Blunted cardiovascular responses to exercise by inhibiting afferent feedback via spinal cord stimulation in heart failure.

This case study investigated the impact of SCS on alterations in blood pressure during constant-load exercise in a female patient with heart failure. Three different SCS frequencies [No SCS (~0 Hz), Low SCS (~100 Hz), and High SCS (~1000 Hz)] with and without ischaemic stimulation of the legs (cuffs) were randomly applied during constant-load exercise. To determine cardiovascular and ventilatory responses to exercise following SCS frequencies, BP, heart rate (HR), and respiratory gas exchange were measured. This experiment was duplicated in visit 1 and visit 2 with a random application of SCS frequency order and the data were averaged. There were no significant differences among three frequencies with no leg ischaemia. However, High SCS demonstrated lower BP, HR, and respiratory gas exchange relative to No SCS and Low SCS. SCS may be effective in improving cardiovascular and ventilatory responses in HF and high-frequency stimulation provides more clinical benefit; however, further studies are needed.

PRecision Event Monitoring for PatienTs with Heart Failure using HeartLogic (PREEMPT-HF) study design and enrolment.

AIMS: The HeartLogic multisensor index has been found to be a sensitive predictor of worsening heart failure (HF). However, there is limited data on this index's association and its constituent sensors with HF readmissions. METHODS AND RESULTS: The PREEMPT-HF study is a global, multicentre, prospective, observational, single-arm, post-market study. HF patients with an implantable defibrillator device or cardiac resynchronization therapy with defibrillator with HeartLogic capabilities were eligible if sensor data collection was turned on and the HeartLogic feature was not enabled. Thus, the HeartLogic Index/alert and heart sounds sensor trends were unavailable via the LATITUDE remote monitoring system to clinicians (blinded). Evaluation of subject medical records at 6 months and a final in-clinic visit at 12 months was required for collection of all-cause hospitalizations and HF outpatient visits. The purpose of this study is exploratory, no formal hypothesis tests are planned, and no adjustment for multiple testing will be performed. A total of 2183 patients were enrolled at 103 sites between June 2018 and June 2020. A significant proportion of the patients were implanted with implantable defibrillator devices (39%) versus cardiac resynchronization therapy with defibrillator (61%); were female (27%); over 65 (61%); New York Heart Association class I (13%), II (53%), and III (33%); ejection fraction < 25% (21%); ischaemic (50%); and with a history of renal dysfunction (23%). CONCLUSIONS: The PREEMPT study will provide clinical data and blinded sensor trends for the characterization of sensor changes with HF readmission, tachyarrhythmias, and event subgroups. These data may help to refine the clinical use of HeartLogic and to improve patient outcomes.

Preliminary results from the LUX-Dx insertable cardiac monitor remote programming and performance (LUX-Dx PERFORM) study.

Despite the wide adoption of insertable cardiac monitors (ICMs), high false-positive rates, suboptimal signal quality, limited ability to detect atrial flutter, and lack of remote programming remain challenging. The LUX-Dx PERFORM study was designed to evaluate novel technologies engineered to address these issues. Here, we present preliminary results from the trial focusing on the safety of ICM insertion, remote monitoring rates, and the feasibility of remote programming. LUX-Dx PERFORM is a multicenter, prospective, single-arm, post-market, observational study with planned enrollment of up to 827 patients from 35 sites in North America. A preliminary cohort consisting of the first 369 patients who were enrolled between March and October 2021 was selected for analysis. Three hundred sixty-three (363) patients had ICM insertions across inpatient and outpatient settings. The mean time followed was 103.4 ± 61.8 days per patient. The total infection rate was 0.8% (3/363). Interim results show high levels of remote monitoring with a median 94% of days with data transmission (interquartile range: 82-99). Thirteen (13) in-clinic and 24 remote programming sessions were reported in 34 subjects. Reprogramming examples are presented to highlight signal quality, the ability to detect atrial flutter, and the positive impact of remote programming on patient management. Interim results from LUX-Dx PERFORM study demonstrate the safety of insertion, high data transmission rates, the ability to detect atrial flutter, and the feasibility of remote programming to optimize arrhythmia detection and improve clinical workflow. Future results from LUX-Dx PERFORM will further characterize improvements in signal quality and arrhythmia detection.

