BackgroundPatients with heart failure (HF) and reduced ejection fraction suffer from a relapsing and remitting disease course, where early treatment changes may improve outcomes. We assessed the clinical integration and safety of the HeartLogic multisensor index and alerts in HF care. MethodsThe Multiple cArdiac seNsors for mAnaGEment of Heart Failure (MANAGE-HF) study enrolled 200 patients with HF and reduced ejection fraction (<35%), New York Heart Association functional class II–III symptoms, implanted with a cardiac resynchronization therapy-defibrillator or and implantable cardioverter defibrillator, who had either a hospitalization for HF within 12 months or unscheduled visit for HF exacerbation within 90 days or an elevated natriuretic peptide concentration (brain natriuretic peptide [BNP] of ≥150 pg/mL or N-terminal pro-BNP [NT-proBNP] of ≥600 pg/mL). This phase included the development of an alert management guide and evaluated changes in medical treatment, natriuretic peptide levels, and safety. ResultsThe mean age of participants was 67 years, 68% were men, 81% were White, and 61% had a HF hospitalization in prior 12 months. During follow-up, there were 585 alert cases with an average of 1.76 alert cases per patient-year. HF medications were augmented during 74% of the alert cases. HF treatment augmentation within 2 weeks from an initial alert was associated with more rapid recovery of the HeartLogic Index. Five serious adverse events (0.015 per patient-year) occurred in relation to alert-prompted medication change. NTproBNP levels decreased from median of 1316 pg/mL at baseline to 743 pg/mL at 12 months (P < .001). ConclusionsHeartLogic alert management was safely implemented in HF care and may optimize HF management. This phase supports further evaluation in larger studies. Trial RegistrationClinicalTrials.gov (NCT03237858)