His primary research topic is the genetic basis of traits involved in cardiovascular disease, particularly lipid levels and electrocardiographic measurements. Recently, he has become involved in a major effort to study the influence of transcription and methylation on those phenotypes. In addition to his involvement with the previous ENGAGE lipid analysis, and ENGAGE's subsequent participation in the Global Lipids Genetics Consortium, Aaron was a lead analyst on the recently published project which sought to determine the influence of factors which might modify the action of genetic determinants on lipid levels (LipidAction). Currently, he is working on the analysis of lipid traits for the ENGAGE 1000 Genomes project.