Predictors of early neurocognitive deficits in low-risk patients undergoing on-pump coronary artery bypass surgery

Bridging the Gap: Investigating the Link between Inflammasomes and Postoperative Cognitive Dysfunction

Postoperative cognitive dysfunction (POCD) is a cluster of cognitive problems that may arise after surgery. POCD symptoms include memory loss, focus inattention, and communication difficulties. Inflammasomes, intracellular multiprotein complexes that control inflammation, may have a significant role in the development of POCD. It has been postulated that the NLRP3 inflammasome promotes cognitive impairment by triggering the inflammatory response in the brain. Nevertheless, there are many gaps in the current literature to understand the underlying pathophysiological mechanisms and develop future therapy. This review article underlines the limits of our current knowledge about the NLRP3 (NOD-, LRR- and pyrin domain-containing protein 3) inflammasome and POCD. We first discuss inflammasomes and their types, structures, and functions, then summarize recent evidence of the NLRP3 inflammasome's involvement in POCD. Next, we propose a hypothesis that suggests the involvement of inflammasomes in multiple organs, including local surgical sites, blood circulation, and other peripheral organs, leading to systemic inflammation and subsequent neuronal dysfunction in the brain, resulting in POCD. Research directions are then discussed, including analyses of inflammasomes in more clinical POCD animal models and clinical trials, studies of inflammasome types that are involved in POCD, and investigations into whether inflammasomes occur at the surgical site, in circulating blood, and in peripheral organs. Finally, we discuss the potential benefits of using new technologies and approaches to study inflammasomes in POCD. A thorough investigation of inflammasomes in POCD might substantially affect clinical practice.

Mechanisms of hypoxia in the hippocampal CA3 region in postoperative cognitive dysfunction after cardiopulmonary bypass

Background

Postoperative cognitive dysfunction (POCD) is a complication with high morbidity and mortality, commonly observed in the elderly who underwent anesthesia and surgery. The incidence is much higher in cardiac surgery. However, the reason and the mechanism of POCD remains unclear, but cerebral hypoxia is a common neurological complication after cardiac surgery. This study aims to investigate what role cerebral hypoxia plays in the pathogenesis of POCD.

Methods

The POCD model was established using cardiopulmonary bypass (CPB) surgery. Cognitive function was detected using Y maze and Morris water maze. The hypoxia in central nervous system was assessed using HE staining, western blot, and immunofluorescence. Inflammatory factors in hippocampus and plasma were detected by enzyme-linked immunosorbent assay. Evans blue was used to detect destruction of the blood brain barrier (BBB).

Results

Cognitive impairment markedly occurred to rats underwent 2-h CPB operation. Cerebral thrombosis and hypoxia occurred in the hippocampal CA3 region of rats after surgery. In addition, microglia in hippocampal was activated and the expression of inflammatory factors such as IL-1β, IL-6 and TNF-α was upregulated. Moreover, the permeability of BBB increased in rats after CPB.

Conclusion

Hypoxia in hippocampal CA3 region was involved in the occurrence and the mechanism may be associated with neuroinflammation and the damage of BBB.

Targeted temperature management in cardiac surgery: a systematic review and meta-analysis on postoperative cognitive outcomes

BACKGROUND

Postoperative cognitive decline occurs commonly after cardiac surgery. The available literature is inconclusive on the role of intraoperative causal or protective factors.

METHODS

We systematically reviewed studies evaluating delayed neurocognitive recovery (DNR), postoperative neurocognitive disorder (NCD), stroke, and the mortality rates among patients undergoing hypothermic or normothermic cardiopulmonary bypass (CPB). We further performed a subgroup analysis for age, surgery type (coronary artery bypass grafting [CABG], valve surgery, or combined), and the mean arterial blood pressure (MAP) during CPB, and conducted a proportion meta-analysis after calculation of single proportions and confidence intervals (CIs).

