Ethnic differences in coronary plaque and epicardial fat volume quantified using computed tomography

Area of Science:

• Cardiovascular imaging
• Radiology
• Public health

Background:

• Epidemiological studies indicate higher coronary atherosclerosis prevalence in South Asians versus Caucasians.
• Quantitative differences in aggregate plaque volume (APV) and epicardial fat volume (EFV) between ethnic groups remain unclear.

Purpose of the Study:

• To compare APV and EFV quantified by computed-tomography-coronary-angiography (CTCA) among South Asian, SEEA, and Caucasian populations in Australia.
• To determine if ethnicity is an independent predictor of APV and EFV.

Main Methods:

• Retrospective analysis of 320-detector CTCA scans from 150 age, gender, and BMI-matched subjects (50 per ethnic group).
• Quantification of percentage APV in the proximal 5 cm of the left anterior descending artery (LAD) and EFV using dedicated software.
• Multivariate analysis to assess the predictive value of ethnicity for APV and EFV, adjusting for traditional risk factors.

Main Results:

• Mean LAD percentage APV was significantly highest in South Asians (44.5%) compared to SEEAs (37.5%) and Caucasians (39.5%).
• South Asian ethnicity independently predicted higher LAD APV (P=0.000002).
• EFV was significantly higher in South Asians (103.2 cm³) and SEEAs (110.8 cm³) compared to Caucasians (85.8 cm³).

Conclusions:

• CTCA-quantified LAD APV and EFV differ significantly across South Asian, SEEA, and Caucasian populations.
• South Asian ethnicity is a strong predictor of increased LAD APV, independent of traditional risk factors.
• Further research is needed to evaluate if APV and EFV quantification can enhance cardiac risk prediction in South Asians.