Biomarker dynamics in cardiac surgery: a prospective observational study on MR-proADM, MR-proANP, hs-CRP and sP-selectin plasma levels in the perioperative period

Background: For many biomarkers in cardiac surgery, there is a lack of knowledge regarding the normal dynamics of plasma levels during the perioperative course. The aim of this study was to investigate the perioperative dynamics of MR-proADM, MR-proANP, hs-CRP and sP-selectin in cardiac surgery. Method: A prospective observational pilot study with 20 patients scheduled for open cardiac surgery procedures with cardiopulmonary bypass (CPB). Plasma samples were taken for each patient and biomarker during the pre-, per- and postoperative period until Day 6 postoperatively. Results: MR-proADM increased significantly from 0.62 [IQR; 0.54-0.93] nmol/L preoperatively to 1.20 [1.04-1.80] nmol/L postoperative Day 1. MR-proANP increased significantly from 125 [77-152] pmol/L preoperatively to 198 [168-307] pmol/L on weaning from CPB. hs-CRP increased significantly from 2.5 mg/L [0.4-12] preoperatively to peak at 208 mg/L [186-239] postoperative Day 3. The preoperative level of sP-selectin at 23.0 [21.3-26.3] ng/mL initially fell at weaning from CPB, followed by a significant peak of 25.5 [22.7-27.7] ng/mL 8 h postoperatively. Conclusions: The findings in this study may help to understand the physiology of the biomarkers analysed and their response to cardiac surgical trauma including CPB. Furthermore, these findings will guide us in further research on the clinical usefulness of these biomarkers.Funding Agencies|ALF Grants, Region Ostergotland</p

Effects of thoracic epidural analgesia on exercise-induced myocardial ischaemia in refractory angina pectoris

Background Thoracic epidural analgesia (TEDA) was offered to patients with refractory angina pectoris. Our primary objectives were to evaluate TEDAs influence on quality of life (QoL, base for power analysis), and hypothesising that TEDA with bupivacaine during 1 month counteracts exercise-induced myocardial hypoperfusion and increase physical performance. Methods Patients with refractory angina and exercise inducible hypoperfusion, as demonstrated by myocardial perfusion imaging (MPI), were randomised to 1-month treatment with TEDA with bupivacaine (B-group, n = 9) or saline (P-group, n = 10) in a double-blind fashion. MPI and bicycle ergometry were performed before TEDA and after 1 month while subjective QoL on a visual analogue scale (VAS) reported by the patients was checked weekly. Results During this month VAS (mean [95%CI]) increased similarly in both groups (B-group from 33 [18-50] to 54 [30-78] P P amp;lt; 0.05). The B-group reduced their exertional-induced myocardial hypoperfusion (from 32% [12-52] to 21% [3-39]; n = 9; P amp;lt; 0.05), while the P-group showed no significant change (before 21% [6-35]; at 1 month 23% [6-40]; n = 10). MPI at rest did not change and no improvement in physical performance was detected in neither of the groups. Conclusions In refractory angina, TEDA with bupivacaine inhibits myocardial ischaemia in contrast to TEDA with saline. Regardless of whether bupivacaine or saline is applied intermittently every day, TEDA during 1 month improves the quality of life and reduces angina, even when physical performance remains low. A significant placebo effect has to be considered.Funding Agencies|Karolinska Institutet; County Council of Ostergotland</p

Comparison of serum cystatin C and creatinine changes after cardiopulmonary bypass in patients with normal preoperative kidney function

Purpose Serum creatinine is used ubiquitously to estimate glomerular filtration rate and to diagnose acute kidney injury after cardiac surgery. Serum cystatin C is a novel biomarker that has emerged as a possible diagnostic alternative to serum creatinine. It is unclear if the dynamic changes in serum cystatin C immediately following cardiopulmonary bypass (CPB) differ from those of serum creatinine in patients with normal preoperative kidney function. Methods We compared changes in serum levels of creatinine and cystatin C by measuring them serially in 19 patients undergoing CPB. Within-patient differences for serum creatinine and serum cystatin C were compared by repeated measures ANOVA. Results Serum creatinine and cystatin C levels showed significant correlation with each other. Both biomarkers showed a significant decrease after CPB, but their serum concentrations reverted to pre-CPB levels within 12 h. Serum levels of serum creatinine remained unchanged from baseline levels throughout 72-h post-CPB. In contrast, serum cystatin C levels rose further and became significantly higher compared to baseline within 48 h. Serum cystatin C remained significantly elevated at 48- and 72-h post-CPB. Conclusions Processes that determine the serum concentrations of serum creatinine and cystatin C in the post-CPB period affect the two biomarkers differently, suggesting that the two are not interchangeable as diagnostic markers of glomerular filtration rate. Future studies are needed to examine if these discrepancies are related to differences in their production rates, in their ability to detect small changes in glomerular filtration rate, or to a combination of these, and to determine the effect of such differences on the diagnostic and prognostic accuracy of the two biomarkers