Browsing by Subject "Heart failure"
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Item Admittance measurement for early detection of congestive heart failure(2010-05) Porterfield, John Edward; Pearce, John A., 1946-; Valvano, Jonathan W.; Yilmaz, Ali; Rylander, Henry G.; Feldman, Marc D.Impedance has been used as a tool for cardiac research since the early 1940’s. Recently there have been many advances in this field in the diagnosis of human heart failure through the measurement of pacemaker and ICD coupled impedance detection to determine the state of pulmonary edema in patients through drops in lung impedance. These new detection methods are far downstream of the initial changes in physiology, which signify heart failure risk, namely, an increased left ventricular (LV) end-diastolic volume (also known as preload). This dissertation presents the first formal validation of the complex admittance technique for more accurate blood volume measurement in vivo in mice. It aims to determine a new configuration of admittance measurement in a large scale animal model (pigs). It also aims to prove that “piggybacking” an admittance measurement system onto previously implanted AICD and bi-ventricular pacemakers is a feasible and practical measurement that will serve as an early warning system for impending heart failure through the measurement of LV preload, which appears before the currently measured drop in lung impedance using previous techniques.Item Comparison of healthcare resource utilization, medication use, and costs among heart failure patients with reduced and preserved ejection fraction(2016-05) Tran, Melody; Rascati, Karen L.; Wilson, James P; Godley, Paul JObjectives: To compare health care resource utilization, medication use, and associated costs among heart failure (HF) patients with reduced versus preserved ejection fraction (EF). Methods: We included patients ≥ 18 years of age who had an inpatient admission with a primary discharge diagnosis of HF between October 1, 2011 and September 30, 2014 along with a recent EF measurement. Those with EF ≤ 40% were placed in the reduced EF group, and those with EF ≥ 50% were placed in the preserved EF group. Patients were excluded if they had an index length of stay (LOS) greater than 30 days, a prior heart transplant or LV atrial defibrillator. Baseline characteristics, healthcare utilization and associated costs, comorbidities, and medication use between the two groups were compared using inferential statistics and generalized linear models adjusted for clinical and demographic covariates were used to address the hypotheses, assessing the effect of EF group on utilization, costs, and medication use. Results: A total of 380 HF patients were identified (54% female; mean [SD] age: 78.1 [12.0]), of which 116 (30%) had a reduced EF and 264 (69%) had a preserved EF. Those with preserved EF had a significantly greater proportion of females (60% vs 39%, p<0.001) and were older (mean [SD]: 79.0 [10.8] vs 76.0 [12.0] years, p=0.044). After adjusting for demographics, baseline utilization, and other clinical factors, EF group was not a significant predictor of any healthcare resource utilization or cost variable. Those with reduced EF had a higher prevalence of coronary heart disease (82% vs 62%, p<0.001) and cardiomyopathy (54% vs 15%, p<0.001) compared to those with preserved EF. Depression was more prevalent in HF patients with preserved EF (22% vs 11%, p=0.014) as compared to those with reduced EF. After controlling for demographics, baseline medication use, and other clinical characteristics, HF patients with reduced EF were shown to be less likely to have use of calcium channel blockers (OR: 0.380, 95% CI: 0.181-0.800, p=0.011). Conclusion: This study demonstrated that healthcare utilization and associated costs are similar between HF patients with reduced and preserved EF, thus HF can be considered a single entity in terms of overall resource use. Findings also showed that HF patients with reduced EF have higher prevalence of coronary heart disease and cardiomyopathy, while having lower prevalence of depression. Those with reduced HF also had less use of calcium channel blockers.Item The cost-effectiveness of cardiac monitoring in breast cancer patients who have received cardiotoxic therapies(2012-05) Mann, Teresa A.; Rascati, Karen L.; Skrepnek, Grant H.; Wilson, James P.; Lawson, Kenneth A.; Strassels, ScottIt has been known that anthracycline-based chemotherapy