Project Abstract Acute myocardial infarction (MI) is characterized by myocardial necrosis due to coronary ischemia and may be precipitated by several mechanisms. Coronary plaque rupture causes ‘type 1 MI,’ the subject of intense investigation for several decades and now with several therapies demonstrated to reduce mortality and improve health status. However, it is now recognized that at least 1 in 5 MIs are ‘type 2 MI,’ which occurs due to a mismatch in myocardial oxygen supply/demand precipitated by a preceding physiologic stress. Persons with type 2 MI are usually older and have more comorbidities than persons with type 1 MI. However, it is unknown whether these characteristic differences translate to differences in health status. Type 2 MI is associated with a poor prognosis; only 40% of individuals are alive at 5 years. Unfortunately, despite the frequency and prognosis of type 2 MI, evidence-based treatment strategies are lacking due to an absence of clinical trials. Exercise-based cardiac rehabilitation (CR) is demonstrably efficacious for type 1 MI. However, CR is virtually unused for type 2 MI. Increasing adoption of CR, a covered therapy, may improve outcomes for persons with type 2 MI. The aims of this research proposal are to (1) determine if differences exist in patient- reported health status between persons with type 2 versus type 1 MI, (2) obtain key information from patients and clinicians on the perceived benefits, acceptability, evidence requirement, and barriers to attendance at CR for type 2 MI compared to type 1 MI, and (3) undertake a pilot hybrid effectiveness-implementation clinical trial to assess if a multifaceted intervention increases attendance at CR and is potentially efficacious in improving health status for persons with type 2 MI as compared to usual care. For this latter aim, physicians will receive a reminder to consider referral to CR and patients will receive access to a patient engagement platform, with CR appointment reminders. Successful completion of the proposed studies will inform whether health status differs according to the subtype of MI and will explore if a multilevel intervention can increase CR attendance and potentially improve health status for those with type 2 MI. The objectives of this research award are to (1) develop an expertise in health status assessment and patient reported outcome measures, (2) learn how to design and interpret patient and clinician surveys, and 3) develop an expertise in clinical trial design, execution, and interpretation. Dr. McCarthy’s career goals are to undertake clinical trials that identify treatment approaches for individuals with type 2 MI. The findings from this proposal will form the foundation of Dr. McCarthy’s R01 application for a definitive effectiveness-implementation trial of CR for type 2 MI. Dr. McCarthy’s mentors and scientific advisors are experts in CR, qualitative and quantitative research, patient- reported outcome measures, and clinical tria...