Prediction of heart failure patients with distinct left ventricular ejection fraction levels using circadian ECG features and machine learning.

Heart failure (HF) encompasses a diverse clinical spectrum, including instances of transient HF or HF with recovered ejection fraction, alongside persistent cases. This dynamic condition exhibits a growing prevalence and entails substantial healthcare expenditures, with anticipated escalation in the future. It is essential to classify HF patients into three groups based on their ejection fraction: reduced (HFrEF), mid-range (HFmEF), and preserved (HFpEF), such as for diagnosis, risk assessment, treatment choice, and the ongoing monitoring of heart failure. Nevertheless, obtaining a definitive prediction poses challenges, requiring the reliance on echocardiography. On the contrary, an electrocardiogram (ECG) provides a straightforward, quick, continuous assessment of the patient's cardiac rhythm, serving as a cost-effective adjunct to echocardiography. In this research, we evaluate several machine learning (ML)-based classification models, such as K-nearest neighbors (KNN), neural networks (NN), support vector machines (SVM), and decision trees (TREE), to classify left ventricular ejection fraction (LVEF) for three categories of HF patients at hourly intervals, using 24-hour ECG recordings. Information from heterogeneous group of 303 heart failure patients, encompassing HFpEF, HFmEF, or HFrEF classes, was acquired from a multicenter dataset involving both American and Greek populations. Features extracted from ECG data were employed to train the aforementioned ML classification models, with the training occurring in one-hour intervals. To optimize the classification of LVEF levels in coronary artery disease (CAD) patients, a nested cross-validation approach was employed for hyperparameter tuning. HF patients were best classified using TREE and KNN models, with an overall accuracy of 91.2% and 90.9%, and average area under the curve of the receiver operating characteristics (AUROC) of 0.98, and 0.99, respectively. Furthermore, according to the experimental findings, the time periods of midnight-1 am, 8-9 am, and 10-11 pm were the ones that contributed to the highest classification accuracy. The results pave the way for creating an automated screening system tailored for patients with CAD, utilizing optimal measurement timings aligned with their circadian cycles.

Superoxide-producing associates from gastrointestinal bacteria: stimulation of its growth by exogenous superoxide-producing complex from raspberries.

Aerobic organisms including the gut microbiota have an essential antioxidant status, as a result of which these bacteria protect organisms from various pathologies and diseases. The goal of the given investigation is (1) the isolation and purification of the isoforms of endogenous О2--producing associate from gastrointestinal bacteria (Lactobacillus rhamnosus, Lactobacillus acidophilus, Bifidobacterium bifidum); (2) determination of the effective concentrations of exogenous О2- produced by a complex of NADPH-containing protein component and Fe(III) (NPC-Fe(III)) from raspberries on the growth of the gastrointestinal bacteria in a nutrient medium in vitro. Ion-exchange chromatography on cellulose DE-52 and gel filtration on Sephadex G-100 at the pH of 9.5 was used to isolate and purify the NLP-Nox isoforms. Specific maximal optical absorption spectra of the Nox isoforms were observed in a weakly opalescent aqueous solution of the NLP-Nox isoforms. The specific contents of these NLP-Nox isoforms, as well as their composition, the stationary concentration of produced О2-, and the mechanism of О2- production were determined. The stimulating effect on the growth of these gastrointestinal bacteria in the nutrient medium of MRS broth and MRS agar in vitro under the influence of О2-, as a product of a new thermostable and acid-stable complex NPC-Fe(III) was determined. The NPC-Fe(III) complex, from raspberries was determined as well. Thus, for the first time, the isolation and purification of О2-- producing thermostable NADPH-containing lipoprotein-NADPH oxidase (NLP-Nox) associate from gastrointestinal bacteria membranes (continuously producing О2- under the aerobic conditions), and the stimulation of these bacteria growth by О2- formed by the complex from raspberries were demonstrated.

