Fixing hearts and protecting minds: a review of the multiple, interacting factors influencing cognitive function after coronary artery bypass graft surgery

Preemptive deep parasternal intercostal plane block for perioperative analgesia in coronary artery bypass grafting with sternotomy: a randomized, observer-blind, controlled study

OBJECTIVE

The precise characteristics of deep parasternal intercostal plane block (DPIP), which is useful for providing analgesia during open heart surgery, have not yet been thoroughly elucidated. In this study, we aimed to establish the efficacy, define the cutaneous sensory block area, and determine the duration of preemptive DPIP block at the T3-4 or T4-5 intercostal spaces in patients undergoing coronary artery bypass grafting (CABG) via sternotomy.

DESIGN

A prospective, single-blind, randomized controlled trial.

SETTING

Patients were randomly divided into three cohorts, each containing thirty patients.

PARTICIPANTS

Ninety patients who underwent elective CABG via sternotomy were included in this study.

INTERVENTIONS

The T3-4 and T4-5 groups received a preoperative single-shot DPIP block at the respective intercostal spaces. The principal objective of the study was to ascertain the optimal dosage of sufentanil administered during surgical procedures involving either a DPIP block or its absence, and to conduct a comparative analysis thereof across distinct injection sites, specifically T3-4 and T4-5. Secondary factors considered were the dosage of postoperative analgesics, the extent of sensory block on the skin, pain levels after extubation, time of recovery from anesthesia (time to extubation), duration of the block, and the occurrence of nausea and vomiting.

MEASUREMENTS & MAIN RESULTS

Preemptive DPIP block significantly reduced intraoperative sufentanil requirement compared to the control group (T3-4:0.38 ± 0.1, T4-5:0.32 ± 0.10, vs. Control:0.88 ± 0.3 μg/kg/h, p < 0.001). It also resulted in decreased analgesic consumption and numeric rating scale scores on the day of surgery (p < 0.01 compared to the control group). The DPIP block provided accurate anesthetic coverage of the dermatomes in the sternal region and reduced the time to extubation and postoperative nausea. However, the injection point (either via the T3-4 intercostal or the T4-5 intercostal) did not affect the efficacy. Preoperative DPIP block failed to provide adequate analgesia beyond 24 h post-surgery.

CONCLUSION

Preemptive bilateral DPIP block provided effective analgesia in patients undergoing CABG during surgery and in the early postoperative period. The analgesic effects of the DPIP block in the T3-4 and T4-5 intercostal spaces were comparable.

Managing common neurological complications following cardiac surgery

Despite recent technological advances in the field of surgery, neurological complications remain a significant post-operative issue. Two of the most common post-operative complications are delirium and post-operative cognitive decline, which occur frequently after cardiac surgery. This article provides an overview of delirium and post-operative cognitive decline, including risk factors, signs and symptoms, and diagnosis. The author also considers the nurse's role in managing patients who are at risk of, or have experienced, delirium or post-operative cognitive decline after cardiac surgery.

Neurologic complications after cardiopulmonary bypass - A narrative review

Neurologic complications, associated with cardiac surgery and cardiopulmonary bypass (CPB) in adults, are common and can be devastating in some cases. This comprehensive review will not only consider the broad categories of stroke and neurocognitive dysfunction, but it also summarises other neurological complications associated with CPB, and it provides an update about risks, prevention and treatment. Where appropriate, we consider the impact of off-pump techniques upon our understanding of the contribution of CPB to adverse outcomes.

Effectiveness of cognitive interventions for adult surgical patients after general anaesthesia to improve cognitive functioning: A systematic review

AIMS AND OBJECTIVES

To examine the effectiveness of cognitive interventions after general anaesthesia to improve cognitive functioning.

BACKGROUND

The number of surgical procedures performed worldwide is large and growing. Postoperative cognitive dysfunction is a common complication associated with poor postoperative outcomes. A variety of cognitive interventions have been developed to maintain or improve cognitive function in one or more cognitive domains. Cognitive interventions have shown to be effective in healthy older populations, those with mild cognitive impairment, and those with heart failure. The impact of cognitive interventions in surgical patients after general anaesthesia is a relatively new focus of research and is therefore less well established.