RESULTS

We included a total of 58 studies with 9609 patients in our analysis. Among these, 1906 of 4010 patients (47.5%) had DNR, and 2071 of 7160 (28.9%) had postoperative NCD. Ninety of 4625 patients (2.0%) had a stroke, and 174 of 7589 (2.3%) died. There was no statistically significant relationship between the considered variables and DNR, NCD, stroke, and mortality. In the subgroup analysis comparing hypothermic with normothermic CPB, we found higher NCD rates after combined surgery; for normothermic CPB cases only, the rates of DNR and NCD were lower after combined surgery compared with CABG surgery. A MAP >70 mm Hg compared with MAP=50-70 mm Hg during CPB was associated with a lower rate of DNR.

CONCLUSIONS

Temperature, MAP during cardiopulmonary bypass age, and surgery type were not associated with neurocognitive disorders, stroke, and mortality in cardiac surgery. Normothermic cardiopulmonary bypass, particularly when performed with MAP >70 mm Hg, may reduce the risk of postoperative neurocognitive decline after cardiac surgery.

PROSPERO REGISTRATION NUMBER

CRD42019140844.

Predictors of cognitive dysfunction after cardiac surgery: a systematic review

AIMS

Postoperative cognitive dysfunction (POCD) is often experienced by cardiac surgery patients; however, it is not known if some groups of patients experience this more frequently or severely than others.The aim of this systematic review was to identify preoperative and postoperative predictors of cognitive dysfunction in adults following cardiac surgery.

METHODS AND RESULTS

Eight bibliographic databases were searched (January 2005 to March 2021) in relation to cardiac surgery and cognition. Studies including adult patients who had undergone open cardiac surgery and using a validated measurement of cognitive function were included. Full-text review for inclusion, quality assessment, and data extraction were undertaken independently by two authors.A total of 2870 papers were identified, of which 36 papers met the inclusion criteria and were included in the review. The majority were prospective observational studies [n = 28 (75.7%)]. In total, 61 independent predictors (45 preoperative and 16 postoperative) were identified as significant in at least one study; advancing age and education level appear important. Age has emerged as the most common predictor of cognitive outcome.

CONCLUSION

Although a number of predictors of POCD have been identified, they have inconsistently been reported as significantly affecting cognitive outcome. Consistent with previous research, our findings indicate that older patients and those with lower educational levels should be prioritized when developing and trialling interventions to improve cognitive function. These findings are less than surprising if we consider the methodological shortcomings of included studies. It is evident that further high-quality research exploring predictors of POCD is required.

Risk Factors for Delirium and Cognitive Decline Following Coronary Artery Bypass Grafting Surgery: A Systematic Review and Meta-Analysis

Background

Coronary artery bypass grafting (CABG) is known to improve heart function and quality of life, while rates of surgery‐related mortality are low. However, delirium and cognitive decline are common complications. We sought to identify preoperative, intraoperative, and postoperative risk or protective factors associated with delirium and cognitive decline (across time) in patients undergoing CABG.

Methods and Results

We conducted a systematic search of Medline, PsycINFO, EMBASE, and Cochrane (March 26, 2019) for peer‐reviewed, English publications reporting post‐CABG delirium or cognitive decline data, for at least one risk factor. Random‐effects meta‐analyses estimated pooled odds ratio for categorical data and mean difference or standardized mean difference for continuous data. Ninety‐seven studies, comprising data from 60 479 patients who underwent CABG, were included. Moderate to large and statistically significant risk factors for delirium were as follows: (1) preoperative cognitive impairment, depression, stroke history, and higher European System for Cardiac Operative Risk Evaluation (EuroSCORE) score, (2) intraoperative increase in intubation time, and (3) postoperative presence of arrythmia and increased days in the intensive care unit; higher preoperative cognitive performance was protective for delirium. Moderate to large and statistically significant risk factors for acute cognitive decline were as follows: (1) preoperative depression and older age, (2) intraoperative increase in intubation time, and (3) postoperative presence of delirium and increased days in the intensive care unit. Presence of depression preoperatively was a moderate risk factor for midterm (1–6 months) post‐CABG cognitive decline.

Conclusions

This meta‐analysis identified several key risk factors for delirium and cognitive decline following CABG, most of which are nonmodifiable. Future research should target preoperative risk factors, such as depression or cognitive impairment, which are potentially modifiable.

Registration

URL: https://www.crd.york.ac.uk/prosp​ero/; Unique identifier: CRD42020149276.