has the potential to cause cardiac dysfunction in breast cancer patients; however, recently evidence has shown that the addition of trastuzumab increases this risk. The study objective was to compare the cost-effectiveness of monitoring for cardiotoxicity with B-type natriuretic peptide (BNP), multi-gated acquisition scanning (MUGA), echocardiography (ECHO) or no monitoring from a payer’s prospective. Cost-effectiveness was compared between alternatives using an incremental cost-effectiveness ratio with outcomes of 1) quality-adjusted life-years and 2) percentage of patients diagnosed with each monitoring strategy. Costs estimates (in 2010 U.S. Dollars) of each strategy (obtained from the Center for Medicare and Medicaid Services website [www.cms.gov]) included the cost of the test, cost of treating heart failure once discovered (which includes medications, routine office visits, medication management) and the cost of potential acute care (which includes emergency department visits and hospitalizations). Estimates for the probabilities of heart failure development, disease progression, need for acute care, and mortality, as well as utility estimates for all disease stages were obtained from published literature. A 15-year time-frame was used with a 3% discount rate for both costs and QALYs. In the base-case analysis, the average costs and QALYs for monitoring patients were $10,062/ 6.92 QALY, $13,627/4.22 QALY, $14,739/ 6.61 QALY and $15,656/ 6.49 QALY for BNP, No Monitoring, ECHO and MUGA respectively. When comparing all alternatives to BNP, the ICER values were negative, indicating that BNP was the dominant monitoring strategy. Percent detection was similar between the three monitoring methods [21-22 % for HER-2(-) and 30-31% for HER-2(+) patients]. Again BNP was dominant over the other monitoring strategies. Sensitivity analyses were robust to changes in discount rate, probability of patients testing HER-2 (+), probability of patients being diagnosed in an asymptomatic stage, incidence of cardiac dysfunction in patients receiving anthracycline therapy ± trastuzumab and estimate of disutility associated with additional testing. A probabilistic sensitivity analysis conducted via Monte Carlo simulation led to the same conclusion as the base-case analysis; BNP was the dominant strategy over all monitoring alternatives.Item Predictive modeling pilot project for readmissions in heart failure patients with preserved ejection fraction(2019-02-06) Xiang, Pin; Wilson, James P.; Rascati, Karen L.Objectives: To pilot a predictive model evaluating hospital readmissions for heart failure with preserved ejection fraction (HFpEF) patients and the association with management by a cardiologist, number of comorbidities, and type of treatment. Methods: This is a retrospective, observational study of claims data to evaluate the effect of various factors: age, gender, provider, baseline inpatient admissions, comorbidities and baseline drug treatment classes (e.g. antiarrhythmic, beta blocker, calcium channel blocker, diuretic, RAAS-inhibiting agents) on number of readmissions, time to readmission, and odds of readmission. Patients ≥18 years of age with an inpatient admission with a primary discharge diagnosis of HFpEF between October 1, 2011 and September 30, 2014 were identified and data were assessed 1-year pre- and post-hospitalization. Patient characteristics were described, and patients treated by a cardiologist were compared to those who were not. Multivariate regression and Cox proportional hazard models were used to assess the association of all-cause and heart failure-related readmissions adjusting for demographic and clinical covariates. Results: A total of 264 patients with HFpEF were identified (60.2% female; mean age of 79 years (SD 10.8) of which 77 [29%] did not see a cardiologist. Patients who saw a cardiologist were more likely to be male and had a greater number of comorbidities including diabetes, dyslipidemia, hypertension, coronary heart disease, cardiomyopathy, and valvular heart disease than those without cardiologist. Overall, 51% of the patients had an all-cause readmission and 15% had an HF-related readmission. Patients who had a cardiologist were associated with more all-cause readmissions (IRR of 2.21, p=0.0003) and a shorter time to all-cause readmissions (HR of 1.91, p=0.004). Being on diuretics was associated with more heart failure-related readmissions (IRR of 2.84, p=0.0301). A higher number of