Pilot Study of StudyU for N-of-1 Trials in HFrEF Patients (N-of-1 App)

Pilot Study of Acceptability and Feasibility of StudyU for N-of-1 Trials

This study will look at whether using a phone app called StudyU can help people with Heart Failure with Reduced Ejection Fraction (HFrEF) reach their recommended dose on their beta blocker.

The overarching goal of this study is to determine feasibility of the StudyU app in N-of-1 trials. The study intervention is N-of-1 trials, facilitated by a mobile-based application, StudyU. The study team will utilize a single-arm sequential design N-of-1 study in which subjects who are not yet at the GDMT for beta blockers will test multiple doses of GDMT to understand the maximally tolerated dose using an N-of-1 trial format. This is similar to an approach used in a previous study, Pilot Deprescribing N-of-1 Trials for beta blockers in HFpEF (NCT04757584) but will test the addition of a mobile-based app to collect vital signs, monitor side effects, and monitor patient-reported outcomes.

Inclusion Criteria:

1. Adults ≥ 65 years old
2. A history of HFrEF per electronic medical record review/clinician impression that is defined as an EF <50% that is shown from any imaging modality
3. Taking less than the maximal dose of beta blocker per physician recommendation at time of enrollment
4. Access to a smartphone or device that can perform many of the same functions as a computer, typically having a touchscreen interface, internet access, and an operating system capable of running downloaded applications

Exclusion Criteria:

1. Clinical instability (this N-of-trial is appropriate for stable conditions only)

   1. Decompensated HF
   2. Hospitalized in the past 30 days
   3. Medication changes or procedures in prior 14 days (to prevent confounding from other interventions) at PI discretion

2. Do not have access to a smartphone or tablet

3. Estimated life expectancy <6 months

4. Moderate-severe dementia or psychiatric disorder precluding informed consent

5. Language barrier that will preclude informed consent and ability to comprehend study procedures

6. History of noncompliance or inability to complete study procedures

7. Enrollment in a clinical trial not approved for co-enrollment

8. Any condition that, in Principal Investigator or treating physician's opinion, makes the patient unsuitable for study participation