AimEarly detection of impending fluid retention and timely adjustment of (medical) therapy can prevent heart failure related hospitalizations. The multisensory cardiac implantable electronic device (CIED) based algorithm HeartLogicTM aims to alert in case of impending fluid retention. The aim of the current analysis is to evaluate the performance of the HeartLogicTM guided heart failure care path in a real-world heart failure population and to investigate whether the height of the index and the duration of the alert state are indicative of the degree of fluid retention.MethodsConsecutive adult heart failure patients with a CIED and an activated HeartLogicTM algorithm were eligible for inclusion. Patients were followed up according to the hospital's heart failure care path. The device technician reviewed alerts for a technical CIED checkup. Afterwards, the heart failure nurse contacted the patient to identify impending fluid retention. An alert was either true positive or false positive. Without an alert a patient was true negative or false negative.ResultsAmong 107 patients, [82 male, 70 (IQR 60–77) years, left ventricular ejection fraction 37 ± 11%] 130 HeartLogicTM alerts were available for analysis. Median follow up was 14 months [IQR 8–23]. The sensitivity to detect impending fluid retention was 79%, the specificity 88%. The positive predictive was value 71% and the negative predictive value 91%. The unexplained alert rate was 0.23 alerts/patient year and the false negative rate 0.17 alerts/patient year. True positive alerts [42 days (IQR 28–63)] lasted longer than false positive alerts [28 days (IQR 21–44)], p = 0.02. The maximal HeartLogicTM index was higher in true positive alerts [26 (IQR 21–34)] compared to false positive alerts [19 (IQR 17–24)], p < 0.01. Patients with higher HeartLogicTM indexes required more intense treatment (index height in outpatient setting 25 [IQR 20–32], day clinic treatment 28 [IQR 24–36] and hospitalized patients 45 [IQR 35–58], respectively), p < 0.01.ConclusionThe CIED-based HeartLogicTM algorithm facilitates early detection of impending fluid retention and thereby enables clinical action to prevent this at early stage. The current analysis illustrates that higher and persistent alerts are indicative for true positive alerts and higher index values are indicative for more severe fluid retention.

Heart failure (HF) hospitalisations due to decompensation are associated with shorter life expectancy and lower quality of life. These hospitalisations pose a significant burden on the patients, doctors and healthcare resources. Early detection of an upcoming episode of decompensation may facilitate timely optimisation of the ambulatory medical treatment and thereby prevent heart-failure-related hospitalisations. The HeartLogicTM algorithm combines data from five sensors of cardiac implantable electronic devices into a cumulative index value. It has been developed for early detection of fluid retention in heart failure patients. This review aims to provide an overview of the current literature and experience with the HeartLogicTM algorithm, illustrate how the index can be implemented in daily clinical practice and discuss ongoing studies and potential future developments of interest.

Background Early detection of an upcoming episode of decompensated heart failure (HF) and timely adjustment of medical therapy may prevent a HF hospitalization. The novel multisensory cardiac implantable electronic device (CIED) based algorithm entitled HeartLogic™ (HL) aims to alert in case of upcoming fluid retention. This study investigates the performance of an HL alert in chronic HF patients in an ambulant HF care-path. Methods All chronic HF patients with a CIED and an activated HL algorithm implanted in our centre since 2018 were included. Patients were followed from 01–01–2018 until 01–02–2021 according to the HL-based care-path (Figure 1). The HL index was automatically generated from sensors assessing S3, S3/S1, thoracic impedance, respiratory- and night heartrate. Indexes were monitored continuously and an alert was issued when the pre-set threshold of 16 was surpassed. An alert was classified as true positive when the patient had at least two symptoms and/or signs of congestion during the alert episode. An alert was considered false positive when the patient had not more than one symptom or sign of congestion during the alert episode. If a patient had at least two symptoms and/or signs of congestion without an HL alert, the episode was classified as false negative. Results In total, 100 patients (median age 69 years [IQR 60–77], 78% male) were included. The etiology of HF was ischemic in 45% and 71% had a CRT-D device. Median follow-up was 13 months [IQR 6–23] and in total the follow-up comprised 126 patient-years. In 56 patients, there were 132 alerts, mean alert rate was 1.05 per patient-year. As it was unfeasible to strictly follow the specific HL care-path in 13 alert episodes, these alerts were excluded from further analyses. Based on the remaining 119 alert episodes, the positive predictive value for early detection of congestion was 77% and the negative predictive value was 97%. Sensitivity was 79% and specificity 97%. Conclusion In a real-world HF population, the HL algorithm can accurately predict an upcoming episode of decompensated heart failure. Funding Acknowledgement Type of funding sources: None. Overview of the HL based care-path

