PurposeAnxiety, depression, poor sleep quality and lower quality of life (QOL) are associated with worse outcomes in heart failure (HF) patients. Motivational interview (MI) has been effective in different patient populations to promote self-care. However, its effect on anxiety, depression, sleep quality and QOL in HF patients is unknown. The aim of this study was to evaluate the effect of MI on anxiety, depression, sleep quality and QOL over 12 months from the intervention.MethodsThis was a planned, secondary outcome analysis of the MOTIVATE-HF study, a three-arm randomized controlled trial (1:1:1) evaluating the effect of MI in improving self-care in HF patients. In Arm 1, the patient received MI, while in Arm 2, the patient and the caregiver received MI. Arm 3, the control group, received standard treatment. Endpoints were evaluated with the Hospital Anxiety and Depression Scale (HADS), the Pittsburgh Sleep Quality Index (PSQI), the 12-Item Short-Form Health Survey (SF-12) and the Kansas City Cardiomyopathy Questionnaire (KCCQ) every three months for one year.ResultsWe enrolled and randomized 510 HF patient and caregiver dyads (155 dyads in Arm 1, 177 dyads in Arm 2, and 178 dyads in Arm 3). A total of 238 HF patients and 235 caregivers completed the 12-month trial. No significant changes were seen in anxiety, depression and sleep quality over time among the three study arms, but disease-specific QOL improved in the intervention groups, especially in Arm 2.ConclusionClinicians may want to include both patients and caregivers when providing MI interventions. Further research is needed to investigate the required intensity of MI to be effective on sleep quality, anxiety and depression (ClinicalTrials.gov Identifier: NCT02894502).