The effects of short-term omission of daily medication on the pathophysiology of heart failure

Aims Pharmacological therapies for heart failure (HF) aim to improve congestion, symptoms, and prognosis. Failing to take medication is a potential cause of worsening HF. Characterizing the effects of short-term medication omission could inform the development of better technologies and strategies to detect and interpret the reasons for worsening HF. We examined the effect of planned HF medication omission for 48 h on weight, echocardiograms, transthoracic bio-impedance, and plasma concentrations of NT-proBNP. Methods and results Outpatients with stable HF and an LVEF <45% were assigned to take or omit their HF medication for 48 h in a randomized, crossover trial. Twenty patients (16 men, LVEF 32 ± 9%, median NT-proBNP 962 ng/L) were included. Compared with regular medication, omission led to an increase in NT-proBNP by 99% (from 962 to 1883 ng/L, P < 0.001), systolic blood pressure by 16% (from 131 to 152 mmHg, P < 0.001), and left atrial volume by 21% (from 69 to 80 mL, P = 0.001), and reductions in transthoracic bio-impedance by 10% (from 33 to 30 Σ, P = 0.001) and serum creatinine by 8% (from 135 to 118 µmol/L, P = 0.012). No significant changes in body weight, heart rate, or LVEF were observed. Conclusions The characteristic pattern of response to short-term medication omission is of increasing congestion but, in contrast to the pattern reported for disease progression, with a rise in blood pressure and improved renal function. In stable HF, weight is not a sensitive marker of short-term diuretic omission

Potential role for clinical calibration to increase engagement with and application of home telemonitoring: a report from the HeartCycle programme

Aims: There is a need for alternative strategies that might avoid recurrent admissions in patients with heart failure. Home Telemonitoring (HTM) to monitor patient’s symptoms from a distance may be useful. This study attempts to assess changes in HTM vital signs in response to daily life activities (variations in medication, salt intake, exercise and stress) and to stablish which variations affect weight, blood pressure (BP) and heart rate (HR). Methods and results: We assessed 76 patients with heart failure (mean age 76 ± 10.8 years, 75% male, mainly in NYHA class II/III and from ischaemic etiology cause). Patients were given a calendar of interventions scheduling activities approximately twice-a-week before measuring their vital signs. Eating salty food or a large meal were the activities that had a significant impact on weight gain (+0.3 kg; p<0.001 and p=0.006, respectively). Exercise and skipping a dose of medication other than diuretics increased heart rate (+3 bpm, p=0.001 and almost +2 bpm, p=0.016, respectively). Conclusions: Our HTM system was able to detect small changes in vital signs related to these activities. Further studies should assess if providing such a schedule of activities might be useful for patient education and could improve long-term adherence to recommended lifestyle changes

Potential role for clinical calibration to increase engagement with and application of home telemonitoring: a report from the HeartCycle programme

Aims: There is a need for alternative strategies that might avoid recurrent admissions in patients with heart failure. home telemonitoring (HTM) to monitor patient's symptoms from a distance may be useful. This study attempts to assess changes in HTM vital signs in response to daily life activities (variations in medication, salt intake, exercise, and stress) and to establish which variations affect weight, blood pressure, and heart rate. Methods and results: We assessed 76 patients with heart failure (mean age 76 ± 10.8 years, 75% male, mainly in NYHA class II/III and from ischaemic aetiology cause). Patients were given a calendar of interventions scheduling activities approximately twice a week before measuring their vital signs. Eating salty food or a large meal were the activities that had a significant impact on weight gain (+0.3 kg; P &lt; 0.001 and P = 0.006, respectively). Exercise and skipping a dose of medication other than diuretics increased heart rate (+3 bpm, P = 0.001 and almost +2 bpm, P = 0.016, respectively). Conclusions: Our HTM system was able to detect small changes in vital signs related to these activities. Further studies should assess if providing such a schedule of activities might be useful for patient education and could improve long-term adherence to recommended lifestyle changes

Detecting Heart Failure Decompensation by Measuring Transthoracic Bioimpedance in the Outpatient Setting: Rationale and Design of the SENTINEL-HF Study