The О₂⁻-producing associate NLP-Nox was isolated and purified from the gut microbiota.NLP-Nox associate produces О₂⁻ by using a protein-bound non-free NADPH as a substrate.The NPC-Fe(III) isolated from raspberries generates О₂⁻.The effective quantities of О₂⁻ promotes the growth and development of bacteria.

Investigating automated regression models for estimating left ventricular ejection fraction levels in heart failure patients using circadian ECG features.

Heart Failure (HF) significantly impacts approximately 26 million people worldwide, causing disruptions in the normal functioning of their hearts. The estimation of left ventricular ejection fraction (LVEF) plays a crucial role in the diagnosis, risk stratification, treatment selection, and monitoring of heart failure. However, achieving a definitive assessment is challenging, necessitating the use of echocardiography. Electrocardiogram (ECG) is a relatively simple, quick to obtain, provides continuous monitoring of patient's cardiac rhythm, and cost-effective procedure compared to echocardiography. In this study, we compare several regression models (support vector machine (SVM), extreme gradient boosting (XGBOOST), gaussian process regression (GPR) and decision tree) for the estimation of LVEF for three groups of HF patients at hourly intervals using 24-hour ECG recordings. Data from 303 HF patients with preserved, mid-range, or reduced LVEF were obtained from a multicentre cohort (American and Greek). ECG extracted features were used to train the different regression models in one-hour intervals. To enhance the best possible LVEF level estimations, hyperparameters tuning in nested loop approach was implemented (the outer loop divides the data into training and testing sets, while the inner loop further divides the training set into smaller sets for cross-validation). LVEF levels were best estimated using rational quadratic GPR and fine decision tree regression models with an average root mean square error (RMSE) of 3.83% and 3.42%, and correlation coefficients of 0.92 (p<0.01) and 0.91 (p<0.01), respectively. Furthermore, according to the experimental findings, the time periods of midnight-1 am, 8-9 am, and 10-11 pm demonstrated to be the lowest RMSE values between the actual and predicted LVEF levels. The findings could potentially lead to the development of an automated screening system for patients with coronary artery disease (CAD) by using the best measurement timings during their circadian cycles.

Non-invasive technologies for heart failure, systolic and diastolic dysfunction modeling: a scoping review.

The growing global prevalence of heart failure (HF) necessitates innovative methods for early diagnosis and classification of myocardial dysfunction. In recent decades, non-invasive sensor-based technologies have significantly advanced cardiac care. These technologies ease research, aid in early detection, confirm hemodynamic parameters, and support clinical decision-making for assessing myocardial performance. This discussion explores validated enhancements, challenges, and future trends in heart failure and dysfunction modeling, all grounded in the use of non-invasive sensing technologies. This synthesis of methodologies addresses real-world complexities and predicts transformative shifts in cardiac assessment. A comprehensive search was performed across five databases, including PubMed, Web of Science, Scopus, IEEE Xplore, and Google Scholar, to find articles published between 2009 and March 2023. The aim was to identify research projects displaying excellence in quality assessment of their proposed methodologies, achieved through a comparative criteria-based rating approach. The intention was to pinpoint distinctive features that differentiate these projects from others with comparable objectives. The techniques identified for the diagnosis, classification, and characterization of heart failure, systolic and diastolic dysfunction encompass two primary categories. The first involves indirect interaction with the patient, such as ballistocardiogram (BCG), impedance cardiography (ICG), photoplethysmography (PPG), and electrocardiogram (ECG). These methods translate or convey the effects of myocardial activity. The second category comprises non-contact sensing setups like cardiac simulators based on imaging tools, where the manifestations of myocardial performance propagate through a medium. Contemporary non-invasive sensor-based methodologies are primarily tailored for home, remote, and continuous monitoring of myocardial performance. These techniques leverage machine learning approaches, proving encouraging outcomes. Evaluation of algorithms is centered on how clinical endpoints are selected, showing promising progress in assessing these approaches' efficacy.

NADPH containing superoxide-producing thermostable complex from raspberry, apricot, grape, and grape seeds: isolation, purification, and properties.