Multiple cArdiac seNsors for mAnaGEment of Heart Failure (MANAGE-HF) - Phase I Evaluation of the Integration and Safety of the HeartLogic Multisensor Algorithm in Patients With Heart Failure.

BACKGROUND: Patients with heart failure (HF) and reduced ejection fraction suffer from a relapsing and remitting disease course, where early treatment changes may improve outcomes. We assessed the clinical integration and safety of the HeartLogic multisensor index and alerts in HF care. METHODS: The Multiple cArdiac seNsors for mAnaGEment of Heart Failure (MANAGE-HF) study enrolled 200 patients with HF and reduced ejection fraction (<35%), New York Heart Association functional class II-III symptoms, implanted with a cardiac resynchronization therapy-defibrillator or and implantable cardioverter defibrillator, who had either a hospitalization for HF within 12 months or unscheduled visit for HF exacerbation within 90 days or an elevated natriuretic peptide concentration (brain natriuretic peptide [BNP] of ≥150 pg/mL or N-terminal pro-BNP [NT-proBNP] of ≥600 pg/mL). This phase included the development of an alert management guide and evaluated changes in medical treatment, natriuretic peptide levels, and safety. RESULTS: The mean age of participants was 67 years, 68% were men, 81% were White, and 61% had a HF hospitalization in prior 12 months. During follow-up, there were 585 alert cases with an average of 1.76 alert cases per patient-year. HF medications were augmented during 74% of the alert cases. HF treatment augmentation within 2 weeks from an initial alert was associated with more rapid recovery of the HeartLogic Index. Five serious adverse events (0.015 per patient-year) occurred in relation to alert-prompted medication change. NTproBNP levels decreased from median of 1316 pg/mL at baseline to 743 pg/mL at 12 months (P < .001). CONCLUSIONS: HeartLogic alert management was safely implemented in HF care and may optimize HF management. This phase supports further evaluation in larger studies. TRIAL REGISTRATION: ClinicalTrials.gov (NCT03237858).

Multiparameter diagnostic sensor measurements in heart failure patients presenting with SARS-CoV-2 infection.

AIMS: Implantable device-based sensor measurements including heart sounds, markers of ventilation, and thoracic impedance have been shown to predict heart failure (HF) hospitalizations. We sought to assess how these parameters changed prior to COVID-19 (Cov-19) and how these compared with those presenting with decompensated HF or pneumonia. METHODS AND RESULTS: This retrospective analysis explores patterns of changes in daily measurements by implantable sensors in 10 patients with Cov-19 and compares these findings with those observed prior to HF (n = 88) and pneumonia (n = 12) hospitalizations from the MultiSENSE, PREEMPT-HF, and MANAGE-HF trials. The earliest sensor changes prior to Cov-19 were observed in respiratory rate (6 days) and temperature (5 days). There was a three-fold to four-fold greater increase in respiratory rate, rapid shallow breathing index, and night heart rate compared with those presenting with HF or pneumonia. Furthermore, activity levels fell more in those presenting with Cov-19, a change that was often sustained for some time. In contrast, there were no significant changes in 1st or 3rd heart sound (S1 and S3 ) amplitude in those presenting with Cov-19 or pneumonia compared with the known changes that occur in HF decompensation. CONCLUSIONS: Multi-sensor device diagnostics may provide early detection of Cov-19, distinguishable from worsening HF by an extreme and fast rise in respiratory rate along with no changes in S3.

Small decreases in biventricular pacing percentages are associated with multiple metrics of worsening heart failure as measured from a cardiac resynchronization therapy defibrillator.