all-cause readmission was associated with patients having more comorbidities (IRR of 1.19, p=0.0038). Conclusion: This study demonstrated that all-cause and heart failure-related readmission is high in patients with HFpEF. The pilot predictive models show that various factors associated with higher risk patients, such as those with cardiologist management, more comorbidities, and use of diuretics, may be associated with increased hospital readmissions.Item Remodeling of the mitral valve : an integrated approach for predicting long-term outcomes in disease and repair(2019-12) Rego, Bruno Vale; Sacks, Michael S.; Baker, Aaron B; Yankeelov, Thomas E; Gorman, Robert CMitral regurgitation (MR) is the most prevalent valvular heart disease, afflicting 2.5% of the western-world population, and is becoming the next cardiac epidemic. MR is characterized by incomplete closure of the mitral valve (MV) caused by either primary (myxomatous degeneration and rheumatic fever) or secondary (ischemic left ventricular remodeling) etiologic factors. Ischemic MR (IMR) afflicts at least 300,000 Americans annually, an alarmingly high number that keeps rising as the population ages and grows. IMR is present in over 50% of patients with reduced left ventricular function induced by myocardial infarction. There are two major treatment strategies for IMR: valve replacement and valve repair. Although repair has long been embraced as the preferred treatment strategy, almost one third of patients experience recurrence of MR within a year of treatment. While new concepts and techniques for MV repair are continually emerging, these novel approaches must be developed with a profound understanding of MV tissue structure and mechanical behavior, which will depend on placing the MV in a larger context of overall left heart function. In addition, a detailed connection must be drawn between stress/strain at the tissue level and cellular deformation, as well as the remodeling pathways triggered via mechanotransduction in response to disease-induced alterations in geometric boundary conditions. In carrying out the research presented in this dissertation, I have aimed to address the questions of when, how, and to what extent the MV apparatus tissues physically remodel in the presence of both pathological (e.g., infarction) and non-pathological (e.g., pregnancy) perturbations to cardiac function. Additionally, I have built advanced computational finite element models to simulate the mechanical effects of disease on valvular function, and to relate disease progression to cellular and tissue-level remodeling phenomena. In parallel, I used state-of-the-art imaging and mechanical characterization tools to develop specialized structural constitutive models for valvular tissues that quantify the effects of microstructural and morphological heterogeneity on local tissue and cellular deformation, both of which play a large role in mediating valvular maintenance (in homeostasis) and remodeling (under non-homeostatic conditions such as disease). The ultimate goal of this work was to progress toward more generalized models of valvular remodeling following perturbations to cardiac function. This, in turn, will lay the groundwork for models that can better predict the outcomes of MV repair, and thus will facilitate the development of computational tools to design and optimize surgical repair strategies in silicoItem The development of a metalloimmunoassay for the detection of NT-proBNP(2021-05-07) Pollok, Nicole Elise; Crooks, Richard M. (Richard McConnell); Richards, Ian; Schiavinato Eberlin, Livia; Anslyn, Eric V.; Hoffman, DavidThe purpose of this doctoral research is to develop a biosensor for the monitoring of heart failure (HF) in humans. Currently, there is no quantitative patient-facilitated method to monitor HF, and the physical symptoms that result are a poor representation of the acute state of the disease. The biomarker of interest is N-terminal prohormone brain natriuretic peptide (NT-proBNP) which is secreted from the cardiac muscle tissue when the heart is experiencing decompensation. The concentration of NT-proBNP has a direct correlation to the severity of HF, and it is used as the antigen in a metalloimmunoassay, where two monoclonal antibodies are used to sandwich NT-proBNP. One is conjugated to a magnetic microbead via a streptavidin-biotin interaction, and the other is conjugated to a 20 nm-diameter silver nanoparticle (AgNP) using a heterobifunctional