Anticoagulation With Enhanced Gastrointestinal Safety (AEGIS) Trial

Inclusion Criteria for Patients: * Enrollment with the Michigan Medicine anticoagulation monitoring service * Currently prescribed warfarin with anticipated use for greater or equal to 90 days on day 1 of trial enrollment, according to electronic medical record documentation * Currently prescribed an antiplatelet drug (aspirin, clopidogrel, ticagrelor, or prasugrel) according to the electronic medical record medication list Exclusion Criteria for Patients: * Prescribed a Proton Pump Inhibitor (PPI) * Documented intolerance or allergy to PPI use * Left ventricular assist device * Heart transplant Inclusion Criteria for Clinicians: * Practicing cardiologists at Michigan Medicine who in the prior year had a face-to-face or virtual visit with a patient who meets eligibility criteria for this study * Practicing clinicians in any specialty who are designated as the clinician of record with the anticoagulation clinic for a patient who meets eligibility criteria Exclusion Criteria for Clinicians: \- Cardiologists specializing in electrophysiology unless they are the clinician of record for a patient followed by the anticoagulation service.