METHODS

Seven bibliographic databases were searched in relation to 'surgery' and 'cognitive interventions'; no date or language limits were imposed. Studies including adult patients who were scheduled for, or who had undergone surgery under general anaesthesia, had a baseline cognitive assessment using a validated measurement, and had engaged with any cognition-based intervention were included. Full-text review for inclusion, quality assessment and data extraction were undertaken independently by two authors. This study is reported in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines.

RESULTS

A total of 550 papers were identified for possible inclusion, of which nine met the inclusion criteria and were included in the review. The majority were randomised controlled trials (RCTs) (n = 6 [66.7%]). Four studies used computerised cognitive interventions, while five used traditional cognitive interventions. Most of the studies used multi-domain cognitive training focusing on two or more domains (n = 7 [77.8%]) while two studies used single-domain cognitive training. Memory (n = 7 [77.8%]) and attention (n = 5 [55.6%]) were the cognitive domains most often targeted during the intervention.

CONCLUSIONS

The use of cognitive interventions demonstrated some efficacy in improving cognitive function after general anaesthesia, particularly those targeting memory.

RELEVANCE FOR CLINICAL PRACTICE

The findings of this review suggest that cognitive interventions show promise at improving cognitive performance in patients with POCD and could be usefully implemented in clinical practice to improve patient outcomes.

Perioperative Neurofilament Light Plasma Concentrations and Cognition before and after Cardiac Surgery: A Prospective Nested Cohort Study

BACKGROUND

Neurofilament light is a marker of neuronal injury and can be measured in blood. Postoperative increases in neurofilament light have been associated with delirium after noncardiac surgery. However, few studies have examined the association of neurofilament light changes with postdischarge cognition in cardiac surgery patients, who are at highest risk for neuronal injury and cognitive decline. The authors hypothesized that increased neurofilament light (both baseline and change) would be associated with worse neuropsychological status up to 1 yr after cardiac surgery.

METHODS

This observational study was nested in a trial of cardiac surgery patients, in which blood pressure during bypass was targeted using cerebral autoregulation monitoring. Plasma concentrations of neurofilament light were measured at baseline and postoperative day 1. Neuropsychological testing was performed at baseline, 1 month after surgery, and 1 yr after surgery. Primary outcomes were baseline and change from baseline in a composite z-score of all cognitive tests.

RESULTS

Among 167 patients, cognitive outcomes were available in 80% (134 of 167) and 61% (102 of 167) at 1 month and 1 yr after surgery, respectively. The median baseline concentration of neurofilament light was 18.2 pg/ml (interquartile range, 13.4 to 28.1), and on postoperative day 1 was 28.5 pg/ml (interquartile range, 19.3 to 45.0). Higher baseline log neurofilament light was associated with worse baseline cognitive z-score (adjusted slope, -0.60; 95% CI, -0.90 to -0.30; P < 0.001), no change in z-score from baseline to 1 month (0.11; 95% CI, -0.19 to 0.41; P = 0.475), and improvement in z-score from baseline to 1 yr (0.56; 95% CI, 0.31 to 0.81; P < 0.001). Whereas some patients had an improvement in cognition at 1 yr and others a decline, an increase in neurofilament light from baseline to postoperative day 1 was associated with a greater decline in cognition at 1 yr.

CONCLUSIONS

Higher baseline neurofilament light concentration was associated with worse baseline cognition but improvement in cognition at 1 yr. A postoperative increase in neurofilament light was associated with a greater cognitive decline at 1 yr.

EDITOR’S PERSPECTIVE

Cerebral infarction after cardiac surgery

Cerebral infarction, a common central nervous system complication after adult cardiac surgery, is one of the main factors leading to the poor prognosis of cardiac surgery patients besides cardiac insufficiency. However, there is currently no effective treatment for cerebral infarction. Therefore, early prevention and diagnosis of postoperative cerebral infarction are particularly important. There are many factors and mechanisms during and after cardiac surgery that play an important role in the occurrence of postoperative cerebral infarction, such as intraoperative embolism, systemic inflammatory response syndrome, atrial fibrillation, temperature regulation, blood pressure control, use of postoperative blood products, and so forth. The mechanism by which most risk factors act on the human body, leading to postoperative cerebral infarction, is not well understood, and further research is needed. Therefore, this paper aims to summarize and explain the relevant risk factors, mechanisms, clinical signs, imaging characteristics, and early diagnosis methods of cerebral infarction complications after cardiac surgery, and provides useful data for the establishment of related diagnosis and treatment standards.

