Neurocognitive Outcomes 3 Years After Coronary Artery Bypass Graft Surgery: A Controlled Study

Association between surgery and rate of incident dementia in older adults: A population-based retrospective cohort study

BACKGROUND

The risk of incident dementia after surgery in older adults is unclear. The study objective was to examine the rate of incident dementia among older adults after elective surgery compared with a matched nonsurgical control group.

METHODS

We conducted a population-based, propensity-matched retrospective cohort study using data from linked administrative databases in Ontario, Canada. All community-dwelling individuals aged 66 years and older who underwent one of five major elective surgeries between April 1, 2007 and March 31, 2011 were included. Each surgical patient was matched 1:1 on surgical specialty of the surgeon at consultation, age, sex, fiscal year of entry, and propensity score with a patient who attended an outpatient visit with a surgeon of the same surgical specialty but did not undergo surgery. Patients were followed for up to 5 years after cohort entry for the occurrence of a new dementia diagnosis, defined from administrative data. Cause-specific hazard models were used to estimate the hazard ratio (HR) and 95% confidence interval (CI) for the association between surgery and the hazard of incident dementia. Subgroup and sensitivity analyses were performed.

RESULTS

A total of 27,878 individuals (13,939 matched pairs) were included in the analysis. A total of 640 (4.6%) individuals in the surgical group and 965 (6.9%) individuals in the control group developed dementia over the 5-year follow-up period. Individuals who underwent surgery had a reduced rate of incident dementia compared with their matched nonsurgical controls (HR 0.88; 95% CI 0.80-0.97; p = 0.01). This association was persistent in most subgroups and after sensitivity analyses.

CONCLUSIONS

Elective surgery did not increase the rate of incident dementia when compared with matched nonsurgical controls. This could be an important consideration for patients and surgeons when elective surgery is considered.

Apolipoprotein E4 allele is genetically associated with risk of the short- and medium-term postoperative cognitive dysfunction: A meta-analysis and trial sequential analysis

The aim of systematic review and meta-analysis was to investigate whether APOE4 was associated with postoperative neurologic dysfunction occurrence in short- or medium-term among surgical patients and to study the potential genetic association among these two entities. We searched electronic databases for reserch studies to evaluate the association of APOE4 with postoperative delirium (POD) or short- and medium term postoperative cognitive dysfunction (POCD). Twenty-two trials (16 prospective and six retrospective) with 6734 patients were included. APOE4 alleles was shown significantly associated with POCD within 1 week (odds ratio, OR, 1.89, 95% confidence interval, CI, 1.36 to 2.6278, p < 0.01) in the random-effects model. A significant association was also noted between APOE4 and POCD in medium-term, 1-3 months, after surgery (OR: 1.67, 95% CI: 1.003-2.839, p = 0.049). However, APOE4 was not significantly associated with POCD 1 year after surgery (OR: 0.98, 95% CI: 0.57-1.70, p = 0.9449) and POD (OR: 1.28, 95% CI: 0.85-1.91, p = 0.23). In conclusion, APOE4 alleles was genetically associated with short- and medium-term postoperative neurological dysfunction and future screening or preventive strategies derived is highly potential to improve 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

Prediction of stroke reconvalescence after coronary bypass surgery indicated by CT scan parameters

BACKGROUND

Stroke in the postoperative time course after heart surgery remains a serious risk. Cranial computer tomography (CCT) is the first line option to detect severe intracranial damage. However, only few data are available to predict neurological outcome. Using visual rating scales (VRSs), this study addresses reliability and effectivity to indicate neurological status and likelyhood of improvement.

METHODS

In a single-center retrospective evaluation, 3719 patients underwent coronary bypass surgery. Because of a delayed recovery phase and neurologic deficits after cardiac surgery 109 patients had a cranial CT scan in the early postoperative period. The incidence of clinically relevant findings within the imaging was rated by an experienced neuroradiologist using two VRS, that is, the age-related white matter changes (ARWMCs) and the Mendes-Ribeiro visual rating scale (MRVRS). Both are computer-assisted measurement schemes to detect stroke-related intracranial damage. Follow-up was investigated with regard to clinical outcome and patient-related risk profiles.

RESULTS

Of 109 patients with postoperative cranial CT scans due to prolonged recovery phases or proven neurological damage 44.5% had one cerebral defect in CCT imaging scans only. The others showed multiple defects. During hospital stay, 92.3% experienced neurological improvement exposing reduced ARWMC, while 7.1% had no improvement and correlating high scores. Of both scales, the ARWMC-VRS demonstrated superior accuracy and discrimination. The preoperative ejection fraction (EF), arteriosclerotic degeneration of carotid arteries, and reduced glomerular filtration rate were found to have a high correlation (r = 0.0005) with the latter group. In-hospital mortality of this cohort was 8.18%.

CONCLUSION

Both the ARWMC and MRVRS were found to be appropriate. They reliably discriminate the groups of stroke patients after coronary artery bypass grafting (CABG)  in the analysis of CCT images. When applied at the onset of neurological symptoms both scales are able to predict neurological reconvalescence upon hospital dismission. The ARWMC scale appeared superior as it demonstrated better accuracy and discrimination. The use of both VRS in patients with suspected stroke after CABG surgery can give insightful information toward a progression of neurological dysfunction or postoperative improvement.

Postoperative but not preoperative depression is associated with cognitive impairment after cardiac surgery: exploratory analysis of data from a randomized trial

BACKGROUND

In this study we hypothesize that depression is associated with perioperative neurocognitive dysfunction and altered quality of life one month after surgery.

