Polygenic risk scores (PRSs) for heart disease and stroke provide modest benefit for predicting incident atherosclerotic cardiovascular disease (ASCVD) in midlife and older people, according to a new study appearing this week in JAMA Cardiology. ASCVD is a significant cause of morbidity and mortality worldwide, and while preventative treatments can decrease this burden, estimating patient risk is a key first step to identifying those who would benefit from such interventions. PRSs have been proposed to improve cardiovascular disease risk stratification, so a team led by Veterans Affairs scientists set out to investigate whether two such scores — derived from coronary heart disease and acute ischemic stroke genome-side association studies involving primarily European individuals — could improve ASCVD risk stratification. In a prognostic study of nearly 80,000 ethnically diverse participants in the Million Veteran Program who were free of ASCVD and had never been treated with cholesterol-lowering statins, the investigators find that the PRSs were statistically significantly associated with incident heart attack, ischemic stroke, and ASCVD death, although reclassification improvement was modest. Consistent with previous studies, the European-derived scores were significantly associated with incident ASCVD events in Black and Hispanic MVP participants, but with reduced or no improvement in net reclassification, highlighting the need for multi-ancestry PRSs to improve risk stratification of non-European populations, the study's authors write.