Wearable Devices Based on Bioimpedance Test in Heart-Failure: Design Issues.

Heart-failure (HF) is a severe medical condition. Physicians need new tools to monitor the health status of their HF patients outside the hospital or medical supervision areas, to better know the evolution of their patients' main biomarker values, necessary to evaluate their health status. Bioimpedance (BI) represents a good technology for sensing physiological variables and processes on the human body. BI is a non-expensive and non-invasive technique for sensing a wide variety of physiological parameters, easy to be implemented on biomedical portable systems, also called "wearable devices". In this systematic review, we address the most important specifications of wearable devices based on BI used in HF real-time monitoring and how they must be designed and implemented from a practical and medical point of view. The following areas will be analyzed: the main applications of BI in heart failure, the sensing technique and impedance specifications to be met, the electrode selection, portability of wearable devices: size and weight (and comfort), the communication requests and the power consumption (autonomy). The different approaches followed by biomedical engineering and clinical teams at bibliography will be described and summarized in the paper, together with results derived from the projects and the main challenges found today.

Wearable Devices Based on Bioimpedance Test in Heart Failure: Clinical Relevance: Systematic Review.

Background: Heart failure (HF) represents a frequent cause of hospital admission, with fluid overload directly contributing to decompensations. Bioimpedance (BI), a physical parameter linked to tissue hydration status, holds promise in monitoring congestion and improving prognosis. This systematic review aimed to assess the clinical relevance of BI-based wearable devices for HF fluid monitoring. Methods: A systematic review of the published literature was conducted in five medical databases (PubMed, Scopus, Cochrane, Web of Science, and Embase) for studies assessing wearable BI-measuring devices on HF patients following PRISMA recommendations on February 4th, 2024. The risk of bias was evaluated using the ROBINS tool. Results: The review included 10 articles with 535 participants (mean age 66.7 ± 8.9 years, males 70.4%). Three articles identified significant BI value differences between HF patients and controls or congestive vs non-congestive HF patients. Four articles focused on the devices' ability to predict HF worsening-related events, revealing an overall sensitivity of 70.0 (95% CI 68.8-71.1) and specificity of 89.1 (95% CI 88.3-89.9). One article assessed prognosis, showing that R80kHz decrease was related to all-cause-mortality with a hazard ratio (HR) of 5.51 (95% CI 1.55-23.32; p = 0.02) and the composite all-cause-mortality and HF admission with a HR of 4.96 (95% CI 1.82-14.37; p = 0.01). Conclusions: BI-measuring wearable devices exhibit efficacy in detecting fluid overload and hold promise for HF monitoring. However, further studies and technological improvements are required to optimize their impact on prognosis compared to standard care before they can be routinely implemented in clinical practice. PROSPERO Registration: The search protocol was registered at PROSPERO (CRD42024509914).

Design of Wearable Textile Electrodes for the Monitorization of Patients with Heart Failure.

Heart failure is a severe medical condition with an important worldwide incidence that occurs when the heart is unable to efficiently pump the patient's blood throughout the body. The monitoring of edema in the lower limbs is one of the most efficient ways to control the evolution of the condition. Impedance spectroscopy has been proposed as an efficient technique to monitor body volume in patients with heart failure. It is necessary to research new wearable devices for remote patient monitoring, which can be easily worn by patients in a continuous way. In this work, we design and implement new wearable textile electrodes for the monitoring of edema evolution in patients with heart failure. Impedance spectroscopy measurements were carried out in 5 healthy controls and 2 patients with heart failure using our wearable electrodes for 3 days. The results show the appropriateness of impedance spectroscopy and our wearable electrodes to monitor body volume evolution. Impedance spectroscopy is shown to be an efficient marker of the presence of edema in heart failure patients. Initial patient positive feedback was obtained for the use of the wearable device.

[Prognostic value of electrical bioimpedance measured with a portable and wireless device in acute heart failure]. / Valor pronóstico de la bioimpedancia eléctrica medida con el dispositivo IVOL en la insuficiencia cardiaca aguda.

INTRODUCTION AND OBJECTIVES: The current evaluation of acute heart failure (HF) does not allow an adequate prediction of its evolution. The electrical bioimpedance (BI) allows knowing the state of blood volume, until now only with fixed equipment. We have developed and validated a portable and wireless device to measure BI at the ankle (IVOL). The objective of the study is to know the long-term prognostic value of the point measurement of BI with IVOL in patients with acute HF. METHODS: A prospective cohort study of unselected patients admitted for acute HF in a tertiary hospital. The association between BI and different clinical, analytical and echocardiographic variables on admission and clinical evolution were analyzed. RESULTS: 76 patients were included (mean age 66.1 years, 71.1% men, 68.4% hypertensive, 34.2% diabetic, mean NT-ProBNP: 7,103 pg / ml). Of these, 52.6% with non-preserved left ventricular ejection fraction (LVEF) (<50%) and 56.6% with right ventricular (RV) dysfunction. 26.3% died during a mean follow-up of 35.8 months. Survival in patients with BI≤21,8Ω was lower, globally and in the subgroups of patients without preserved LVEF and with RV dysfunction, P<.008). In the multivariate analysis, a BI≥21.8Ω was an independent survival factor (HR: 0.242; 95% CI: 0.86-0.681; P=.007). CONCLUSIONS: BI values measured with IVOL may be an independent predictor of long-term mortality in patients hospitalized for acute HF. This prognostic value is maintained in patients without preserved LVEF function and with RV dysfunction.