Cancer-Related Anemia Is a Risk Factor for Medium-Term Postoperative Cognitive Dysfunction in Laparoscopic Surgery Patients: An Observational Prospective Study

Anemia in the elderly may impair cognitive function. Our primary objective was to determine whether cancer-related anemia was associated with postoperative cognitive dysfunction (POCD) in nonelderly patients. We conducted an observational prospective study of 177 patients scheduled for laparoscopic surgery. Patients aged 18-64 were divided into two groups according to whether they were anemic due to cancer or not. The cognitive function was assessed by the Mini-Mental State Examination (MMSE) 1 day before and 1 week after operation. The cognitive function of the patients was evaluated by using the Telephone Interview for Cognitive Status-Modified (TICS-M) 3 months after operation. The quality of life of patients was evaluated after operation. The hemoglobin level and other clinical data were recorded before operation. Of the 170 patients, 100 without anemia and 70 anemia patients had been evaluated 1 week after operation. POCD was detected in 43 cases (25.3% of 170 cases) at 1 week and 30 cases (19% of 158 cases) at 3 months postoperatively. Anemia was an independent risk factor for 3-month POCD occurrence (P = 0.034). The education level of the patients who had POCD at 1 week and 3 months after operation was lower (P < 0.001, P = 0.011, respectively). Age was independently associated with the incidence of POCD at 3 months (P = 0.011). In general, these findings suggested that anemia may increase the incidence of medium-term POCD in cancer patients undergoing laparoscopic surgery.

Abnormal expression of circRNA_089763 in the plasma exosomes of patients with post‑operative cognitive dysfunction after coronary artery bypass grafting

Post-operative cognitive dysfunction (POCD) is a complication of the central nervous system characterized by mental disorders, anxiety, personality changes and impaired memory. POCD occurs frequently after coronary artery bypass grafting (CABG) and can severely affect quality of life for patients. To date, the development of POCD biomarkers remains a challenge. Alterations in the expression of non-coding RNAs from brain tissue and peripheral blood have been linked to POCD. The present study aimed to detect the differential circular RNAs (circRNAs) in plasma exosomes of patients with POCD after CABG. The relative expression levels of circRNAs were analyzed using circRNA microarray analysis in the plasma exosomes of patients with POCD. Differentially altered circRNAs (P<0.05, fold change >1.5) were validated by reverse transcription-quantitative PCR in the plasma exosomes of patients with POCD. The target genes of the microRNAs were predicted using bioinformatics analysis. The functions and signaling pathways of these target genes were investigated by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes analyses. The microarray results indicated that the levels of nine circRNAs in patients with POCD were higher than those in the control subjects; and six circRNAs were at a lower level than those in control subjects. The RT-qPCR results from patients with POCD showed that only circRNA_089763 of the 15 circRNAs identified was significantly increased compared with control subjects. circRNA target gene prediction and functional annotation analysis showed significant enrichment in several GO terms and pathways associated with POCD. The present study provides evidence for the abnormal expression of POCD-induced circRNA_089763 in human plasma exosomes, as well as the involvement of POCD.

[Factors for the development of persistent postoperative cognitive dysfunction in patients undergoing coronary artery bypass surgery under extracorporeal circulation]

AIM

To analyze the factors contributing to the increased risk of persistent postoperative cognitive dysfunction (POCD) in patients undergoing coronary artery bypass surgery (CABS) under extracorporeal circulation (EC).

SUBJECTS AND METHODS

257 male patients aged 45 to 69 years with coronary heart disease (CHD) undergoing elective CABS under EC were examined. In addition to conventional clinical examination, all the patients underwent neuropsychological testing 3-5 days before, 7-14 days and 1 year after CABS. Persistent POCD was diagnosed if there was a 20% decline in cognitive domains at 1-year postoperatively versus preoperatively in 20% of the tests of an entire neuropsychological battery. Binary logistic regression analysis was applied to identify the factors supposedly increasing the risk of persistent POCD.

RESULTS

It was found that high baseline cognitive status, early POCD after CABG under EC, low adherence to the prescribed treatment regimen, as well as progressive carotid artery (CA) stenosis could predict with a high (85%) probability that persistent POCD might develop at 1 year after surgery.

