What is a myxomatous aortic valve?

Myxomatous Aortic Valve: Definition and Clinical Significance

A myxomatous aortic valve refers to an abnormality of the aortic valve related to the presence of myxomatous tissue on the valve leaflets or related structures, characterized by thickening, redundancy, and abnormal tissue composition of the valve leaflets.

Definition and Pathology

• Myxomatous degeneration is a non-inflammatory degenerative process leading to disruption of the fibrosa layer of the valve with acid mucopolysaccharide accumulation 1
• While myxomatous degeneration commonly affects the mitral valve, it can also affect the aortic valve, though this is less frequent 1, 2
• Histologically, myxomatous degeneration of the aortic valve appears similar to that seen in mitral valve prolapse 2

Clinical Presentation and Diagnosis

• Myxomatous degeneration of the aortic valve can lead to aortic regurgitation (AR) due to abnormal valve leaflet structure and function 1
• Echocardiography is the first-line imaging modality for diagnosis of valvular regurgitation, including myxomatous aortic valve disease 3
• Key echocardiographic findings in myxomatous aortic valve disease include:
  • Thickened, redundant valve leaflets 3
  • Abnormal leaflet motion (often excessive motion/prolapse) 3
  • Presence of aortic regurgitation 1

Classification and Mechanism

• According to the Carpentier's classification of leaflet motion, myxomatous aortic valve disease typically presents as Type II (excessive motion) 3
• The El Khoury functional classification (adapted from Carpentier) can help appraise the mechanism of aortic regurgitation in myxomatous disease 3
• Myxomatous degeneration can cause aortic regurgitation through:
  • Leaflet prolapse due to tissue redundancy 3, 4
  • Fenestrations in the valve tissue 4
  • Loss of proper coaptation 4

Complications and Clinical Significance

• Myxomatous degeneration of the aortic valve can lead to:
  • Aortic regurgitation 1, 4
  • Heart failure symptoms (dyspnea, fatigue, edema) 1
  • Need for surgical intervention when severe 1, 4

Management Considerations

• Surgical options for myxomatous aortic valve disease include:
  • Valve repair techniques such as plication of the free margin for prolapse correction 4
  • Triangular resection of redundant cusp tissue 4
  • Closure of fenestrations with pericardial patches when present 4
  • Valve replacement when repair is not feasible 1

Differential Diagnosis

• Myxomatous aortic valve should be distinguished from:
  • Aortic valve myxoma (a rare primary cardiac tumor) 5, 6
  • Degenerative valve disease related to aging and calcification 3
  • Rheumatic heart disease 3
  • Bicuspid aortic valve with degeneration 3

Prognosis

• When treated appropriately with surgical intervention, patients with myxomatous aortic valve disease can have good outcomes 4
• Studies have shown freedom from reoperation at 5 and 8 years to be approximately 96% following appropriate surgical repair 4

Common Pitfalls

• Failure to distinguish between myxomatous degeneration and other causes of aortic regurgitation may lead to inappropriate management 2
• Echocardiography has been shown to be more helpful than angiography in the diagnosis of myxomatous valve degeneration 2
• Myxomatous aortic valve disease may be part of a more generalized connective tissue disorder in some patients 2