Using Indoor Air Filtration to Slow Atherothrombosis Progression in Adults With Ischemic Heart Disease History

Inclusion Criteria: * Age between 65 and 84 years old; * Weight ≥ 110 pounds; * Nonsmokers for at least 1 year; * Have ischemic heart disease history, clinically stable for 6 months, without any deterioration in symptoms or episodes of angina based on past electronic medical records; * Both English and Spanish speaking participants will be included in the recruitment; * Live in the Los Angeles County. Exclusion Criteria: * Have history of degenerative disease of the nervous system such as dementia and Alzheimer's; * Currently have active cancer treatments; * The residential house has already had HEPA filters; * Participants will move out from the current residential address in the next 2 years; * Participants will spend more than 1 month living outside the primary home; * Have any health conditions that prohibit collecting health and covariate data and biospecimens; * Participants' residential houses are not feasible for setting up air purifiers and air pollutants monitors.