BACKGROUND: Lower BiVentricular (BiV) pacing percentages have been associated with significantly worse survival in patients with chronic heart failure (HF). However, the pathophysiology behind this observation has not been further delineated. This analysis evaluated whether small incremental decreases in BiV pacing percentages were associated with worse measures, related to HF physiology using individual sensor trends and the HeartLogic composite index. METHODS: Sensor data was obtained from 900 ambulatory HF patients with implanted CRT devices. The percent of cardiac cycles with BiV pacing was assessed for periods (median = 7.3 days) between data downloads (median = 55 periods/patient). RESULTS: The third heart sound (S3), respiration rate, RSBI, and night-time heart rate were significantly elevated with sub-optimal pacing (<98%), while the first heart sound (S1), thoracic impedance, and activity were significantly lower. All sensor changes were in the direction associated with worsening HF. While IN the HeartLogic alert state (threshold above an Index of 16) the odds of optimal BiV pacing (≥98%) were less than when OUT of the HeartLogic alert state for a given subject (OR: 0.655; 95% CI: 0.626-0.686; p < 0.0001). The percent BiV pacing was reduced and the HeartLogic Index was increased in the periods surrounding HFhospitalizations. CONCLUSION: Lower BiV pacing percent is associated with multiple sensor changes indicative of worsening HF, and patients in HeartLogic alert are more likely to have suboptimal BiV pacing. Collectively, these data provide strong evidence that even small decreases in BiV percent pacing can lead to worsening HF.

Case Reports of Implantable Cardiac Device Physiologic Sensor Changes in Subjects with Coronavirus Disease-2019 Infection.

The severe acute respiratory syndrome novel coronavirus-2 pandemic has established a new set of challenges to health care delivery. Remotely monitored physiologic sensors on implantable cardiac devices can provide insight into the differential diagnosis of dyspnea in the heart failure population. We report on a unique pattern of sensor deviations that seem to occur specifically with severe acute respiratory syndrome novel coronavirus-2 infection.

Obesity of mice lacking VAP-1/SSAO by Aoc3 gene deletion is reproduced in mice expressing a mutated vascular adhesion protein-1 (VAP-1) devoid of amine oxidase activity.

The product of Aoc3 gene is known as vascular adhesion protein-1 (VAP-1), a glycoprotein contributing to leukocyte extravasation and exhibiting semicarbazide-sensitive amine oxidase activity (SSAO). Regarding the immune functions of VAP-1/SSAO, it is known that mice bearing Aoc3 gene knock-out (AOC3KO) exhibit defects in leukocyte migration similar to those of mice expressing a mutated VAP-1 lacking functional SSAO activity (knock-in, AOC3KI). However, it has not been reported whether these models differ regarding other disturbances. Thus, we further compared endocrine-metabolic phenotypes of AOC3KO and AOC3KI mice to their respective control. Special attention was paid on adiposity, glucose and lipid handling, since VAP-1/SSAO is highly expressed in adipose tissue (AT). In both mouse lines, no tissue SSAO activity was found, while Aoc3 mRNA was absent in AOC3KO only. Although food consumption was unchanged, both AOC3KO and AOC3KI mice were heavier and fatter than their respective controls. Other alterations commonly found in adipocytes from both lines were loss of benzylamine insulin-like action with unchanged insulin lipogenic responsiveness and adiponectin expression. A similar downregulation of inflammatory markers (CD45, IL6) was found in AT. Glucose handling and liver mass remained unchanged, while circulating lipid profile was distinctly altered, with increased cholesterol in AOC3KO only. These results suggest that the lack of oxidase activity found in AOC3KI is sufficient to reproduce the metabolic disturbances observed in AOC3KO mice, save those related with cholesterol transport. Modulation of SSAO activity therefore constitutes a potential target for the treatment of cardiometabolic diseases, especially obesity when complicated by low-grade inflammation.

Development of a biomarker panel to predict cardiac resynchronization therapy response: Results from the SMART-AV trial.

