Context: Cardiac troponins have become the gold standard for diagnosing acute myocardial infarction (AMI) in the general population; however, their diagnostic accuracy for hemodialysis (HD) patients presenting with chest pain or dyspnea is uncertain. Objective: To examine the diagnostic accuracy of high-sensitivity cardiac troponin T (hs-cTnT) assay for AMI in HD patients. Design: In this prospective study, we enrolled 670 consecutive stable HD patients presenting with chest pain or dyspnea on routine predialysis therapy in the nephrology department. Receiver operating characteristic (ROC) curves were used to examine the diagnostic accuracy of hs-cTnT levels at enrollment in HD patients presenting with chest pain or dyspnea, and the dynamic change in these levels after 3 hours. Results: Acute myocardial infarction was the adjudicated final diagnosis in 12% of HD patients. Among patients with a final diagnosis other than AMI, 97% had a plasma hs-cTnT concentration above the 99th percentile. At the time of enrollment, the area under the ROC curve of hs-cTnT levels for diagnosis of AMI was 0.68 (95% confidence interval [CI], 0.62–0.74; P < .001) with a cutoff value of 107.7 ng/L; the relative change after 3 hours was 0.90 (95% CI, 0.82–0.96, P < .001) with a cutoff value of 24%, and the absolute change was 0.88 (95% CI, 0.82–0.94, P < .001) with a cutoff value of 32.6 ng/L. The prognostic value for 40-day mortality varied with the magnitude of elevation in hs-cTnT levels. Conclusions: Tracking the dynamic change in hs-cTnT levels during the short term significantly increased this measure's diagnostic accuracy for AMI in HD patients.

The microstructure, mechanical performance, and tribological properties of SiC ceramic coatings prepared via atmospheric plasma spraying (APS) and chemical vapor deposition (CVD) method were compared to provide good anti-wear protection for carbon/carbon composites. The surface morphology of the APS-SiC coating was characterized as having a porous structure, whilst the CVD-SiC coating presented with many pyramidal-shaped crystals constituting the surface. The APS-SiC coating consists of a dominating SiC phase and a small fraction of the Si phase, while the XRD pattern of the CVD-SiC coating mainly consists of the SiC phase. The dense crystalline microstructure of the CVD-SiC coating made it possess a higher hardness and Young’s modulus at 31.0 GPa and 275 GPa, respectively. The higher H/E and H³/E² parameters of the CVD-SiC coating implied that it exhibited better plastic resistance, which is also beneficial for anti-wear properties. The scratch test reflected the critical loads of the spallation of the APS-SiC coating and CVD-SiC coating, which were evaluated to be 25.9 N and 36.4 N, respectively. In the tribological test, the friction coefficient of the APS-SiC coating showed obvious fluctuations at high load due to damage to the SiC coating. The wear mechanism of the APS-SiC coating was dominated by abrasive wear and fatigue wear, while CVD-SiC was mainly dominated by abrasive wear. The wear rate of the CVD-SiC coating was far below that of the APS-SiC coating, suggesting the better wear-resistance of the CVD-SiC coating.