Management of Aortic Stenosis
All symptomatic patients with severe aortic stenosis require aortic valve replacement (AVR), either surgical or transcatheter, as this is the only effective treatment and medical management alone leads to 50% mortality within 2-3 years. 1, 2
Defining Severe Aortic Stenosis
Severe AS is defined by any of the following echocardiographic criteria 2:
- Aortic valve area (AVA) ≤1.0 cm²
- Peak aortic jet velocity (Vmax) ≥4.0 m/s
- Mean pressure gradient ≥40 mmHg
Symptomatic Severe AS: Immediate Intervention Required
Valve replacement is a Class I indication for all symptomatic patients with severe AS. 1, 2 The three classic symptoms that mandate urgent intervention are 3:
- Angina pectoris
- Syncope or near-syncope
- Heart failure symptoms/dyspnea
Once symptoms develop, prognosis deteriorates rapidly with sudden cardiac death risk of 8-34%, making intervention urgent. 3 Medical therapy alone is rarely appropriate and should be avoided in symptomatic severe AS. 1
Choosing Between SAVR and TAVR
The choice between surgical AVR (SAVR) and transcatheter AVR (TAVR) depends primarily on surgical risk stratification and anatomic suitability: 1
Prohibitive surgical risk (≥50% mortality/irreversible morbidity at 30 days, or factors like frailty, porcelain aorta, prior chest radiation, severe hepatic/pulmonary disease): TAVR is recommended 1
High surgical risk (STS score ≥8%): TAVR is a reasonable alternative to SAVR 1, 3
Intermediate and low surgical risk: Both TAVR and SAVR are reasonable options based on Heart Team discussion and patient factors 1, 4
Age considerations: TAVR is proposed as first-line for patients >74 years old 5
Asymptomatic Severe AS: Risk Stratification Determines Management
Most asymptomatic patients with normal left ventricular function should undergo watchful waiting with regular monitoring. 2 However, intervention is appropriate or recommended in specific high-risk scenarios:
Class I Indications for AVR in Asymptomatic Patients
Intervention is mandatory when: 1, 2
LVEF <50% without another cause - this carries Class I recommendation regardless of surgical risk 1
Undergoing other cardiac surgery (CABG, aortic surgery, or other valve surgery) - concomitant AVR is indicated 1
Abnormal exercise stress test demonstrating 1:
- Decreased exercise tolerance (normalized for age/sex)
- Fall in systolic BP ≥10-20 mmHg from baseline to peak exercise
- Development of symptoms during exercise
Class IIa/IIb Indications: Consider Intervention
AVR should be considered in asymptomatic patients with low surgical risk when any of the following are present: 1
Very severe AS: Vmax ≥5.0 m/s or mean gradient ≥60 mmHg 1
Rapid progression: Increase in aortic velocity ≥0.3 m/s per year with severe valve calcification 1
Markedly elevated BNP: >3 times age- and sex-corrected normal range (confirmed on repeated measurements) 1
High-risk profession or lifestyle: Airline pilots, competitive athletes, or anticipated prolonged time away from medical supervision 1
The evidence supporting these criteria comes from registry studies showing that patients with LVEF <55% have significantly higher mortality rates, and early surgical intervention reduces all-cause mortality risk in this population. 1
Special Clinical Scenarios
Low-Flow, Low-Gradient AS with Reduced LVEF
Dobutamine stress echocardiography is required to distinguish true-severe from pseudo-severe AS. 2, 3 Patients demonstrating contractile reserve (increase in stroke volume >20% with dobutamine) should undergo AVR, as they have true severe AS. 3
Concomitant Coronary Artery Disease
Coronary angiography must be performed before AVR in elderly patients with: 3
- History of cardiovascular disease or suspected myocardial ischemia
- Men >40 years or post-menopausal women
- One or more cardiovascular risk factors
Combined SAVR and CABG is the Class I indication for patients with severe AS and significant coronary disease requiring revascularization. 3 For high-risk patients undergoing TAVR, percutaneous coronary intervention before TAVR is appropriate for less complex coronary disease (guided by SYNTAX score). 3
Moderate AS Undergoing Other Cardiac Surgery
Symptomatic moderate AS warrants valve replacement during CABG or other cardiac surgery (Class IIa). 1 This is particularly important in elderly patients with calcified valves where progression may be rapid. 3
Medical Management: Limited Role
There is no specific medical therapy to prevent or slow AS progression. 1, 6 Key principles include 1, 2:
- Statins are NOT indicated for preventing AS progression 1
- Standard cardiac risk factor modification and treatment of hypertension 1
- Avoid diuretics, vasodilators, and positive inotropes in patients awaiting surgery due to risk of hemodynamic destabilization 1
- Maintain adequate preload and avoid excessive diuresis 2
- Control heart rate to maintain adequate diastolic filling time 2
Balloon Aortic Valvuloplasty: Palliative Only
Balloon valvuloplasty is reasonable only for: 1
- Palliation in patients who cannot undergo AVR due to serious comorbidities (Class IIb)
- Bridge to surgical AVR (Class IIb)
This procedure does not provide definitive treatment and is associated with high restenosis rates. 1
Monitoring Strategy for Asymptomatic Patients
Asymptomatic patients require regular clinical and echocardiographic surveillance: 1, 2
- Serial imaging to document progression (velocity increase ≥0.3 m/s/year is concerning) 1
- Patient education about symptom recognition 6
- Exercise testing in apparently asymptomatic patients to unmask symptoms 1
Critical Pitfalls to Avoid
Never delay intervention in symptomatic severe AS - survival drops dramatically once symptoms develop 1, 2, 3
Don't miss reduced LVEF - this mandates intervention even without symptoms 1, 2
Avoid vasodilators and aggressive diuresis in severe AS patients awaiting surgery - these can precipitate hemodynamic collapse 1
Don't rely on statins to slow AS progression - they are ineffective for this purpose 1
Recognize that "asymptomatic" patients may have subtle symptoms - exercise testing can unmask functional limitations 1