Risk Factors for Aortic Regurgitation
The primary risk factors for developing aortic regurgitation include bicuspid aortic valve, aortic root dilatation, degenerative valve disease, and connective tissue disorders such as Marfan syndrome. 1
Anatomical and Structural Risk Factors
Congenital Abnormalities
- Bicuspid aortic valve: One of the most common congenital risk factors, leading to accelerated valve degeneration and earlier presentation of severe disease 1
- Congenital valve malformations affecting leaflet morphology, commissure variations, or root structure
Aortic Root and Ascending Aorta Disorders
- Aortic root dilatation/annulo-aortic ectasia: Causes secondary AR by distorting leaflet coaptation 1
- Marfan syndrome: Associated with progressive aortic root dilatation leading to AR 1
- Other connective tissue disorders that affect aortic integrity
- Aortic dissection: Can cause acute severe AR 2
Valvular Degeneration
- Age-related degenerative changes: Most common etiology of chronic AR in adults 1
- Calcification of valve leaflets leading to restricted mobility or inadequate coaptation
- Fibrosis of valve tissue affecting leaflet pliability
Inflammatory and Infectious Causes
- Infective endocarditis: Can cause acute AR through valve destruction or perforation 1
- Rheumatic heart disease: Less common in developed countries but still significant globally
- Collagen vascular diseases: Can affect valve integrity
- Antiphospholipid syndrome: Rare cause of acute valvular regurgitation during pregnancy 1
Functional Mechanisms
According to the El Khoury functional classification (adapted from Carpentier), AR can result from 1:
- Type I: Aortic root dilatation with normal leaflets
- Type II: Leaflet prolapse (excessive leaflet tissue)
- Type III: Leaflet restriction (rheumatic disease, calcification)
Iatrogenic and Procedure-Related Risk Factors
- Transcatheter aortic valve interventions: Can cause paravalvular AR due to 1:
- Incomplete expansion of prosthesis
- Incorrect positioning
- Undersized prosthesis
- Severe asymmetric calcification preventing proper stent accommodation
- Balloon aortic valvuloplasty: May cause leaflet damage
- Failed bioprosthetic valves: Can develop regurgitation over time 1
Systemic Conditions
- Hypertension: Contributes to aortic root dilatation and increases hemodynamic stress on the valve 3
- Syphilis (tertiary): Historical cause affecting the aortic root
- Coarctation of the aorta: Associated with bicuspid aortic valve and risk of aortic dilatation 1
Progression Risk Factors
Factors that accelerate progression of existing AR include:
- Family history of aortic dissection
- Aortic size increase >2 mm/year on serial measurements 1
- Systemic hypertension, particularly in patients with bicuspid valves 1
- Severe asymmetric calcification of the native valve 1
Clinical Implications
Early identification of risk factors is crucial as severe AR is associated with significant cardiovascular morbidity and mortality. Within 10 years of diagnosis of severe AR, 75% of patients die or require aortic valve replacement, and even asymptomatic severe AR carries a mortality rate of up to 19% within 6.6 years 1.
For patients with identified risk factors, regular echocardiographic monitoring is essential to detect progression. Surgical intervention should be considered before irreversible left ventricular dysfunction develops, particularly when the ejection fraction falls below 50% or significant left ventricular dilatation occurs 1.
In patients with aortic root disease, prophylactic surgery may be indicated at specific aortic diameter thresholds depending on associated risk factors, particularly for those with Marfan syndrome (≥50 mm) or bicuspid aortic valve with risk factors (≥50 mm) 1.