Effects of Isolated Impaired Fasting Glucose on Brain Injury During Cardiac Surgery Under Cardiopulmonary Bypass

The Effects of Carotid Revascularization on 1-Year Cognitive Performance in Patients With Carotid Artery Stenosis

PURPOSE

The impact of carotid revascularization on cognitive function for patients with severe carotid artery stenosis remains uncertain. This study is aimed to investigate the 1-year neurocognitive outcomes of patients who accept carotid revascularization and identify the risk factors associated with postoperative cognitive decline.

METHODS

From April 2019 to April 2021, patients with ≥70% carotid artery stenosis who were treated with carotid endarterectomy (CEA) or carotid artery stenting (CAS) were recruited for this study. The Montreal Cognitive Assessment (MoCA) instrument was used to evaluate cognitive function preoperatively and at 3, 6, and 12 months postoperatively. Logistic regression analysis was built to identify potential risk factors for postoperative long-term cognitive decline.

RESULTS

A total of 89 patients who met the criteria were enrolled and completed 1-year follow-up. At 3, 6, and 12 months after carotid revascularization, the total MoCA score, attention, language fluency, and delayed recall score were significantly improved compared with the baseline scores (p<0.05). At 12 months, there was also a significant improvement in cube copying compared with baseline (p=0.034). Logistic regression analysis showed that the advancing age, left side, and symptomatic carotid artery stenosis were independent risk factors for cognitive deterioration at 12 months after surgery.

CONCLUSIONS

Overall, carotid revascularization has a beneficial effect on cognition function in patients with severe carotid artery stenosis, while advancing age, left side, and symptomatic carotid artery stenosis were significantly related to a decreased cognitive score after carotid revascularization.

CLINICAL IMPACT

This study focused on the changes in cognitive function within 1 year after carotid revascularization in patients with severe carotid stenosis. Of course, carotid revascularization can improve the cognition function in these patients. On the other hand, we found the advancing age, left side and symptomatic carotid artery stenosis were significantly associated with decreased cognitive scores at 1 year after carotid revascularization, which suggests that clinicians may need to be aware of patients with these characteristics.

The Role of Insulin Resistance in the Development of Complications after Coronary Artery Bypass Grafting in Patients with Coronary Artery Disease

The aim of the study was to investigate the effect of carbohydrate metabolism disorders and insulin resistance indices on the immediate results of coronary artery bypass grafting (CABG).

METHOD

Patients with coronary artery disease who underwent CABG (n = 383) were examined to determine glycemic status, free fatty acid and fasting insulin levels, and insulin resistance indices (Homeostasis Model Assessment of Insulin Resistance (HOMA-IR), McAuley index, Quantitative Insulin Sensitivity Check Index (QUICKI), Revised-QUICKI). Patients were assessed for the development of perioperative complications and their length of stay in the hospital. Two groups were formed: group 1, patients with a combined endpoint (CEP, any complication and/or duration of hospital stay >10 days), n = 291; and group 2 (n = 92) without a CEP. Perioperative characteristics were analyzed, and predictors of hospital complications and prolonged hospital stay were evaluated.

RESULTS

Patients in the CEP group were older, and there were more women among them (p = 0.003). Additionally, in this group, there were more patients with diabetes mellitus (37.5% vs 17.4%, p < 0.001), obesity (p < 0.001), and a higher percentage of combined operations (p = 0.007). In the group with a CEP, the levels of glucose (p = 0.031), glycated hemoglobin (p = 0.009), and free fatty acids (p = 0.007) and the Revised-QUICKI (p = 0.020) were higher than in the group without complications. In a regression analysis, the independent predictors of complications were combined operations (p = 0.016) and the predictors of a long hospital stay (>14 days) were female gender, the left atrium size, and diabetes mellitus (p < 0.001). The predictors of a composite endpoint included female gender, age, the left atrium size, and free fatty acid levels (p < 0.001).