BACKGROUND: NADPH oxidase (Nox) plays a crucial role in reactive oxygen spices (ROS) production and mediates different diseases' development. Under aerobic conditions, the NADPH-containing protein component of the (NCP)-Fe (III) complex produces O2- continuously and intensively. However, after the removal of Fe (III), the isolated NCP shows only antioxidant properties at the expense of NADPH composite. Based on the fact that the mentioned fruit juices are widely used in everyday life and also in biomedicine, it was aimed to use a universal method: 1. to obtain superoxide generating complex from available and relatively cheap raw materials without using any toxic substances; 2. to isolate, purify and study the components of prooxidant nature: the isoforms of O2--producing NCP-Fe (III) complexes obtained from Armenian fruits (raspberries, apricot, grapes), as well, grape seeds. RESULTS: Using a licensed method, for the first time isoforms of the superoxide (O2-) producing a thermostable complex of the NCP component with Fe (III), (NCP-Fe (III)), were isolated and purified from Armenian fruits-raspberries, apricots, grapes, and grapes seeds. The process of isolation and purification of isoforms of these complexes included the following stages of processing: 1. alkaline hydrolysis at pH9,5; 2. their sedimentation at pH4.8; 3. Dissolving of the sediments in water at pH9.5, followed by ion-exchange chromatography on cellulose DE-52, and gel filtration on Sephadex G-100. Further, the heat treatment of the mentioned complexes was carried out. In a lyophilized state, under the anaerobic conditions, the isoforms of the given complexes, hybrid associates (hNCP-Nox), and NCP were stored practically without losing their activity in a mass of 1-1.5 g. CONCLUSIONS: Isoforms of O2- -producing complexes are new liquid-phase, thermo-stable prooxidant components found in raspberries, apricots, grapes, and grapes seeds.

Utility of erythrocyte indices in identifying iron depletion in pregnancy.

BACKGROUND: Iron deficiency anaemia in pregnancy is common and is a major cause of maternal and neonatal morbidity worldwide. Serum ferritin is the current gold standard test for identifying iron depletion, with a cut-off value of 30 µg/L. Recent studies in low- and middle-income countries have identified mean cell haemoglobin concentration as a surrogate marker for the prediction of iron depletion. METHODS: We studied values from 786 antenatal blood results from 2018 in Oxford, UK, and correlated the red cell indices with serum ferritin measurements. RESULTS: Haemoglobin, mean cell volume, mean cell haemoglobin and mean cell haemoglobin concentration have low specificity and sensitivity for the identification of iron depletion. CONCLUSIONS: We found that haemoglobin, mean cell volume, mean cell haemoglobin and mean cell haemoglobin concentration do not have sufficient predictive value in this population to be used as a screening test for non-anaemic iron depletion.

The 2019-2020 Novel Coronavirus (Severe Acute Respiratory Syndrome Coronavirus 2) Pandemic: A Joint American College of Academic International Medicine-World Academic Council of Emergency Medicine Multidisciplinary COVID-19 Working Group Consensus Paper.

