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.