Background Hospitalization for decompensated heart failure may be prevented by early detection of fluid retention. The multisensory HeartLogic™ algorithm, incorporated in a cardiac implantable electronic device (CIED) aims to detect impending fluid retention and thereby enables timely adjustment of medical therapy. However, it is to be investigated whether HeartLogic™ provides clinical benefit compared to heart failure care with conventional telemonitoring. This analysis investigates the effects of activating HeartLogic™ on top of heart failure care with telemonitoring on the number of episodes with fluid retention and heart failure related hospitalizations. Methods Heart failure patients with a CIED were recruited from the outpatient clinics of four European cardiology departments. All patients were included from January 2017 until December 2020, and followed-up for 365 days. Patients with a CIED and an activated HeartLogic™ algorithm were compared to a 1:1 propensity score-based matched control group consisting of patients with CIED on routine telemonitoring. Data of all episodes of (impending) fluid retention with ≥2 signs and symptoms of congestion were included for analyses. Results Data of 127 patients with an activated HeartLogic™ algorithm were adequately matched with 127 heart failure patients with a CIED on routine telemonitoring. Median age was 68 [59–75], majority of patients were male (80%), 46% had an ischemic etiology of heart failure. Total follow-up consisted of 254 patient years. During follow up, 77 (61%) individual patients with HeartLogic™ experienced an episode of fluid retention, compared to 85 (67%) induvial patients on routine telemonitoring. Patients with an activated HeartLogic™ algorithm had 1.62±1.78 events of fluid retention per patient year (PPY) compared to 2.61±3.71 events PPY in patients on routine telemonitoring, p<0.01 (Figure 1). Hospitalization for fluid retention occurred in 7 (6%) HeartLogic™ patients (0.06±0.27 hospitalizations PPY) compared to 13 (10%) patients on routine telemonitoring (0.15±0.45 PPY), p=0.07 (Figure 2A). Mean length of hospitalization in days PPY was 0.29±1.46 in patients with HeartLogic™ and 1.59±6.30 in patients on routine telemonitoring, p=0.02 (Figure 2B). Conclusion In a real-world multicenter heart failure population, activation of the HeartLogic™ algorithm was associated with a lower number of episodes of fluid retention per patient and a shorter duration of hospitalization for congestive heart failure. Funding Acknowledgement Type of funding sources: None.

Background Hospitalization for decompensated heart failure may be prevented by early detection of fluid retention. The multisensory HeartLogic™ algorithm, incorporated in a cardiac implantable electronic device (CIED) aims to detect impending fluid retention and thereby enables timely adjustment of medical therapy. However, it is to be investigated whether HeartLogic™ provides clinical benefit compared to heart failure care with conventional telemonitoring. This analysis investigates the effects of activating HeartLogic™ on top of heart failure care with telemonitoring on the number of episodes with fluid retention and heart failure related hospitalizations. Methods Heart failure patients with a CIED were recruited from the outpatient clinics of four European cardiology departments. All patients were included from January 2017 until December 2020, and followed-up for 365 days. Patients with a CIED and an activated HeartLogic™ algorithm were compared to a 1:1 propensity score-based matched control group consisting of patients with CIED on routine telemonitoring. Data of all episodes of (impending) fluid retention with ≥2 signs and symptoms of congestion were included for analyses. Results Data of 127 patients with an activated HeartLogic™ algorithm were adequately matched with 127 heart failure patients with a CIED on routine telemonitoring. Median age was 68 [59–75], majority of patients were male (80%), 46% had an ischemic etiology of heart failure. Total follow-up consisted of 254 patient years. During follow up, 77 (61%) individual patients with HeartLogic™ experienced an episode of fluid retention, compared to 85 (67%) induvial patients on routine telemonitoring. Patients with an activated HeartLogic™ algorithm had 1.62±1.78 events of fluid retention per patient year (PPY) compared to 2.61±3.71 events PPY in patients on routine telemonitoring, p<0.01 (Figure 1). Hospitalization for fluid retention occurred in 7 (6%) HeartLogic™ patients (0.06±0.27 hospitalizations PPY) compared to 13 (10%) patients on routine telemonitoring (0.15±0.45 PPY), p=0.07 (Figure 2A). Mean length of hospitalization in days PPY was 0.29±1.46 in patients with HeartLogic™ and 1.59±6.30 in patients on routine telemonitoring, p=0.02 (Figure 2B). Conclusion In a real-world multicenter heart failure population, activation of the HeartLogic™ algorithm was associated with a lower number of episodes of fluid retention per patient and a shorter duration of hospitalization for congestive heart failure. Funding Acknowledgement Type of funding sources: None.