What are the CAC (Coronary Artery Calcification) score values indicating low, moderate, and high risk in men and women with aortic stenosis and normal ejection fraction (EF)?

Coronary Artery Calcium Score Values in Aortic Stenosis with Normal EF: Gender-Specific Risk Stratification

For patients with aortic stenosis and normal ejection fraction, CAC scores above 723 indicate high risk for adverse cardiovascular events regardless of gender, while scores below 100 generally indicate low risk.

Gender Differences in CAC Scores

Coronary artery calcium (CAC) scoring provides valuable prognostic information for patients with aortic stenosis (AS) and normal ejection fraction (EF). However, important gender differences exist:

• Women typically have less prevalent and less severe CAC than men
• Women's CAC prevalence lags approximately 10 years behind men across age groups 1
• CAC prevalence is particularly low in premenopausal women 1

Risk Stratification Based on CAC Scores

Low Risk

• CAC score of 0: Excellent prognosis with very low event rates (<1% annually) 1
• CAC score 1-100: Relative risk of 3.4 compared to score of 0 1

Moderate Risk

• CAC score 101-400: Relative risk of 7.1 compared to score of 0 1
• Annual cardiac death/MI rate approximately 4.6% 1

High Risk

• CAC score >400: Relative risk of 10.8 compared to score of 0 1
• Annual cardiac death/MI rate approximately 7.1% 1
• Specific to AS: Scores ≥723 associated with significantly worse outcomes 2

Special Considerations for Aortic Stenosis

In patients with AS and normal EF, CAC scoring has particular significance:

• AVCS (Aortic Valve Calcium Score) ≥723 is associated with significantly worse outcomes (p<0.0001) 2
• CAC evaluation provides incremental prognostic value beyond traditional risk factors and echocardiographic measures 2
• Patients with AS often have higher baseline CAC scores than the general population

Clinical Application in Aortic Stenosis Management

The presence and severity of CAC in AS patients should guide management:

• Low CAC (<100): Consider conservative management with regular monitoring
• Moderate CAC (101-400): Consider more aggressive risk factor modification and closer follow-up
• High CAC (>400, especially ≥723): Consider earlier intervention, particularly with concurrent symptoms or other high-risk features 2

Important Caveats

• CAC scoring is not appropriate as a surrogate for angiographic disease detection due to modest relationship between CAC and obstructive coronary artery disease 1
• CAC distributions have been primarily studied in white populations and may not apply equally to all ethnicities 1
• The "power of zero" CAC score is less reliable in younger patients who may have predominantly non-calcified plaque

Practical Approach to CAC Interpretation in AS

1. Obtain CAC score as part of comprehensive AS evaluation
2. Interpret score with gender and age considerations (women typically have lower scores)
3. Use CAC score ≥723 as a high-risk threshold specific to AS patients 2
4. Incorporate CAC findings with other risk factors and AS severity measures for optimal risk stratification

By understanding gender-specific CAC score values in AS patients with normal EF, clinicians can better identify high-risk individuals who may benefit from more aggressive management or earlier intervention.