Chinese Pharmacopoeia Revisited: A Review of Anti-Depression Herbal Sources

Depression, which can be accompanied by many fatal diseases and a low life quality, has become the leading cause of ill health and disability worldwide. However, Chinese Pharmacopoeia, the most authoritative and evidence-based encyclopedia of Traditional Chinese Medicine (TCM), could contain leads and insights into the development of new antidepressant drugs. In this work, nine herbal medicines with ‘dispel melancholy functions’ specifically documented in Chinese Pharmacopoeia have been comprehensively reviewed with respect to clinical trials, and phytochemical and pharmacological aspects. The nine drugs are Rosae Chinensis Flos, Croci Stigma, Albiziae Cortex and Flos, Roase Rugosae Flos, Curcumae Radix, Hyperici Perforati Herba, Cyperi Rhizoma and Bupleuri Radix. The mechanisms of action of their functional antidepressant compounds, including gallic acid, hypericin, kaempferol, crocetin, crocin, quercetin, luteolin, isorhamnetin, curcumin, hyperforin, adhyperforin, catechin, rutin, puerarin, and saikosaponins A and D, have been collected and discussed. These traditional Chinese herbs and their active compounds provide a promising resource to develop effective new antidepressant drugs in future. Moreover, mechanistic investigations, safety verification and large-scale clinical trials are still expected to finally transform such TCM-based antidepressant resources to new drugs for patients suffering from depression.

Effects of 12-Week Supervised Early Resistance Training (SEcReT) Versus Aerobic-Based Rehabilitation on Cognitive Recovery Following Cardiac Surgery via Median Sternotomy: A Pilot Randomised Controlled Trial

AIMS

To investigate the effects of a 12-week early moderate-intensity resistance training program compared to aerobic-based rehabilitation on postoperative cognitive recovery following cardiac surgery via median sternotomy.

METHODS

This was a multicentre, prospective, pragmatic, non-blinded, pilot randomised controlled trial (1:1 randomisation) of two parallel groups that compared a 12-week early moderate-intensity resistance training group to a control group, receiving aerobic-based rehabilitation. English-speaking adults (≥18 years) undergoing elective cardiac surgery via median sternotomy were randomised using sealed envelopes, with allocation revealed before surgery. The primary outcome was cognitive function, assessed using the Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog), at baseline, 14 weeks and 6 months postoperatively.

RESULTS

The ADAS-cog score at 14 weeks was significantly better for the resistance training group (n=14, 7.2±1.4; 95% CI 4.3, 10.2, vs n=17, 9.2±1.3; 95% CI 6.6, 11.9, p=0.010). At 14 weeks postoperatively, 53% of the aerobic-based rehabilitation group (n=9/17) experienced cognitive decline by two points or more from baseline ADAS-cog score, compared to 0% of the resistance training group (n=0/14; p=0.001).

CONCLUSION

Early resistance training appears to be safe and may improve cognitive recovery compared to standard, aerobic-based rehabilitation following cardiac surgery via median sternotomy, however as this was a pilot study, the sample size was small and further research is needed to determine a causal relationship.

Dynamic Change of Lymphocyte-to-Monocyte Is Associated With the Occurrence of POCD After Cardiovascular Surgery: A Prospective Observational Study