CONCLUSIONS

In the group with in-hospital complications after CABG, not only was the presence of diabetes mellitus more often detected, but there were also higher levels of free fatty acids and a higher Revised-QUICKI. Therefore, additional assessments of insulin resistance and free fatty acid levels are advisable in patients before CABG.

S100B in cardiac surgery brain monitoring: friend or foe?

Recent advances in perioperative management of adult and pediatric patients requiring open heart surgery (OHS) and cardiopulmonary bypass (CPB) for cardiac and/or congenital heart diseases repair allowed a significant reduction in the mortality rate. Conversely morbidity rate pattern has a flat trend. Perioperative period is crucial since OHS and CPB are widely accepted as a deliberate hypoxic-ischemic reperfusion damage representing the cost to pay at a time when standard of care monitoring procedures can be silent or unavailable. In this respect, the measurement of neuro-biomarkers (NB), able to detect at early stage perioperative brain damage could be especially useful. In the last decade, among a series of NB, S100B protein has been investigated. After the first promising results, supporting the usefulness of the protein as predictor of short/long term adverse neurological outcome, the protein has been progressively abandoned due to a series of limitations. In the present review we offer an up-dated overview of the main S100B pros and cons in the peri-operative monitoring of adult and pediatric patients.

An Update on Postoperative Cognitive Dysfunction Following Cardiac Surgery

Postoperative cognitive dysfunction is extremely prevalent following cardiac surgery. The increasing patient age and comorbidity profile increases their susceptibility to cognitive impairment. The underlying pathophysiological mechanisms leading to cognitive impairment are not clearly elucidated. Using the contemporary literature (2015-present), this narrative review has three aims. Firstly, to provide an overview of postoperative cognitive impairment. Secondly, to analyse the predominant pathophysiological mechanisms leading to cognitive dysfunction following cardiac surgery such as inflammation, cerebral hypoperfusion, cerebral microemboli, glycaemic control and anaesthesia induced neurotoxicity. Lastly, to assess the current therapeutic strategies of interest to address these pathophysiological mechanisms, including the administration of dexamethasone, the prevention of prolonged cerebral desaturations and the monitoring of cerebral perfusion using near-infrared spectroscopy, surgical management strategies to reduce the neurological effects of microemboli, intraoperative glycaemic control strategies, the effect of volatile vs. intravenous anaesthesia, and the efficacy of dexmedetomidine.

Effects of Carotid Artery Stent and Carotid Endarterectomy on Cognitive Function in Patients with Carotid Stenosis

BACKGROUND

Carotid artery stenosis is closely related to cognitive dysfunction, in which decreased cerebral perfusion is one of the important factors. Both carotid artery stent implantation and carotid endarterectomy can relieve stenosis and increase cerebral perfusion. In this study, we aimed to compare the effects of carotid artery stent implantation and endarterectomy on cognitive function.

METHODS

A total of 98 patients with carotid artery stenosis hospitalized in our hospital from July 2015 to January 2017 were included. Among them, 50 cases underwent carotid artery stent implantation treatment as stent implantation group (CAS group), and 48 cases underwent carotid artery endarterectomy treatment as carotid endarterectomy group (CEA group). Using the Mini-Mental State Examination Scale (MMSE Scale) and the Montreal Cognitive Assessment Scale (MoCA Scale), the cognitive function scores of the two groups of patients before and after 3 and 6 months of operation were measured, and the patients were also measured before and after surgery, after the serum NSE, hs-CRP content.

RESULTS

The serum NSE, hs-CRP content, MMSE score, and MoCA score of the two groups before treatment were not statistically significant (P > 0.05). The MMSE score and MoCA score of the two groups of patients before treatment were lower than the normal value, suggesting carotid artery stenosis combined with different degrees of cognitive dysfunction. Carotid artery stenosis is different, and patients' cognitive function is also different. The MMSE score and MoCA score of the two groups at 3 and 6 months after operation were higher than before treatment, and there was a statistically significant difference between 6 and 3 months after operation (P < 0.05), but at each time There was no statistically significant difference between the two groups (P > 0.05). The NSE content of the two groups of patients after operation decreased compared with that before treatment, and the decrease in 6 months after operation was more obvious than that in March (P < 0.05). However, the difference between the two groups at each time point was not statistically significant (P > 0.05). The content of hs-CRP in the two groups of patients was higher than that before the operation, and the CAS group was significantly higher than the CEA group; the difference was statistically significant (P < 0.05).