CONCLUSION

The findings are suggestive of the multifactorial origin of persistent POCD, a significant role in the development of which is played by not only the preoperative cognitive status, but also by postoperative factors, such as the degree of adherence to the prescribed treatment regimen, early POCD, and progressive CA stenosis.

Effects of Heart Bypass Surgery on Plasma Aβ40 and Aβ42 Levels in Infants and Young Children

Accumulation of β-amyloid (Aβ) plaques is a pathological hallmark of Alzheimer disease. Aβ levels in animals and adults were reported to be associated with postoperative cognitive dysfunction (POCD). Our goal was to determine the plasma levels of Aβ in infants and young children after cardiac surgery with cardiopulmonary bypass (CPB).Forty-two infants and young children aged from 1 to 35 months undergoing cardiac surgery with general anesthetics were prospectively enrolled from January to June 2014 at a tertiary medical center. Perioperative plasma samples were obtained, and Aβ42 and Aβ40 levels were measured using ELISA. Other clinical characteristics of the patients were also recorded.Plasma levels of Aβ42 and Aβ40 decreased dramatically 2 hours after surgery and remained significantly lower 6 hours after operation. Baseline Aβ42 level correlated significantly with surgical intensive care unit (SICU) length of stay (LOS) and was an independent predictor for SICU LOS on multivariate analysis.Cardiac surgery with CPB decreases plasma Aβ levels. Plasma levels of Aβ42 and Aβ40 might be used as novel biomarkers for predicting outcomes in the patient population.

Risk Factors Associated with Cognitive Decline after Cardiac Surgery: A Systematic Review

Modern day cardiac surgery evolved upon the advent of cardiopulmonary bypass machines (CPB) in the 1950s. Following this development, cardiac surgery in recent years has improved significantly. Despite such advances and the introduction of new technologies, neurological sequelae after cardiac surgery still exist. Ischaemic stroke, delirium, and cognitive impairment cause significant morbidity and mortality and unfortunately remain common complications. Postoperative cognitive decline (POCD) is believed to be associated with the presence of new ischaemic lesions originating from emboli entering the cerebral circulation during surgery. Cardiopulmonary bypass was thought to be the reason of POCD, but randomised controlled trials comparing with off-pump surgery show contradictory results. Attention has now turned to the growing evidence that perioperative risk factors, as well as patient-related risk factors, play an important role in early and late POCD. Clearly, identifying the mechanism of POCD is challenging. The purpose of this systematic review is to discuss the literature that has investigated patient and perioperative risk factors to better understand the magnitude of the risk factors associated with POCD after cardiac surgery.

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.

Intracisternal administration of an interleukin-6 receptor antagonist attenuates surgery-induced cognitive impairment by inhibition of neuroinflammatory responses in aged rats

Postoperative cognitive dysfunction (POCD) is common in elderly patients, and may persist or even evolve into Alzheimer's disease. It has been hypothesized that POCD is mediated by surgery-induced inflammatory processes. As a pro-inflammatory cytokine, the detailed role of interleukin (IL)-6 in POCD remains largely unknown. In this study, laparotomy was used to mimic human abdominal surgery in aged Sprague-Dawley rats. It was found that memory and learning were impaired following surgery, accompanied by the significant upregulation of the pro-inflammatory cytokines tumor necrosis factor α (TNF-α), IL-1β, IL-4, and IL-6. Moreover, the intracisternal administration of the IL-6 receptor (IL-6R) antagonist (tocilizumab, also know as MRA) at the time of surgery notably attenuated the surgery-induced cognitive deficit, and significantly inhibited the upregulated expression of pro-inflammatory cytokines. Further investigation indicated that the intracisternal administration of MRA inhibited the activation of the NF-κB signaling pathway in aged rats following surgery. In summary, the findings of this study suggest that IL-6 plays a crucial role in POCD, and that IL-6R antagonists may serve as novel agents for the prevention or treatment of POCD.

Perioperative hyperglycemia is associated with postoperative neurocognitive disorders after cardiac surgery

OBJECTIVE

Neurocognitive disorders commonly occur following cardiac surgery. However, the underlying etiology of these disorders is not well understood. The current study examined the association between perioperative glucose levels and other risk factors and the onset of neurocognitive disorders in adult patients following coronary artery bypass and/or valvular surgery.