Objective: Postoperative cognitive dysfunction (POCD) is a common and severe complication of cardiovascular surgery. Lymphocyte-to-monocyte ratio (LMR) has been reported to be an independent predictor of lots of diseases associated with inflammation, but the association between the LMR and POCD is not clear. The present study aimed to investigate the potential value of LMR level to predict POCD in patients undergoing cardiovascular surgery. Methods: A prospective observational study was performed on the patients diagnosed with heart diseases undergoing cardiovascular surgeries with cardiopulmonary bypass. The leukocyte counts were measured by blood routine examination preoperatively. Then we calculated the LMR by dividing the lymphocyte count by the monocyte count. Neurocognitive functions were assessed 1 day before and 7 days after surgery. Perioperative factors were recorded to explore the relationship between LMR and POCD. Results: In total, 75 patients finished the whole study, while 34 patients developed POCD. The preoperative LMR level in the POCD group was higher than that in the non-POCD group. A cutoff value of 4.855 was identified to predict POCD occurrence according to ROC curve. The perioperative dynamic change of LMR level in the POCD group was higher than those in the non-POCD group. A cutoff value of 2.255 was identified to predict POCD occurrence according to ROC curve and the dynamic LMR change had similar varying trend with preoperative LMR level. Conclusions: The dynamic change of LMR level in the peripheral blood is associated with occurrence of POCD, and preoperative LMR level seems to be a prognostic biomarker of postoperative cognitive dysfunction in patients after cardiovascular surgery.

Cognitive Dysfunction and Mortality After Carotid Endarterectomy

Background: Carotid endarterectomy (CEA) has been associated with both postoperative cognitive dysfunction (POCD) and improvement (POCI). However, the prognostic significance of postoperative cognitive changes related to CEA is largely unknown. The aim of this study was to examine the associations between postoperative cognitive changes after CEA and long-term survival.

Methods: We studied 43 patients 1 day before CEA as well as 4 days and 3 months after surgery with an extensive neuropsychological test array, and followed them for up to 14 years. POCD and POCI relative to baseline were determined with the reliable change index derived from 17 healthy controls. Associations between POCD/POCI and mortality within the patient group were studied with Cox regression analyses adjusted for confounders.

Results: POCD in any functional domain was evident in 28% of patients 4 days after surgery and in 33% of patients 3 months after surgery. POCI was shown in 23% of patients at 4 days and in 44% of patients at 3 months. POCD at 3 months was associated with higher long-term mortality (hazard ratio 5.0, 95% CI 1.8–13.9, p = 0.002) compared with patients with no cognitive decline.

Conclusions: Our findings suggest that POCD in a stable phase, 3 months after CEA predicts premature death. Evaluation of postoperative cognitive changes is essential, and POCD in a stable phase after CEA should prompt scrutiny of underlying factors and better adherence to therapies to prevent recurrences and to promote early intervention in imminent deterioration.

Postoperative cognitive change after cardiac surgery predicts long-term cognitive outcome

OBJECTIVES

Postoperative cognitive dysfunction (POCD) is a common consequence of coronary artery bypass grafting. However, domain-specific associations between postoperative changes and long-term performance are poorly known. The aim of this study was to investigate whether domain-specific cognitive changes after cardiac surgery predict long-term cognitive outcome.

MATERIALS AND METHODS

We assessed 100 patients (86 men, mean age 60) before coronary artery bypass grafting, with re-examinations after one week, three months, and a mean of 6.7 years. The extensive neuropsychological test battery was organized into seven functional cognitive domains. Cognitive decline and improvement were defined with the reliable change index derived from 17 matching healthy controls. Analyses were adjusted for baseline cognitive performance, age, gender, education and cardiovascular risks factors.

RESULTS

On group level, one week after surgery 71% patients showed cognitive decline and 9% improvement in any functional domain, as compared to preoperative results. Three months postsurgery, decline was observed in 47% and improvement in 25% of patients. Executive functioning was the most sensitive domain to both decline and improvement. Postoperative dysfunction predicted long-term cognitive deterioration six years after operation, particularly in the domain of executive functioning.

CONCLUSIONS

POCD after coronary artery bypass grafting is an essential risk factor for long-term deterioration and an indication for neuropsychological follow-up. Assessment of change in executive functioning after coronary artery bypass grafting may help to identify patients at risk for unfavorable long-term outcome.

Safety and Efficacy of Saffron (Crocus sativus L.) for Treating Mild to Moderate Depression: A Systematic Review and Meta-analysis

BACKGROUND

Herbal remedies are becoming increasingly popular for the treatment of depression. Recently, accumulating evidences reveal a positive effect of saffron (Crocus sativus L.) in relieving depressive symptoms. The objective of this meta-analysis was to assess the safety and efficacy of saffron in treating mild to moderate depression by synthesizing all available data.