Survival Impact of an On-Site Medicalization Program in the Control of COVID-19 Outbreaks in 11 Nursing Homes.

BACKGROUND: The elderly admitted to nursing homes have especially suffered the havoc of the COVID-19 pandemic since most of them are not prepared to face such health problems. METHODS: An innovative coordinated on-site medicalization program (MP) in response to a sizeable COVID-19 outbreak in three consecutive waves was deployed, sharing coordination and resources among primary care, the referral hospital, and the eleven residences. The objectives were providing the best possible medical care to residents in their environment, avoiding dehumanization and loneliness of hospital admission, and reducing the saturation of hospitals and the risk of spreading the infection. The main outcomes were a composite endpoint of survival or optimal palliative care (SOPC), survival, and referral to the hospital. RESULTS: 587 of 1199 (49%) residents were infected, of whom 123 (21%) died. Patients diagnosed before the start of the MP presented SOPC, survival, and referrals to the hospital of 83%, 74%, and 22.4%, opposite to 96%, 84%, and 10.6% of patients diagnosed while the MP was set up. The SOPC was independently associated with an MP (OR 3.4 [1.6-7.2]). CONCLUSION: During the COVID-19 outbreak, a coordinated MP successfully obtained a better rate of SOPC while simultaneously reducing the need for hospital admissions, combining optimal medical management with a more compassionate and humanistic approach in older people.

Diagnostic Yield of 16S Ribosomal Ribonucleic Acid Gene-Based Targeted Metagenomic Sequencing for Evaluation of Pleural Space Infection: A Prospective Study.

Objective: To better understand the microbial profile of complicated parapneumonic effusions and empyema, and to evaluate whether antimicrobial selection would differ if guided by targeted metagenomic sequencing (tMGS) vs conventional cultures (CCs) alone. Patients and Methods: We analyzed the pleural fluid of a cohort of 47 patients undergoing thoracentesis from January 1, 2017 to August 31, 2019, to characterize their microbial profile. All samples underwent 16S ribosomal ribonucleic acid gene polymerase chain reaction, followed by tMGS. Results: Pleural space infection was deemed clinically present in 20 of the 47 (43%) participants. Of those, n=7 (35%) had positive pleural fluid cultures and n=14 (70%) had positive tMGS results. The organisms identified by tMGS were concordant with CCs; however, tMGS detected additional bacterial species over CCs alone. Streptococcus and Staphylococcus species were the most common organisms identified, with Streptococcus intermedius/constellatus identified in 5 patients. Polymicrobial infections were found in 6 of the 20 patients, with anaerobes being the most common organisms identified in these cases. Conclusion: Streptococci and staphylococci were the most common organisms identified in infected pleural fluid. Anaerobes were common in polymicrobial infections. When compared with CCs, tMGS had higher sensitivity than CCs. Targeted metagenomic sequencing identified additional organisms, not identified by CCs, with associated potential management implications.

Pancreas fat content, insulin homeostasis and circulating endothelial microparticles in male essential hypertensive patients.

The pancreas fat content has been poorly investigated in essential hypertension. The authors aim to relate pancreas and liver fat content with parameters measuring insulin resistance, beta-cell function and also with markers of endothelial dysfunction and platelet or endothelial cell destruction. The authors studied a group of 40 male hypertensive patients with well-controlled blood pressure, maintaining a stable weight, and having not changed their medication during the last year. Pancreas fat content was correlated with HOMA-IR (r = .616, p < .001), HOMA-S (r = -.439, p < .005), beta cell function parameter (r = .457, p < .005), and QUICKI (r = .412, p < .01), whereas liver fat was not patients in the highest quartile of pancreas fat content had more circulating endothelial microparticles than patients in the other quartiles (median 129 [94.3-200] vs. 60.9 [49.4-88.8], p = .002). However, patients in the highest quartile of the pancreas fat content distribution did not differ from the lowest in hyperemic response after ischemia nor circulating platelet microparticles count. Liver fat content was not related to any of the parameters studied. In a multivariate stepwise binary logistic regression analysis (Wald Method) circulating endothelial microparticles remain significantly associated with pancreas fat content after adjusting for confounding factors, such as tobacco, diabetes mellitus, hypercholesterolemia, or metabolic syndrome. Our results reflect that in essential hypertension, pancreas fat content is superior to liver fat to study beta-cell functionality and insulin resistance. Moreover, the authors described for the first time that pancreas fat content is related to endothelial cell destruction. Further studies are needed to confirm this point.

PostCOVID effect on endothelial function in hypertensive patients: A new research opportunity.

SARS-CoV-2 is causing devastation both in human lives and economic resources. When the world seems to start overcoming the pandemics scourge, the threat of long-term complications of COVID-19 is rising. Reports show that some of these long-term effects may contribute to the main cause of morbimortality worldwide: the vascular diseases. Given the evidence of damage in the endothelial cells due to SARS-CoV-2 and that endothelial dysfunction precedes the development of arteriosclerosis, the authors propose to measure endothelial function around 6-12 months after acute disease in hypertensive patients, especially if they have other cardiovascular risk factors or overt vascular disease. The methods the authors propose are cost-effective and can be made available to any hypertension unit. These methods could be the "in vivo" assessment of endothelial function by flow mediated vasodilatation after ischemia by Laser-Doppler flowmetry and the measurement of plasma free circulating DNA and microparticles of endothelial origin.