ADAPTABLE Inclusion/Exclusion Known atherosclerotic cardiovascular disease (ASCVD), defined by a history of myocardial infarction, coronary angiography showing ≥75% stenosis of at least one epicardial coronary vessel, or coronary revascularization procedure (coronary artery bypass surgery or percutaneous coronary intervention) Age ≥ 18 years No known intolerance to an aspirin dose of ≤ 325 mg/day (intolerance includes a true allergic reaction or a side effect, including gastrointestinal issues, that preclude using aspirin 325 mg/day) Access to the Internet or agreement to collect follow-up information by the Call Center from patients without Internet access Not currently using warfarin or novel anticoagulant (dabigatran, rivaroxaban, apixaban, edoxaban) Not pregnant or nursing an infant Estimated risk of a major cardiovascular event (MACE) >8% over next 3 years as evidenced by one or more of the following risk factors: age > 65 years, creatinine > 1.5, diabetes, known 3 vessel coronary artery disease, current cerebrovascular disease and/or peripheral artery disease, known ejection fraction <50%, current smoker. Able and willing to provide informed consent and agreeing to be followed through the Internet and/or through calls by the Call Center for the duration of the trial (maximum expected follow-up of 30 months) There will be no exclusion for any upper age limit or comorbid conditions.