Effectiveness of the heartinsight system in predicting heart failure rehospitalization in Japanese patients with severe heart failure

Background In Japan, the HeartInsight (HI) remote monitoring system became available for Biotronik Implantable Cardioverter Defibrillator (ICD) and Cardiac Resynchronization Therapy Defibrillator (CRT-D) users in November 2023. The HI score is designed to predict heart failure (HF) hospitalization and has shown utility in the SELENE-HF trial conducted in Italy. However, its applicability and predictive accuracy in Asian populations, including Japan, remain underexplored. Purpose To evaluate the usefulness of the HI system in predicting worsening heart failure in Japanese patients with severe heart failure. Methods We analyzed 293 patients who underwent Biotronik ICD or CRT-D implantation at two institutions between March 2019 and February 2025. Of those, 140 patients with heart failure and left ventricular ejection fraction (LVEF) ≤35％ were retrospectively analyzed (female: [%]; age: 72 ± 5 years; non-ischemic cardiomyopathy: 80 [57%]). The mean LVEF was 27.4%. An HI alert was defined as a score of 45 or higher sustained for three consecutive days. Patient demographics, HI alert status, and remote monitoring parameters were analyzed. Results HI scores were available for 101 patients. Between September 2024 and February 2025, 30 patients experienced HI score alerts and 6 patients required HF hospitalization, including 1 appropriate ICD shock therapy due to ventricular fibrillation, or outpatient treatment, yielding a positive predictive value of 20%. Among 68 patients without HI alerts, only 3 required HF hospitalization, yielding a negative predictive value of 96%. Conclusions In Japanese patients with severe heart failure, the HI system demonstrated a high negative predictive value, similar to the SELENE-HF trial, confirming its reliability in identifying patients at low risk for HF events. Heart failure management using the HI score guide with remote monitoring may have the potential to improve patient outcomes. A large-scale study in Asia to predict worsening HF using the HI system is needed.