MATERIALS AND METHODS

Relevant studies were retrieved from electronic databases and cross-checking of reference lists. Eligible trials were carefully reviewed, and necessary data were extracted. The Hamilton Rating Scale for Depression or Beck Depression Inventory scores, response rate, remission rate, and adverse effects were compared between saffron and placebo or saffron and antidepressants to assess the efficacy of saffron for depression.

RESULTS

Twelve studies were included in the meta-analysis. Overall results showed that saffron possessed better efficacy in the improvement of depressive symptoms when compared with placebo, whereas saffron was as effective as synthetic antidepressants. No significant difference was detected in the incidence of adverse effects between saffron and placebo or between saffron and antidepressants.

CONCLUSIONS

Saffron could be considered as an alternative to synthetic antidepressants in the treatment of mild to moderate depression. However, multicenter trials with larger sample size, longer treatment duration, and different ethnic groups are required to verify our results.

Neurocognitive Function after Cardiac Surgery: From Phenotypes to Mechanisms

For half a century, it has been known that some patients experience neurocognitive dysfunction after cardiac surgery; however, defining its incidence, course, and causes remains challenging and controversial. Various terms have been used to describe neurocognitive dysfunction at different times after cardiac surgery, ranging from "postoperative delirium" to "postoperative cognitive dysfunction or decline." Delirium is a clinical diagnosis included in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). Postoperative cognitive dysfunction is not included in the DSM-5 and has been heterogeneously defined, though a recent international nomenclature effort has proposed standardized definitions for it. Here, the authors discuss pathophysiologic mechanisms that may underlie these complications, review the literature on methods to prevent them, and discuss novel approaches to understand their etiology that may lead to novel treatment strategies. Future studies should measure both delirium and postoperative cognitive dysfunction to help clarify the relationship between these important postoperative complications.

Effects of Saffron on Cognition, Anxiety, and Depression in Patients Undergoing Coronary Artery Bypass Grafting: A Randomized Double-Blind Placebo-Controlled Trial

OBJECTIVES

Cognitive decline, depression, and anxiety are among the major concerns in patients undergoing coronary artery bypass grafting (CABG). Crocus sativus L. (saffron) seems to be a promising candidate for treatment of these conditions.

DESIGN

In this 12-week, randomized, double-blind, placebo-controlled clinical trial, men and women with on-pump CABG, who had Wechsler Memory Scale (WMS) score >70 and age <70 years, received either saffron capsules (15 mg/twice daily) or placebo. Patients were excluded if they had history of treatment with saffron or acetylcholinesterase inhibitors, comorbid neuropsychiatric disorders, serious medical conditions other than cardiovascular diseases, and hypersensitivity to herbal compounds. The primary outcome was defined as the difference in mean total score changes for WMS-Revised from the baseline to week 12 between the saffron and placebo groups. Secondary outcomes included difference in mean score changes from baseline to endpoint between the two treatment groups for Mini Mental Status Examination and subscales of Hospital Anxiety and Depression Scale ( www.irct.ir ; IRCT201408071556N63).

RESULTS

No significant difference was detected in primary or secondary outcomes between the saffron and placebo groups. Also, no significant time × treatment interaction effect was found for any of the scales.

CONCLUSIONS

The results of this trial do not support the hypothesis of potential benefits of saffron in treatment of CABG-related neuropsychiatric conditions.

Coronary Artery Bypass Graft Surgery and Dementia Risk in the Cardiovascular Health Study

INTRODUCTION

The association between history of coronary artery bypass graft surgery (CABG) and dementia risk remains unclear.

METHODS

We conducted a prospective cohort analysis using data on 3155 elderly adults free from prevalent dementia from the US population-based Cardiovascular Health Study (CHS) with adjudicated incident all-cause dementia, Alzheimer disease (AD), vascular dementia (VaD), and mixed dementia.