BACKGROUND: Predicting a favorable cardiac resynchronization therapy (CRT) response holds great clinical importance. OBJECTIVE: The purpose of this study was to examine proteins from broad biological pathways and develop a prediction tool for response to CRT. METHODS: Plasma was collected from patients before CRT (SMART-AV [SmartDelay Determined AV Optimization: A Comparison to Other AV Delay Methods Used in Cardiac Resynchronization Therapy] trial). A CRT response was prespecified as a ≥15-mL reduction in left ventricular end-systolic volume at 6 months, which resulted in a binary CRT response (responders 52%, nonresponders 48%; n = 758). RESULTS: Candidate proteins (n = 74) were evaluated from the inflammatory, signaling, and structural domains, which yielded 12 candidate biomarkers, but only a subset of these demonstrated predictive value for CRT response: soluble suppressor of tumorgenicity-2, soluble tumor necrosis factor receptor-II, matrix metalloproteinase-2, and C-reactive protein. These biomarkers were used in a composite categorical scoring algorithm (Biomarker CRT Score), which identified patients with a high/low probability of a response to CRT (P <.001) when adjusted for a number of clinical covariates. For example, a Biomarker CRT Score of 0 yielded 5 times higher odds of a response to CRT compared to a Biomarker CRT Score of 4 (P <.001). The Biomarker CRT Score demonstrated additive predictive value when considered against a composite of clinical variables. CONCLUSION: These unique findings demonstrate that developing a biomarker panel for predicting individual response to CRT is feasible and holds potential for point-of-care testing and integration into evaluation algorithms for patients presenting for CRT.

Long-term vagal stimulation for heart failure: Eighteen month results from the NEural Cardiac TherApy foR Heart Failure (NECTAR-HF) trial.

BACKGROUND: The NECTAR-HF study evaluated safety and feasibility of vagal nerve stimulation (VNS) for the treatment of heart failure patients. The first six-month randomized phase of the study did not show improvement in left ventricular remodelling in response to VNS. This study reports the 18-month results and provides novel findings aiming to understand the lack of efficacy of VNS, including a new technique assessing the effects of VNS. METHODS: Ninety-six patients were randomized 2:1 to active or inactive VNS for 6months, thereafter VNS was activated for all patients. The primary safety endpoint was 18-month all-cause mortality. RESULTS: Ninety-one patients continued in the long-term evaluation with active VNS. The on-therapy survival estimate at 18months was 95% with a 95% one-sided lower confidence limit of 91%, (better than the predefined criterion). Left ventricular systolic volume decreased in the crossover group (VNS OFF→ON; 144±37 to 139±40, p<0.05) after VNS activation; LVESD (5.02±0.77 to 4.96±0.82, p>0.05) and LVEF (33.2±4.9 to 33.3±6.5, p>0.05) did not change. A new technique to detect subtle heart rate changes during Holter recordings, i.e. "heat maps", revealed that VNS evoked heart rate response in only 13/106 studies (12%) at 6 and 12months with active VNS. CONCLUSIONS: Although a favourable long-term safety profile was found, improvements in the efficacy endpoints were not seen with VNS. A new technique for detecting acute heart rate responses to VNS suggests that the recruitment of nerve fibres responsible for heart rate changes were substantially lower in NECTAR-HF than in pre-clinical models.

A Multisensor Algorithm Predicts Heart Failure Events in Patients With Implanted Devices: Results From the MultiSENSE Study.

