What is the most appropriate management for an asymptomatic patient in their 70s with severe aortic stenosis, normal ejection fraction (EF), and normal left ventricle (LV) function?

Management of Asymptomatic Severe Aortic Stenosis in a 70-Year-Old Patient

For this asymptomatic patient in their 70s with severe aortic stenosis, normal ejection fraction, and normal left ventricular function, the most appropriate management is C: Follow up with echocardiography and close clinical monitoring, not immediate valve replacement. 1, 2

Rationale for Conservative Management

Current ACC/AHA and ESC guidelines explicitly do not recommend routine aortic valve replacement for asymptomatic patients with severe AS and preserved LV function (EF ≥50%) unless specific high-risk features are present. 1, 2 The evidence demonstrates that asymptomatic patients maintain relatively benign short-term outcomes, with 1-year survival of 67% without intervention, whereas symptomatic patients face 25% mortality at 1 year and 50% at 2 years. 2

During the asymptomatic phase, survival is similar to age-matched controls with a low risk of sudden death (<1% per year) when patients are followed prospectively and promptly report symptom onset. 1

Why Not Immediate Valve Replacement?

Mechanical Valve (Option A) is Inappropriate

• Bioprosthetic valves are recommended for patients over 65 years, making mechanical valve replacement inappropriate for this 70-year-old patient. 2
• Mechanical valves require lifelong anticoagulation, which carries significant bleeding risks in elderly patients. 2

TAVR (Option B) is Premature

• TAVR is indicated for symptomatic patients or asymptomatic patients with specific high-risk features, neither of which applies to this patient. 1
• For patients aged 75-80 years, both TAVR and SAVR are equivalent options, but only when intervention is indicated. 2
• This patient lacks any Class I indication for intervention. 1

Appropriate Monitoring Protocol

Serial transthoracic echocardiography should assess valve area, gradients, and LV function every 12 months for severe asymptomatic AS with normal LV function, with clinical follow-up every 6 months. 2

More frequent monitoring (every 6 months) is warranted when:

• LV ejection fraction approaches borderline values (60-65%) 2
• LV end-systolic diameter reaches 40-45 mm 2
• Predictors of rapid progression are present (elevated BNP, severe valve calcification, excessive LV hypertrophy, rapid velocity progression >0.3 m/s per year) 1, 2

When Intervention Becomes Indicated

Aortic valve replacement becomes appropriate when any of the following develop:

Class I Indications (Must Intervene):

• Development of any cardinal symptoms (dyspnea, angina, syncope, presyncope) either by history or on exercise testing 1, 2
• LV ejection fraction drops below 50% 1, 2
• Need for concomitant cardiac surgery (CABG, ascending aorta surgery, or another valve) 1

Class IIa Indications (Reasonable to Intervene):

• Very severe AS (aortic velocity ≥5.0 m/s) with low surgical risk 1
• Abnormal exercise stress test showing symptoms or fall in blood pressure below baseline 1, 2
• Rapid disease progression with low surgical risk 1

Critical Role of Exercise Testing

Exercise stress testing should be performed if symptom status is unclear, particularly in elderly patients where symptoms may be masked by reduced activity levels or comorbidities. 2 This is crucial because patients may subconsciously limit activities, and a positive exercise test (development of symptoms or hypotensive response) effectively reclassifies the patient as symptomatic, making intervention appropriate. 1, 2

Patient Education Requirements

The patient must be carefully educated about:

• The importance of immediately reporting any symptoms (dyspnea, chest pain, lightheadedness, decreased exercise tolerance) 1
• The wide variability in rate of AS progression, necessitating adherence to follow-up schedules 1
• That once symptoms develop, outcomes deteriorate rapidly without intervention 1, 2

Critical Pitfalls to Avoid

Do not dismiss subtle symptoms in elderly patients - breathlessness on exercise may be difficult to interpret in patients with low physical activity, making decision-making more difficult. 1 Consider exercise testing to objectively assess functional capacity. 1, 2

Do not delay intervention once true symptoms develop - event-free survival drops dramatically after symptom onset, with mean time to sudden death (1.32 years) being shorter than time to other symptoms. 3

Monitor for subclinical LV dysfunction - progressive LV ejection fraction reduction even within normal limits (approaching 60%) identifies patients at high risk for events in whom valve replacement should be considered. 3