What started as a cluster of patients with a mysterious respiratory illness in Wuhan, China, in December 2019, was later determined to be coronavirus disease 2019 (COVID-19). The pathogen severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel Betacoronavirus, was subsequently isolated as the causative agent. SARS-CoV-2 is transmitted by respiratory droplets and fomites and presents clinically with fever, fatigue, myalgias, conjunctivitis, anosmia, dysgeusia, sore throat, nasal congestion, cough, dyspnea, nausea, vomiting, and/or diarrhea. In most critical cases, symptoms can escalate into acute respiratory distress syndrome accompanied by a runaway inflammatory cytokine response and multiorgan failure. As of this article's publication date, COVID-19 has spread to approximately 200 countries and territories, with over 4.3 million infections and more than 290,000 deaths as it has escalated into a global pandemic. Public health concerns mount as the situation evolves with an increasing number of infection hotspots around the globe. New information about the virus is emerging just as rapidly. This has led to the prompt development of clinical patient risk stratification tools to aid in determining the need for testing, isolation, monitoring, ventilator support, and disposition. COVID-19 spread is rapid, including imported cases in travelers, cases among close contacts of known infected individuals, and community-acquired cases without a readily identifiable source of infection. Critical shortages of personal protective equipment and ventilators are compounding the stress on overburdened healthcare systems. The continued challenges of social distancing, containment, isolation, and surge capacity in already stressed hospitals, clinics, and emergency departments have led to a swell in technologically-assisted care delivery strategies, such as telemedicine and web-based triage. As the race to develop an effective vaccine intensifies, several clinical trials of antivirals and immune modulators are underway, though no reliable COVID-19-specific therapeutics (inclusive of some potentially effective single and multi-drug regimens) have been identified as of yet. With many nations and regions declaring a state of emergency, unprecedented quarantine, social distancing, and border closing efforts are underway. Implementation of social and physical isolation measures has caused sudden and profound economic hardship, with marked decreases in global trade and local small business activity alike, and full ramifications likely yet to be felt. Current state-of-science, mitigation strategies, possible therapies, ethical considerations for healthcare workers and policymakers, as well as lessons learned for this evolving global threat and the eventual return to a "new normal" are discussed in this article.

Interplay of π-stacking and inter-stacking interactions in two-component crystals of neutral closed-shell aromatic compounds: periodic DFT study.

This paper bridges the gap between high-level ab initio computations of gas-phase models of 1 : 1 arene-arene complexes and calculations of the two-component (binary) organic crystals using atom-atom potentials. The studied crystals consist of electron-rich and electron-deficient compounds, which form infinite stacks (columns) of heterodimers. The sublimation enthalpy of crystals has been evaluated by DFT periodic calculations, while intermolecular interactions have been characterized by Bader analysis of the periodic electronic density. The consideration of aromatic compounds without a dipole moment makes it possible to reveal the contribution of quadrupole-quadrupole interactions to the π-stacking energy. These interactions are significant for heterodimers formed by arenes with more than 2 rings, with absolute values of the traceless quadrupole moment (Q zz) larger than 10 D Å. The further aggregation of neighboring stacks is due to the C-H⋯F interactions in arene/perfluoroarene crystals. In crystals consisting of arene and an electron-deficient compound such as pyromellitic dianhydride, aggregation occurs due to the C-H⋯O interactions. The C-H⋯F and C-H⋯O inter-stacking interactions make the main contribution to the sublimation enthalpy, which exceeds 150 kJ mol-1 for the two-component crystals formed by arenes with more than 2 rings.

Afternoon ward rounds: bad for patients, bad for doctors?

Hospital medicine in the UK is under unprecedented pressure, with increasing demand on physicians as well as challenges in recruiting new doctors into the physicianly specialties. We sought to assess the prevalence of the afternoon ward round and its effect on those undertaking them. We sampled each hospital within our postgraduate region, surveying junior doctors working on inpatient medical wards. We surveyed roughly two-thirds of eligible doctors, -finding that 30% of juniors had some commitment, of varying frequency, to ward rounds beginning after 1.00pm. Of the -doctors involved in afternoon ward rounds, the majority felt they contributed to late finishes, delayed discharge of -patients, reduced team efficiency and reduced job -satisfaction. Just under 80% felt they were less likely to consider a career in hospital medicine as a result The afternoon ward round lives on, and we should not -underestimate its effect. Low junior doctor morale coupled with high work intensity can lead to burnout as well as -impairing the effectiveness of the clinical service. Clinical -leaders should consider leaving this practice in the past so we can cope with the challenges of the future.

Cardiac resynchronization therapy: A comparative analysis of mortality in African Americans and Caucasians.

