What is considered a high Atherosclerotic Cardiovascular Disease (ASCVD) risk score?

What is Considered a High ASCVD Risk Score?

An ASCVD risk score of 10% or greater is considered high risk according to the ACC/AHA guidelines, warranting consideration of statin therapy and aggressive risk factor modification. 1

Understanding ASCVD Risk Assessment

The Atherosclerotic Cardiovascular Disease (ASCVD) risk score is calculated using the Pooled Cohort Equations developed by the American College of Cardiology (ACC) and American Heart Association (AHA). This score estimates the 10-year risk of developing a first ASCVD event, defined as nonfatal myocardial infarction, coronary heart disease death, or fatal or nonfatal stroke.

Risk Categories:

• High Risk: ≥10% 10-year ASCVD risk 1
• Borderline Risk: 5% to <7.5% 10-year ASCVD risk 1
• Intermediate Risk: 7.5% to <10% 10-year ASCVD risk 1
• Low Risk: <5% 10-year ASCVD risk 1

Clinical Implications of High ASCVD Risk

Treatment Recommendations Based on Risk Score:

• ≥10% (High Risk):

  • Moderate to high-intensity statin therapy recommended 1
  • BP target of <130/80 mmHg for hypertensive patients 1
  • Consideration of additional non-statin therapies in selected high-risk individuals 1

• 7.5% to <10% (Intermediate Risk):

  • Moderate-intensity statin therapy should be considered 1
  • For diabetic patients with this risk level, high-intensity statin may be considered 1

Additional Risk Factors That May Elevate Risk Classification

The 2013 ACC/AHA guidelines identify several factors that may indicate elevated risk beyond the calculated ASCVD score 1:

• Primary LDL-C ≥160 mg/dL or evidence of genetic hyperlipidemias
• Family history of premature ASCVD (onset <55 years in male first-degree relative or <65 years in female first-degree relative)
• High-sensitivity C-reactive protein ≥2 mg/L
• Coronary artery calcium (CAC) score ≥300 Agatston units or ≥75th percentile for age, sex, and ethnicity
• Ankle-brachial index <0.9
• Elevated lifetime risk of ASCVD

Extreme Risk Category

Some experts recognize an "extreme risk" category, defined as ≥30% 10-year risk for ASCVD events, which includes patients with 2:

• Recent acute coronary syndrome
• Multiple comorbidities (diabetes, heart failure, CKD stage 3 or higher)
• Familial hypercholesterolemia
• Multiple or progressive ASCVD events

Important Considerations and Caveats

• The Pooled Cohort Equations are validated for adults aged 40-79 years 1
• For adults <40 years of age, lifetime risk assessment is encouraged 1
• Risk may be underestimated in women according to some studies 3
• Recent research suggests the original PCE may overestimate risk in some populations, but newer equations like PREVENT may offer better calibration 4
• Biomarkers (hs-CRP, homocysteine, albuminuria, NT-proBNP, troponin T) can improve risk prediction when added to traditional risk factors 5

Risk Assessment Algorithm

1. Calculate 10-year ASCVD risk using the Pooled Cohort Equations for patients 40-79 years old
2. Classify risk: <5% (low), 5-7.5% (borderline), 7.5-10% (intermediate), ≥10% (high)
3. Consider additional risk-enhancing factors if risk is borderline or intermediate
4. For patients <40 years, assess lifetime risk
5. For high-risk patients (≥10%), initiate appropriate preventive therapies including statins and BP management

Remember that risk assessment should be repeated every 4-6 years to improve long-term risk prediction 1.