METHODS

Adult patients who underwent their first cardiac surgery at a large tertiary care medical center were identified and those with neurocognitive disorders prior to surgery were excluded. Demographic, perioperative, and postoperative neurocognitive outcome data were extracted from the Society for Thoracic Surgery database, and from electronic medical records, between January 2004 and June 2009. Multiple clinical risk factors and measures associated with insulin resistance, such as hyperglycemia, were assessed. Multivariable Cox competing risk survival models were used to assess hyperglycemia and postoperative neurocognitive disorders at follow up, adjusting for other risk factors and confounding variables.

RESULTS

Of the 855 patients included in the study, 271 (31.7%) had new onset neurocognitive disorders at follow-up. Age, sex, New York Heart Failure (NYHF) Class, length of postoperative intensive care unit stay, perioperative blood product transfusion, and other key factors were identified and assessed as potential risk factors (or confounders) for neurocognitive disorders at follow-up. Bivariate analyses suggested that new onset neurocognitive disorders were associated with NYHF Class, cardiopulmonary bypass, history of diabetes, intraoperative blood product use, and number of diseased coronary vessels, which are commonly-accepted risk factors in cardiac surgery. In addition, higher first glucose level (median =116 mg/dL) and higher peak glucose >169 mg/dL were identified as risk factors. Male sex and nonuse of intra-operative blood products appeared to be protective. Controlling for potential risk factors and confounders, multivariable Cox survival models suggested that increased perioperative first glucose measured in 20 unit increments, was significantly associated with the onset of postoperative neurocognitive disorders at follow-up (hazard ratio [HR] =1.16, P<0.001) and that women had an elevated risk for this outcome (HR =4.18, P=0.01).

CONCLUSION

Our study suggests that perioperative hyperglycemia was associated with new onset of postoperative neurocognitive disorders in adult patients after cardiac surgery, and that men tended to be protected from these outcomes. These findings may suggest a need for the revision of clinical protocols for perioperative insulin therapy to prevent long-term neurocognitive complications.

Phenotypic profiling of cognitive impairment risk among patients with heart failure: a literature review of the usefulness of cardiac-related variables

BACKGROUND

Mild cognitive impairment among patients with heart failure can be subtle. Heart failure-related variables such as ejection fraction, low systolic blood pressure and functional status are reportedly associated with cognitive impairment among heart failure patients. The purpose of this literature review was to examine the value of cardiac variables commonly assessed during heart failure-related hospitalizations for a phenotypic profile of the risk of cognitive impairment.

METHOD

A literature review of primary research studies was conducted. Electronic databases (PubMed and CINAHL) were searched using the keywords heart failure, blood pressure, ejection fraction, functional status, and B-type natriuretic peptide (BNP) in combination with the terms cognition, cognitive function, cognitive dysfunction, and cognitive impairment.

RESULTS

Thirty-seven studies met the inclusion criteria. Evidence supports the potential utility of lower ejection fraction, lower blood pressure and functional status and elevated B-type natriuretic peptide as a phenotypic profile for an increased risk of cognitive impairment.

IMPLICATIONS

If the risk for cognitive impairment is suspected, specific evaluations of cognition can be performed. For community-dwelling heart failure patients with mild cognitive impairment, more intense interventions to support self-care, increased family involvement and more frequent follow up may be necessary.

Postoperative cognitive dysfunction in geriatric patients

Postoperative cognitive dysfunction (POCD) is a severe long-term complication after surgical procedures. POCD is mainly seen among geriatric patients. Hospitalization, extent of surgery, and systemic inflammatory response might contribute to POCD. The possible influence of the type of anesthesia is discussed. POCD is often not recognized; thus, incidence rates are likely to be underestimated (19-40%). POCD is associated with major consequences for the individual patient, e.g., delayed long-term recovery, reduced quality of life, and an increased mortality rate. Multiple risk factors have been identified over the last decade. However, the exact etiology is still unknown. This mini-review summarizes the recent developments concerning POCD prevention, diagnosis, and treatment.