RESULTS

In the CHS, the hazard ratio (HR) for all-cause dementia was 1.93 [95% confidence interval (CI), 1.36-2.74] for those with CABG history compared with those with no CABG history after adjustment for potential confounders. Similar HRs were observed for AD (HR=1.71; 95% CI, 0.98-2.98), VaD (HR=1.42; 95% CI, 0.56-3.65), and mixed dementia (HR=2.73; 95% CI, 1.55-4.80). The same pattern of results was observed when these CHS findings were pooled with a prior prospective study, the pooled HRs were 1.96 (95% CI, 1.42-2.69) for all-cause dementia, 1.71 (95% CI, 1.04-2.79) for AD and 2.20 (95% CI, 0.78-6.19) for VaD.

DISCUSSION

Our results suggest CABG history is associated with long-term dementia risk. Further investigation is warranted to examine the causal mechanisms which may explain this relationship or whether the association reflects differences in coronary artery disease severity.

Neurologic complications of cardiac and vascular surgery

This chapter will provide an overview of the major neurologic complications of common cardiac and vascular surgeries, such as coronary artery bypass grafting and carotid endarterectomy. Neurologic complications after cardiac and vascular surgeries can cause significant morbidity and mortality, which can negate the beneficial effects of the intervention. Some of the complications to be discussed include ischemic and hemorrhagic stroke, seizures, delirium, cognitive dysfunction, cerebral hyperperfusion syndrome, cranial nerve injuries, and peripheral neuropathies. The severity of these complications can range from mild to lethal. The etiology of complications can include a variety of mechanisms, which can differ based on the type of cardiac or vascular surgery that is performed. Our knowledge about neuropathology, prevention, and management of surgical complications is growing and will be discussed in this chapter. It is imperative for clinicians to be familiar with these complications in order to narrow the differential diagnosis, start early management, anticipate the natural history, and improve outcomes.

Cognitive Outcomes of Cardiovascular Surgical Procedures in the Old: An Important but Neglected Area

Older individuals can now undergo invasive cardiovascular procedures without serious concern about mortality, and the numbers and proportions of the over 65s and 85s doing so in Australia has been increasing over the last 20 years. There is overwhelming evidence linking cardiovascular conditions to late-life (65 years and over) cognitive impairment and dementia including Alzheimer's Disease, primarily due to impaired cerebrovascularisation and cascading neuropathological processes. Somewhat paradoxically, these cardiovascular interventions, carried out with the primary aim of revascularisation, are not usually associated with short- or long-term improvements in cognitive function in older adults. We discuss factors associated with cognitive outcomes post-cardiovascular surgeries in patients over 65 years of age. There are many opportunities for future research: we know almost nothing about cognitive outcomes following invasive cardiac procedures in the oldest old (85 years and over) nor how to predict the cognitive/delirium outcome using pre-surgical data, and lastly, intervention opportunities exist both pre and postoperatively that have not been tested. As our population ages with increased cardiovascular burden and rates of cardiovascular interventions and surgeries, it is critical that we understand the cognitive consequences of these procedures, who is at greatest risk, and ways to optimise cognition.

Improved cognitive flexibility after aortic valve replacement surgery

OBJECTIVES

Aortic valve replacement (AVR) surgery is associated with potential risk to cerebral injury. On the other hand, improved cardiovascular functioning after the surgery may have positive impact on brain health. The aim of this preliminary study was to investigate the impact of AVR surgery on cognition, specifically on higher cognitive control functions, i.e. executive functions, that are typically implicated in cognitive decline due to vascular origin.

METHODS

Patients (n = 16) undergoing elective AVR surgery due to aortic stenosis were recruited and their cognitive performance was assessed using a computer-based Executive Reaction Time (RT) test. Testing was performed 1 day prior to AVR surgery and ∼3 months after the surgery. In addition, the Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A) was used to assess everyday challenges in executive functions and self-regulation. Patient's postoperative test results were compared with each patient's preoperative results to determine changes in executive functions.