OBJECTIVES: The aim of this study was to develop and validate a device-based diagnostic algorithm to predict heart failure (HF) events. BACKGROUND: HF involves costly hospitalizations with adverse impact on patient outcomes. The authors hypothesized that an algorithm combining a diverse set of implanted device-based sensors chosen to target HF pathophysiology could detect worsening HF. METHODS: The MultiSENSE (Multisensor Chronic Evaluation in Ambulatory Heart Failure Patients) study enrolled patients with investigational chronic ambulatory data collection via implanted cardiac resynchronization therapy defibrillators. HF events (HFEs), defined as HF admissions or unscheduled visits with intravenous treatment, were independently adjudicated. The development cohort of patients was used to construct a composite index and alert algorithm (HeartLogic) combining heart sounds, respiration, thoracic impedance, heart rate, and activity; the test cohort was sequestered for independent validation. The 2 coprimary endpoints were sensitivity to detect HFE >40% and unexplained alert rate <2 alerts per patient-year. RESULTS: Overall, 900 patients (development cohort, n = 500; test cohort, n = 400) were followed for up to 1 year. Coprimary endpoints were evaluated using 320 patient-years of follow-up data and 50 HFEs in the test cohort (72% men; mean age 66.8 ± 10.3 years; New York Heart Association functional class at enrollment: 69% in class II, 25% in class III; mean left ventricular ejection fraction 30.0 ± 11.4%). Both endpoints were significantly exceeded, with sensitivity of 70% (95% confidence interval [CI]: 55.4% to 82.1%) and an unexplained alert rate of 1.47 per patient-year (95% CI: 1.32 to 1.65). The median lead time before HFE was 34.0 days (interquartile range: 19.0 to 66.3 days). CONCLUSIONS: The HeartLogic multisensor index and alert algorithm provides a sensitive and timely predictor of impending HF decompensation. (Evaluation of Multisensor Data in Heart Failure Patients With Implanted Devices [MultiSENSE]; NCT01128166).

Soluble ST2 and Risk of Arrhythmias, Heart Failure, or Death in Patients with Mildly Symptomatic Heart Failure: Results from MADIT-CRT.

Soluble ST2 is an established biomarker of heart failure (HF) progression. Data about its prognostic implications in patients with mildly symptomatic HF eligible to receive cardiac resynchronization therapy defibrillators (CRT-D) are limited. In a cohort of 684 patients enrolled in Multicenter Automated Defibrillator Implantation Trial (MADIT)-CRT, levels of soluble ST2 (sST2) were serially assessed at baseline and 1 year (n = 410). In multivariable-adjusted models, elevated baseline sST2 was associated with an increased risk of death, death or HF, and death or ventricular arrhythmia (VA) even when adjusting for baseline brain natriuretic protein (BNP) levels. In addition, patients with lower baseline sST2 levels had greater risk reduction with CRT-D (p = 0.006). Serial assessment revealed increased risk of VA and death or VA (HR per 10 % increase in sST2 1.11 (1.04-1.20), p = 0.004). Among patients with mildly symptomatic HF and eligibility for CRT-D, baseline and serial assessments sST2 may provide important information for risk stratification.

Vagal Nerve Stimulation Evoked Heart Rate Changes and Protection from Cardiac Remodeling.

This study investigated whether vagal nerve stimulation (VNS) leads to improvements in ischemic heart failure via heart rate modulation. At 7 ± 1 days post left anterior descending artery (LAD) ligation, 63 rats with myocardial infarctions (MI) were implanted with ECG transmitters and VNS devices (MI + VNS, N = 44) or just ECG transmitters (MI, N = 17). VNS stimulation was active from 14 ± 1 days to 8 ± 1 weeks post MI. The average left ventricular (LV) end diastolic volumes at 8 ± 1 weeks were MI = 672.40 µl and MI + VNS = 519.35 µl, p = 0.03. The average heart weights, normalized to body weight (± std) at 14 ± 1 weeks were MI = 3.2 ± 0.6 g*kg(-1) and MI + VNS = 2.9 ± 0.3 g*kg(-1), p = 0.03. The degree of cardiac remodeling was correlated with the magnitude of acute VNS-evoked heart rate (HR) changes. Further research is required to determine if the acute heart rate response to VNS activation is useful as a heart failure biomarker or as a tool for VNS therapy characterization.

Review and Updates in Regenerative and Personalized Medicine, Preclinical Animal Models, and Clinical Care in Cardiovascular Medicine.

The goal of this paper is to provide an updated review for scientists and clinicians on the major areas in cardiovascular medicine published in the Journal. Leading topics in regenerative and personalized medicine are presented along with a critical overview of the field. New standards in large preclinical animal models of pulmonary hypertension and left bundle branch block are highlighted. Finally, clinical care in the areas of atherosclerosis, the aortic valve, platelet biology, and myocarditis is discussed as well as autonomic modulation therapies.

Chronic vagal stimulation for the treatment of low ejection fraction heart failure: results of the NEural Cardiac TherApy foR Heart Failure (NECTAR-HF) randomized controlled trial.

