet tethering 1
• Severe tricuspid regurgitation: Should be treated whenever possible, as it is a poor prognostic sign 1

Bicuspid Aortic Valve with Ascending Aortic Aneurysm

• If ascending aorta ≥4.5 cm, surgical management of both the valve and aorta should be considered 1
• Experience with TAVR in bicuspid disease is relatively limited 1

Pre-Operative Non-Cardiac Surgery Considerations

In symptomatic severe AS requiring major non-cardiac surgery:

• It is rarely appropriate to proceed without intervening on the aortic valve due to markedly increased perioperative morbidity/mortality 1, 3
• SAVR or TAVR before surgery is appropriate 1, 3
• Balloon valvuloplasty may be appropriate as a temporizing bridge 1

In asymptomatic severe AS requiring elective major surgery:

• More conservative approach (no intervention) may be appropriate 1
• AVR (TAVR or SAVR) is also appropriate 1

Medical Therapy: What NOT to Do

The following are Class III (contraindicated) interventions:

• Statins are NOT indicated for slowing AS progression; multiple trials have shown no benefit 2, 3, 8
• Aggressive diuretics should be avoided before AVR due to risk of hemodynamic collapse 2
• Vasodilators should be avoided before AVR due to potential destabilization 2
• Positive inotropes should be avoided in patients awaiting AVR 2

There is no medical therapy that halts or reverses AS progression 2, 3, 8

Surveillance Strategy for Asymptomatic Patients

• Severe AS: Clinical assessment and echocardiography every 6 months 2, 4
• Moderate AS: Every 1-2 years 4
• Mild AS: Every 3-5 years 4
• Rapid progression (velocity increase ≥0.3 m/s per year) signals disease acceleration and should prompt re-evaluation for AVR 2

Mandatory Heart Team Evaluation

All decisions regarding valve replacement must involve a multidisciplinary Heart Team including: 5, 2, 3

• Cardiologists with valvular expertise
• Structural interventional cardiologists
• Cardiovascular surgeons
• Imaging specialists
• Cardiovascular anesthesiologists
• Geriatrics (when appropriate)

The Heart Team must evaluate: 5, 2

• Individual patient surgical risk (STS-PROM score)
• Technical and anatomic suitability for TAVR vs SAVR
• Life expectancy and patient goals
• Frailty and comorbidities not captured in risk scores

TAVR must only be performed in hospitals with on-site cardiac surgery capability 5, 2

Critical Pitfalls to Avoid

• Delaying AVR after symptom onset markedly reduces survival; prompt intervention is essential 2
• Missing a reduced LVEF (<50%) in an asymptomatic patient constitutes a missed Class I indication for AVR 2
• Failing to perform exercise testing in apparently asymptomatic patients can miss latent symptoms 2, 3
• Proceeding with major non-cardiac surgery without addressing symptomatic severe AS dramatically increases perioperative mortality 1, 3
• Prescribing medical therapy (statins, antihypertensives) with expectation of slowing AS progression is futile 2, 3, 8