What is the management approach for aortic regurgitation?

Management of Aortic Regurgitation

Surgical intervention is indicated for all patients with symptomatic severe aortic regurgitation regardless of left ventricular systolic function, while asymptomatic patients with severe AR should undergo surgery when left ventricular dysfunction or significant dilation develops. 1

Diagnosis and Assessment

Definition of Severe AR

• Vena contracta >0.6 cm
• Regurgitant volume ≥60 mL/beat
• Effective regurgitant orifice area (EROA) ≥0.3 cm²
• Holodiastolic flow reversal in the descending aorta
• Evidence of LV dilation
• Doppler jet width ≥65% of LVOT
• Regurgitant fraction ≥50%
• Pressure half-time of regurgitant jet <200 m/s 1

Imaging

• Echocardiography is the primary imaging modality for diagnosis, determining etiology, and grading severity
• CMR is recommended when there is diagnostic uncertainty to assess regurgitant fraction, biventricular volumes, and systolic function
• CT may be appropriate to obtain aortic root dimensions and exclude dissection in acute AR 1

Management Algorithm

Acute Severe AR

1. Immediate surgical intervention is required, especially with hypotension, pulmonary edema, or evidence of low flow
2. Medical therapy to reduce LV afterload may provide temporary stabilization but should not delay surgery
3. Avoid intra-aortic balloon counterpulsation as it is contraindicated in acute severe AR
4. Use beta blockers cautiously, if at all, except in cases of aortic dissection 1

Chronic AR

Symptomatic Severe AR (Stage D)

• Surgical AVR is indicated regardless of LV systolic function (Class I recommendation) 1

Asymptomatic Severe AR with LV Dysfunction (Stage C2)

• Surgical AVR is indicated when:
  • LVEF ≤50-55% (ACC/AHA uses ≤55%, JCS uses <50%)
  • LVESD >50 mm or >25 mm/m² 1

Asymptomatic Severe AR with Normal LV Function (Stage C1)

• Surgical AVR is reasonable when:
  • LVESD >50 mm (Class I recommendation)
  • LVESD >45 mm (Class IIa recommendation)
  • Progressive LV dilation into severe range (LVEDD >65 mm)
  • Progressive decline in LVEF on serial studies 1

Mild to Moderate AR (Stage B)

• Medical follow-up without intervention
• Treat hypertension if present 1

AR with Concurrent Cardiac Surgery

• AVR is indicated for patients with severe AR undergoing CABG or surgery of the ascending aorta or other heart valves
• AVR is reasonable for patients with moderate AR undergoing cardiac surgery for other indications 1

AR with Aortic Root Dilation

• Replacement of aortic sinuses/ascending aorta is reasonable when aortic dimension is ≥45 mm if surgery is performed at a comprehensive valve center
• In patients with bicuspid aortic valve, valve-sparing surgery may be considered at comprehensive valve centers 1

Medical Therapy

Role in Chronic AR

• Medical therapy with ACE inhibitors or dihydropyridine calcium channel blockers may provide symptomatic improvement when surgery is not feasible
• For asymptomatic patients with hypertension and chronic AR, treatment of hypertension (systolic BP >140 mmHg) is recommended
• In patients with LV systolic dysfunction but prohibitive surgical risk, guideline-directed medical therapy for reduced LVEF with ACE inhibitors, ARBs, and/or sacubitril/valsartan is recommended 1

Limitations of Medical Therapy

• Long-term vasodilator therapy with nifedipine or enalapril has not been shown to reduce or delay the need for aortic valve replacement in asymptomatic patients with severe AR and normal LV function 2
• Medical therapy should not be used as a substitute for surgical intervention when surgery is indicated 3

Follow-up and Surveillance

Monitoring Schedule

• Severe asymptomatic AR: Every 6-12 months
• If significant changes in LVEF or LV size are observed: Every 3-6 months
• Mild-moderate AR: Every 1-2 years
• Mild AR: Every 3-5 years 1

Monitoring Parameters

• LV size and function (LVEF, LVESD, LVEDD)
• Symptoms (exercise intolerance, dyspnea, angina)
• Aortic dimensions if aortic root pathology is present 1

Special Considerations

Mixed Valve Disease

• When AR coexists with aortic stenosis, careful assessment is needed to identify the predominant valve pathology
• In symptomatic patients with both AR and AS, AVR is recommended when peak transvalvular velocity is ≥4.0 m/s or mean gradient is ≥40 mmHg 1

Risk Assessment

• Comprehensive surgical risk assessment is essential, especially when considering valve-sparing procedures
• Heart valve team involvement is crucial for decision-making 1

Pitfalls and Caveats

1. Delayed Intervention: Waiting for symptoms to develop before referring for surgery may result in irreversible LV dysfunction
2. Overlooking Progression: Disease progression in chronic AR is often insidious and variable; regular monitoring is essential
3. Relying on Medical Therapy: Using vasodilators as a substitute for indicated surgery is not supported by evidence
4. Intra-aortic Balloon Counterpulsation: This is contraindicated in acute severe AR and can worsen the condition
5. Inconsistent Measurements: Using different imaging modalities or techniques for serial measurements may lead to inconsistent assessment of disease progression

By following this evidence-based approach to AR management, clinicians can optimize outcomes by intervening at the appropriate time to prevent irreversible LV dysfunction while avoiding unnecessary early surgery in patients who can be safely monitored.