CONCLUSION

Carotid artery stent and carotid endarterectomy are effective in improving the cognitive function of patients with carotid stenosis, but there is no significant difference between the two.

Current Evidence Regarding Biomarkers Used to Aid Postoperative Delirium Diagnosis in the Field of Cardiac Surgery-Review

Postoperative cognitive disorders after cardiac surgery may manifest as postoperative delirium (POD) or later as postoperative cognitive dysfunction (POCD). The incidence of POD after cardiac surgery ranges from 16% to 73%. In contrast to POD, POCD is usually diagnosed after the discharge from hospital, with an incidence of 30 to 70% of cases, very often noticed only by close relative or friends, decreasing after six (20–30%) and twelve (15–25%) months after surgery. Perioperative cognitive disorders are associated with adverse short- and long-term effects, including increased morbidity and mortality. Due to the complexity of delirium pathomechanisms and the difficulties in the diagnosis, researchers have not yet found a clear answer to the question of which patient will be at a higher risk of developing delirium. The risk for POD and POCD in older patients with numerous comorbidities like hypertension, diabetes, and previous ischemic stroke is relatively high, and the predisposing cognitive profile for both conditions is important. The aim of this narrative review was to identify and describe biomarkers used in the diagnosis of delirium after cardiac surgery by presenting a search through studies regarding this subject, which have been published during the last ten years. The authors discussed brain-derived biomarkers, inflammation-related biomarkers, neurotransmitter-based biomarkers, and others. Work based on inflammation-related biomarkers, which are characterized by the low cost of implementation and the effectiveness of delirium diagnosis, seems to be the closest to the goal of discovering an inexpensive and effective marker. Currently, the use of a panel of tests, and not a single biomarker, brings us closer to the discovery of a test, or rather a set of tests ideal for the diagnosis of delirium after cardiac surgery.

Role of Phosphorylated AMP-Activated Protein Kinase (AMPK) in Myocardial Insulin Resistance After Myocardial Ischemia-Reperfusion During Cardiopulmonary Bypass Surgery in Dogs

Background

The aim of this study was to determine the role of AMP-activated protein kinase (AMPK) in myocardial insulin resistance after myocardial ischemia-reperfusion during cardiopulmonary bypass surgery in dogs.

Material/Methods

Twenty-four mongrel dogs were randomly assigned to 4 groups. The control group did not undergo aortic cross-clamping; the model group underwent 60 mins of aortic cross-clamping with 150 ml cardioplegic solution. The treatment group, the inhibition group respectively with 0.11mg/kg AICAR (AMPK agonist) in 150 ml cardioplegic solution and 0.11 mg/kg Compound C (AMPK inhibitor) in 150 ml cardioplegic solution. The blood flow was determined and left ventricular myocardial tissue were taken at pre-bypass, 15, 60, and 90 min after aorta declamping, respectively. Expression of AMPK mRNA, p-AMPK and GLUT-4 proteins was determined by RT-PCR, IHC and WB.

Results

Compared with the control group, receiving 60 min ischemia at 15 min after reperfusion, Myocardial Glucose Extraction Ratio were significantly decreased in the other 3 groups, it was significantly decreased from 20.0% to 1.2% at 60 min of reperfusion, and recovered to 6.1% after 90 min reperfusion in model group, while recovered to 4.1%, 12.0% after 90 min reperfusion respectively exposed to Compound C and AICAR. The expressions of p-AMPK, GLUT-4 protein and AMPK mRNA in myocardium were decreased in different experiment groups, but these changes occurred to a lesser extent in the treatment group.

Conclusions

The inability of GLUT-4 expression induced by the decreases in p-AMPK protein expression that may be one of the reasons for myocardial insulin resistance.