METHODS

Data were obtained as part of a study evaluating cerebral autoregulation monitoring for targeting arterial pressure during cardiopulmonary bypass. Neuropsychological testing was performed before surgery and one month postoperatively. Testing included the Beck Depression Inventory, a depression symptoms questionnaire (0-63 scale), as well as anxiety and quality of life assessments. Depression was defined as a Beck Depression Inventory score > 13.

RESULTS

Beck Depression data were available from 320 patients of whom cognitive domain endpoints were available from 88-98% at baseline and 69-79% after surgery. This range in end-points data was due to variability in the availability of each neuropsychological test results between patients. Depression was present in 50 (15.6%) patients before surgery and in 43 (13.4%) after surgery. Baseline depression was not associated with postoperative domain-specific neurocognitive function compared with non-depressed patients. Those with depression one month after surgery, though, had poorer performance on tests of attention (p = 0.017), memory (p = 0.049), verbal fluency (p = 0.010), processing speed (p = 0.017), and fine motor speed (p = 0.014). Postoperative neurocognitive dysfunction as a composite outcome occurred in 33.3% versus 14.5% of patients with and without postoperative depression (p = 0.040). Baseline depression was associated with higher anxiety and lower self-ratings on several quality of life domains, these measures were generally more adversely affected by depression one month after surgery.

CONCLUSIONS

The results of this exploratory analysis suggests that preoperative depression is not associated with perioperative neurocognitive dysfunction, but depression after cardiac surgery may be associated with impairment in in several cognitive domains, a higher frequency of the composite neurocognitive outcome, and altered quality of life.

TRIAL REGISTRATION

www.

CLINICALTRIALS

gov, NCT00981474 (parent study).

Apolipoprotein E ε4 and cognitive function after surgery in middle-aged and elderly Danish twins

BACKGROUND

Transient cognitive impairment is common in adult patients of all ages following anaesthesia and surgery. Apolipoprotein E (APOE) ε4 carriers may have a larger deterioration in short-term cognitive function after major surgery compared with APOE ε4 noncarriers.

OBJECTIVES

The aim was to examine the effect of APOE ε4 on the association between exposure to surgery and anaesthesia, and subsequent cognitive functioning. A more pronounced deterioration in cognitive function in APOE ε4 carriers was hypothesised.

DESIGN

An observational cross-sectional and a 6 to 10 years longitudinal twin cohort design.

SETTING

Survey and register study of 2936 Danish twins aged 45 to 92 years.

MAIN OUTCOME MEASURES

Cognitive function was assessed using five age-sensitive cognitive tests. In the cross-sectional study, we compared twins exposed to surgery with a reference group (unexposed). Linear regression models were used adjusting for sex and age and stratified by APOE ε4 carrier status. In the longitudinal cognitive follow-up study 1671 twins participated. Intrapair analyses were also performed using 70 same-sexed twin pairs concordant for APOE ε4 carrier status, but discordant for major surgery.

RESULTS

APOE ε4 carriers had lower cognitive scores compared with noncarriers, and this was statistically significant in elderly twins 70+ years of age (mean difference, -0.67; 95% CI, -1.14 to -0.17). There was no significant impact on cognitive function after surgery according to APOE ε4 carrier status in the cross-sectional study. Similarly, there was no APOE ε4 modification in the longitudinal study. Also, in the intrapair analyses no evidence was found of lower cognitive score after major surgery compared with the nonexposed cotwins among APOE ε4 carriers.

CONCLUSION

No evidence was found of more pronounced long-term deterioration in cognitive function after surgery among APOE ε4 carriers, but elderly APOE ε4 carriers in general performed worse on the cognitive tests than noncarriers.

Methodology of measuring postoperative cognitive dysfunction: a systematic review

BACKGROUND

Postoperative cognitive dysfunction (POCD) is an adverse outcome that impacts patients' quality of life. Its diagnosis relies on formal cognitive testing performed before and after surgery. The substantial heterogeneity in methodology limits comparability and meta-analysis of studies. This systematic review critically appraises the methodology of studies on POCD published since the 1995 Consensus Statement and aims to provide guidance to future authors by providing recommendations that may improve comparability between future studies.

METHODS

This systematic review of literature published between 1995 and 2019 included studies that used baseline cognitive testing and a structured cognitive test battery, and had a minimal follow-up of 1 month. For cohorts with multiple publications, data from the primary publication were supplemented with available data from later follow-up studies.

RESULTS

A total of 274 unique studies were included in the analysis. In the included studies, 259 different cognitive tests were used. Studies varied considerably in timing of assessment, follow-up duration, definition of POCD, and use of control groups. Of the 274 included studies, 70 reported POCD as a dichotomous outcome at 1 to <3 months, with a pooled incidence of 2998/10 335 patients (29.0%).

CONCLUSIONS

We found an overwhelming heterogeneity in methodology used to study POCD since the publication of the 1995 Consensus Statement. Future authors could improve study quality and comparability through optimal timing of assessment, the use of commonly used cognitive tests including the Consensus Statement 'core battery', application of appropriate cut-offs and diagnostic rules, and detailed reporting of the methods used.

PROSPERO REGISTRY NUMBER

CRD42016039293.

Psychiatric disturbances in patients undergoing open-heart surgery

Background

Emotional and behavioral problems have been noted in a considerable number of patients after open-heart surgery. However, great discrepancy exists in the literature regarding the frequency and the course of psychiatric symptoms, cognitive performance, and quality of life among those patients. This prospective study was designed to assess the pre- and postoperative psychiatric profile, as well as the quality of life of patients undergoing open-heart surgery.

