Physician-Directed Patient Self-Management Using an Implantable IVC Congestion Sensor

BACKGROUND: Prior self-management strategies to prevent heart failure (HF) hospitalizations using symptoms and weight have shown limited effectiveness caused by delayed and nonspecific signals. Ambulatory congestion monitoring may enable safe and actionable self-management. OBJECTIVES: The purpose of this study was to evaluate the safety, feasibility of signal-driven intervention, and clinical signals associated with physician-directed patient self-management using an implantable inferior vena cava (IVC) sensor. METHODS: The authors performed a comparison of 2 sequential prospective cohorts enrolled in FUTURE-HFII (Early Feasibility Study of the NORM System in Heart Failure Patients) using an IVC-based congestion management system: clinician-managed care (n = 15) and physician-directed patient self-management (n = 10). The sole difference between cohorts was the smartphone delivery of prespecified physician-developed care plans to patients. Outcomes included safety, device adherence, medication adjustments, congestion metrics, HF events, and quality of life at 90 days. RESULTS: Across 1,927 measurements, daily usage was high in both groups and numerically greater with self-management (90.5% vs 84.8%). No safety signals were observed, and congestion control (NORM score time-in-range) was comparable between groups. Signal intervention frequency was higher with self-management (10.4 vs 2.8 diuretic changes per patient; RR: 3.71; P < 0.01). HF events were directionally lower in the self-managed cohort (0.11 vs 0.33 events/patient-month; RR: 0.30 [95% CI: 0.04-2.57]). Quality-of-life scores improved in both groups, with larger gains (≥5 points in Kansas City Cardiomyopathy Questionnaire-Clinical Summary Score) in the self-managed cohort (60.0% vs 46.7%). CONCLUSIONS: Physician-directed patient self-management using ambulatory IVC-based congestion monitoring was feasible, associated with increased signal-driven intervention, and not associated with adverse safety signals. This strategy demonstrated favorable clinical signals. These findings support further evaluation of congestion-based self-management strategies in a randomized trial. (Early Feasibility Study of the NORM System in Heart Failure Patients [FUTURE-HFII]; NCT05763407).