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SummaryAimTo determine whether there is a correlation between cardiac markers and peri-operative myocardial injury (PMI) and apoptosis in coronary artery bypass graft (CABG) surgery and to compare the efficacy of cardiac markers to detect PMI.MethodsThe study population consisted of 37 patients (24 male, 13 female, mean age 63.4 ± 8.9 years) undergoing elective CABG. Arterial and coronary sinus blood samples were collected just before aortic cross-clamping (pre-ACC) and after aortic declamping (post-ACC). Creatine kinase-MB isoenzyme (CK-MB) activity, and high-sensitivity cardiac troponin T (hs-cTnT), creatine kinase-MB isoenzyme mass (CK-MB mass) and cardiac troponin I (cTnI) concentrations were measured in blood samples. Myocardial injury and apoptosis were examined in atrial biopsies.ResultsCABG caused PMI and apoptosis in all cases. Concentrations and net releases of cardiac markers significantly increased after aortic declamping (p < 0.001 for CK-MB and CK-MB mass, p < 0.01 for cTnI, p < 0.05 for hs-cTnT). A positive correlation was found between apoptotic index (r = 0.611, p < 0.001 for cTnI; r = 0.806, p < 0.001 for hs-cTnT), myocardial injury score (r = 0.544, p < 0.001 for cTnI; r = 0.719, p < 0.001 for hs-cTnT) and cTnI and hs-cTnT values in the post-ACC period. A positive correlation was found between apoptotic index (r = 0.507, p < 0.001), myocardial injury score (r = 0.416, p = 0.010) and net release of hs-cTnT. Furthermore, a positive correlation was found between aortic cross-clamp (ACC) time (r = 0.448, p = 0.007), cardiopulmonary bypass (CPB) time (r = 0.342, p = 0.047) and net release of hs-cTnT.ConclusionAlthough both cTnI and hs-cTnT may be specific and efficacious markers of myocardial apoptosis and injury occurring during CABG with CPB, hs-cTnT may be a more useful marker than cTnI to detect peri-operative myocardial apoptosis and injury.

IntroductionTotal 25-hydroxyvitamin D [25(OH)D] is the most reliable indicator of vitamin D status. In this study, we compared two automated immunoassay methods, the Abbott Architect 25-OH Vitamin D assay and the Roche Cobas Vitamin D total assay, with the liquid chromatography-tandem mass spectrometry (LC-MS/MS).Materials and methodsOne hundred venous blood samples were randomly selected from routine vitamin D tests. Two of the serum aliquots were analyzed at the Abbott Architect i2000 and the Roche Cobas 6000’s module e601 in our laboratory within the same day. The other serum aliquots were analyzed at the LC-MS/MS in different laboratory. Passing-Bablok regression analysis and Bland-Altman plot were used to compare methods. Inter-rater agreement was analyzed using kappa (κ) analysis.ResultsThe Roche assay showed acceptable agreement with the LC-MS/MS based on Passing-Bablok analysis (intercept: -5.23 nmol/L, 95% CI: -8.73 to 0.19; slope: 0.97, 95% CI: 0.77 to 1.15). The Abbott assay showed proportional (slope: 0.77, 95% CI: 0.67 to 0.85) and constant differences (intercept: 17.08 nmol/L; 95% CI: 12.98 to 21.39). A mean bias of 15.1% was observed for the Abbott and a mean bias of -14.1% was observed for the Roche based on the Bland-Altman plots. We found strong to nearly perfect agreement in vitamin D status between the immunoassays and LC-MS/MS. (κ: 0.83 for Abbott, κ: 0.93 for Roche) using kappa analysis.ConclusionBoth immunoassays demonstrated acceptable performance, but the Roche Cobas assay demonstrated better performance than the Abbott Architect in the studied samples.

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IntroductionMeasurements of blood ethanol concentrations must be accurate and reliable. The most important factors affecting blood ethanol stability are temperature and storage time. In this study, we aimed to compare ethanol stability in plasma samples at -20 °C for the different storage periods.Materials and methodsBlood samples were collected from intoxicated drivers (N = 80) and initial plasma ethanol concentrations were measured immediately. Plasma samples were then stored at -20 °C and re-assessed after 2, 3, 4, or 5 months of storage. Differences between the initial and stored ethanol concentrations in each group (N = 20) were analyzed using Wilcoxon matched-pairs test. The deviation from the initial concentration was calculated and compared with Clinical Laboratory Improvement Amendments (CLIA’88) Proficiency Testing Limits. Relationships between the initial concentrations and deviations from initial concentrations were analyzed by Spearman’s correlation analysis. For all statistical tests, differences with P values of less than 0.05 were considered statistically significant.ResultsStatistically significant differences were observed between the initial and poststorage ethanol concentrations in the overall sample group (P < 0.001). However, for the individual storage duration groups, analytically significant decreases were observed only for samples stored for 5 months, deviations from the initial concentrations exceeded the allowable total error (TEa). Ethanol decreases in the other groups did not exceed the TEa.ConclusionAccording to our results, plasma ethanol samples can be kept at -20 °C for up to 3-4 months until re-analysis. However, each laboratory should also establish its own work-flow rules and criterion for reliable ethanol measurement in forensic cases.