The Potential of the HeartLogicTM Algorithm in Patients with a Left Ventricular Assist Device, an Initial Report

BACKGROUND

Survival and quality-of-life of left ventricular assist device (LVAD) recipients improved significantly because of growing experience and technological advances. However, LVAD-related complication rates, including recurrent episodes of congestion, remain high. Early detection of fluid retention to provide a time-window for medical intervention is the pillar in preventing hospitalizations. The multisensory HeartLogicTM algorithm accurately detected impending congestion in ambulant heart failure patients. The aim of the current study is to investigate the feasibility of HeartLogicTM-driven care in LVAD patients.

METHODS

Consecutive LVAD destination therapy patients were followed-up according the structured HeartLogicTM-based heart failure carepath. An alert triggered a device check-up, and the heart failure team contacted the patient to evaluate for signs and symptoms of impending congestion. An alert was adjudicated as true positive or unexplained. An episode of congestion not preceded by an alert was deemed as a false negative.

RESULTS

Data from 7 patients were included: the median age was 67 years [IQR 61-71], 71% were male and 71% had a non-ischemic aetiology. Total follow-up entailed 12 patient-years. All patients experienced at least one alert. In total, 33 alerts were observed. Majority of alerts (70%, n = 23) were driven by congestion and one alerts (15%) were clinically meaningful but not primarily fluid-retention-related (e.g., altered hemodynamic triggered by a pump thrombosis). Of all the alerts, five (15%) were classified as an unexplained alert, and during follow-up, four false negative episodes were documented.

CONCLUSIONS

HeartLogicTM-driven care with continuous monitoring to detect impending fluid retention in LVAD patients was feasible and deserves further prospective validation.

Fewer Worsening Heart Failure Events With HeartLogic on top of Standard Care: a Propensity-Matched Cohort Analysis

BACKGROUND

The implantable cardiac defibrillator-based HeartLogic algorithm aims to detect impending fluid retention in patients with heart failure (HF). Studies show that HeartLogic is safe to integrate into clinical practice. The current study investigates whether HeartLogic provides clinical benefit on top of standard care and device telemonitoring in patients with HF.

METHODS

A multicenter, retrospective, propensity-matched cohort analysis was performed in patients with HF and implantable cardiac defibrillators, and it compared HeartLogic to conventional telemonitoring. The primary endpoint was the number of worsening HF events. Hospitalizations and ambulatory visits due to HF were also evaluated.

RESULTS

Propensity score matching yielded 127 pairs (median age 68 years, 80% male). Worsening HF events occurred more frequently in the control group (2; IQR 0-4) compared to the HeartLogic group (1; IQR 0-3; P = 0.004). The number of HF hospitalization days was higher in controls than in the HeartLogic group (8; IQR 5-12 vs 5; IQR 2-7; P = 0.023), and ambulatory visits for diuretic escalation were more frequent in the control group than in the HeartLogic group (2; IQR 0-3 vs 1; IQR 0-2; P = 0.0001).

CONCLUSION

Integrating the HeartLogic algorithm in a well-equipped HF care path on top of standard care is associated with fewer worsening HF events and shorter duration of fluid retention-related hospitalizations.

A case report of an intracardiac paraganglioma attached to the left main coronary artery in a patient with a succinate dehydrogenase complex subunit D mutation

Background

Cardiac paragangliomas are extremely rare neuroendocrine tumours derived from neural crest cells that represent <2% of all paragangliomas. Approximately 35-40% of all paragangliomas are associated with inherited syndromes such as mutation in the succinate dehydrogenase (SDH) enzyme.

Case summary

A 44-year-old male with an SDH complex subunit D (SDHD) mutation was diagnosed with an intracardiac paraganglioma attached to the left main coronary artery. Multimodality imaging, including gallium dotatate positron emission tomography computed tomography, cardiac magnetic resonance imaging, and coronary computed tomography angiography (CCTA) confirmed the suspected intracardiac paraganglioma. During follow-up with a CCTA, the mass showed growth, and surgical removal was recommended to anticipate on the risk of compression of the left main coronary artery. Prior to surgery, coronary angiography was performed, which showed no coronary calcifications. The highly vascularized paraganglioma was visible near the left main and proximal left anterior descending artery. The intracardiac paraganglioma was successfully removed through a median sternotomy with cardiopulmonary bypass, without any complications. The post-operative course was uneventful, and histological examination confirmed the diagnosis of a paraganglioma.

Discussion

Intracardiac paragangliomas in the vicinity of the left main coronary artery are rare, and surgical removal may be challenging. Therefore, screening and the use of multiple imaging modalities in patients with SDHD mutations prior to surgery is of major importance.

