Incidence and impact of silent brain lesions after coronary artery bypass grafting

Cognitive Training for Reduction of Delirium in Patients Undergoing Cardiac Surgery: A Randomized Clinical Trial

IMPORTANCE

Postoperative delirium is a common and impactful neuropsychiatric complication in patients undergoing coronary artery bypass grafting surgery. Cognitive training may enhance cognitive reserve, thereby reducing postoperative delirium.

OBJECTIVE

To determine whether preoperative cognitive training reduces the incidence of delirium in patients undergoing coronary artery bypass grafting.

DESIGN, SETTING, and PARTICIPANTS

This prospective, single-blind, randomized clinical trial was conducted at 3 university teaching hospitals in southeastern China with enrollment between April 2022 and May 2023. Eligible participants included those scheduled for elective coronary artery bypass grafting who consented and enrolled at least 10 days before surgery.

INTERVENTIONS

Participating patients were randomly assigned 1:1, stratified by site, to either routine care or cognitive training, which included substantial practice with online tasks designed to enhance cognitive functions including memory, imagination, reasoning, reaction time, attention, and processing speed.

MAIN OUTCOMES AND MEASURES

The primary outcome was occurrence of delirium during postoperative days 1 to 7 or until hospital discharge, diagnosed using the Confusion Assessment Method or the Confusion Assessment Method for Intensive Care Units. Secondary outcomes were postoperative cognitive dysfunction, delirium characteristics, and all-cause mortality within 30 days following the operation.

RESULTS

A total of 218 patients were randomized and 208 (median [IQR] age, 66 [58-70] years; 64 female [30.8%] and 144 male [69.2%]) were included in final analysis, with 102 randomized to cognitive training and 106 randomized to routine care. Of all participants, 95 (45.7%) had only a primary school education and 54 (26.0%) had finished high school. In the cognitive training group, 28 participants (27.5%) developed delirium compared with 46 participants (43.4%) randomized to routine care. Those receiving cognitive training were 57% less likely to develop delirium compared with those receiving routine care (adjusted odds ratio [aOR] 0.43; 95% CI, 0.23-0.77; P = .007). Significant differences were observed in the incidence of severe delirium (aOR, 0.46; 95% CI, 0.25-0.82; P = .01), median (IQR) duration of delirium (0 [0-1] days for cognitive training vs 0 [0-2] days for routine care; P = .008), and median (IQR) number of delirium-positive days (0 [0-1] days for cognitive training vs 0 [0-2] days for routine care; P = .007). No other secondary outcomes differed significantly.

CONCLUSIONS AND RELEVANCE

In this randomized trial of 208 patients undergoing coronary artery bypass grafting, preoperative cognitive training reduced the incidence of postoperative delirium. However, our primary analysis was based on fewer than 75 events and should therefore be considered exploratory and a basis for future larger trials.

Trial Registration

Chinese Clinical Trial Registry Identifier: ChiCTR2200058243.

Electrical Activity Changes and Neurovascular Unit Markers in the Brains of Patients after Cardiac Surgery: Effects of Multi-Task Cognitive Training

BACKGROUND

There is growing interest in finding methods to enhance cognitive function and comprehend the neurophysiological mechanisms that underlie these improvements. It is assumed that non-pharmacological interventions have better results in cognitive recovery. The aim of this study was to assess the effect of multi-task cognitive training (MTT) on electroencephalographic (EEG) changes and markers of the neurovascular unit in patients undergoing coronary artery bypass grafting (CABG).

METHODS

This prospective cohort study involved 62 CABG patients aged 45-75 years, 30 of whom underwent a 5-7-day MTT course. The groups of patients were comparable with respect to baseline clinical and anamnestic characteristics. An EEG study was performed before surgery and 11-12 days after CABG. Markers of the neurovascular unit (S100β, NSE, and BDNF) were examined at three time points: before surgery, within the first 24 h after surgery, and 11-12 days after CABG.