BACKGROUND: Recurrent hospital admissions are common among patients admitted for acute decompensated heart failure (ADHF), but identification of patients at risk for rehospitalization remains challenging. Contemporary heart failure (HF) management programs have shown modest ability to reduce readmissions, partly because they monitor signs or symptoms of HF worsening that appear late during decompensation. Detecting early stages of HF decompensation might allow for immediate application of effective HF therapies, thereby potentially reducing HF readmissions. One of the earliest indicators of HF decompensation is intrathoracic fluid accumulation, which can be assessed using transthoracic bioimpedance. OBJECTIVE: The SENTINEL-HF study is a prospective observational study designed to test a novel, wearable HF monitoring system as a predictor of HF decompensation among patients discharged after hospitalization for ADHF. METHODS: SENTINEL-HF tests the hypothesis that a decline in transthoracic bioimpedance, as assessed daily with the Philips fluid accumulation vest (FAV) and transmitted using a mobile phone, is associated with HF worsening and rehospitalization. According to pre-specified power calculations, 180 patients admitted with ADHF are enrolled. Participants transmit daily self-assessments using the FAV-mobile phone dyad for 45 days post-discharge. The primary predictor is the deviation of transthoracic bioimpedance for 3 consecutive days from a patient-specific normal variability range. The ADHF detection algorithm is evaluated in relation with a composite outcome of HF readmission, diuretic up-titration, and self-reported HF worsening (Kansas City Cardiomyopathy Questionnaire) during a 90-day follow-up period. Here, we provide the details and rationale of SENTINEL-HF. RESULTS: Enrollment in the SENTINEL-HF study is complete and the 90-days follow-up is currently under way. Once data collection is complete, the study dataset will be used to evaluate our ADHF detection algorithm and the results submitted for publication. CONCLUSION: SENTINEL-HF emerged from our long-term vision that advanced home monitoring technology can improve the management of chronic HF by extending clinical care into patients\u27 homes. Monitoring transthoracic bioimpedance with the FAV may identify patients at risk of recurrent HF decompensation and enable timely preventive measures. TRIAL REGISTRATION: Clinicaltrials.gov NCT01877369: https://clinicaltrials.gov/ct2/show/NCT01877369 (Archived by WebCite at http://www.webcitation.org/6bDYl0dGy)

Who approves/pays for additional monitoring?

Major considerations in the provision of healthcare are availability, affordability, accessibility, and appropriateness, especially in the setting of heart failure where disease burden is growing, developments have been rapid and newer biomarkers, diagnostic and imaging techniques, monitoring systems, devices, procedures, and drugs have all been developed in a relatively short period of time. Many monitoring and diagnostic systems have been developed but the disproportionate cost of conducting trials of their effectiveness has limited their uptake. There are added complexities, in that the utilization of doctors for the supervision of the monitoring results may be optimal in one setting and not in another because of differences in the characteristics of organization of healthcare provision, making even interpretation of the trials we have had, still difficult to interpret. New technologies are continuously changing the approach to healthcare and will reshape the structure of the healthcare systems in the future. Mobile technologies can empower patients and carers by giving them more control over their health and social care needs and reducing their dependence on healthcare professionals for monitoring their health, but a significant problem is the integration of the multitude of monitored parameters with clinical data and the recognition of intervention thresholds. Digital technology can help, but we need to prove its cost/efficacy and how it will be paid for. Governments in many European countries and worldwide are trying to establish frameworks that promote the convergence of standards and regulations for telemedicine solutions and yet simultaneously health authorities are closely scrutinizing healthcare spending, with the objective of reducing and optimizing expenditure in the provision of health services. There are multiple factors to be considered for the reimbursement models associated with the implementation of physiological monitoring yet it remains a challenge in cash-strapped health systems

Bioimpedance-Based Heart Failure Deterioration Prediction Using a Prototype Fluid Accumulation Vest-Mobile Phone Dyad: An Observational Study

BACKGROUND: Recurrent heart failure (HF) events are common in patients discharged after acute decompensated heart failure (ADHF). New patient-centered technologies are needed to aid in detecting HF decompensation. Transthoracic bioimpedance noninvasively measures pulmonary fluid retention. OBJECTIVE: The objectives of our study were to (1) determine whether transthoracic bioimpedance can be measured daily with a novel, noninvasive, wearable fluid accumulation vest (FAV) and transmitted using a mobile phone and (2) establish whether an automated algorithm analyzing daily thoracic bioimpedance values would predict recurrent HF events. METHODS: We prospectively enrolled patients admitted for ADHF. Participants were trained to use a FAV-mobile phone dyad and asked to transmit bioimpedance measurements for 45 consecutive days. We examined the performance of an algorithm analyzing changes in transthoracic bioimpedance as a predictor of HF events (HF readmission, diuretic uptitration) over a 75-day follow-up. RESULTS: We observed 64 HF events (18 HF readmissions and 46 diuretic uptitrations) in the 106 participants (67 years; 63.2%, 67/106, male; 48.1%, 51/106, with prior HF) who completed follow-up. History of HF was the only clinical or laboratory factor related to recurrent HF events (P=.04). Among study participants with sufficient FAV data (n=57), an algorithm analyzing thoracic bioimpedance showed 87% sensitivity (95% CI 82-92), 70% specificity (95% CI 68-72), and 72% accuracy (95% CI 70-74) for identifying recurrent HF events. CONCLUSIONS: Patients discharged after ADHF can measure and transmit daily transthoracic bioimpedance using a FAV-mobile phone dyad. Algorithms analyzing thoracic bioimpedance may help identify patients at risk for recurrent HF events after hospital discharge. Sert Kuniyoshi, Joseph Rock, Theo E Meyer, David D McManus. Originally published in JMIR Cardio (http://cardio.jmir.org), 13.03.2017

