Search

Background: Ischemia/reperfusion injury contributes to periprocedural myocardial injury (PMI) in patients undergoing percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). PMI can be estimated by the elevation of troponin (Tn) and creatine kinase-MB (CKMB) plasma levels, and it is associated with increased risk of cardiovascular events and mortality. Vitamin C might have a beneficial effect on PMI by improving endothelial function, improving myocardial perfusion, and by reducing oxidative stress generated during/after reperfusion. In several small animal models of cardiac stress, vitamin C reduced the increase in Tn and CKMB levels. The aim of this meta-analysis was to investigate whether vitamin C administration may have an effect on Tn and CKMB levels in patients undergoing PCI or CABG. Methods: We searched PubMed, Cochrane, Embase and Scopus databases for controlled clinical trials reporting on Tn and CKMB levels in adult patients who underwent PCI or CABG and received vitamin C. As secondary outcomes we collected data on biomarkers of oxidative stress in the included trials. In our meta-analysis, we used the relative scale and estimated the effect as the ratio of means. Results: We found seven controlled trials which included 872 patients. All included trials administered vitamin C intravenously, with a range from 1 to 16 g/day, and all initiated vitamin administration prior to the procedure. Vitamin C decreased peak Tn plasma levels in four trials on average by 43% (95% CI: 13 to 63%, p = 0.01) and peak CKMB plasma levels in five trials by 14% (95% CI: 8 to 21%, p < 0.001). Vitamin C also significantly decreased the biomarkers of oxidative stress. Conclusions: Vitamin C may decrease cardiac enzyme levels in patients undergoing elective PCI or CABG. This may be explained partially by its antioxidant effects. Our findings encourage further research on vitamin C administration during cardiac procedures and in other clinical contexts that increase the level of cardiac enzymes. Future studies should search for an optimal dosing regimen, taking baseline and follow-up plasma vitamin C levels into account. [ABSTRACT FROM AUTHOR]

The myocardial infarction (MI) types 4a and 5 guidelines recommend cardiac troponin (cTn) diagnostic decision limits of 5 and 10 times the 99th percentile, respectively. Different cTn kits elicit different responses, so the MI diagnosis is still challenging. The study aimed to establish the cutoff values and the accuracy of three different cTnI kits in the diagnosis of post-procedural MI. We analyzed 115 patients with multivessel stable chronic coronary artery disease; 26 underwent percutaneous coronary intervention, and 89 underwent coronary artery bypass graft. Delayed-enhancement magnetic resonance imaging was performed before and after each intervention for definitive MI diagnoses. Two contemporary and one high-sensitivity cTnI immunoassays were used. ROC curves determined the accuracy of each assay. Low accuracy was observed after applying the current guidelines recommendations. The three cTnI assays accuracies improved when adjusted by the new ROC cutoffs, reaching 82% for MI type 5 for all assays, and 78%, 88%, and 87% for MI type 4 for Siemens, Beckman, and Abbott, respectively. The ultrasensitive and contemporary tests' accuracy for MI types 4a and 5 diagnoses are equivalent when adjusted for these new cutoffs. The hs-cTnI assays had lower accuracy than contemporary tests for MI types 4a and 5 diagnoses. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Surgery & Medicine (JOSAM) is the property of Journal of Surgery & Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objectives. While long-term endurance exercise is known to increase cardiac biomarkers, only a few studies on short-term exercise and these markers have been reported. The aim of this study was to investigate the acute effects of a one-hour bicycle spinning on cardiac biomarkers in healthy individuals. Design. Serum levels of high-sensitive troponin T (TnT), creatinine kinase MB fraction (CK-MB), N-terminal pro-brain natriuretic peptide (NT-proBNP), creatinine kinase (CK) and myoglobin were measured at baseline, 1 and 24 hour after one hour of spinning exercise in ten healthy and fit (age 31.0 ± 6.6 years) individuals. Results. TnT doubled one hour post-exercise (All values ≤ 5 - 9.7 ± 6.0 ng/L, p < 0.001). Two individuals had TnT levels above upper reference limit, URL (20.7 and 20.2 ng/L, URL == 12 ng/L). Myoglobin levels increased 72% one hour post-exercise (38 ± 20 - 66 ± 41 mg/L, p < 0.02). TnT and myoglobin levels returned to baseline 24 hour post-exercise. Serum levels of CK-MB, NT-proBNP and CK were not significantly changed. Conclusions. A single-bout of one-hour bicycle spinning transiently increases TnT and myoglobin in healthy subjects. Some subjects even have TnT release above URL. Thus, recently performed exercise also of short duration should be taken into consideration in the evaluation of acute chest pain with release of cardiac TnT. [ABSTRACT FROM AUTHOR]

: ObjectivesTo examine the proportion of patients admitted to CCU because of chest pain with a negative quantitative troponin t-test (Cardiac reader; Roche), who despite the negative test, would fulfil the new myocardial infarction criteria. A second aim was to evaluate the clinical utility of troponin I.: Design and methodsTroponin T (Cardiac reader; Roche) was measured 12 h after the last chest pain episode. If Troponin T was negative the subjects were included in the study. All included subjects were also examined with troponin I (Stratus CS; Dade Behring) and troponin T at the central laboratory (Elecsys 2010) at the same time. 187 patients were included. CKMB was also measured 6 h after the last chest pain (Stratus CS; Dade Behring).: ResultsFifth teen patients (8.0%) fulfilled the criteria of myocardial infarction, despite a negative Troponin T (Cardiac reader; Roche). CKMB measures did not add useful diagnostic information. The sensitivity and specificity were 100% and 95.3%, respectively for troponin I, when 0.2 μg/L was used as cut off level for myocardial infarction.: ConclusionIn this low risk group, eight percent of the patients with a negative Troponin T (Cardiac reader; Roche) fulfilled the new criteria of myocardial infarction. Troponin I (Stratus CS; Dade Behring) appeared to be a reliable method in this group. [Copyright &y& Elsevier]