Methods

One hundred patients who were prepared for cardiac surgery and met our selection criteria were recruited in this study. Each patient was subjected to the Hospital Anxiety and Depression Scale, the Mini-Mental State Examination with selective subtests of Wechsler Adult intelligence scale, and the Short Form 36 questionnaire to assess psychiatric symptoms, cognitive performance, and quality of life respectively. Assessment was done for each of the evaluated items before surgery as well as at 1 week and 6 months postoperatively.

Results

The anxiety and depressive symptoms were significantly lower at 6 months postoperatively than preoperatively. The cognitive performance declined after 1 week, then improved significantly at the 6-month follow-up. The quality of life scale was significantly lower preoperatively than after surgery.

Conclusions

Anxiety and depressive symptoms, which occurred in substantial percentage of patients undergoing open-heart surgery, were gradually improved with time. Cognitive functions showed early deterioration with significant improvement at 6 months. Psychiatric problems had an adverse impact on patients’ quality of life which raised the importance of psychiatric consultation before and after cardiac surgeries to shorten recovery time.

A systematic review of the next-day effects of heavy alcohol consumption on cognitive performance

BACKGROUND AND AIMS

Studies examining the next-day cognitive effects of heavy alcohol consumption have produced mixed findings, which may reflect inconsistencies in definitions of 'hangover'. Recent consensus has defined hangover as 'mental and physical symptoms, experienced the day after a single episode of heavy drinking, starting when blood alcohol concentration (BAC) approaches zero'. In light of this, we aimed to review the literature systematically to evaluate and estimate mean effect sizes of the next-day effects of heavy alcohol consumption on cognition.

METHODS

Embase, PubMed and PsycNET databases were searched between December 2016 and May 2018 using terms based on 'alcohol' and 'hangover'. Studies of experimental designs which reported the next-day cognitive effects of heavy alcohol consumption in a 'hangover' group with BAC < 0.02% were reviewed. A total of 805 articles were identified. Thirty-nine full-text articles were screened by two independent reviewers and 19 included in the systematic review; 11 articles provided sufficient data to be included in the meta-analysis; 1163 participants across 19 studies conducted since 1970 were included in the analysis. Data for study design, hangover severity, BAC at testing and cognitive performance were extracted and effect estimates calculated.

RESULTS

The systematic review suggested that sustained attention and driving abilities were impaired during hangover. Mixed results were observed for: psychomotor skills, short- (STM) and long-term memory (LTM) and divided attention. The meta-analysis revealed evidence of impairments in STM [g = 0.64, 95% confidence interval (CI) = 0.15-1.13], LTM (Hedges' g = 0.59, 95% CI = 0.01-1.17) sustained attention (g = 0.47, 95% CI = 0.07-0.87) and psychomotor speed (Hedges' g = 0.66, 95% CI = 0.31-1.00) during alcohol hangover.

CONCLUSION

The research literature suggests that alcohol hangovers may involve impaired cognitive functions and performance of everyday tasks such as driving.

Cognitive Decline after Delirium in Patients Undergoing Cardiac Surgery

WHAT WE ALREADY KNOW ABOUT THIS TOPIC

Cardiac surgery is associated with cognitive decline and postoperative delirium. The relationship between postoperative delirium and cognitive decline after cardiac surgery is unclear

WHAT THIS ARTICLE TELLS US THAT IS NEW

The development of postoperative delirium is associated with a greater degree of cognitive decline 1 month after cardiac surgery. The development of postoperative delirium is not a predictor of cognitive decline 1 yr after cardiac surgery.

BACKGROUND

Delirium is common after cardiac surgery and has been associated with morbidity, mortality, and cognitive decline. However, there are conflicting reports on the magnitude, trajectory, and domains of cognitive change that might be affected. The authors hypothesized that patients with delirium would experience greater cognitive decline at 1 month and 1 yr after cardiac surgery compared to those without delirium.

METHODS

Patients who underwent coronary artery bypass and/or valve surgery with cardiopulmonary bypass were eligible for this cohort study. Delirium was assessed with the Confusion Assessment Method. A neuropsychologic battery was administered before surgery, at 1 month, and at 1 yr later. Linear regression was used to examine the association between delirium and change in composite cognitive Z score from baseline to 1 month (primary outcome). Secondary outcomes were domain-specific changes at 1 month and composite and domain-specific changes at 1 yr.

RESULTS

The incidence of delirium in 142 patients was 53.5%. Patients with delirium had greater decline in composite cognitive Z score at 1 month (greater decline by -0.29; 95% CI, -0.54 to -0.05; P = 0.020) and in the domains of visuoconstruction and processing speed. From baseline to 1 yr, there was no difference between delirious and nondelirious patients with respect to change in composite cognitive Z score, although greater decline in processing speed persisted among the delirious patients.

CONCLUSIONS

Patients who developed delirium had greater decline in a composite measure of cognition and in visuoconstruction and processing speed domains at 1 month. The differences in cognitive change by delirium were not significant at 1 yr, with the exception of processing speed.

Fish Oil Supplementation Does Not Affect Cognitive Outcomes in Cardiac Surgery Patients in the Omega-3 Fatty Acids for Prevention of Post-Operative Atrial Fibrillation (OPERA) Trial

Background

Cognitive decline has been reported following cardiac surgery, leading to great interest in interventions to minimize its occurrence. Long-chain n-3 (ω-3) polyunsaturated fatty acids (PUFAs) have been associated with less cognitive decline in observational studies, yet no trials have tested the effects of n-3 PUFAs on cognitive decline after surgery.

Objective

We sought to determine whether perioperative n-3 PUFA supplementation reduces postoperative cognitive decline in patients postcardiac surgery.

