iCardia4HF: A multi-component mHealth app and tailored text-messaging intervention to promote self-care adherence and improve outcomes in patients with chronic heart failure - Abstract Heart failure (HF) is one of the most frequent principal diagnoses for hospitalization and a leading cause of death in the United States. It has been estimated that up to 65% of HF hospitalizations are the results of insufficient HF self-care. Despite clear evidence that HF self-care reduces the risk of mortality and hospital readmissions, many HF patients struggle to take medications as prescribed, maintain a low sodium diet, monitor their weight and HF symptoms daily, and engage in physical activity. Existing HF self-care interventions delivered face-to-face or via telephone have had limited impact and reach because they require significant provider time and are not always accessible to patients due to socioeconomic constraints, geographic barriers, and other obstacles. There is a critical need for accessible and scalable interventions that are designed to assist patients with HF self-care while in the community. Consumer mobile health (mHealth) technologies (e.g., apps and sensor devices) hold promise for promoting HF self-care and expanding intervention delivery. However, their efficacy remains largely underexplored. To address this gap, our team developed a patient-centered HF self-care intervention (iCardia4HF) that combines the use of three commercially available mobile health apps and connected health devices (MyApps) with a program of individually tailored text messages (Text4HF) targeting modifiable behavioral factors to promote HF self-care adherence and improve clinical outcomes. We recently completed a NIH-funded pilot randomized controlled trial (RCT) to test the feasibility and preliminary efficacy of the iCardia4HF intervention over 3 months in a predominantly minority and socioeconomically disadvantaged HF population. Results from this study provide important feasibility and preliminary data. The next step in our program of research and purpose of the proposed study is to conduct a fully powered, 2x2 factorial RCT to determine the independent and combined efficacy of the two iCardia4HF intervention components (MyApps and Text4HF) at 6 months, as well as their maintenance efficacy at 6 months post-intervention. A total of 360 HF patients with suboptimal adherence to HF self-care will be recruited and randomized to one of four conditions for 12 months: (1) Usual care, (2) Text4HF, (3) MyApps, or (4) MyApps&Text4HF. The primary outcome is percent of days lost due to cardiovascular hospitalization or death for any cause. Secondary outcomes are objective measures of HF self- care adherence (medication [MEMS], daily weighing and BP monitoring [Withings scale and BP monitor], low- sodium diet [urinary sodium], and physical activity [accelerometer]), self-reported HF self-care, HRQL, and major cardiac events (mortality, hospitalizations, ER visits). This study will provide important new knowledge that will critically shape our understanding about the potential of commercially available mHealth technologies and tailored TMs to improve HF self-care adherence and reduce hospital readmissions in patients with HF.