What are the treatment options for degenerative aortic stenosis?

Treatment of Degenerative Aortic Stenosis

Aortic valve replacement (either SAVR or TAVR) is the definitive treatment for symptomatic severe degenerative aortic stenosis, as medical management does not alter the natural history and delays lead to increased mortality. 1

Primary Treatment Algorithm

The treatment decision follows a risk-stratified approach based on surgical risk assessment and symptom status:

For Symptomatic Patients (Dyspnea, Heart Failure, Angina, Syncope, or Presyncope)

Valve replacement is appropriate for ALL symptomatic patients regardless of surgical risk stratification. 1 The choice between SAVR and TAVR depends on surgical risk:

• Low-risk patients (STS-PROM <3%): SAVR is preferred, particularly if concomitant cardiac surgery is needed (CABG, ascending aorta surgery, or other valve procedures). 1

• High or prohibitive surgical risk (STS-PROM ≥8% or prohibitive risk factors): TAVR is appropriate, including patients with frailty, porcelain aorta, hostile chest anatomy, or significant comorbidities not captured by scoring systems. 1, 2

• Intermediate-risk patients (STS-PROM 4-8%): Either SAVR or TAVR is appropriate, with the choice determined by a multidisciplinary Heart Team based on anatomic factors, patient age, frailty, and comorbidities. 1

For Asymptomatic Patients

Determining true symptom status is critical, as elderly sedentary patients may underreport symptoms. 3

• Exercise stress testing is essential when symptom status is uncertain. An abnormal test (exercise-induced angina, excessive early dyspnea, dizziness, syncope, limited exercise capacity below predicted METs, abnormal blood pressure response, or mean gradient increase ≥18 mmHg) reclassifies the patient as symptomatic, making intervention appropriate regardless of surgical risk. 3, 2

Special Clinical Scenarios Requiring Additional Evaluation

Low-Flow, Low-Gradient Aortic Stenosis with Reduced LVEF

Dobutamine stress echocardiography is essential to distinguish true severe stenosis from pseudosevere stenosis. 1, 2

• If true severe stenosis is confirmed (AVA ≤1.0 cm² and Vmax >4 m/sec at any flow rate) and contractile reserve is present: Intervention is appropriate. 1

• If pseudosevere stenosis or profound LV dysfunction without contractile reserve: Medical management is appropriate. 1, 2

Critically Ill Patients with Cardiogenic Shock

Balloon aortic valvuloplasty (BAV) is recommended as a bridge to definitive treatment in hemodynamically unstable patients. 4 After stabilization, patients should undergo either TAVI or SAVR based on surgical risk assessment. 4

Patients Requiring Urgent/Elective Major Noncardiac Surgery

• Symptomatic severe AS: Definitive AVR (SAVR or TAVR) is appropriate before surgery; proceeding without intervention carries marked perioperative mortality risk. 1

• Asymptomatic severe AS with elective surgery: AVR is appropriate; conservative management may be appropriate depending on surgical urgency. 1

• BAV may be appropriate as a temporizing bridge in urgent situations but is rarely appropriate for elective scenarios where definitive treatment is preferable. 1

Failing Bioprosthetic Valves

Valve-in-valve TAVR has FDA approval for symptomatic bioprosthetic valve failure in high-risk patients. 1

• TAVR in bioprostheses ≤19 mm is generally discouraged due to high residual gradients and increased mortality, particularly in non-high-risk cohorts. 1

• Higher (more aortic) valve positioning during valve-in-valve procedures is associated with lower residual gradients and potentially improved survival. 1

Limited Role for Medical Management

Medical management is only appropriate in highly specific circumstances: 2

• Life expectancy <1 year where overall health is influenced more by comorbidities than by aortic stenosis 2
• Moderate to severe dementia 2
• Pseudosevere stenosis identified by dobutamine stress echocardiography 2
• Profoundly deteriorated LV systolic dysfunction without contractile reserve 2

BAV as a palliative procedure may be appropriate only in patients with life expectancy <1 year or moderate to severe dementia. 2

Decision-Making Framework

All treatment decisions should be made by a multidisciplinary Heart Team comprising cardiac surgeons, interventional cardiologists, cardiac imaging specialists, anesthesiologists, and geriatricians. 3, 1 Complex transcatheter or surgical procedures, particularly on asymptomatic patients, should be performed at centers with appropriate expertise to minimize complications. 3

Critical Pitfalls to Avoid

• Delaying intervention in symptomatic patients significantly increases mortality risk. 1, 4 There is no pharmacologic therapy that alters the natural history of degenerative calcific aortic stenosis. 2

• Do not rely solely on transvalvular gradients for diagnosis in low-flow states; valve area calculation is essential. 4

• Diuretics and heart failure medications provide only temporary symptomatic relief without changing prognosis. 2

• Recognize that even modest regurgitation developing acutely may cause severe pulmonary congestion and systemic hypotension in critically ill patients. 4

• In elderly sedentary populations, distinguish normal exercise limitations from abnormal symptoms due to AS through careful history and exercise stress testing when feasible. 3