What are the management options for aortic stenosis?

Management of Aortic Stenosis

Diagnosis and Severity Assessment

Echocardiography is the primary diagnostic tool, with severe aortic stenosis defined by aortic valve area ≤1.0 cm², peak velocity ≥4 m/sec, or mean gradient ≥40 mmHg 1, 2. This single test is sufficient for guiding management in 65-70% of patients 1. When echocardiographic findings are uncertain or discordant, multimodality imaging including cardiac CT or dobutamine stress echocardiography is required in 25-30% of cases 1.

For low-flow, low-gradient aortic stenosis, dobutamine stress echocardiography is essential to distinguish true-severe from pseudo-severe stenosis before proceeding with intervention 3, 2. Intervention is only recommended if flow reserve is present and truly severe stenosis is confirmed 1, 3.

Symptomatic Severe Aortic Stenosis

Valve replacement is mandatory for all symptomatic patients with severe aortic stenosis—this is a Class I recommendation with the highest level of evidence 4, 1, 3. Without treatment, average survival plummets to only 2-3 years once symptoms develop 1. Medical management alone is rarely appropriate and should be considered palliative 2.

Choosing Between TAVR and SAVR

The decision algorithm proceeds sequentially through these factors 4, 1:

1. Surgical Risk Assessment (STS-PROM Score):

• Low risk (STS <4%): SAVR is preferred, particularly in younger patients, though TAVR is a reasonable alternative in selected cases 1, 2
• Intermediate risk (STS 4-8%): Either TAVR or SAVR is appropriate—the Heart Team should consider anatomy, frailty, and patient preference 1, 2
• High risk (STS >8%): TAVR is generally preferred 1, 2
• Prohibitive surgical risk: TAVR is the only reasonable option 2

2. Age Considerations:

• <65 years: SAVR strongly preferred 4
• 65-75 years: SAVR preferred over TAVR, though both are options 4
• 75-80 years: TAVR and SAVR are equivalent 4
• >80 years: TAVR preferred 4

3. Anatomical and Technical Factors:

• Non-transfemoral access requirements favor SAVR 4
• Bicuspid aortic valve or hostile calcium patterns may favor SAVR due to limited long-term TAVR data 4, 5
• Concomitant coronary artery disease requiring revascularization favors SAVR with CABG 1
• Concomitant severe disease of other valves favors surgical approach 1

Asymptomatic Severe Aortic Stenosis

Most asymptomatic patients with normal left ventricular function should undergo watchful waiting with clinical and echocardiographic surveillance every 6-12 months 3, 2. However, this is a critical area where the European and American guidelines diverge.

Indications for Intervention in Asymptomatic Patients

Proceed with valve replacement if any of the following are present 1, 3, 2:

• Left ventricular ejection fraction <55% (ESC/EACTS) or <60% with decline on serial imaging (ACC/AHA) without another cause 4, 2
• Very severe aortic stenosis: peak velocity ≥5 m/sec or mean gradient ≥60 mmHg 2
• Rapid progression: velocity increase >0.3 m/sec per year 4
• Abnormal exercise stress test revealing symptoms, hypotensive response, or complex ventricular arrhythmias 1, 2
• Undergoing cardiac surgery for another indication 2
• Elevated BNP or abnormal LV global longitudinal strain in low-risk patients 4

Common pitfall: Symptoms may be difficult to ascertain in elderly patients due to comorbidities or reduced mobility 1. Exercise testing can unmask occult symptoms in apparently asymptomatic patients and should be considered 1.

Medical Management Principles

There is no medical therapy that halts progression of aortic stenosis or improves outcomes 6. Statins do not prevent progression and should not be used for this purpose 2, 6. Medical management serves only as a bridge to intervention or palliation 2.

Hemodynamic Management

While awaiting valve replacement or in non-candidates 1, 3, 2:

• Maintain adequate preload: Avoid excessive diuresis, as these patients are preload-dependent 3, 2
• Control heart rate: Maintain adequate diastolic filling time; both bradycardia and tachycardia cause decompensation 1, 3
• Blood pressure control: Target systolic BP 100-120 mmHg in acute settings; beta-blockers are preferred agents 1
• Avoid vasodilators and positive inotropes in acute decompensation 2

Non-Cardiac Surgery in Aortic Stenosis Patients

For urgent non-cardiac surgery in severe aortic stenosis, proceed with careful hemodynamic monitoring 4, 3.

For elective non-cardiac surgery 4, 1, 3:

• Symptomatic patients: Aortic valve replacement should be performed first; TAVR is an option for increased surgical risk 4
• Asymptomatic patients: Elective non-cardiac surgery can proceed safely, though with increased risk of heart failure 4, 3
• High-volume shift procedures: Consider aortic valve replacement before the non-cardiac surgery even in asymptomatic patients 4, 3

Heart Team Approach

All complex decisions require a multidisciplinary Heart Team including cardiac surgery, interventional cardiology, cardiac imaging, anesthesiology, and geriatrics expertise 1, 2. This is particularly critical for asymptomatic patients being considered for intervention, patients with challenging anatomy, and those with multiple comorbidities 2.

The Heart Team must 1:

• Review medical condition and valve severity
• Determine which interventions are indicated, technically feasible, and reasonable
• Establish patient goals and life expectancy expectations early
• Discuss benefits and risks with patient and family
• Consider medical futility in patients with life expectancy <1 year or severe dementia 1

Surveillance Intervals

For patients not undergoing intervention 7:

• Severe aortic stenosis: Every 6-12 months 3, 7
• Moderate aortic stenosis: Every 1-2 years 7
• Mild aortic stenosis: Every 3-5 years 7

Key Complications and Outcomes

TAVR demonstrates sustained mortality benefit at 2 years compared to medical therapy in inoperable patients 2. However, key complications include stroke, paravalvular aortic regurgitation, permanent pacemaker requirement (10-20% of cases), vascular access complications, and acute kidney injury 2.

Critical caveat: Long-term durability data beyond 5-10 years for TAVR remain limited, particularly in younger patients, making lifetime management considerations essential in patients <75 years 5.