One-Year Mortality in Patients Undergoing an Implantable Cardioverter Defibrillator or Cardiac Resynchronization Therapy Pulse Generator Replacement: Identifying Patients at Risk

Implantable cardioverter defibrillators (ICDs) significantly contribute to the prevention of sudden cardiac death in selected patients. However, it is essential to identify those who are likely to not have benefit from an ICD and to defer a pulse generator exchange. Easily implementable guidelines for individual risk stratification and decision making are lacking. This study investigates the 1-year mortality of patients who underwent an ICD or cardiac resynchronization therapy with defibrillator function (CRT-D) pulse generator replacement in a contemporary real-world tertiary hospital setting. The cause of death and patient- and procedure-related factors are stratified, and predictive values for 1-year mortality are evaluated. Patients with a follow-up of ≥365 days (or prior mortality) after an ICD or CRT-D exchange at the Leiden University Medical Center from 1 January 2018 until 31 December 2021 were eligible. In total, 588 patients were included (77% male, 69 [60-76] years old, 59% primary prevention, 46% ischemic cardiomyopathy and 37% mildly reduced left ventricular ejection fraction (LVEF)). Patients undergoing a CRT-D replacement or upgrade had a significantly higher 1-year all-cause mortality (10.7% and 11.9%, respectively) compared to patients undergoing ICD (2.8%) exchange (p = 0.002). LVEF ≤ 30%, New York Heart Association class ≥ 3, estimated glomerular filtration rate ≤ 30 mL/min/m2 and haemoglobin ≤ 7 mmol/L were independently associated with mortality within 1 year after pulse generator replacement. There is a growing need for prospectively validated risk scores to weight individualized risk of mortality with the expected ICD therapy benefit and to support a well-informed, shared decision-making process.

Activation of the HeartLogic algorithm on top of heart failure care: a multicenter propensity-matched cohort analysis

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&lt;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.

Performance of a HeartLogicTM Based Care Path in the Management of a Real-World Chronic Heart Failure Population

Aim

Early 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.

Methods

Consecutive 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.

Results

Among 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 &lt; 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 &lt; 0.01.

Conclusion

The 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.

Performance of the multisensory cardiac implantable electronic device algorithm HeartLogic in a real-world ambulant chronic heart failure population

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

Early Detection of Fluid Retention in Patients with Advanced Heart Failure: A Review of a Novel Multisensory Algorithm, HeartLogicTM

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 HeartLogic^TM 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 HeartLogic^TM algorithm, illustrate how the index can be implemented in daily clinical practice and discuss ongoing studies and potential future developments of interest.

The effect of the food matrix on in vivo immune responses to purified peanut allergens

There is little knowledge about the factors that determine the allergenicity of food proteins. One aspect that remains to be elucidated is the effect of the food matrix on immune responses to food proteins. To study the intrinsic immunogenicity of allergens and the influence of the food matrix, purified peanut allergens (Ara h 1, Ara h 2, Ara h 3, or Ara h 6) and a whole peanut extract (PE) were tested in the popliteal lymph node assay (PLNA) and in an oral model of peanut hypersensitivity. In the PLNA, peanut proteins were injected into the hind footpad of BALB/c mice; in the oral exposure experiments C3H/HeOuJ mice were gavaged weekly with PE or allergens in the presence of cholera toxin (CT). Upon footpad injection, none of the allergens induced significant immune activation. In contrast, PE induced an increase in cell number, cytokine production, and activation of antigen-presenting cells. Furthermore, the presence of a food matrix enhanced the immune response to the individual allergens. Oral exposure to the purified allergens in the presence of CT induced specific IgE responses, irrespective of the presence of a food matrix. These results suggest that purified peanut allergens possess little intrinsic immune-stimulating capacity in contrast to a whole PE. Moreover, the data indicate that the food matrix can influence responses to individual proteins and, therefore, the food matrix must be taken into account when developing models for allergenic potential assessment.

Genetics of allergic disease

Atopy can express itself as asthma, rhinitis and eczema. The presence of atopy can be assessed by increased levels of total serum IgE and specific IgE to common allergens, skin test positivity and increased numbers of peripheral blood eosinophils. Genetic studies indicate that multiple genes are involved in the pathogenesis of atopy and that different genes regulate the presence of increased levels of serum total IgE and specific IgE. Linkage of these traits to chromosomal regions likely to contain atopic susceptibility genes has been replicated in several studies. Genome-wide screens have identified several new chromosomal locations that are likely to contain atopic genes. These regions also contain candidate genes. Moreover, the available literature suggests that multiple, yet different genes may be involved in the translation of atopy to a distinct clinical phenotype. We anticipate that understanding of the genetic basis of atopy will lead to new therapeutic interventions and early diagnosis.