Methods

The study comprised a randomized, double-blind, placebo-controlled, multicenter, clinical trial conducted on cardiac surgery recipients at 9 tertiary care medical centers across the United States. Patients were randomly assigned to receive fish oil (1-g capsules containing ≥840 mg n-3 PUFAs as ethyl esters) or placebo, with preoperative loading of 8-10 g over 2-5 d followed postoperatively by 2 g/d until hospital discharge or postoperative day 10, whichever came first. Global cognition was assessed using in-person testing over 30 d with the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) (primary outcome), Mini-Mental State Exam (secondary outcome), and Trails A and B (secondary outcome) tests. All end points were prespecified. Statistical methods were employed, including descriptive statistics, logistic regression, and various sensitivity analyses.

Results

A total of 320 US patients were enrolled in the Omega-3 Fatty Acids for Prevention of Post-Operative Atrial Fibrillation (OPERA) Cognitive Trial (OCT), a substudy of OPERA. The median age was 62 y (IQR 53, 70 y). No differences in global cognition were observed between placebo and fish oil groups at day 30 (P = 0.32) for the primary outcome, a composite neuropsychological RBANS score. The population demonstrated resolution of initial 4-d cognitive decline back to baseline function by 30 d on the RBANS.

Conclusion

Perioperative supplementation with n-3 PUFAs in cardiac surgical patients did not influence cognition ≤30 d after discharge. Modern anesthetic, surgical, and postoperative care may be mitigating previously observed long-term declines in cognitive function following cardiac surgery. This trial was registered at clinicaltrials.gov as NCT00970489.

Orthopedic Surgery and Post-Operative Cognitive Decline in Idiopathic Parkinson's Disease: Considerations from a Pilot Study

BACKGROUND

Post-operative cognitive dysfunction (POCD) demarks cognitive decline after major surgery but has been studied to date in "healthy" adults. Although individuals with neurodegenerative disorders such as Parkinson's disease (PD) commonly undergo elective surgery, these individuals have yet to be prospectively followed despite hypotheses of increased POCD risk.

OBJECTIVE

To conduct a pilot study examining cognitive change pre-post elective orthopedic surgery for PD relative to surgery and non-surgery peers.

METHODS

A prospective one-year longitudinal design. No-dementia idiopathic PD individuals were actively recruited along with non-PD "healthy" controls (HC) undergoing knee replacement surgery. Non-surgical PD and HC controls were also recruited. Attention/processing speed, inhibitory function, memory recall, animal (semantic) fluency, and motor speed were assessed at baseline (pre-surgery), 3 weeks, 3 months, and 1 year post- orthopedic surgery. Reliable change methods examined individual changes for PD individuals relative to control surgery and control non-surgery peers.

RESULTS

Over two years we screened 152 older adult surgery or non-surgery candidates with 19 of these individuals having a diagnosis of PD. Final participants included 8 PD (5 surgery, 3 non-surgery), 47 Control Surgery, and 21 Control Non-Surgery. Eighty percent (4 of the 5) PD surgery declined greater than 1.645 standard deviations from their baseline performance on measures assessing processing speed and inhibitory function. This was not observed for the non-surgery PD individuals.

CONCLUSION

This prospective pilot study demonstrated rationale and feasibility for examining cognitive decline in at-risk neurodegenerative populations. We discuss recruitment and design challenges for examining post-operative cognitive decline in neurodegenerative samples.

Postoperative Cognitive Dysfunction: Minding the Gaps in Our Knowledge of a Common Postoperative Complication in the Elderly

Postoperative cognitive dysfunction (POCD) is a common complication associated with significant morbidity and mortality in elderly patients. There is much interest in and controversy about POCD, reflected partly in the increasing number of articles published on POCD recently. Recent work suggests surgery may also be associated with cognitive improvement in some patients, termed postoperative cognitive improvement (POCI). As the number of surgeries performed worldwide approaches 250 million per year, optimizing postoperative cognitive function and preventing/treating POCD are major public health issues. In this article, we review the literature on POCD and POCI, and discuss current research challenges in this area.

Association between APOE epsilon 4 allele and postoperative cognitive dysfunction: a meta-analysis

BACKGROUND

Carriers of the apolipoprotein E epsilon 4 allele (APOEε4) may be at increased risk of postoperative cognitive dysfunction (POCD), but this association has not been reported consistently. We conducted a meta-analysis to derive a more precise conclusion.

METHODS

The PubMed, EBSCO and EMBASE databases were searched for eligible studies published in English before March 2013. The association between APOEε4 and POCD was expressed by the odds ratio (OR) with 95% confidence interval (CI). Funnel plots were constructed and publication bias assessed by Egger's test.

RESULTS

Nine studies encompassing 1063 APOEε4 carriers and 2983 noncarriers were included. At about 1-week postsurgery, a significant association between APOEε4 and POCD was found (OR 1.83, 95% CI: 1.18-2.85), but the association was no longer significant after removing one large study (OR 1.35, 95% CI: 0.92-1.97). Stratified analysis of cardiac/vascular surgery patients also yielded no significant correlation (OR 1.62, 95% CI: 0.80-3.28). One to three months postsurgery, neither the overall analysis (OR 1.56, 95% CI: 0.87-2.81) nor the stratified analysis of cardiac/vascular surgery patients (OR 3.33, 95% CI: 0.55-20.22) indicated a significant correlation. APOEε4 was also not correlated with POCD at 1-year postsurgery (OR 1.15, 95% CI: 0.71-1.86). No evidence of publication bias was revealed by Egger's test.

CONCLUSIONS

The APOEε4 allele was associated with a significantly increased POCD risk about 1-week postsurgery, but the association depended on one large study. No association was found 1-3 months and 1-year postsurgery.