RESULTS

Patients without training demonstrated higher relative theta power changes compared to the MTT patients. The course of MTT was associated with low plasma S100β concentration but high BDNF levels at the end of the training course.

CONCLUSIONS

The theta activity changes and the markers of the neurovascular unit (S100β, BDNF) indicated that the severity of brain damage in cardiac surgery patients after a short course of MTT was slightly reduced. Electrical brain activity indicators and vascular markers can be informative for monitoring the process of cognitive rehabilitation in cardiac surgery patients.

[A comparative assessment of neurochemical and neurophysiological parameters of cardiac surgery patients who underwent different versions of multitasking cognitive training]

OBJECTIVE

To compare biomarkers of neurovascular unit (NVU) - S100β, NSE, BDNF and indicators of the brain electrical activity in patients who underwent coronary artery bypass grafting (CABG) depending on the use of different versions of multi-tasking cognitive training (CT).

MATERIAL AND METHODS

The study included 89 people, of whom 47 completed the CTI (postural and three cognitive tasks (counting backwards, verbal fluency and the open-ended task «Unusual use of an ordinary object») and 42 patients, who underwent CTII (visuomotor reaction and the same cognitive tasks) in the early postoperative CABG period. The patients of both groups underwent complex testing of psychomotor, executive functions, attention, short-term memory and EEG study in the perioperative period of CABG. Concentrations of NVU markers in peripheral blood serum were also analyzed.

RESULTS

The highest values of S100β protein concentration in both patients with CTI and CTII were observed on the 1st-2nd days after CABG, followed by a significant decrease on the 10th-12th days to preoperative values only in the CTII group. Also, during CTI, low concentrations of S100β and NSE protein were associated with higher indicators of cognitive status, such as short-term memory and general integral index. In patients with CTI, the concentration of BDNF on days 10-12 of CABG was significantly higher compared to patients with CTII, and its higher levels were associated with higher levels of attention. Only if the training was successful, the patients with CTI had greater preoperative levels of EEG alpha-1 and alpha-2 activity compared to patients with CTII.

CONCLUSION

The version of multitasking CT using the postural motor component more actively triggered the processes of neuroplasticity due to the expression of BDNF and its success was due to the greater presence of alpha-activity in the preoperative period of CABG. Further research is needed to study the neurophysiological mechanisms of recovery of cognitive functions after cardiac surgery.

Future insights of pharmacological prevention for AKI post cardiopulmonary bypass surgery (based on PK/PD approach)

The incidence of acute kidney injury (AKI) post-cardiopulmonary bypass (CPB) can cause an increase in the rate of renal replacement therapy (RRT) and mortality rate. Compared to brain and liver damage post-CPB, AKI has the highest incidence of 83%. Based on this phenomenon, various efforts have been made to reduce the incidence of AKI post-CPB, both pharmacologically and non-pharmacologically interventions. The purpose of this review is to emphasize several renal protector agents which under optimal conditions can provide significant benefits in reducing the incidence of AKI post-CPB. This article was obtained by conducting a study on several kinds of literature, including the original article, RCT study, systematic review and meta-analysis, and other review articles. There are five renal protector agents that are the focus of this article, those are fenoldopam which effectively works to prevent the incidence of AKI post-CPB, while furosemide has shown satisfactory results in patients with decreased renal function when administered in the Renal Guard (RG) system, mannitol, and nitric oxide, both of these can also effectively reduce the incidence of AKI post‐CPB by controlling its blood concentration and timing of administration, and another form of N-Acetylcysteine, namely N‐Acetylcysteine amide has better activity as a renoprotective agent than N‐Acetylcysteine itself. The benefits of these agents can be obtained by developing devices that can control drug levels in the blood and create optimal conditions for drugs during the use of a CPB machine.

