What is the management of severe aortic regurgitation without aortic stenosis and with a normal ejection fraction?

Management of Severe Aortic Regurgitation with Normal Ejection Fraction

In patients with severe aortic regurgitation and normal ejection fraction, surgical intervention is indicated when symptoms develop regardless of left ventricular systolic function, or in asymptomatic patients when left ventricular dimensions increase beyond established thresholds. 1

Diagnosis and Assessment of Severe AR

Severe aortic regurgitation is defined by:

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

Causes of Severe Aortic Regurgitation

Severe AR can result from:

• Primary valve leaflet pathology (intrinsic disease of aortic valve leaflets) 1
• Secondary to aortic root distortion and dilatation 1
• Mixed pathology (especially in bicuspid aortic valve disease) 1
• Degeneration of the valve (most common etiology of chronic AR) 1

Surveillance of Asymptomatic Patients

For patients with severe asymptomatic AR and normal LV function:

• Clinical and echocardiographic follow-up every 6-12 months 1
• More frequent monitoring (every 3-6 months) if there is:
  • Significant fall in ejection fraction 1
  • Significant changes in LV dimensions 1
  • Clinical deterioration 1

Indications for Intervention in Asymptomatic Patients

Surgery is recommended in asymptomatic patients with:

• LVEF <50-55% (threshold varies by guideline) 1
• Left ventricular end-systolic diameter (LVESD) >50 mm 1
• LVESD >45 mm (reasonable consideration) 1
• Progressive increase in LV dilation into severe range (LVEDD >65 mm) 1
• Progressive decline in LVEF on serial studies 1

Management of Symptomatic Patients

• Surgical aortic valve replacement (SAVR) is indicated for symptomatic severe AR regardless of LV systolic function (Class I recommendation) 1
• Symptoms warranting intervention include exertional dyspnea, heart failure, angina, syncope, or presyncope 1

Medical Therapy

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

Surgical Options

• Aortic valve replacement (mechanical or bioprosthetic valve) is the standard intervention 1
• Valve-sparing surgery may be considered in selected patients at experienced centers, particularly when aortic root replacement is needed 1
• Transcatheter aortic valve implantation (TAVI) may be considered in experienced centers for selected patients ineligible for SAVR 1

Special Considerations

• If aortic root is dilated (≥45 mm), replacement of aortic sinuses and/or ascending aorta is reasonable when performed at comprehensive valve centers 1
• In patients with bicuspid aortic valve, valve-sparing surgery may be considered if performed at comprehensive valve centers 1
• For patients undergoing cardiac surgery for other indications with severe AR, concomitant aortic valve replacement is indicated 1

Prognosis

• Without intervention, severe AR is associated with significant morbidity and mortality 1
• Within 10 years of diagnosis, 75% of patients with severe AR die or require AVR 1
• Even in asymptomatic severe AR, mortality can be as high as 19% within 6.6 years of diagnosis 1
• High-risk features in asymptomatic patients include LVEF <55% and LVESD ≥25 mm/m² 2

Common Pitfalls to Avoid

• Relying on symptoms alone to guide intervention timing, as symptoms often occur late in the disease process 3, 2
• Delaying surgery in patients with progressive LV dilation or declining LVEF, even if asymptomatic 2
• Failing to recognize that even mild symptoms (NYHA class II) in severe AR are associated with increased mortality (6.3% yearly) 2
• Underestimating the importance of regular surveillance with consistent measurement techniques for accurate assessment of disease progression 1