Aortic no-touch technique makes the difference in off-pump coronary artery bypass grafting

OBJECTIVES

Both off-pump surgery (OPCAB) and aortic no-touch technique reduce stroke after coronary artery bypass grafting (CABG). We evaluate the impact of partial aortic clamping (PC) versus a no-touch technique using either the HEARTSTRING system (HS) or total arterial revascularization (TAR) on the incidence of stroke.

METHODS

From 1999 [corrected] to 2009, 4314 patients underwent myocardial revascularization. Patients either underwent OPCAB (n = 2203) or conventional on-pump CABG (n = 2111). The OPCAB cohort was divided into 2 subgroups: patients requiring proximal anastomosis applying PC (n = 567) or a "no-touch" technique with the HS (n = 1365). Patients who received TAR (n = 271) served as a control group (gold-standard). Data collection was performed prospectively using a propensity score (PS)-adjusted regression analysis. End points were stroke, mortality, major adverse cardiac and cerebrovascular events (MACCE), and a noncardiac composite end point including respiratory failure, renal failure, and bleeding.

RESULTS

The mortality rate (1.6% vs 2.4%; propensity-adjusted odds ratio [PAOR] = 0.51; CI 95%, 0.26-0.99; P = .047), MACCE (7.9% vs 17.1%; PAOR = 0.67; CI 95%, 0.52-0.84; P = .001) including myocardial infarction (1.1% vs 2.2%; PAOR = 0.50; CI 95%, 0.26-0.98; P = .044) and stroke (1.1% vs 2.4%; PAOR = 0.35; CI 95%, 0.17-0.72; P = .005) as well as the noncardiac composite (PAOR = 0.46; CI 95%, 0.35-0.91; P < .001) were significantly lower for OPCAB when compared with on-pump CABG. In comparison with PC, OPCAB patients undergoing the HS approach had significantly lower frequencies of stroke (0.7% vs 2.3%; PAOR = 0.39; CI 95%, 0.16-0.90; P = .04) and MACCE (6.7% vs 10.8%; PAOR = 0.55; CI 95%, 0.38-0.79; P = .001), and these results were similar to those of the control group, who underwent no-touch TAR (stroke rate, 0.8%; MACCE, 7.9%).

CONCLUSIONS

Our results confirm that OPCAB is superior with regard to risk-adjusted outcomes. There is no difference in the stroke rate when comparing on-pump CABG versus applying partial aortic crossclamping in OPCAB. Whenever a proximal anastomosis is needed, a no-touch technique should be applied, that is, using the HS device.

Independent association between preoperative cognitive status and discharge location after cardiac surgery

BACKGROUND

Among cardiac surgery patients, those with impaired cognitive status before surgery may have longer postoperative stays than do patients with normal status and may require additional care upon discharge.

OBJECTIVES

To determine if preoperative scores on a screening measure for cognitive status (the Clock-in-the-Box), were associated with postoperative length of stay and discharge to a location other than home in patients who had cardiac surgery.

METHODS

A total of 181 consecutive patients scheduled for cardiac surgery at a single site were administered the Clock-in-the-Box as part of the preoperative evaluation. Scores on the Clock-in-the-Box tool, demographic and operative information, postoperative length of stay, and discharge location were collected retrospectively from medical records.

RESULTS

The mean age of the patients was 68.1 years (SD, 0.7), and 99% were men. Mean postoperative length of stay was 10.5 days (SD, 8.2), and 35 patients (19%) were discharged to a facility. Scores on the Clock-in-the-Box assessment were not associated with postoperative length of stay. Increasing age, living alone before surgery, and duration of cardiopulmonary bypass were associated with discharge to a facility and were used as covariates in adjusted analyses. After adjustment, better preoperative cognitive status reduced the risk of being discharged to a facility (adjusted relative risk, 0.93; 95% confidence interval, 0.89-0.98) after cardiac surgery.

CONCLUSIONS

Cognitive screening before cardiac surgery can identify patients with impaired cognitive status who are less likely than patients with normal cognitive status to return home after cardiac surgery.

Longitudinal trajectories of cognitive decline among older adults with cardiovascular disease

BACKGROUND

The long-term course of cognitive impairments secondary to cardiovascular disease (CVD) is unclear. In this study, we prospectively investigated the temporal pattern, rate and hierarchy of cognitive decline attributable to CVD--a risk factor for the development of vascular cognitive impairment (VCI)--and examined the influence of cardiac surgery and heart failure on cognitive decline.

METHODS

A total of 172 older adults with CVD were administered a comprehensive battery of neuropsychological tests at study entry, and at 12 and 36 months thereafter. Random coefficient regressions were used to investigate the temporal course, rate and hierarchy of cognitive decline, as well as to examine the effect of heart failure (reported by 21% of the sample) and cardiac surgery (reported by 44% of the sample) on trajectories of cognitive change.

RESULTS

The course of decline in cognition was linear for language and attention-executive function-psychomotor speed, and curvilinear for visuospatial abilities, memory and overall cognition. The decline in attention-executive function-psychomotor speed was smaller than the decline in other domains. The greatest decline occurred in visuospatial abilities. The rate of decline in cognition was not altered by a history of heart failure. Patients who had undergone cardiac surgery exhibited slower deceleration in their rates of decline in overall cognition. At baseline, patients with a history of heart failure had comparatively poorer attention-executive function-psychomotor speed, overall cognition and, to a lesser extent, visuospatial scores.

CONCLUSION

There is measurable decline in neurocognitive function among patients with CVD. This decline is linear in some cognitive domains and curvilinear in others and is not attributable to the normal aging process. Cardiac surgery, but not heart failure, significantly affects the trajectory of cognitive decline. Because most vascular risk factors are modifiable, preventive measures such as lifestyle changes may be useful in retarding cognitive decline among patients with CVD, thus preventing the onset of VCI.