BACKGROUND: Cardiac resynchronization therapy (CRT) is recommended in patients with heart failure, reduced left ventricular ejection fraction, and a prolonged QRS duration. African Americans are underrepresented in clinical trials and CRT is underutilized; consequently, the benefits and outcomes of CRT are not well-defined. METHODS: We evaluated 294 patients, determined survival using Kaplan-Meier analysis, and used Cox proportional hazards regression model to determine predictors of mortality. Propensity score-match analysis was applied to balance covariates in African Americans and Caucasians. RESULTS: The mean age for African Americans (n  =  131) and Caucasians (n  =  163) was 65 ± 12 and 70 ± 13 years (P  =  0.0003). Mortality in African Americans was 28% compared to 37% in Caucasians (P  =  0.14) over a median follow-up of 8.1 ± 0.6 years. Survival was significantly reduced in African Americans and Caucasians with a glomerular filtration rate (GFR) < 60 (6.7 ± 0.4, 95% confidence interval [CI]: 5.9-7.5 vs 8.6 ± 0.5 CI: 7.7-9.5 years, P  =  0.005), and those not treated with an aldosterone antagonist (7.1 ± 0.4, 95% CI: 6.5-7.9 vs 8.7 ± 0.6, 7.6-9.9 years, P  =  0.04), respectively. Independent predictors of mortality were a GFR <60 and low left ventricular ejection fraction. In African Americans, ischemic cardiomyopathy (ICM) and lack of therapy with an angiotensin-converting enzyme inhibitor (ACEI) or angiotensin II receptor blocker (ARB) were associated with increased mortality. CONCLUSIONS: Long-term survival benefit from CRT was similar in African Americans and Caucasians. A GFR < 60 and lack of therapy with an aldosterone antagonist were associated with decreased survival. Survival also was inversely related to the number of comorbidities. In African Americans, underutilization of an ACEI or ARB, and ICM were additional factors associated with increased mortality.

Sinus Bradycardia in Habitual Cocaine Users.

Common physiological manifestations of cocaine are related to its adrenergic effects, due to inhibition of dopamine and norepinephrine uptake at the postsynaptic terminal. Few studies have documented bradycardia secondary to cocaine use, representing the antithesis of its adrenergic effects. We assessed the prevalence of sinus bradycardia (SB) in habitual cocaine users and postulated a mechanism for this effect. One hundred sixty-two patients with a history of cocaine use were analyzed and compared with age- and gender-matched controls. SB was defined as a rate of <60 beats/min and habitual cocaine use as 2 or more documented uses >30 days apart. Propensity score-matching analysis was applied to balance covariates between cocaine users and nonusers and reduce selection bias. Patients with a history of bradycardia, hypothyroidism, or concomitant beta-blocker use were excluded. Mean age of study patients was 44 ± 8 years. SB was observed in 43 of 162 (27%) cocaine users and in 9 of 149 (6%) nonusers (p = 0.0001). Propensity score-matching analysis matched 218 patients from both groups. Among matched patients SB was observed in 25 of 109 (23%) cocaine users and in 5 of 109 (5%) nonusers (p = 0.0001). Habitual cocaine use was an independent predictor of SB and associated with a sevenfold increase in the risk of SB (95% CI 2.52 to 19.74, p = 0.0002). In conclusion, habitual cocaine use is a strong predictor of SB and was unrelated to recency of use. A potential mechanism for SB may be related to cocaine-induced desensitization of the beta-adrenergic receptor secondary to continuous exposure. Symptomatic SB was not observed; thus, pacemaker therapy was not indicated.

Degeneracy Lifting Effect in the FTIR Spectrum of Fluoroform Trapped in a Nitrogen Matrix. An Experimental and Car-Parrinello Molecular Dynamics Study.

The FTIR spectra of fluoroform trapped in argon and nitrogen matrixes are studied at T ∼ 10-30 K. The bands of E symmetry show the splitting effect in a nitrogen matrix, which is absent in an argon matrix. The effect is the most prominent in the case of the ν4 CH bending vibration. It decreases slightly with increasing temperature. Both static and Car-Parrinello molecular dynamic simulations suggest that the degeneracy lifting is due to C3v symmetry lowering caused by interactions between fluoroform and all neighbor N2 matrix molecules.

Mortality in African-Americans Following Cardiac Resynchronization Therapy: A Single Center Experience.

