What is the Atherosclerotic Cardiovascular Disease (ASCVD) risk score for the Indian population?

ASCVD Risk Assessment for Indian Population

There is no specific ASCVD risk calculator validated for the Indian population, and the American College of Cardiology/American Heart Association Pooled Cohort Equations may underestimate risk in South Asians. 1

Current Risk Assessment Tools for South Asians

The assessment of cardiovascular risk in the Indian population presents unique challenges due to the higher prevalence and earlier onset of cardiovascular disease in this demographic compared to other populations.

Available Risk Calculators:

• ACC/AHA Pooled Cohort Equations (PCE): The 2019 ACC/AHA guidelines recommend using PCE for 10-year ASCVD risk estimation, but these were primarily developed for non-Hispanic Whites and African Americans 1
• Framingham Risk Score-Cardiovascular Disease (FRS-CVD): Research suggests this may be more appropriate for Indians compared to other calculators 2
• QRISK2, JBS3, and WHO risk charts: These have shown intermediate performance in Indian populations 2

Risk Underestimation in South Asians

South Asians have several unique characteristics that affect their cardiovascular risk profile:

• Higher rates of hospitalization for ASCVD compared to other racial/ethnic groups (HR 2.4 compared to non-Hispanic Whites) 1
• Higher proportionate mortality from ischemic heart disease 1
• Smaller coronary artery luminal diameters 1
• Higher coronary artery calcium (CAC) burden, with Asian Indian race being an independent predictor of CAC severity 1
• Higher prevalence of diabetes, dyslipidemia, and metabolic syndrome 1

Recommended Approach for ASCVD Risk Assessment in Indians

1. Calculate baseline risk using FRS-CVD as it has shown better performance in identifying high-risk Indian patients 2

2. Consider using PCE with caution - the 2013 ACC/AHA guidelines state that "use of the sex-specific Pooled Cohort Equations for non-Hispanic Whites may be considered when estimating risk in patients from populations other than African Americans and non-Hispanic Whites" 1

3. Adjust risk estimation upward due to the known underestimation of risk in South Asians 1

4. Incorporate risk enhancers specific to South Asians:

   • Family history of premature ASCVD
   • Metabolic syndrome
   • Chronic kidney disease
   • Elevated triglycerides ≥175 mg/dL
   • Elevated LDL-C ≥160 mg/dL 3

5. Consider CAC scoring for further risk stratification, especially in those with:

   • Borderline (5% to <7.5%) or intermediate (≥7.5% to <20%) 10-year risk 1
   • Family history of premature ASCVD 4
   • Age >60 years (where South Asians show higher CAC burden) 1

Limitations and Caveats

• The absence of a validated ASCVD risk calculator specifically for Indians is a significant limitation
• Traditional risk calculators may underestimate risk in younger South Asians with subclinical disease 4
• South Asians have higher rates of non-calcified plaque which may not be detected by CAC scoring 1
• Consider lifetime risk estimation for adults 20-39 years or those 40-59 years with <7.5% 10-year risk 4

Clinical Implementation

For clinical practice in India, the FRS-CVD appears to be the most useful risk assessment tool, identifying 51.9% of at-risk patients compared to only 28.3% with the ASCVD calculator in one study 2. However, this difference may be because FRS-CVD estimates risk for several additional outcomes compared to other risk scores.

For statin eligibility decisions, the NICE guideline approach appears most appropriate for the Indian population, identifying 76% of at-risk patients compared to 69% with ACC/AHA guidelines 2.