Neuropsychological status in children after repair of acyanotic congenital heart disease

OBJECTIVES

The majority of previous studies that described the neuropsychological effects of cardiopulmonary bypass (CPB) in children were performed after surgery in infancy for complex congenital heart disease (CHD). We sought to limit confounding variables and isolate potential independent effects of CPB by describing neuropsychological function in school-aged children after repair of acyanotic CHD.

METHODS

This was a prospective study of patients who were aged 5 to 18 years and undergoing repair of acyanotic CHD. Neuropsychological testing battery included assessment of intelligence, memory, motor, attention, executive function, and behavior before and 6 months after CPB. The independent effects of anesthesia, surgery, and hospitalization on neuropsychological function were assessed by testing a surgical control group of patients who were undergoing repair of pectus deformities. In addition, an outpatient group of children with mild CHD were enrolled to assess the practice effects of serial testing.

RESULTS

Patients included CPB (n = 35), surgical control (n = 19), and nonsurgical (n = 12). Groups were comparable in age, gender, and race and demonstrated similar unadjusted group mean scores on baseline and 6-month follow-up neuropsychological testing. When adjusted for practice effects, the CPB group performed similar to the non-CPB groups in all assessed neuropsychological domains, with the exception of 1 of 4 tests of executive function.

CONCLUSIONS

When controlling for the non-CPB effects of surgery (eg, hospitalization, anesthesia, thoracotomy) and the practice effects of serial testing, there were no consistent independent effects of CPB on neuropsychological status in a cohort of children and adolescents 6 months after repair of acyanotic CHD.

Measurement of post-operative cognitive dysfunction after cardiac surgery: a systematic review

Post-operative cognitive dysfunction (POCD) is a decline in cognitive function from pre-operative levels, which has been frequently described after cardiac surgery. The purpose of this study was to examine the variability in the measurement and definitions for POCD using the framework of a 1995 Consensus Statement on measurement of POCD. Electronic medical literature databases were searched for the intersection of the search terms 'thoracic surgery' and 'cognition, dementia, and neuropsychological test.' Abstracts were reviewed independently by two reviewers. English articles with >50 participants published since 1995 that performed pre-operative and post-operative psychometric testing in patients undergoing cardiac surgery were reviewed. Data relevant to the measurement and definition of POCD were abstracted and compared with the recommendations of the Consensus Statement. Sixty-two studies of POCD in patients undergoing cardiac surgery were identified. Of these studies, the recommended neuropsychological tests were carried out in less than half of the studies. The cognitive domains measured most frequently were attention (n=56; 93%) and memory (n=57; 95%); motor skills were measured less frequently (n=36; 60%). Additionally, less than half of the studies examined anxiety and depression, performed neurological exam, or accounted for learning. Four definitions of POCD emerged: per cent decline (n=15), standard deviation decline (n=14), factor analysis (n=13), and analysis of performance on individual tests (n=12). There is marked variability in the measurement and definition of POCD. This heterogeneity may impede progress by reducing the ability to compare studies on the causes and treatment of POCD.

Delirium after coronary artery bypass graft surgery and late mortality

OBJECTIVE

Delirium is common after cardiac surgery, although under-recognized, and its long-term consequences are likely underestimated. The primary goal of this study was to determine whether patients with delirium after coronary artery bypass graft (CABG) surgery have higher long-term out-of-hospital mortality when compared with CABG patients without delirium.

METHODS

We studied 5,034 consecutive patients undergoing CABG surgery at a single institution from 1997 to 2007. Presence or absence of neurologic complications, including delirium, was assessed prospectively. Survival analysis was performed to determine the role of delirium in the hazard of death, including a propensity score to adjust for potential confounders. These analyses were repeated to determine the association between postoperative stroke and long-term mortality.

RESULTS

Individuals with delirium had an increased hazard of death (adjusted hazard ratio [HR], 1.65; 95% confidence interval [CI], 1.38-1.97) up to 10 years postoperatively, after adjustment for perioperative and vascular risk factors. Patients with postoperative stroke had a HR of 2.34 (95% CI, 1.87-2.92). The effect of delirium on subsequent mortality was the strongest among those without a prior stroke (HR 1.83 vs HR 1.11 [with a prior stroke] [p-interaction = 0.02]) or who were younger (HR 2.42 [<65 years old] vs HR 1.49 [>/=65 years old] [p-interaction = 0.04]).

INTERPRETATION

Delirium after cardiac surgery is a strong independent predictor of mortality up to 10 years postoperatively, especially in younger individuals and in those without prior stroke. Future studies are needed to determine the impact of delirium prevention and/or treatment in long-term patient mortality.

Lower perfusion pressure during hypothermic cardiopulmonary bypass is associated with decreased cerebral blood flow and impaired memory performance 6 months postoperatively

OBJECTIVES

We undertook to determine the influence of perfusion pressure during hypothermic cardiopulmonary bypass (CPB) on cerebral blood flow (CBF) and cognitive memory outcome at 6 months postoperatively.

METHODS

Nineteen patients who underwent hypothermic nonpulsatile CPB for elective coronary artery bypass (CAB) surgery were evaluated by (133)Xe measurement of the CBF and by the Incidental Memory Assessment for evaluating cognitive memory (IMTscore), both at baseline before the operation (T(1)) and again at 5 to 6 months postoperatively (T(2)).