cross-linker. The fully formed metalloimmunoassay is placed on a carbon screen-printed and Au electrodeposited sensing electrode to detect AgNP labels electrochemically. Ag charge collected from the assay is representative of the concentration of NT-proBNP in the sample. A phenomenon known as galvanic exchange (GE) is utilized in the detection of Ag. GE is a process that occurs when a zerovalent metal is immersed in a solution containing the oxidized form of a more noble metal. In this specific case, the exchange occurs between AgNP in the metalloimmunoassay and Au³⁺ generated on the sensing electrode. GE occurs because the standard reduction potential of Ag⁺ is slightly lower than Au³⁺. Significant findings of this project reveal that GE between AgNP and Au³⁺ is a process that results in only a partial exchange of AgNP with the Au³⁺ under physiologic conditions. It has also been found that, implementing two subsequent Au³⁺ electrogeneration steps improve the Ag collection efficiency and the reproducibility. Additionally, using heterobifunctional cross-linkers to covalently attach antibodies to AgNP and silver nanocubes (AgNCs) results in a lower limit of detection. These findings have led to the detection of NT-proBNP in buffer within clinically relevant ranges of 0.06-3.49 nM.Item Utilizing the All of Us Research Program : exploring the use of wearable activity trackers in adults with heart failure(2023-04-21) Leggio, Katelyn E.; Radhakrishnan, Kavita; Koleck, Theresa A; Zuniga, Julie A; Kesler, ShelliHeart Failure (HF) continues to be a social and economic problem in the United States (US). Interventions to improve outcomes have focused on reducing 30-day readmissions while concerns remain with increasing post-discharge mortality and 60- and 90-day readmission rates. Self-care interventions are essential to improve outcomes, yet there remain issues with the sustained engagement of behavioral changes. Activity trackers have been shown to increase physical activity for adults with HF; however, questions remain if they motivate individuals for sustained engagement over time as well as influence health care utilization and quality of life (QoL). This study aims to understand the overall impact of wearable activity trackers as a self-care tool on health behaviors and health outcomes in adults with HF using the All of Us dataset. Firstly, a systematic review examined six research articles using a Fitbit or Apple Watch as an intervention in adults with HF. Study participants improved or had no change from baseline in QoL, health behaviors (steps/day or general daily activity), and physical parameters (6MWT, weight, or blood pressure); not all results were statistically significant. Subsequently, a cross-sectional analysis of the All of Us Research Program participant data (survey responses, Fitbit, and electronic health record [EHR] data) of adults with HF (n = 93) was conducted. Multiple linear regression was performed to predict scores for Patient-Reported Outcomes Measurement Information System (PROMIS) Global Health Short Form subscale scores for Physical Health and Mental Health based on Fitbit usage (duration and level of activity), social support, perceived stress, food security, and neighborhood safety. People with HF and reported Fitbit use (n = 93) and lack of reported perceived stress (B = -0.312, p = .022) and level of activity (B = 3.868, p= 0.044) were significant predictors for Physical Health. Perceived stress (B= -0.689, p < 0.001) was a significant predictor of Mental Health. Fitbit users (n = 93) were compared to non-reported users (n = 1,577) and the analysis failed to demonstrate a difference in days hospitalized and self-reported Physical Health and Mental Health. Finally, the last aim of this dissertation was to demonstrate methods for using the All of Us Research Program in a nursing dissertation by providing a step-by-step guide for designing a research project, exemplar R codes for calculating outcome scores such as PROMIS Global Health, and a review of the facilitators and barriers encountered. This dissertation advances science in several ways, including (1) addressing personalized self-care strategies important for developing precision health interventions in adults with HF, (2) providing a longitudinal perspective on the influence of Fitbit usage in adults with HF, and (3) providing a guide for nursing doctoral students to utilize the All of Us Research Program in dissertation studies.