AIM: The neural cardiac therapy for heart failure (NECTAR-HF) was a randomized sham-controlled trial designed to evaluate whether a single dose of vagal nerve stimulation (VNS) would attenuate cardiac remodelling, improve cardiac function and increase exercise capacity in symptomatic heart failure patients with severe left ventricular (LV) systolic dysfunction despite guideline recommended medical therapy. METHODS: Patients were randomized in a 2 : 1 ratio to receive therapy (VNS ON) or control (VNS OFF) for a 6-month period. The primary endpoint was the change in LV end systolic diameter (LVESD) at 6 months for control vs. therapy, with secondary endpoints of other echocardiography measurements, exercise capacity, quality-of-life assessments, 24-h Holter, and circulating biomarkers. RESULTS: Of the 96 implanted patients, 87 had paired datasets for the primary endpoint. Change in LVESD from baseline to 6 months was -0.04 ± 0.25 cm in the therapy group compared with -0.08 ± 0.32 cm in the control group (P = 0.60). Additional echocardiographic parameters of LV end diastolic dimension, LV end systolic volume, left ventricular end diastolic volume, LV ejection fraction, peak V02, and N-terminal pro-hormone brain natriuretic peptide failed to show superiority compared to the control group. However, there were statistically significant improvements in quality of life for the Minnesota Living with Heart Failure Questionnaire (P = 0.049), New York Heart Association class (P = 0.032), and the SF-36 Physical Component (P = 0.016) in the therapy group. CONCLUSION: Vagal nerve stimulation as delivered in the NECTAR-HF trial failed to demonstrate a significant effect on primary and secondary endpoint measures of cardiac remodelling and functional capacity in symptomatic heart failure patients, but quality-of-life measures showed significant improvement.

Plasma galectin-3 and heart failure outcomes in MADIT-CRT (multicenter automatic defibrillator implantation trial with cardiac resynchronization therapy).

BACKGROUND: Elevated circulating levels of the protein galectin-3, a mediator of fibrogenesis, have previously been associated with adverse outcomes in heart failure (HF) patients and appear to modify response to certain pharmacologic therapies. This study investigated the relationship between galectin-3 level and clinical outcomes in HF patients randomized to implantable cardioverter defibrillator (ICD-only) or cardiac resynchronization therapy (CRT-D). METHODS AND RESULTS: Plasma galectin-3 concentrations were measured in 654 New York Heart Association functional class I/II patients participating in the MADIT-CRT trial. A heterogeneity of response was detected between pre-implantation galectin-3 and randomization group (CRT-D or ICD-only) on the primary MADIT-CRT trial end point of nonfatal HF event or death (P = .045). Among patients with baseline galectin-3 levels in the top quartile of the distribution, CRT-D was associated with a 65% reduction in risk of the primary end point (hazard ratio [HR] 0.35, 95% confidence interval [CI] 0.19-0.67), whereas among patients with lower baseline galectin-3 values CRT-D was associated with a 25% decrease in risk (HR 0.75, 95% CI. 0.51-1.11). Baseline galectin-3 level also was observed to be an independent predictor of the primary end point (multivariable adjusted HR per log unit increase: 1.55; 95% CI 1.01-2.38; P = .043). CONCLUSIONS: Elevated galectin-3 was found to be an independent predictor of adverse HF outcome in patients with mildly symptomatic HF. A significant interaction of device randomization group with pre-implantation galectin-3 level was detected, with HF patients with the highest baseline galectin-3 levels deriving a disproportionately larger benefit from CRT-D.

Advances in induced pluripotent stem cells, genomics, biomarkers, and antiplatelet therapy highlights of the year in JCTR 2013.

The Journal provides the clinician and scientist with the latest advances in discovery research, emerging technologies, preclinical research design and testing, and clinical trials. We highlight advances in areas of induced pluripotent stem cells, genomics, biomarkers, multimodality imaging, and antiplatelet biology and therapy. The top publications are critically discussed and presented along with anatomical reviews and FDA insight to provide context.