What is the recommended treatment for patients with chronic stable nonrheumatic aortic stenosis?

Treatment of Chronic Stable Nonrheumatic Aortic Stenosis

Aortic valve replacement (either SAVR or TAVR) is the only treatment that improves survival in patients with severe aortic stenosis, and should be performed in all symptomatic patients regardless of age or surgical risk. 1, 2

Symptomatic Patients: Intervention is Mandatory

For symptomatic patients with severe aortic stenosis, valve replacement is appropriate across all surgical risk categories and should not be delayed. 1, 2

Choice of Intervention by Risk Profile:

• Low to moderate surgical risk: Surgical aortic valve replacement (SAVR) remains the standard of care 3

• High or prohibitive surgical risk: Transcatheter aortic valve replacement (TAVR) is recommended 1, 3

• Intermediate surgical risk: Either TAVR or SAVR is appropriate; the decision should be made by a Heart Team 1

• Patients with frailty, porcelain aorta, hostile chest, or significant comorbidities (severe lung/liver disease): TAVR is preferred over SAVR 1, 2

Critical Timing Consideration:

• Once symptoms develop (dyspnea, angina, syncope), survival drops dramatically to 38% at 5 years without intervention versus 90% with valve replacement 4
• Delaying intervention in symptomatic patients directly increases mortality 2

Asymptomatic Patients: Watchful Waiting with Important Exceptions

Most asymptomatic patients should undergo close surveillance rather than immediate intervention, but specific high-risk features mandate earlier valve replacement. 3

Indications for Intervention in Asymptomatic Patients:

• Left ventricular ejection fraction <50%: Valve replacement is recommended 1

• Positive exercise stress test (development of symptoms, hypotension, or arrhythmias): Patient is reclassified as symptomatic and intervention is appropriate 2

• Very severe stenosis with rapid progression: Consider intervention 3

• Undergoing other cardiac surgery (e.g., CABG): Concurrent valve replacement should be performed 1

Surveillance Protocol for Asymptomatic Patients:

• Severe aortic stenosis: Doppler echocardiography every 6-12 months 3
• Moderate aortic stenosis: Every 1-2 years 3
• Mild aortic stenosis: Every 3-5 years 3

Medical Management: Only for Specific Scenarios

Medical management alone does not modify the natural history of severe aortic stenosis and should only be considered appropriate in limited circumstances. 2, 5

When Medical Management is Appropriate:

• Life expectancy <1 year where overall health is dominated by comorbidities rather than aortic stenosis 1, 2

• Moderate to severe dementia 1, 2

• Pseudo-severe aortic stenosis identified by low-dose dobutamine stress echocardiography (where apparent stenosis is due to low flow rather than true fixed obstruction) 2

• Profoundly depressed LV systolic dysfunction without contractile reserve on dobutamine stress testing 2

Palliative Balloon Valvuloplasty:

• May be appropriate as a palliative measure only in patients with life expectancy <1 year or moderate-to-severe dementia 1, 2
• Considered rarely appropriate in most other scenarios 1

Special Scenario: Low-Flow, Low-Gradient Aortic Stenosis

In patients with valve area <1 cm², LVEF <40%, and mean gradient <40 mmHg, low-dose dobutamine stress echocardiography should be performed to differentiate true severe stenosis from pseudo-stenosis. 1

• If mean gradient increases to >40 mmHg with dobutamine: True severe stenosis is present, and there is theoretically no lower EF limit for valve replacement in symptomatic patients 1

• Presence of contractile reserve: Associated with lower operative mortality and better long-term prognosis 1

• Absence of contractile reserve: Medical management may be more appropriate 2

Concomitant Coronary Artery Disease

For patients with severe symptomatic aortic stenosis and significant coronary disease, combined SAVR and CABG is appropriate. 1

• In intermediate or high surgical risk patients with less complex coronary disease (lower SYNTAX score), TAVR with or without PCI may be appropriate 1

Critical Pitfalls to Avoid

• Do not use vasodilators (ACE inhibitors, ARBs, CCBs, hydralazine, nitrates) in severe aortic stenosis: These can cause substantial hypotension and should only be used with extreme caution 1

• Do not delay surgery for medical optimization: Optimization should not postpone surgical decision-making in symptomatic patients 1

• Do not assume asymptomatic patients are truly asymptomatic: Exercise stress testing may unmask symptoms and reclassify patients as needing intervention 2

• No pharmacologic therapy slows progression: Statins, antihypertensives, and anticalcific agents have not been shown to halt disease progression in clinical trials 5

• Beta blockers and statins may improve survival in unoperated patients: In those who cannot undergo surgery, these medications showed potential benefit in observational data 4

• Sudden cardiac death risk is low (3-5%) in truly asymptomatic patients but rises dramatically (8-34%) once symptoms develop 1