What is the recommended management for severe aortic stenosis?

Management of Severe Aortic Stenosis

All symptomatic patients with severe aortic stenosis require valve replacement, with the choice between TAVR and SAVR determined by surgical risk stratification using the STS-PROM score and Heart Team assessment. 1, 2

Diagnostic Confirmation

• Confirm severe aortic stenosis using echocardiographic criteria: aortic valve area ≤1.0 cm², peak velocity ≥4 m/sec, or mean gradient ≥40 mmHg 1, 2
• Assess for specific symptoms including exertional dyspnea, angina, syncope, or dizziness, and evaluate exercise capacity limitations below age and sex-specific predicted metabolic equivalents 1
• In low-flow, low-gradient AS (valve area <1 cm², LVEF <40%, mean gradient <40 mmHg), perform low-dose dobutamine stress echocardiography to distinguish true-severe from pseudo-severe stenosis and evaluate for contractile or flow reserve 3, 1, 4

Risk Stratification

Calculate surgical risk using the STS-PROM score with the following categories 1:

• Low risk: STS-PROM <3% with no additional risk factors
• Intermediate risk: STS-PROM 4-8%
• High risk: STS-PROM >8%
• Prohibitive risk: Not suitable for surgery as assessed by Heart Team

Management Algorithm for Symptomatic Patients

For symptomatic severe AS, proceed immediately with valve replacement—medical management alone is rarely appropriate and significantly increases mortality risk 2, 4:

• Low surgical risk (STS <3%): SAVR is preferred, with TAVR as a reasonable alternative in selected patients 1
• Intermediate risk (STS 4-8%): Either TAVR or SAVR is appropriate, with Heart Team considering patient anatomy, frailty, and patient preference 1
• High surgical risk (STS >8%): TAVR is a reasonable alternative to SAVR 1
• Prohibitive surgical risk: TAVR is the recommended approach if predicted post-TAVR survival >1 year 3, 1

Special Consideration for Critically Ill Patients

• In patients with cardiogenic shock, balloon aortic valvuloplasty (BAV) is recommended as a bridge to definitive treatment with either TAVI or SAVR 4
• After stabilization with BAV, patients should be evaluated for definitive treatment based on surgical risk assessment 4

Management Algorithm for Asymptomatic Patients

Most asymptomatic patients with normal left ventricular function should undergo watchful waiting with regular clinical and echocardiographic follow-up every 6-12 months 1, 2:

Proceed with valve replacement in asymptomatic patients if any of the following are present 1, 2:

• Left ventricular ejection fraction <50%
• Very severe AS with peak velocity ≥5 m/sec or mean gradient ≥60 mmHg
• Abnormal exercise stress test
• Rapid progression of stenosis
• Undergoing cardiac surgery for another indication

Surveillance intervals for asymptomatic patients 5:

• Severe AS: Every 6-12 months
• Moderate AS: Every 1-2 years
• Mild AS: Every 3-5 years

Medical Management Principles

While awaiting valve replacement or in patients not candidates for intervention 1, 2:

• Maintain adequate preload and avoid excessive diuresis
• Control heart rate to maintain adequate diastolic filling time and avoid tachycardia
• Avoid vasodilators and positive inotropes
• Control blood pressure and other cardiovascular risk factors
• Do not use statins to prevent progression of AS

Critical Pitfall to Avoid

Delaying intervention in symptomatic patients with severe aortic stenosis significantly increases mortality risk—once symptoms appear, survival decreases rapidly 4, 5

Special Populations

Low-Flow, Low-Gradient AS with Reduced LVEF

• Perform dobutamine stress echocardiography to confirm true stenosis severity 3, 1, 4
• If mean gradient is >40 mmHg with dobutamine, there is theoretically no lower LVEF limit for aortic valve replacement in symptomatic patients 3
• Proceed with AVR if flow reserve is present and truly severe AS is confirmed 1

Patients Requiring Non-Cardiac Surgery

• Asymptomatic patients can undergo elective non-cardiac surgery safely, though with increased risk of heart failure 1
• Consider AVR before non-cardiac surgery if the procedure involves large volume shifts or if symptomatic 1

Palliative Care Considerations

• For patients with prohibitive surgical risk and life expectancy <1 year or moderate-to-severe dementia, palliative care with medical management may be considered 4

Heart Team Approach

All complex decisions should involve a multidisciplinary Heart Team comprising cardiac surgery, interventional cardiology, cardiac imaging, anesthesiology, and geriatrics expertise 1, particularly for:

• Asymptomatic patients being considered for intervention
• Complex transcatheter or surgical procedures
• Patients with challenging anatomy

Key TAVR Outcomes and Complications

TAVR demonstrates sustained mortality benefit at 2 years compared to medical therapy in inoperable patients, with improved functional status and reduced rehospitalization 1. In high-risk patients, TAVR and SAVR show similar survival rates at 1 year, though with different periprocedural risk profiles 6:

TAVR-specific complications include 1, 6:

• Stroke (3.8% at 30 days, 5.1% at 1 year)
• Paravalvular aortic regurgitation
• Permanent pacemaker requirement
• Vascular access complications (11.0% at 30 days)
• Acute kidney injury

SAVR-specific complications include 6:

• Major bleeding (19.5% vs 9.3% with TAVR)
• New-onset atrial fibrillation (16.0% vs 8.6% with TAVR)