Abstract Body (Do not enter title and authors here): Background
South Asians face a disproportionately high burden of atherosclerotic cardiovascular disease (ASCVD), often presenting at younger ages and with fewer traditional risk factors than other populations. Widely used risk prediction tools such as the Framingham Risk Score (FRS), ASCVD Pooled Cohort Equations, and QRISK were developed primarily in White cohorts, while others like WHO/ISH were based on broad regional estimates that may not reflect the higher risk in South Asians. This can lead to under-treatment and missed opportunities for early prevention.

Methods
We conducted a systematic review guided by PRISMA methodology, evaluating studies published between 2014 and 2024 that assessed cardiovascular risk in South Asian adults. A PubMed search was performed using the keywords: ("South Asian" OR "Indian" OR "Pakistani" OR "Bangladeshi") AND ("cardiovascular risk" OR "heart disease risk" OR "ASCVD") AND ("Framingham" OR "QRISK" OR "Pooled Cohort Equations" OR "risk prediction"). Studies were included if they evaluated the calibration or performance of models such as FRS, ASCVD, QRISK, JBS3, WHO/ISH, or NORRISK2, or assessed surrogate markers like coronary artery calcium (CAC) or carotid intima-media thickness (CIMT).

Results
Fifteen studies met inclusion criteria. Most demonstrated consistent underestimation of ASCVD risk in South Asians using standard models. In one study, recalibration of the FRS resulted in a 9.8% net reclassification into higher-risk categories. Several studies showed that WHO/ISH charts and NORRISK2 poorly correlated with imaging-based risk markers like CAC and CIMT in South Asians, indicating limited predictive value. U.S. based MASALA and MESA analyses reported that South Asians had greater subclinical atherosclerosis than White peers at equivalent risk levels. Across studies key risk factors including elevated lipoprotein(a), family history of premature ASCVD, and CAC scoring were frequently unaccounted for, suggesting missed stratification opportunities.

Conclusion
Common cardiovascular risk calculators often underestimate ASCVD risk in South Asian populations. Adapting existing models using South Asian-specific data and incorporating markers such as CAC and lipoprotein(a) may improve risk assessment. These findings highlight the need to reevaluate how South Asian ethnicity is incorporated into risk assessment, potentially deserving greater consideration in risk stratification beyond a secondary enhancer.