RESULTS

Overall, the mean CBF fell significantly from 39 +/- 5 mL.(100 g)(-1).min(-1) at T(1) to 33 +/- 3 mL.(100 g)(-1).min(-1) at T(2) (P < .001). The decrease in CBF from T(1) to T(2) (DeltaCBF(2-1)) correlated with a significant reduction in the IMTscore from T1 to T2 (DeltaIMTscore(2-1)) (P < .001) and with a mean arterial pressure during CPB (MAPCPB) of <60 mm Hg (P = .05). Cluster analysis of DeltaCBF(2-1) and DeltaIMTscore(2-1) demonstrated that the patients with the greatest decrease in CBF showed the greatest decrease in IMTscore, whereas cluster analysis of DeltaCBF(2-1) and MAPCPB indicated that patients with a perfusion pressure maintained at a mean of <60 mm Hg during CPB were prone to a greater decrease in later postoperative CBF.

CONCLUSION

This study demonstrated that a MAPCPB of <60 mm Hg during CPB was associated with a significant decrease in CBF 6 months after CAB surgery and with an associated decrease in memory performance.

Have improvements in myocardial protection influenced a surgeon's choice of coronary artery bypass surgery?

The aim of this study is to determine whether improvements in myocardial protection strategy have influenced the surgeon's choice of coronary artery bypass surgery. Between February 2002 and April 2009, a total of 662 patients underwent coronary artery bypass surgery under the provision of a single consultant surgeon. Operative mortality was defined as in-hospital death and comparison was made based on both the observed and expected mortalities as derived from the logistic EuroSCORE. Of the 662 patients who underwent cardiac surgery, 155 had off-pump whilst 507 had conventional coronary artery bypass surgery. The observed mortalities improved over the years in line with the improvements in myocardial protection strategy despite the increasing risk as predicted by the logistic EuroSCORE, with a reduction in the ratio of observed to expected mortalities of 1.2 in the off-pump group to 0.4 in the conventional group who had better myocardial protection. This has lead to a change in practice being predominantly off-pump at the beginning to that of conventional surgery in the later part of the study. As the case mix of patients gets worse with the increasing severity of multi-vessel disease and poor ventricular function, myocardial protection becomes crucial to the surgeon's preoperative assessment.

Cerebral Emboli Generation during Off-Pump Coronary Artery Bypass Grafting with a Clampless Device versus Partial Clamping of the Ascending Aorta

Objective

It is not known whether use of a clampless facilitating device during proximal graft anastamosis decreases intraoperative cerebral emboli in patients with mild atherosclerotic ascending aorta (AAA) having off-pump coronary artery bypass.

Methods

After intraoperative epiaortic ultrasound showed no more than mild (grade I–II) atherosclerotic ascending aorta, 20 patients were randomized to receive either partial clamping (PC, n = 10) or the HEARTSTRING clampless device (HS, n = 9) for proximal graft construction on the ascending aorta. Continuous transcranial Doppler monitoring, with capability to discern gaseous from solid particulates, was used intraoperatively to monitor high-intensity transient signals (HITS) in the middle cerebral arteries. Postoperative diffusion-weighted brain magnetic resonance imaging documented old and new ischemic brain lesions.

Results

There were no significant differences between the groups in the number of proximals (P = 0.14), distals (P = 0.4), or intraoperative cell saver transfusions (P = 0.69). The total number of HITS was not significantly different between the PC and HS groups (P = 0.2). However, the number of solid HITS was significantly lower in the HS than in the PC group (2.7 ± 2.6 versus 14.0 ± 8.1; P < 0.001). The number of gaseous emboli in the HS group was fourfold greater when a mister-blower rather than a suction device was used to clear blood away from the HS site. Postoperatively, there were no deaths, myocardial infarctions, or clinical strokes observed in either group. Diffusion-weighted cerebral magnetic resonance imaging revealed no statistical difference between groups for new infarct lesions.

Conclusions

Use of the HS device during off-pump coronary artery bypass was associated with significantly fewer intraoperative solid emboli in the middle cerebral artery than PC of the ascending aorta.

Four-year outcome of OPCAB no-touch with total arterial Y-graft: making the best treatment a daily practice

BACKGROUND

A retrospective, single-center 4-year clinical study of the off-pump coronary artery bypass grafting no-touch technique with arterial conduits (Y-graft) was compared with the Syntax trial.

METHODS

Four hundred consecutive patients ("all-comers") who underwent coronary surgery between 2004 and 2008 at the Thorax Center Twente (TCT) formed the study group. The primary end point was in-hospital and 12-month major cardiovascular or cerebrovascular event (MACCE). Event rates of MACCE were based on life tables, and overall MACCE was determined by Kaplan-Meier analysis.

RESULTS

In-hospital mortality was 0.2%. Cumulative 1-year survival was 98.2%, and freedom from MACCE was 94.7% +/- 1.1%. Cumulative 4-year survival and freedom from MACCE were 91.2% +/- 2.4% and 82.1% +/- 3.0%, respectively. There were no significant differences in the baseline characteristics between the patients of the TCT group and the surgical arm of the Syntax trial. Repeat revascularization, MACCE, and symptomatic graft occlusion in the TCT group were significantly lower than in the Syntax trial. The event rate of myocardial infarction and all-cause death in the TCT group were significantly lower than those of the percutaneous coronary intervention arm of the Syntax trial. There was a clear trend toward a reduction of the event rate of stroke in the TCT group (0.8%) compared with the surgical arm of the Syntax trial (2.2%). There was no significant difference of stroke rate between the TCT group and the percutaneous coronary intervention arm of the Syntax trial.

CONCLUSIONS

A state-of-the-art surgical technique such as off-pump coronary artery bypass grafting no-touch can further improve the advantage of surgical treatment with respect to percutaneous coronary intervention. Off-pump coronary artery bypass grafting no-touch surgery can be the treatment of choice for patients with three-vessel disease and left main stenosis.

Do management strategies for coronary artery disease influence 6-year cognitive outcomes?