Silent Brain Infarction, Delirium, and Cognition in Three Invasive Cardiovascular Procedures: a Systematic Review

Silent brain infarctions (SBIs) are brain lesions noted on neuroimaging that are not associated with clinical symptoms. SBIs are associated with a number of vascular risk factors and are common following invasive cardiovascular procedures such as atrial fibrillation (AF) ablation, coronary artery bypass graft (CABG), and transcatheter aortic valve replacement (TAVR). Although not eliciting signs of clinical stroke, SBIs are associated with increased frailty, and motor and mood features. Less is known, however, about the relationship between SBI, cognition, and delirium following invasive cardiac procedures and most investigations into these relationships have been reported in large-scale epidemiological studies. In the current paper, we conducted a systematic review to evaluate evidence of a relationship between SBI, delirium, and cognitive decline following CABG, AF ablation, and TAVR. Twenty studies met inclusion criteria. In general, our review identified conflicting results for each cardiac procedure, with some studies suggesting a relationship between SBI, cognitive impairment, and delirium, whereas others showed no relationship between SBI, cognitive impairment, and delirium. Potential reasons for this discrepancy as well as suggestions for future research are discussed.

Does the technique used in coronary artery bypass graft surgery affect patients' anxiety, depression, mental and physical health? First 3-month outcomes

PURPOSE

This study was aimed at investigating the effect of coronary artery bypass graft surgery conducted with different techniques on patients' anxiety, depression, mental and physical health.

DESIGN AND METHODS

This cross-sectional study included 60 patients who completed the Beck Anxiety Inventory, the Beck Depression Inventory, and the 36-Item Short-Form Health Survey.

FINDINGS

Anxiety, depression, and mental health showed significant differences in different time measurements, and combined effects of surgical technique and time factor.

PRACTICE IMPLICATIONS

Preoperative routine evaluations can speed up recovery, reduce cost, and improve quality of life by preventing the possible negative effects of anxiety and depression.

Frailty Test Battery Development including Physical, Socio-Psychological and Cognitive Domains for Cardiovascular Disease Patients: A Preliminary Study

Frailty is an age-related decline in physical, socio-psychological and cognitive function that results in extreme vulnerability to stressors. Therefore, this study aimed to elucidate which tests have to be selected to detect frailty in a comprehensive and feasible manner in cardiovascular disease (CVD) patients based on multivariate regression and sensitivity/specificity analyses. Patients (n = 133, mean age 78 ± 7 years) hospitalised for coronary revascularisation or heart failure (HF) were examined using the Fried and Vigorito criteria, together with some additional measurements. Moreover, to examine the association of frailty with 6-month clinical outcomes, hospitalisations and mortality up to 6 months after the initial hospital admission were examined. Some level of frailty was detected in 44% of the patients according to the Vigorito criteria and in 65% of the patients according to the Fried criteria. Frailty could best be detected by a score based on: sex, Mini Nutritional Assessment (MNA), Katz scale, timed up-and-go test (TUG), handgrip strength, Mini-Mental State Examination (MMSE), Geriatric Depression Scale (GDS-15) and total number of medications. Frailty and specific markers of frailty were significantly associated with mortality and six-month hospitalisations. We thus can conclude that, in patients with CVD, sex, MNA, Katz scale, TUG, handgrip strength, MMSE, GDS-15 and total number of medications play a key role in detecting frailty, assessed by a new time- and cost-efficient test battery.

