Local Ancestry and Clinical Cardiovascular Events Among African Americans From the Atherosclerosis Risk in Communities Study

BACKGROUND Local ancestry in relation to clinical cardiovascular events (CVEs) among African Americans can provide insight into their genetic susceptibility to the disease. METHODS AND RESULTS We examined local European ancestry (LEA) association with CVEs among 3000 African Americans from the Atherosclerosis Risk in Communities Study (ARIC). We estimated LEA using Local Ancestry Inference in adMixed Populations using Linkage Disequilibrium (LAMP-LD) and examined its association with myocardial infarction, stroke, coronary heart disease and its composite and cardiovascular disease composite using logistic regression. Genome-wide significance was achieved by 121 LEA regions in relation to myocardial infarction and 2 in relation to the cardiovascular disease composite. The LEA region downstream of 4q32.1 was significantly associated with 2 times higher odds of myocardial infarction (P=1.45×10-6). The LEA region upstream of 6q11.1 was associated with 0.37 times lower odds of fatal coronary heart disease (P=7.34×10-4), whereas the LEA region downstream of 21q21.1 was associated with 1.55 times higher odds of composite coronary heart disease (P=3.45×10-4). Association of LEA with stroke was observed in the region upstream of 6p22.3 with a 1.57 times higher odds of stroke (P=9.69×10-4). Likewise, the LEA region on 4q32.3 was associated with a 1.53 times higher odds of composite cardiovascular disease (P=3.04×10-4). We also found 20 of the LEA regions at previously significant cardiovascular disease single-nucleotide polymorphisms to be associated with CVE in our study. CONCLUSIONS Future studies are needed to replicate and/or determine the causal variants driving our associations and explore clinical applications for those consistently associated with CVEs.