BACKGROUND

Previous uncontrolled studies have suggested that there is late cognitive decline after coronary artery bypass grafting that may be attributable to use of the cardiopulmonary bypass pump.

METHODS

In this prospective, nonrandomized, longitudinal study, we compared cognitive outcomes after on-pump coronary artery bypass surgery (n = 152) with off-pump bypass surgery patients (n = 75); nonsurgical cardiac comparison subjects (n = 99); and 69 heart-healthy comparison (HHC) subjects. The primary outcome measure was change from baseline to 72 months in the following cognitive domains: verbal memory, visual memory, visuoconstruction, language, motor speed, psychomotor speed, attention, executive function, and a composite global score.

RESULTS

There were no consistent differences in 72-month cognitive outcomes among the three groups with coronary artery disease (CAD). The CAD groups had lower baseline performance, and a greater degree of decline compared with HHC. The degree of change was small, with none of the groups having more than 0.5 SD decline. None of the groups was substantially worse at 72 months compared with baseline.

CONCLUSIONS

Compared with subjects with no vascular disease risk factors, the CAD patients had lower baseline cognitive performance and greater degrees of decline over 72 months, suggesting that in these patients, vascular disease may have an impact on cognitive performance. We found no significant differences in the long-term cognitive outcomes among patients with various CAD therapies, indicating that management strategy for CAD is not an important determinant of long-term cognitive outcomes.

Predicting risk of dementia in older adults: The late-life dementia risk index

OBJECTIVE

To develop a late-life dementia risk index that can accurately stratify older adults into those with a low, moderate, or high risk of developing dementia within 6 years.

METHODS

Subjects were 3,375 participants in the Cardiovascular Health Cognition Study without evidence of dementia at baseline. We used logistic regression to identify those factors most predictive of developing incident dementia within 6 years and developed a point system based on the logistic regression coefficients.

RESULTS

Subjects had a mean age of 76 years at baseline; 59% were women and 15% were African American. Fourteen percent (n = 480) developed dementia within 6 years. The final late-life dementia risk index included older age (1-2 points), poor cognitive test performance (2-4 points), body mass index <18.5 (2 points), > or =1 apolipoprotein E epsilon4 alleles (1 point), cerebral MRI findings of white matter disease (1 point) or ventricular enlargement (1 point), internal carotid artery thickening on ultrasound (1 point), history of bypass surgery (1 point), slow physical performance (1 point), and lack of alcohol consumption (1 point) (c statistic, 0.81; 95% confidence interval, 0.79-0.83). Four percent of subjects with low scores developed dementia over 6 years compared with 23% of subjects with moderate scores and 56% of subjects with high scores.

CONCLUSIONS

The late-life dementia risk index accurately stratified older adults into those with low, moderate, and high risk of developing dementia. This tool could be used in clinical or research settings to target prevention and intervention strategies toward high-risk individuals.

Cyclohexanone contamination from extracorporeal circuits impairs cardiovascular function

Extracorporeal circulation provides critical life support in the face of cardiopulmonary or renal failure, but it also introduces a host of unique morbidities characterized by edema formation, cardiac insufficiency, autonomic dysfunction, and altered vasomotor function. We tested the hypothesis that cyclohexanone (CHX), a solvent used in production of extracorporeal circuits and intravenous (IV) bags, leaches into the contained fluids and can replicate these clinical morbidities. Crystalloid fluid samples from circuits and IV bags were analyzed by gas chromatography-mass spectrometry to provide a range of clinical CHX exposure levels, revealing CHX contamination of sampled fluids (9.63-3,694 microg/l). In vivo rat studies were conducted (n = 49) to investigate the effects of a bolus IV infusion of CHX vs. saline alone on cardiovascular function, baroreflex responsiveness, and edema formation. Cardiovascular function was evaluated by cardiac output, heart rate, stroke volume, vascular resistance, arterial pressure, and ventricular contractility. Baroreflex function was assessed by mean femoral arterial pressure responses to bilateral carotid occlusion. Edema formation was assessed by the ratio of wet to dry organ weights for lungs, liver, kidneys, and skin. CHX infusion led to systemic hypotension; pulmonary hypertension; depressed contractility, heart rate, stroke volume, and cardiac output; and elevated vascular resistance (P < 0.05). Mean arterial pressure responsiveness to carotid occlusion was dampened after CHX infusion (from +17.25 +/- 1.8 to +5.61 +/- 3.2 mmHg; P < 0.05). CHX infusion led to significantly higher wet-to-dry weight ratios vs. saline only (3.8 +/- 0.06 vs. 3.5 +/- 0.05; P < 0.05). CHX can reproduce clinical cardiovascular, neurological, and edema morbidities associated with extracorporeal circulatory treatment.

Neurological complications of cardiac surgery

Neurological injury resulting from cardiac surgery has a range of manifestations from focal neurological deficit to encephalopathy or coma. As the safety of drug-eluting stents comes into question, more patients will likely undergo coronary artery bypass graft surgery. These projections, along with the growing proportions of elderly patients and those with comorbidities, portend the potential for rising rates of perioperative neurological complications. The risk for neurological injury may be determined by the type of procedure, by patient-specific characteristics, and by the extent of cerebral embolization and hypoperfusion during and after surgery. Changes in surgical techniques, including the use of off-pump surgery, have not decreased rates of brain injury from cardiac surgery. When appropriate, modern neuroimaging techniques should be used in postoperative patients to confirm diagnosis, to provide information on potential etiology, to direct appropriate therapy, and to help in prognostication. Management of postoperative medications and early use of rehabilitation services is a recommended strategy to optimize the recovery for individuals with neurological injury after cardiac surgery.