What are the current guidelines for screening women for Abdominal Aortic Aneurysm (AAA)?

Current Guidelines for Screening Women for Abdominal Aortic Aneurysm (AAA)

Current guidelines do not recommend routine screening for AAA in women who have never smoked, and there is insufficient evidence to make a recommendation for or against screening in women who have ever smoked.

Recommendations for Women by Risk Category

Women Who Have Never Smoked

• Routine screening for AAA is not recommended in women who have never smoked as the harms likely outweigh the benefits 1, 2
• This recommendation is based on the low prevalence of AAA in women who have never smoked, estimated to be rare compared to men 1, 2

Women Who Have Ever Smoked (Ages 65-75)

• There is insufficient evidence to make a recommendation for or against screening in women ages 65-75 who have ever smoked 1, 2
• The U.S. Preventive Services Task Force (USPSTF) has issued an "I Statement" indicating that the current evidence is insufficient to assess the balance of benefits and harms in this population 1, 2

Women with Family History of AAA

• There is insufficient evidence to determine the net benefit of screening for women aged 65-75 years with a family history of AAA 2
• However, screening is recommended for first-degree relatives (FDRs) of patients with AAA aged ≥50 years, unless an acquired cause can be clearly identified 1

Rationale Behind Current Recommendations

Prevalence and Risk Factors

• The prevalence of AAA in women aged 65 years is estimated to be only 0.43% compared to higher rates in men 3
• Women have a lower risk of developing AAA compared to men, with smoking being the strongest modifiable risk factor 4, 5
• Other risk factors include age, family history of AAA, coronary artery disease, hypertension, and peripheral artery disease 4

Cost-Effectiveness Analysis

• Modeling studies have shown that population screening for AAA in women is not cost-effective with an incremental cost-effectiveness ratio (ICER) of £31,000 per QALY gained, which exceeds typical thresholds for cost-effectiveness 3
• Even with alternative screening strategies (such as increasing screening age to 70 years or lowering diameter thresholds), the cost-effectiveness remains unfavorable 3

Potential Harms vs. Benefits

• Potential harms of screening include anxiety, unnecessary follow-up testing, and surgical interventions for aneurysms that would never have ruptured 1
• For women who have never smoked, these harms likely outweigh the potential benefits due to the low prevalence of disease 2

Potential Gaps in Current Guidelines

• Recent research suggests that female smokers older than 65 years represent 19% of patients with ruptured AAA who were ineligible for screening under current guidelines 6
• This suggests a potential benefit from expanding screening guidelines to include this high-risk population 6

Screening Method and Follow-up

• When screening is performed, it is done using ultrasound, which is safe, painless, and non-invasive 1
• Opportunistic screening may be considered in women aged ≥75 years during transthoracic echocardiography (TTE) 1
• Treatment decisions for identified AAAs depend on size:
  • Small aneurysms (<5.5 cm) are typically monitored with periodic ultrasound 1
  • Surgical intervention is generally recommended for aneurysms ≥5.5 cm or those growing rapidly 1, 4

Summary of Current Guidelines by Organization

U.S. Preventive Services Task Force (2014/2019)

• Recommends against routine screening in women who have never smoked (D recommendation) 1, 2
• Insufficient evidence for women aged 65-75 who have ever smoked or have family history (I statement) 1, 2

European Society of Cardiology (2024)

• Screening may be considered in women aged ≥75 years who are current smokers, hypertensive, or both 1
• Recommends screening for first-degree relatives of patients with AAA aged ≥50 years 1