Criteria for Aortic Stenosis Valve Replacement
Aortic valve replacement is indicated in all patients with severe aortic stenosis who have symptoms related to AS, left ventricular dysfunction (LVEF <50%), or abnormal exercise test showing symptoms clearly related to AS, regardless of surgical risk. 1
Primary Indications for Aortic Valve Replacement (Class I)
- Symptomatic severe AS: Any symptoms related to AS (angina, syncope, dyspnea) warrant valve replacement 1
- Severe AS with LVEF <50% not due to another cause 1
- Severe AS in patients undergoing other cardiac surgery (CABG, ascending aorta surgery, or another valve surgery) 1
- Asymptomatic severe AS with abnormal exercise test showing symptoms clearly related to AS 1
Secondary Indications for Aortic Valve Replacement (Class IIa)
- Asymptomatic severe AS with abnormal exercise test showing fall in blood pressure below baseline 1
- Moderate AS in patients undergoing other cardiac surgery (CABG, ascending aorta surgery, or another valve surgery) 1
- Symptomatic low-flow, low-gradient (<40 mmHg) AS with normal EF after careful confirmation of severe AS 1
- Symptomatic low-flow, low-gradient AS with reduced EF and evidence of flow reserve on dobutamine stress echocardiography 1
Additional Considerations for Asymptomatic Patients (Class IIa)
- Very severe AS defined by peak velocity >5.5 m/s or mean gradient ≥60 mmHg, especially with low surgical risk 1
- Severe valve calcification with rapid progression (peak velocity increase ≥0.3 m/s per year) 1
- High-risk profession (e.g., airline pilot) or lifestyle (competitive athlete) or anticipated prolonged time away from medical supervision 1
Special Populations (Class IIb)
- Symptomatic low-flow, low-gradient AS with LV dysfunction without flow reserve 1
- Asymptomatic severe AS with markedly elevated natriuretic peptide levels confirmed by repeated measurements without other explanations 1
- Asymptomatic severe AS with increase of mean pressure gradient with exercise >20 mmHg 1
- Asymptomatic severe AS with excessive LV hypertrophy in the absence of hypertension 1, 2
Transcatheter vs. Surgical Approach
- TAVR is recommended for patients with severe, symptomatic AS with prohibitive surgical risk (≥50% risk of mortality/morbidity at 30 days) 1
- TAVR is a reasonable alternative to surgical AVR in patients at high surgical risk (STS score ≥8%) 1
- Surgical AVR remains the standard for younger, low-risk patients due to limited long-term data on TAVR durability 3
- Heart Team approach is essential for determining the optimal intervention strategy based on individual risk profile and anatomic suitability 1
Diagnostic Criteria for Severe AS
- High-gradient severe AS: AVA ≤1.0 cm² with peak velocity ≥4 m/s or mean gradient ≥40 mmHg 1
- Low-flow, low-gradient severe AS: AVA ≤1.0 cm² with peak velocity <4 m/s or mean gradient <40 mmHg 1
- Very severe AS: Peak velocity ≥5 m/s or mean gradient ≥60 mmHg 1
- Extremely severe AS: AVA ≤0.6 cm², mean gradient ≥50 mmHg, or jet velocity ≥5 m/s 1
Common Pitfalls and Caveats
- Pseudosevere AS can be misdiagnosed as true severe AS in patients with low flow states; dobutamine stress echocardiography can help differentiate 1
- Symptoms may be subtle or denied by patients who gradually reduce their activity levels; exercise testing can unmask symptoms in apparently asymptomatic patients 1
- Low-gradient AS with preserved EF requires careful evaluation to confirm true stenosis severity, potentially using CT calcium scoring 1
- Natural history of asymptomatic severe AS is not benign as previously thought; mortality benefit has been demonstrated with early AVR in selected asymptomatic patients 4
- Patients with low-flow, low-gradient AS and LV dysfunction represent a high-risk group with complex decision-making requirements 5