Xenon pretreatment may prevent early memory decline after isoflurane anesthesia and surgery in mice

Postoperative cognitive decline (POCD) is a common complication following surgery, but its aetiology remains unclear. We hypothesized that xenon pretreatment prevents POCD by suppressing the systemic inflammatory response or through an associated protective signaling pathway involving heat shock protein 72 (Hsp72) and PI3-kinase. Twenty-four hours after establishing long-term memory using fear conditioning training, C57BL/6 adult male mice (n = 12/group) received one of the following treatments: 1) no treatment group (control); 2) 1.8% isoflurane anesthesia; 3) 70% xenon anesthesia; 4) 1.8% isoflurane anesthesia with surgery of the right hind leg tibia that was pinned and fractured; or 5) pretreatment with 70% xenon for 20 minutes followed immediately by 1.8% isoflurane anesthesia with the surgery described above. Assessments of hippocampal-dependent memory were performed on days 1 and 7 after treatment. Hsp72 and PI3-kinase in hippocampus, and plasma IL-1β, were measured using western blotting and ELISA respectively, from different cohorts on day 1 after surgery. Isoflurane induced memory deficit after surgery was attenuated by xenon pretreatment. Xenon pretreatment prevented the memory deficit typically seen on day 1 (P = 0.04) but not on day 7 (P = 0.69) after surgery under isoflurane anesthesia, when compared with animals that underwent surgery without pretreatment. Xenon pretreatment modulated the expression of Hsp72 (P = 0.054) but had no significant effect on PI3-kinase (P = 0.54), when compared to control. Xenon pretreatment also reduced the plasma level increase of IL-1β induced by surgery (P = 0.028). Our data indicated that surgery and/or Isoflurane induced memory deficit was attenuated by xenon pretreatment. This was associated with a reduction in the plasma level of IL-1β and an upregulation of Hsp72 in the hippocampus.

Heat shock protein 72 overexpression prevents early postoperative memory decline after orthopedic surgery under general anesthesia in mice

BACKGROUND

Problems with learning and memory are common after surgery in the elderly and are associated with high morbidity. Heat shock protein 72 (Hsp72) confers neuroprotection against acute neurologic injury. We hypothesized that overexpression of Hsp72 would prevent the development of postoperative memory loss.

METHODS

C57BL/6 wild-type and Hsp72 overexpressing transgenic mice were randomly allocated to the following: control, isoflurane anesthesia alone, or tibial fracture during isoflurane anesthesia. Animals were trained 24 h before surgery using a fear conditioning protocol and assessed in their training environment and in a novel context on posttreatment days 1, 3, and 7. Microglial activation was assessed by immunostaining.

RESULTS

Adult male C57BL/6 wild-type mice exhibited reduced memory evidenced by a decreased percentage freezing time on days 1 and 3 after anesthesia alone (58.8 ± 5, 46.5 ± 5 mean ± SEM) and after surgery (53.4 ± 6, 44.1 ± 7), compared with controls (78.8 ± 5, 63.4 ± 6; P < 0.05 and P < 0.001, respectively). Hsp72 mice showed no difference by treatment on any day. Similarly, nonhippocampal-dependent memory was significantly impaired on days 1 and 3 after surgery and day 3 after anesthesia. The genotype effect was significant on days 1 and 7. CD68-immunopositive activated microglia in the hippocampus varied modestly with subregion and time; on day 7, there was a significant treatment effect with no genotype effect, with more activated microglia after surgery in all regions.

CONCLUSION

Hsp72 overexpression is associated with prevention of postoperative hippocampal-dependent and -independent memory deficit induced by anesthesia and/or surgery. Memory deficit is not correlated with numbers of activated hippocampal microglia.

