Is postoperative cognitive decline after cardiac surgery associated with plasma beta amyloid 1–42 levels?

Background Postoperative cognitive decline following cardiac surgery is one of the frequently reported complications affecting postoperative outcome, characterized by impairment of memory or concentration. The aetiology is considered multifactorial and the research conducted so far has presented contradictory results. The proposed mechanisms to explain the cognitive decline associated with cardiac surgery include the neurotoxic accumulation of β-amyloid (Aβ) proteins similar to Alzheimer's disease. The comparison of coronary artery bypass grafting procedures concerning postoperative cognitive decline and plasmatic Aβ1-42 concentrations has not yet been conducted. Methods The research was designed as a controlled clinical study of patients with coronary artery disease undergoing surgical myocardial revascularization with or without the use of a cardiopulmonary bypass machine. All patients completed a battery of neuropsychological tests and plasmatic Aβ1-42 concentrations were collected. Results The neuropsychological test results postoperatively were significantly worse in the cardiopulmonary bypass group and the patients had larger shifts in the Aβ1-42 preoperative and postoperative values than the group in which off-pump coronary artery bypass was performed. Conclusions The conducted research confirmed the earlier suspected association of plasmatic Aβ1-42 concentration to postoperative cognitive decline and the results further showed that there were less changes and lower concentrations in the off-pump coronary artery bypass group, which correlated to less neurocognitive decline. There is a lot of clinical contribution acquired by this research, not only in everyday decision making and using amyloid proteins as biomarkers, but also in the development and application of non-pharmacological and pharmacological neuroprotective strategies.

Effect of different storage solutions on oxidative stress in human saphenous vein grafts

Background Ischemia–reperfusion injury of saphenous vein grafts (SVG) during coronary artery bypass grafting surgery negatively impacts endothelial integrity and functionality and is associated with vein graft failure. The aim of this study was to evaluate the level of oxidative stress in human SVG segments following ischemic storage in three intraoperative graft storage solutions: saline (S), autologous heparinized blood (HB) and DuraGraft (DG). Methods 3 mm tissue rings derived from surplus SVG segments from 50 patients were stored at room temperature for 30 min in DG, S or HB. Total oxidative status (TOS) and total antioxidant status (TAS) levels were determined from which the oxidative stress index (OSI: TOS/TAS ratio) was calculated. A p-value < 0.017 was considered significant implementing a Bonferroni correction. Results TOS values were significantly lower for DG stored samples in comparison to both S and HB; there was no difference between S and HB (DG: 32.6 ± 1.8, S: 39.6 ± 2.8 and HB: 40.6 ± 2.4 µmol H2O2 eqv.; DG vs. S and DG vs. HB p < 0.0001, S vs. HB p = 0.047). TAS was higher for both DG and HB in comparison to S (DG: 8.9 ± 0.9, S: 6.9 ± 1.0 and HB: 8.6 ± 0.9 mmol Trolox eqv.; DG vs S p < 0.0001, DG vs. HB p = 0.263, S vs. HB p < 0.0001). OSI differed between all groups with the lowest value for DG (DG: 3.7 ± 0.2, S: 5.8 ± 0.4 and HB: 4.7 ± 0.2 µmol H2O2 eqv./mmol Trolox eqv.; all p < 0.0001). Conclusions Saphenous veins grafts stored in DuraGraft had a lower oxidative level, higher antioxidant level and a lower oxidative stress index in comparison to saphenous vein grafts stored in saline or heparinized blood. ClinicalTrials.gov Identifier NCT02922088.

The Neutrophil to Lymphocyte Ratio and Serum Albumin as Predictors of Acute Kidney Injury After Coronary Artery Bypass Grafting

Postoperative acute kidney injury (AKI) is a highly prevalent and serious complication after cardiac surgery. The aim of this study is to identify the predictors of AKI and the cut-off values after isolated off-pump coronary artery bypass grafting (OPCAB). A total of 329 adult patients, who underwent isolated OPCAB between December 2008 and February 2021, were retrospectively analyzed. The patients were divided into three groups: non-AKI, early AKI and late AKI groups. The early AKI group or the late AKI group were defined as ‘having AKI that occurred before or after 48 hours postoperatively’, respectively. Multivariate logistic regression analysis was performed to identify the predictors of AKI. Receiver operating characteristic (ROC) curve analysis was used to evaluate the cutoff value, the sensitivity, and the specificity of the predictors. On the multivariate analysis, the emergency surgery, the preoperative serum albumin, and the postoperative day 1 neutrophil to lymphocyte ratio (NL ratio) were identified as the independent predictors of AKI. However, neither albumin nor the NL ratio predicted late AKI. The present study showed the preoperative albumin and the postoperative day 1 NL ratio were the robust and independent predictors of postoperative early AKI in isolated OPCAB.

