The overall objective of this study is to test a personalized mHealth intervention designed to increase physical activity and improve medication adherence in subjects with heart failure and diabetes mellitus. The study will leverage consumer technology as both an intervention and as a tool for data collection.

This is a multi-center randomized controlled study in eligible subjects with heart failure and diabetes mellitus. Step counts, self-reported quality of life, medication adherence, blood samples and relevant clinical measures will be collected from all study subjects. The mobile health (mHealth) intervention will combine personalized text messages to encourage physical activity and a medication adherence teaching tool. A total of approximately 200 eligible subjects will be randomized in in a 1:1 ratio to either mHealth intervention + usual care/data collection or the control group (usual care/data collection only). The study duration is 6 months for all subjects; those in the intervention group will receive the mHealth intervention during the initial 3 months followed by 3 months of data collection only. The underlying hypotheses is that the proposed mHealth intervention can favorably impact specific health behaviors (physical activity and medication adherence) and physiologic measures of disease status for both heart failure and diabetes. Additional hypotheses to be tested will assess the persistence of behavioral changes (daily physical activity and medication adherence) and physiologic measures (NT-proBNP, HbA1c) beyond the 3-month time point of the active mHealth intervention (i.e. through 6 months).

Inclusion Criteria:

• ≥ 18 years of age
• Chronic heart failure, New York Heart Association (NYHA) class II-IV, with ongoing treatment with medications for heart failure for at least 1 month prior to enrollment
• Prior diabetes mellitus diagnosis, with ongoing treatment with anti-diabetes medications for at least 1 month prior to enrollment
• Adequate clinical stability in the judgment of the investigator to allow participation in study assessments and the intervention
• Independent with basic activities of daily living (ADLs), including the ability to ambulate independently
• No plan for revascularization (cardiac or peripheral), outpatient continuous intravenous inotrope administration, cardiac transplant or ventricular assist device implantation, or other cardiac surgery within 6 months of randomization
• Access to a compatible smart phone (iOS or Android)
• Signed informed consent

Exclusion Criteria:

• Acute myocardial infarction within prior 4 weeks
• Already actively participating in formal, facility-based cardiac rehabilitation
• Severe stenotic valvular disease (e.g., severe aortic stenosis)
• Implanted left ventricular assist device (LVAD)
• Recipient of a heart transplant
• Terminal illness other than heart failure with life expectancy < 6 months
• Impairment from stroke, injury or other medical disorder that precludes participation in the intervention
• Inability or unwillingness to comply with the study requirements