The effects of short-term omission of daily medication on the pathophysiology of heart failure

Aims Pharmacological therapies for heart failure (HF) aim to improve congestion, symptoms, and prognosis. Failing to take medication is a potential cause of worsening HF. Characterizing the effects of short-term medication omission could inform the development of better technologies and strategies to detect and interpret the reasons for worsening HF. We examined the effect of planned HF medication omission for 48 h on weight, echocardiograms, transthoracic bio-impedance, and plasma concentrations of NT-proBNP. Methods and results Outpatients with stable HF and an LVEF <45% were assigned to take or omit their HF medication for 48 h in a randomized, crossover trial. Twenty patients (16 men, LVEF 32±9%, median NT-proBNP 962 ng/L) were included. Compared with regular medication, omission led to an increase in NT-proBNP by 99% (from 962 to 1883 ng/L, P <0.001), systolic blood pressure by 16% (from 131 to 152 mmHg, P <0.001), and left atrial volume by 21% (from 69 to 80 mL, P =0.001), and reductions in transthoracic bio-impedance by 10% (from 33 to 30 Σ, P =0.001) and serum creatinine by 8% (from 135 to 118 μmol/L, P =0.012). No significant changes in body weight, heart rate, or LVEF were observed. Conclusions The characteristic pattern of response to short-term medication omission is of increasing congestion but, in contrast to the pattern reported for disease progression, with a rise in blood pressure and improved renal function. In stable HF, weight is not a sensitive marker of short-term diuretic omission

Monitoring thoracic fluid content using bioelectrical impedance spectroscopy and Cole modeling

Heart failure is a chronic disease marked by frequenthospitalizations due to pulmonary fluid congestion. Monitoringthe thoracic fluid status may favor the detection of fluidcongestion in an early stage and enable targeted preventivemeasures. Bioelectrical impedance spectroscopy (BIS) has beenused in combination with the Cole model for monitoring bodycomposition including fluid status. The model parameters reflectintracellular and extracellular fluid volume as well as cell sizes,types and interactions. Transthoracic BIS may be a suitableapproach to monitoring variations in thoracic fluid content.The aim of this study was to identify BIS measures, which canbe derived based on the Cole model, that are sensitive to earlystages of thoracic fluid accumulation. We simulated this medicalcondition in healthy subjects by shifting a part of the whole bloodfrom the periphery towards the thorax. The redistribution ofblood was achieved non-invasively through leg compression usinginflatable leg sleeves. We acquired BIS data before, during andafter compression of the legs and examined the effect of thoracicfluid variations on parameters derived based on the Cole modeland on geometrical properties of the impedance arc. Indicatordilution measurements obtained through cardiac magneticresonance imaging were used as a reference for the changes inpulmonary fluid volume.Eight healthy subjects were included in the study. The Colemodel parameters of the study group at baseline were: R0 = 51.4 ±6.7 Ω, R∞ = 25.0 ± 7.0 Ω, fc = 49.0 ± 10.5 kHz, α = 0.687 ± 0.027, theresistances of individual fluid compartments were RE = 51.4 ± 6.7Ω, RI = 50.5 ± 22.9 Ω, the fluid distribution ratio was K = 1.1 ± 0.3,and the radius, area and depression of the arc’s center were: R =15.7 ± 1.3 Ω, XC = −8.5 ± 1.5 Ω, A = 134.0 ± 15.6 Ω2. The effect ofleg compression was a relatively small, reversible increase inpulmonary blood volume of 90 ± 57 mL. We observed significantchanges in parameters associated with intracellular, extracellularand total fluid volume (R0: -1.5 ± 0.9 %, p < 0.01; R∞: −2.1 ± 1.1, p <0.01; RI: −2.6 ± 1.6 %, p < 0.01), and in the arc’s geometricalproperties (R: -1.6 ± 1.3 %, p < 0.05; XC: −1.7 ± 1.5 %, p < 0.05, A:−2.9 ± 1.2 %, p < 0.01). K and the parameters associated withtissue structure fc and α remained stable.Transthoracic BIS is sensitive to small variations in intrathoracicblood volume, in particular the resistances of fluidcompartments and the geometric properties of the impedancearc. Taken together with previous studies, our findings suggestthat R0 may be a suitable parameter to monitor congestion. Use ofadditional parameters such as RI, K, XC, fc and α may enable thediscrimination between different types and stages of thoracic fluidaccumulation and should be the focus of future research