Microcirculatory Response to Blood vs. Crystalloid Cardioplegia During Coronary Artery Bypass Grafting With Cardiopulmonary Bypass

Background: Blood cardioplegia attenuates cardiopulmonary bypass (CPB)-induced systemic inflammatory response in patients undergoing cardiac surgery, which may favorably influence the microvascular system in this cohort. The aim of this study was to investigate whether blood cardioplegia would offer advantages over crystalloid cardioplegia in the preservation of microcirculation in patients undergoing coronary artery bypass grafting (CABG) with CPB.Methods: In this prospective observational cohort study, 20 patients who received crystalloid (n = 10) or blood cardioplegia (n = 10) were analyzed. The microcirculatory measurements were obtained sublingually using incident dark-field imaging at five time points ranging from the induction of anesthesia (T0) to discontinuation of CPB (T5).Results: In the both crystalloid [crystalloid cardioplegia group (CCG)] and blood cardioplegia [blood cardioplegia group (BCG)] groups, perfused vessel density (PVD), total vessel density (TVD), and proportion of perfused vessels (PPV) were reduced after the beginning of CPB. The observed reduction in microcirculatory parameters during CPB was only restored in patients who received blood cardioplegia and increased to baseline levels as demonstrated by the percentage changes from T0 to T5 (%Δ)T0−T5 in all the functional microcirculatory parameters [%ΔTVDT0−T5(CCG): −10.86 ± 2.323 vs. %ΔTVDT0−T5(BCG): 0.0804 ± 1.107, p &lt; 0.001; %ΔPVDT0−T5(CCG): −12.91 ± 2.884 vs. %ΔPVDT0−T5(BCG): 1.528 ± 1.144, p &lt; 0.001; %ΔPPVT0−T5(CCG): −2.345 ± 1.049 vs. %ΔPPVT0−T5(BCG): 1.482 ± 0.576, p &lt; 0.01].Conclusion: Blood cardioplegia ameliorates CPB-induced microcirculatory alterations better than crystalloid cardioplegia in patients undergoing CABG, which may reflect attenuation of the systemic inflammatory response. Future investigations are needed to identify the underlying mechanisms of the beneficial effects of blood cardioplegia on microcirculation.

Trend, Predictors and Outcomes of Combined Mitral Valve Replacement and Coronary Artery Bypass Graft in Patients with Concomitant Mitral Valve and Coronary Artery Disease; A National Inpatient Sample Database Analysis

Combined mitral valve replacement (MVR) and coronary artery bypass graft (CABG) procedures have been the norm for patients with concomitant mitral valve disease (MVD) and coronary artery disease (CAD) with no large-scale data on their safety and efficacy. Methods The National Inpatient Sample (NIS) database (2002-2018) was queried to identify patients undergoing MVR and CABG. The major adverse cardiovascular events (MACE) and its components were compared using a propensity score-matched (PSM) analysis to calculate adjusted odds ratios (OR). Results A crude population of 6,145,694 (CABG-only 3,971,045, MVR-only 1,933,459, MVR+CABG 241,190), while a subset of matched cohort 724,237 (CABG-only 241,436, MVR-only 241,611 vs. MVR+CABG 241,190) was included in the PSM analysis. The combined MVR+CABG procedure had significantly higher adjusted odds of MACE (OR 1.13, 95% CI 1.11-1.14 and OR 1.96, 95% CI 1.93-1.99) and in-hospital mortality (OR 1.29, 95% CI 1.27-1.31 and OR 2.1, 95% CI 2.05-2.14) compared with CABG and MVR-alone, respectively. Similarly, the risk of post-procedure bleeding, major bleeding, acute kidney injury, cardiogenic shock, sepsis, need for intra-aortic balloon pump (IABP), mean length of stay (LOS) and total charges per hospitalization were significantly higher for patients undergoing the combined procedure. These findings remained consistent on yearly trend analysis favoring the isolated CABG and MVR groups. Conclusion Combined procedure (MVR+CABG) in patients with MVD and CAD appears to be associated with worse in-hospital outcomes, increased mortality and higher resource utilization compared with isolated CABG and MVR procedures. Randomized controlled trials are needed to determine the relative safety of these procedures in the full spectrum of baseline valvular and angiographic characteristics.

Risk and benefits of temporary pacemaker electrodes in adult open-heart surgery—a systematic review

Background To assess the achieved risk and benefits of inserting temporary epicardial pacemaker electrodes after open-heart surgery for potential treatment of postoperative cardiac arrhythmias, and to investigate the extent of its use in clinical practice. Main text A systematic search was conducted in PubMed and repeated in Embase and Scopus using the PRISMA guidelines. The search identified 905 studies and resulted in 12 included studies, where the type of surgery, study design, total number of included patients, number of patients having temporary pacemaker electrodes inserted, number of patients requiring temporary pacing, primary reason for pacing, significant factors predicting temporary pacing, registered complications and study conclusion were assessed. Eight papers concluded that routine insertion of temporary pacemaker electrodes in all postoperative patients is unnecessary. One paper concluded that they should always be inserted, while three papers concluded that pacing is useful in the postoperative period, but did not recommend a frequency of which they should be inserted. Conclusions The literature suggests that the subgroup of younger otherwise healthy patients without preoperative arrhythmia having isolated coronary artery bypass grafting surgery or single valve surgery should not routinely have temporary pacemaker electrodes inserted.