BACKGROUND: Cardiac resynchronization therapy (CRT) improves clinical outcomes and reduces mortality in heart failure patients who remain symptomatic despite optimal medical therapy. CRT trials have reported significant hemodynamic benefits, improvement in functional status, and reduced mortality and heart failure hospitalizations. However, African-American patient representation in these studies is limited thus the results may not be applicable to them. We described baseline clinical characteristics of African-American patients undergoing CRT and determined their outcomes relative to those reported in clinical trials. METHODS: We evaluated 131 African-American patients with New York Heart Association functional class II-IV heart failure undergoing CRT and determined predictors of all-cause mortality. Kaplan-Meier survival estimates and a Cox proportional hazards model determined mortality and risk of death. RESULTS: The mean age was 65 ± 12 years. Over a 6-year period, total mortality in African-Americans was 23% as compared with 29% in the MADIT-CRT trial. Increased mortality was associated with older age (hazard rate (HR) 1.04, 95% confidence interval (CI) 1.01-1.07, P=.01), ischemic cardiomyopathy (HR 2.86, 95% CI 1.36-6.04, P=.006), and absence of treatment with either an angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker (HR 2.75, 95% CI 1.30-5.80, P=.008), or beta-blocker (HR 2.56, 95% CI 0.98-6.69, P=.05). Hydralazine plus nitrate therapy was used in a small number of patients and did not influence mortality outcomes. CONCLUSION: African-Americans experience the same survival benefits from CRT as Caucasian patients reported in major clinical trials. Publication indices used to find publications listed in references: PubMed.

Biventricular paced QRS predictors of left ventricular lead locations in relation to mortality in cardiac resynchronization therapy.

BACKGROUND: Left ventricular (LV) lead location during cardiac resynchronization therapy (CRT) has influenced mortality and heart failure events; however the biventricular paced QRS morphology has not been established as a predictor of LV lead location or mortality. METHODS: We evaluated the biventricular paced QRS morphology in 306 patients undergoing CRT in relation to specific anatomic locations. A logistic regression model and Kaplan-Meier survival estimates were used to determine predictors of LV lead location and survival. RESULTS: The mean age was 68±13years. Predictors of LV lead location from anterior, lateral, and posterior segments were: absence of R in V1, QS in aVL; and R in aVL, respectively. Absence of an R in II, III, or aVF predicted an inferior site. A QS in V4-V6 differentiated apical from basal sites (p=0.01). LV pacing from sites along the middle cardiac vein revealed a higher mortality (34%), than lateral sites (20%, p=0.02). CONCLUSIONS: Biventricular paced QRS criteria were predictive of LV lead locations. The proposed algorithm enhanced the predictive accuracy of these criteria. LV pacing sites along the middle cardiac vein were associated with increased mortality.

Exenatide's effect in reducing weight and glycosylated hemoglobin level in an Arab population with type 2 diabetes.

OBJECTIVES: To determine whether exenatide is effective in reducing weight and glycosylated hemoglobin level (HbA1c), and to investigate its efficacy in improving lipid profile, blood pressure, and creatinine levels in the Arab population. METHODS: This study was conducted at the Endocrine Unit, Dubai Hospital, Dubai, United Arab Emirates. We retrospectively collected data from patients with type 2 diabetes started on exenatide between November 2011 and February 2012. Data included demographics, clinical, laboratory results, and medications used. A general linear model adjusted by baseline characteristics (weight, HbA1C, age, use of statins, and duration of diabetes) was used to assess changes between baseline and end of trial in HbA1C, weight, low density lipoprotein cholesterol, total cholesterol, triglycerides, creatinine, and blood pressure. RESULTS: After 6 months of treatment with exenatide, the HbA1c decreased by 0.47% (95% confidence level [CI]: -0.01 - 0.95) (p=0.055). Weight reduction was highly significant; 5.6 kg (95% CI: 3.34 - 7.85) (p<0.001). Those reductions remained significant after adjustment for confounding factors. CONCLUSION: This study showed that weight reduction was highly significant with exenatide. The borderline significance in HbA1c reduction can be attributed to the small sample size.