RESULTS

Subjects' overall cognitive performance improved after AVR surgery. After surgery, patients responded in the Executive RT test more accurately with the same response speed (change from 297 to 298 ms). Their overall probability to commit an error (total errors) was reduced by 47%, reflecting improved executive functions in general (OR = 0.53, 95% CI = 0.46-0.59, error rate change from 44.8 to 28.0%). Furthermore, one key component of executive functions, inhibitory control, was improved after AVR surgery. This was seen in reduced probability of failing to withhold a response, i.e. making a commission error, by 89% (OR = 0.11, CI = 0.08-0.16, error rate change from 11.8 to 2.6%). The probability of missing a response was reduced by 48%, reflecting improved attention (OR = 0.52, 0.44-0.64, error rate change from 18.1 to 11.0%). No statistically significant differences in BRIEF-A scores were found.

CONCLUSIONS

There was a marked improvement in cognitive performance following AVR surgery, specifically in executive control functions indicating improved cognitive flexibility. Cognitive improvement, as opposed to the typical trajectory of cognitive decline in an elderly population with vascular disease, emphasizes the importance of these results and points to AVR surgery as having potential benefits on brain health in general.

CLINICAL TRIALS IDENTIFIER

NCT01953068. https://www.clinicaltrials.gov/ct2/show/NCT01953068?term=NCT01953068&rank=1.

Proximal occlusion versus distal filter for cerebral protection during carotid stenting: updated meta-analysis of randomised and observational MRI studies

AIMS

Proximal occlusion (PO) and distal filter (DF) serve for cerebral embolic protection during carotid artery stenting (CAS). New cerebral lesions at diffusion-weighted magnetic resonance imaging (DW-MRI) represent a surrogate endpoint for embolisation, though their clinical impact is controversial. We performed a meta-analysis of randomised and observational DW-MRI studies comparing PO and DF during CAS.

METHODS AND RESULTS

We searched electronic scientific databases. The primary endpoint was the incidence of new cerebral lesions at DW-MRI; secondary endpoints were the incidence of new ipsilateral and new contralateral cerebral lesions at DW-MRI and death/cerebrovascular events (CVE). A total of 392 patients (seven studies) received CAS. At DW-MRI after 48 hours 178 patients (48.3%) presented new cerebral lesions. The use of PO versus DF reduced neither the risk of new cerebral lesions (OR [95% confidence interval] 0.65 [0.28-1.52], p=0.32) nor the risk of death/CVE (0.59 [0.22-1.60], p=0.30). Diabetes, baseline stenosis and symptoms significantly modified the risk estimates for new cerebral lesions.

CONCLUSIONS

In this meta-analysis, one half of patients receiving protected CAS developed new embolic cerebral lesions at DW-MRI, although the overwhelming majority were asymptomatic. Cerebral protection with PO versus DF neither reduced cerebral embolisation nor impacted on clinical outcomes.

Atrial Fibrillation, Neurocognitive Decline and Gene Expression After Cardiopulmonary Bypass

OBJECTIVE

Atrial fibrillation and neurocognitive decline are common complications after cardiopulmonary bypass. By utilizing genomic microarrays we investigate whether gene expression is associated with postoperative atrial fibrillation and neurocognitive decline.

METHODS

Twenty one cardiac surgery patients were prospectively matched and underwent neurocognitive assessments pre-operatively and four days postoperatively. The whole blood collected in the pre-cardiopulmonary bypass, 6 hours after-cardiopulmonary bypass, and on the 4^th postoperative day was hybridized to Affymetrix Gene Chip U133 Plus 2.0 Microarrays. Gene expression in patients who developed postoperative atrial fibrillation and neurocognitive decline (n=6; POAF+NCD) was compared with gene expression in patients with postoperative atrial fibrillation and normal cognitive function (n=5; POAF+NORM) and patients with sinus rhythm and normal cognitive function (n=10; SR+NORM). Regulated genes were identified using JMP Genomics 4.0 with a false discovery rate of 0.05 and fold change of >1.5 or <-1.5.

RESULTS

Eleven patients developed postoperative atrial fibrillation. Six of these also developed neurocognitive decline. Of the 12 patients with sinus rhythm, only 2 developed neurocognitive decline. POAF+NCD patients had unique regulation of 17 named genes preoperatively, 60 named genes six hours after cardiopulmonary bypass, and 34 named genes four days postoperatively (P<0.05) compared with normal patients. Pathway analysis demonstrated that these genes are involved in cell death, inflammation, cardiac remodeling and nervous system function.

