Enhancing Cardiac Rehabilitation Attendance After Secondary Myocardial Infarction Through Clinician Messaging and Motivational Calls

Inclusion Criteria: * Age ≥ 18 years * Inpatient at MGH with an index secondary (type 2) MI * Primary care provider (PCP) within the Mass General Brigham (MGB) network with at least one visit in the past 2 years * Anticipated ability to ambulate independently without walking aids or supplemental ambulatory oxygen at discharge * Ability to provide informed consent Exclusion Criteria: * Known severe untreated valvular heart disease or severe prosthetic valve dysfunction * Known hypertrophic obstructive cardiomyopathy * End-stage heart failure (VAD, transplant patient, or undergoing evaluation for VAD or transplant) * Hemodynamic instability at the time of pre-screening * Terminal illness with life expectancy \< 1 year * Severe anemia (hemoglobin \< 8 g/dL) at the time of pre-screening * Active, unstable cancer (excluding non-metastatic skin cancer) or currently receiving intensive cancer therapy * Advanced kidney disease requiring renal replacement therapy * Receiving palliative or comfort care only * Recurrent falls (≥2) or falls with injury in the past year * Physical or cognitive impairment likely to prevent safe participation in exercise over the next 5 months (e.g., significant stroke deficits, dementia) * High-risk for non-adherence to study requirements * Incarcerated individuals * Currently pregnant or within 3 months postpartum * Previously referred to or participated in CR within the past year * Alternative MI subtype (spontaneous \[type 1 MI\] or procedural MI \[t…