How is atherosclerotic cardiovascular disease (ASCVD) risk assessed and managed using the ASCVD risk calculator?

ASCVD Risk Assessment and Management Using the ASCVD Risk Calculator

The ASCVD risk calculator is an essential tool for estimating 10-year risk of atherosclerotic cardiovascular disease events and guiding preventive therapy decisions, particularly statin therapy in primary prevention. 1

What is the ASCVD Risk Calculator?

• The American College of Cardiology/American Heart Association ASCVD risk calculator (Risk Estimator Plus) estimates the 10-year risk of atherosclerotic cardiovascular disease events including myocardial infarction, stroke, and cardiovascular death 1
• Available online at tools.acc.org/ASCVD-Risk-Estimator-Plus 1
• The calculator incorporates traditional risk factors including age, sex, race, total cholesterol, HDL cholesterol, systolic blood pressure, blood pressure treatment status, diabetes, and smoking status 1

Risk Categories and Their Interpretation

The 2018 AHA/ACC guidelines categorize 10-year ASCVD risk into four levels:

• Low risk: <5% 1
• Borderline risk: 5% to <7.5% 1
• Intermediate risk: 7.5% to <20% 1
• High risk: >20% 1

Using ASCVD Risk to Guide Management

Statin Therapy Recommendations

• High risk (>20%): Statin therapy strongly recommended 1
• Intermediate risk (7.5% to <20%): Statin therapy should be considered after clinician-patient risk discussion 1
• Borderline risk (5% to <7.5%): Consider statin therapy in selected patients with risk-enhancing factors 1
• Low risk (<5%): Generally lifestyle management only 1

Risk Refinement Strategies

When risk assessment is uncertain, particularly in borderline or intermediate risk patients:

1. Consider risk-enhancing factors 1, 2:

   • Family history of premature ASCVD
   • Persistent elevated LDL-C ≥160 mg/dL
   • Chronic kidney disease
   • Metabolic syndrome
   • Inflammatory conditions
   • High-sensitivity C-reactive protein ≥2.0 mg/L
   • Lipoprotein(a) ≥50 mg/dL
   • Apolipoprotein B ≥130 mg/dL

2. Coronary Artery Calcium (CAC) scoring 1:

   • CAC = 0: Consider withholding or deferring statin therapy (except in diabetics, smokers, or those with strong family history)
   • CAC 1-99: Favors statin therapy
   • CAC ≥100 or ≥75th percentile for age/sex: Strongly favors statin therapy
   • CAC is particularly useful for reclassifying risk in intermediate-risk patients 1

Special Populations

Diabetes

• Diabetes is included in the risk calculator as a risk factor 1
• The calculator does not account for diabetes duration or complications such as albuminuria 1
• For individuals with diabetes and hypertension at higher cardiovascular risk (existing ASCVD or 10-year ASCVD risk ≥15%), a blood pressure target of <130/80 mmHg may be appropriate 1
• For those with diabetes and hypertension at lower risk (10-year ASCVD risk <15%), a blood pressure target of <140/90 mmHg is recommended 1

Limitations and Considerations

• Risk calculators are bound by the underlying data that informs them and may become less accurate as population health changes 1
• There is variability in calibration across subgroups including sex, race, and diabetes status 1
• Traditional risk factors are strong population-based markers but poor individual discriminators of coronary atherosclerotic disease 1
• The new PREVENT equations (2023) tend to estimate lower risk compared to the older Pooled Cohort Equations, which may reduce the number of adults eligible for statin therapy 3

Practical Application in Clinical Practice

1. Calculate 10-year ASCVD risk using the Risk Estimator Plus tool 1
2. Categorize risk level (low, borderline, intermediate, high) 1
3. Consider risk-enhancing factors if risk is borderline or intermediate 1, 2
4. Consider CAC scoring for further risk stratification when the decision about statin therapy remains uncertain 1
5. Engage in shared decision-making with the patient about preventive strategies 1
6. Implement appropriate therapy based on risk level:
   • Lifestyle modifications for all risk levels 1
   • Statin therapy for those at appropriate risk thresholds 1
   • Blood pressure management tailored to ASCVD risk level 1

Common Pitfalls to Avoid

• Relying solely on the risk calculator without considering other clinical factors 1
• Using CAC scoring in symptomatic patients (not recommended) 1
• Failing to reassess risk periodically as risk factors may change over time 1
• Not engaging patients in shared decision-making about preventive strategies 1
• Overlooking the importance of lifestyle modifications regardless of pharmacological therapy 1