Prospective evaluation of the Multisensor ICD Algorithm for Heart Failure Monitoring

Background:The HeartLogic algorithm measures data from multiple implantable cardioverter-defibrillator-based sensors and combines them into a single index. The associated alert has proved to be a sensitive and timely predictor of impending heartfailure (HF) decompensation.Objective:To describe a multicenter experience of remote HF management by means of HeartLogic and appraise the value of an alert-based follow-up strategy.Methods:HeartLogic was activated in 104 patients. All patients were followed up according to a standardized protocol that included remote data reviews and patient phone contacts every month and at the time of HeartLogic alerts. In-office examinations were performed every 6 months or when deemed necessary. Results: During a median follow-up of 13 [10-16] months, the overall number of HF hospitalizations was 16 (rate 0.15 hospitalizations/patient-year) and 100 HeartLogic alerts were reported in 53 patients. Sixty alerts were judged clinically meaningful, and were associated with multiple HF-related conditions. In 48 of the 60 alerts, the clini-cian was not previously aware of the condition. Of these 48 alerts, 43 triggered clini-cal actions. The rate of alerts judged non-clinically meaningful was 0.37/patient-year,and the rate of hospitalizations not associated with an alert was 0.05/patient-year.Centers performed remote follow-up assessments of 1113 scheduled monthly trans-missions (10.3/patient-year) and 100 alerts (0.93/patient-year). Monthly remote datareview allowed to detect 11 (1%) HF events requiring clinical actions (versus 43¬tionable alerts, p<0.001).Conclusions:HeartLogic allowed relevant HF-related clinical conditions to beidentified remotely and enabled effective clinical actions to be taken; the rates ofunexplained alerts and undetected HF events were low. An alert-based management strategy seemed more efficient than a scheduled monthly remote follow-up scheme.