CONCLUSION

Patients who developed postoperative atrial fibrillation and neurocognitive decline after cardiopulmonary bypass may have differential genomic responses compared to normal patients and patients with only postoperative atrial fibrillation, suggesting common pathophysiology for these conditions. Further exploration of these genes may provide insight into the etiology and improvements of these morbid outcomes.

Cognitive Outcomes following Transcatheter Aortic Valve Implantation: A Systematic Review

Severe aortic stenosis is the most common valvular heart disease in the elderly in the Western world and contributes to a large proportion of all deaths over the age of 70. Severe aortic stenosis is conventionally treated with surgical aortic valve replacement; however, the less invasive transcatheter aortic valve implantation (TAVI) is suggested for those at high surgical risk. While TAVI has been associated with improved survival and favourable outcomes, there is a higher incidence of cerebral microembolisms in TAVI patients. This finding is of concern given mechanistic links with cognitive decline, a symptom highly prevalent in those with cardiovascular disease. This paper reviews the literature assessing the possible link between TAVI and cognitive changes. Studies to date have shown that global cognition improves or remains unchanged over 3 months following TAVI while individual cognitive domains remain preserved over time. However, the association between TAVI and cognition remains unclear due to methodological limitations. Furthermore, while these studies have largely focused on memory, cognitive impairment in this population may be predominantly of vascular origin. Therefore, cognitive assessment focusing on domains important in vascular cognitive impairment, such as executive dysfunction, may be more helpful in elucidating the association between TAVI and cognition in the long term.

Preoperative gene expression may be associated with neurocognitive decline after cardiopulmonary bypass

OBJECTIVE

Despite advances in surgical techniques, neurocognitive decline after cardiopulmonary bypass remains a common and serious complication. We have previously demonstrated that patients with neurocognitive decline have unique genetic responses 6 hours after cardiopulmonary bypass when compared with normal patients. We used genomic microarray to objectively investigate whether patients with neurocognitive decline had associated preoperative gene expression profiles and how these profiles changed up to 4 days after surgery.

METHODS

Patients undergoing cardiac surgery underwent neurocognitive assessments preoperatively and 4 days after surgery. Skeletal muscle was collected intraoperatively. Whole blood collected before cardiopulmonary bypass, 6 hours after cardiopulmonary bypass, and on postoperative day 4 was hybridized to Affymetrix Gene Chip U133 Plus 2.0 microarrays (Affymetrix Inc, Santa Clara, Calif). Gene expression in patients with neurocognitive decline was compared with gene expression in the normal group using JMP Genomics (SAS Institute Inc, Cary, NC). Only genes that were commonly expressed in the 2 groups with a false discovery rate of 0.05 and a fold change greater than 1.5 were carried forward to pathway analysis using Ingenuity Pathway Analysis (Ingenuity Systems, Redwood City, Calif). Microarray gene expression was validated by Green real-time polymerase chain reaction and Western blotting.

RESULTS

Neurocognitive decline developed in 17 of 42 patients. A total of 54,675 common transcripts were identified on microarray in each group across all time points. Preoperatively, there were 140 genes that were significantly altered between the normal and neurocognitive decline groups (P < .05). Pathway analysis demonstrated that preoperatively, patients with neurocognitive decline had increased regulation in genes associated with inflammation, cell death, and neurologic dysfunction. Of note, the number of significantly regulated genes between the 2 groups changed over each time point and decreased from 140 preoperatively to 64 six hours after cardiopulmonary bypass and to 25 four days after surgery. There was no correlation in gene expression between the blood and the skeletal muscle.

CONCLUSIONS

Patients in whom neurocognitive decline developed after cardiopulmonary bypass had increased differential gene expression before surgery versus patients in whom neurocognitive decline did not develop. Although significant differences in gene expression also existed postoperatively, these differences gradually decreased over time. Preoperative gene expression may be associated with neurologic injury after cardiopulmonary bypass. Further investigation into these genetic pathways may help predict patient outcome and guide patient selection.