Browsing by Subject "stress test"
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Item Open Access Predictors of Stress-Delta High-Sensitivity Troponin T in Emergency Department Patients Undergoing Stress Testing.(Cureus, 2022-09) White, Emily J; Susman, Stephen J; Bouffler, Andrew; Leahy, J Clancy; Griffin, S Michelle; Christenson, Robert; Newby, L Kristin; Gordee, Alexander; Kuchibhatla, Maragatha; Limkakeng, Alexander TBackground and objective Elevations in high-sensitivity troponin T (hs-TnT) are frequently observed following extreme physical exercise. In light of this, we sought to determine whether specific clinical characteristics are associated with this phenomenon in patients undergoing cardiac exercise tolerance testing (ETT). Methods We conducted a retrospective analysis of a prospectively collected biospecimen repository of 257 patients undergoing a stress echocardiogram for possible acute coronary syndrome (ACS). Ischemic electrocardiogram (ECG) changes during ETT and the presence or absence of ischemia on imaging were determined by a board-licensed cardiologist. N-terminal pro-brain natriuretic peptide (NT-proBNP) and hs-TnT assays were obtained immediately before and two hours following ETT. We developed linear regression models including several clinical characteristics to predict two-hour stress-delta hs-TnT. Variable selection was performed using the least absolute shrinkage and selection operator (LASSO). Results The mean age of the patients was 52 years [standard deviation (SD): 11.4]; 125 (48.6%) of them were men, and 88 (34.2%) were African-American. Twenty-two patients (8.6%) had ischemia evident on echocardiography, and 31 (12.1%) had ischemic ECG changes during exercise. The mean baseline hs-TnT was 5.6 ng/L (SD: 6.4) and the mean two-hour hs-TnT was 7.1 ng/L (SD: 10.2). Age and ischemic ECG changes were associated with two-hour stress-delta hs-TnT values. Conclusions Based on our findings, ischemic changes in stress ECG and age were associated with an increase in hs-TnT levels following exercise during a stress echo.Item Open Access Revealing Asset Quality: Liquidity Signaling and Optimal Stress Tests(2015) Williams, BasilIn my first chapter, I present a model in which sellers can signal the quality of an asset both by retaining a fraction of the asset and by choosing the liquidity of the market in which they search for buyers. Although these signals may seem interchangeable, I present two settings which show they are not. In the first setting, sellers have private information regarding only asset quality, and I show that liquidity dominates retention as a signal in equilibrium. In the second setting, both asset quality and seller impatience are privately known, and I show that both retention and liquidity operate simultaneously to fully separate the two dimensions of private information. Contrary to received theory, the fully separating equilibrium of the second setting may contain regions where market liquidity is increasing in asset quality. Finally, I show that if sellers design an asset-backed security before receiving private information regarding its quality, then the optimality of standard debt is robust to the paper's various settings.
In my second chapter, I explore the question of how informative bank stress tests should be. I use Bayesian persuasion to formalize stress tests and show that regulators can reduce the likelihood of a bank run by performing tests which are only partially informative. Optimal stress tests give just enough failing grades to keep passing grades credible enough to avoid runs. The worse the state of the banking system, the more stringent stress tests must be to prevent runs. I find that optimal stress tests, by reducing the probability of runs, reduce the optimal level of banks' capital cushions. I also examine the impact of anticipated stress tests on banks' ex ante incentive to invest in risky versus safe assets.