NLRP3 inflammasomes are involved in the progression of postoperative cognitive dysfunction: from mechanism to treatment

Postoperative cognitive dysfunction (POCD) involves patient memory and learning decline after surgery. POCD not only presents challenges for postoperative nursing and recovery but may also cause permanent brain damage for patients, including children and the aged, with vulnerable central nervous systems. Its occurrence is mainly influenced by surgical trauma, anesthetics, and the health condition of the patient. There is a lack of imaging and experimental diagnosis; therefore, patients can only be diagnosed by clinical observation, which may underestimate the morbidity, resulting in decreased treatment efficacy. Except for symptomatic support therapy, there is a relative lack of effective drugs specific for the treatment of POCD, because the precise mechanism of POCD remains to be determined. One current hypothesis is that postoperative inflammation promotes the progression of POCD. Accumulating research has indicated that overactivation of NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasomes contribute to the POCD progression, suggesting that targeting NLRP3 inflammasomes may be an effective therapy to treat POCD. In this review, we summarize recent studies and systematically describe the pathogenesis, treatment progression, and potential treatment options of targeting NLRP3 inflammasomes in POCD patients.

Increased Carotid Intima-Media Thickness was not Associated With Cognitive Dysfunction After Off-Pump Coronary Surgery in Older Adult Patients Without Carotid Stenosis

Increased carotid intima-media thickness (C-IMT), a marker of atherosclerosis, is known to be associated with cerebrovascular and cortical abnormalities and cognitive impairment. This prospective observational study investigated the association between increased C-IMT and postoperative cognitive dysfunction (POCD) in older adult patients undergoing off-pump coronary artery bypass surgery. A total of 201 patients (57 females, 144 males; >60 years) were classified into increased (n = 105) or normal (n = 96) C-IMT groups by a cut-off value of 0.9 mm (bilateral C-IMT mean). Cognitive function was serially assessed with the Korean Mini-Mental State Examination, and Korean Montreal Cognitive Assessment scores preoperatively and at 7 days and 3 months postoperatively. POCD was defined as the deterioration of 1 standard deviation in at least one of the postoperative tests compared with their corresponding baseline scores. Independent risk factors for POCD were evaluated using multivariable analysis. Overall, POCD occurred in 46 patients (23%) over the 3 months. The incidences of POCD at 7 days and 3 months after surgery were similar, and there was no difference in both Korean Mini-Mental State Examination and Korean Montreal Cognitive Assessment test scores before and after surgery between groups. Chronic obstructive lung disease and intraoperative hyperglycemia episodes (>180 mg/dL), but not increased C-IMT, were independent risk factors for POCD. Unlike in nonsurgical cohorts, increased C-IMT was not significantly associated with the occurrence of POCD in older adult patients undergoing off-pump coronary artery bypass surgery.

Early mobilization reduces delirium after coronary artery bypass graft surgery

BACKGROUND

Postoperative delirium is common in patients undergoing coronary artery bypass grafting, characterized by cognitive decline. This study aimed to evaluate the effect of early planned mobilization on delirium after coronary artery bypass grafting.

METHODS

This double-blind randomized clinical trial enrolled 92 consecutive patients who underwent coronary artery bypass grafting from September to December 2018. The patients were divided into two groups of 46: a mobilization protocol was applied in the intervention group in the first 2 days after surgery; the control group received routine nursing care only. Demographic data, medical records, and Neecham confusion scores were analyzed.

RESULTS

Patients in the control group used cigarettes (31.1% vs. 11.1%, p = 0.020) and opium poppy for recreation (35.6% vs. 8.9%, p = 0.002) more frequently, had longer intubation times (11.91 ± 3.87 vs. 10.23 ± 2.71 h, p = 0.020), and fewer blood components infused (15.6% vs. 33.3%, p = 0.05). More patients in the intervention group had normal function on the 2nd postoperative day compared to the control group (25 vs. 2, respectively, p = 0.001). The intervention group had significantly higher Neecham scores on postoperative day 2 (22.49 ± 2.03 vs. 26.82 ± 2.10, p = 0.001). Multivariable analysis showed significant associations between Neecham score and age (p = 0.022), ejection fraction (p = 0.015), myocardial infarction (p = 0.016), systolic pressure (p = 0.009), and diastolic pressure (p = 0.008).

CONCLUSIONS

Early planned mobilization was effective in reducing postoperative delirium in patients undergoing coronary artery bypass grafting.