What is the management approach for abnormal aortic valve gradients indicating severe stenosis or regurgitation?

Management of Abnormal Aortic Valve Gradients

Patients with abnormal aortic valve gradients indicating severe stenosis or regurgitation should undergo valve intervention (surgical or transcatheter) based on symptom status, left ventricular function, and surgical risk factors. 1

Assessment of Aortic Valve Stenosis

Diagnostic Criteria for Severe Aortic Stenosis

• High-gradient severe AS: mean gradient ≥40 mmHg or peak velocity ≥4.0 m/s
• Low-flow, low-gradient severe AS with reduced LVEF (<50%): requires dobutamine stress echocardiography to confirm true severity
• Low-flow, low-gradient severe AS with preserved LVEF: requires careful confirmation of severity

Management Algorithm for Aortic Stenosis

Symptomatic Severe AS

• Intervention is indicated for all symptomatic patients with severe high-gradient AS (Class I) 1
• Symptoms include: exertional dyspnea, heart failure, angina, syncope, or presyncope
• Choice between SAVR and TAVI depends on:
  • Age: <65 years → SAVR preferred; >80 years → TAVI preferred
  • Surgical risk: STS-PROM >8% → TAVI preferred
  • Anatomical considerations: bicuspid valve, coronary access issues → SAVR may be preferred
  • Life expectancy and valve durability requirements

Asymptomatic Severe AS

• Intervention indicated if:
  • LVEF <50% (Class I) 1
  • LVEF declining to <55% without other cause 1
  • Abnormal exercise test showing symptoms clearly related to AS 1
  • Very severe AS (peak velocity >5 m/s) 1
  • Rapid progression (increase in peak velocity >0.3 m/s/year) 1

Assessment of Aortic Regurgitation

Management Algorithm for Aortic Regurgitation

Symptomatic Severe AR

• Surgery is indicated in all symptomatic patients with severe AR regardless of LV function (Class I) 1
• Symptoms include: exertional dyspnea, heart failure, angina, or syncope

Asymptomatic Severe AR

• Surgery indicated if:
  • LVEF <50% (Class I) 1
  • LVEF <55% (Class I) 1
  • LVESD >50 mm or >45 mm (Class I or IIa) 1
  • Progressive LV dilatation into severe range (LVEDD >65 mm) (Class IIb) 1
  • Concurrent aortic root disease with diameter ≥45 mm 1

Special Considerations

Low-Flow, Low-Gradient Aortic Stenosis

• Requires careful assessment to distinguish true-severe from pseudo-severe AS
• Dobutamine stress echocardiography is essential to confirm severity and assess contractile reserve 1
• Multidetector computed tomography for aortic valve calcium scoring can help confirm severity 2
• Patients with true-severe AS and contractile reserve benefit from valve replacement 2

Acute Severe Aortic Regurgitation

• Medical therapy to reduce LV afterload may be used for stabilization
• Surgery should not be delayed, especially with hypotension, pulmonary edema, or evidence of low flow 1
• Intra-aortic balloon counterpulsation is contraindicated 1

Mixed Valve Disease

• When both stenosis and regurgitation are present, intervention should follow recommendations for the predominant lesion 1
• Mixed valve disease may have pathological consequences beyond either lesion alone, potentially requiring earlier intervention 1
• Exercise hemodynamic studies should be considered for patients with symptoms disproportionate to resting findings 1

Choice of Intervention

Surgical Aortic Valve Replacement (SAVR)

• Preferred for patients at low surgical risk (STS or EuroSCORE II <4%) 1
• Indicated when concurrent procedures needed (CABG, other valve surgery, aortic surgery) 1
• Preferred in younger patients (<65 years) for valve durability 1

Transcatheter Aortic Valve Implantation (TAVI)

• Recommended for patients unsuitable for SAVR 1
• Favored in elderly patients (>80 years) with suitable transfemoral access 1
• May be considered in patients at increased surgical risk (STS or EuroSCORE II ≥4%) 1
• Not recommended for isolated severe AR in surgical candidates 1

Prognostic Implications

The natural history of untreated severe aortic valve disease is poor:

• Symptomatic severe AS: 60% first-year survival without intervention 3
• Symptomatic severe AR: 96% first-year survival but progressive deterioration 3
• After 10 years, only 9% of patients with severe AS and 17% with severe AR remain event-free without intervention 3

Timely intervention significantly improves survival and quality of life, particularly in symptomatic patients and those with LV dysfunction 4, 3.