Minocycline may be useful to prevent/treat postoperative cognitive decline in elderly patients

Postoperative cognitive dysfunction (POCD) is reported to occur frequently after all types especially cardiac surgery in elderly patients. It can be short-term or long-term and some cases even develop into Alzheimer's disease (AD). Although multi-risk factors associated with POCD have been identified, the etiology and pathophysiological mechanisms of this surgical complication remain elusive. Therefore, developing strategies for preventing or treating POCD is still challenging. However, increasing evidence suggests that central and systemic inflammation triggered by surgery likely plays a fundamental role in POCD developing and progression. Minocycline, a tetracycline derivative with anti-inflammatory properties, has been shown to be effective in treating neuroinflammatory related conditions or neurodegenerative diseases such as AD, Parkinson's disease, Huntington's disease. Considering that inflammation may be a potential factor of POCD and minocycline is effective in improving cognitive dysfunction induced by inflammation, we hypothesize that minocycline may be useful to treat/prevent the POCD development after surgery in elderly patients.

Predictive accuracy of SYNTAX score for predicting long-term outcomes of unprotected left main coronary artery revascularization

The American College of Cardiology/American Heart Association recently updated recommendations for percutaneous coronary intervention (PCI) of unprotected left main coronary artery (ULMCA) disease from class III to II(b) according to the results of the SYNergy between percutaneous coronary intervention with TAXus and cardiac surgery (SYNTAX) trial. The SYNTAX score is an angiographic tool using solely the coronary anatomy. We studied the effect of co-morbidities (Parsonnet's score) on the ability of the SYNTAX score to predict long-term outcomes in patients with ULMCA disease treated by revascularization. A total of 328 patients underwent revascularization of ULMCA from April 2003 to February 2007. Of the 328 patients, 120 underwent PCI (median follow-up 973 days) and 208 underwent coronary artery bypass grafting (CABG) (median follow-up 1,298 days). The ability of the SYNTAX score to predict outcomes was assessed using the Cox proportional hazards model. The outcomes between the PCI and CABG groups were compared by propensity analysis. The median SYNTAX score was 26 in the PCI and 28 in the CABG group (p = 0.5). In the PCI group, greater quartiles were associated with worse survival (62.1% at SYNTAX score of ≥36 vs 82.4% at SYNTAX score of <36, p = 0.03) and all-cause mortality, myocardial infarction, cerebrovascular events, and target vessel revascularization-free (MACCE) survival (47.7%, SYNTAX score ≥20 vs 76.6%, SYNTAX score <20, p = 0.02). Using the Parsonnet score as a covariate, the SYNTAX score continued to be an independent predictor of MACCE and demonstrated a trend toward predicting mortality in the PCI group. In contrast, the SYNTAX score did not predict the outcomes for the CABG group. No difference was found in mortality between the PCI and CABG groups for ULMCA disease, regardless of coronary complexity; although greater SYNTAX scores were associated with increased MACCE rates with PCI compared to CABG. Both the coronary anatomy (SYNTAX score) and co-morbidities (Parsonnet's score) predicted long-term outcomes for PCI of ULMCA disease. In contrast, the SYNTAX score did not predict the outcomes after CABG. In conclusion, the ideal scoring system to guide an appropriate revascularization decision for ULMCA disease should take into account both the coronary anatomy and the co-morbidities.

Current state of surgical myocardial revascularization

Despite increasing competition from percutaneous interventions and other novel methods of non-surgical coronary revascularization, coronary artery bypass grafting (CABG) remains one of the most definitive and durable treatments for coronary artery disease, especially for those patients with extensive and diffuse disease. In recent years the CABG procedure itself has undergone innovation and evolution. This review article provides a brief historical perspective on the procedure, and examines the current state of modern variations including off-pump, limited-access, and robotic-assisted CABG.

Impact of hypothermia (below 36 degrees C) in the rural trauma patient

BACKGROUND

Hypothermia is an independent predictor of mortality based on urban studies. But this association has not been described in the rural setting. This study's purpose was to evaluate hypothermia as a cofactor to mortality, complications, and hospital length of stay (LOS) parameters in the rural trauma setting.

STUDY DESIGN

The National Trauma Registry of the American College of Surgeons database for our rural, Level I trauma center was queried for a 5-year period (July 2002 to June 2007) to identify adult trauma patients. Multivariate regression models were used to evaluate the association of hypothermia with mortality; infectious complications; organ dysfunction; and, among survivors, hospital LOS parameters.

RESULTS

Of 9,482 adult patients admitted, 1,490 (15.7%) patients were hypothermic. Hypothermia had an adjusted odds ratio of 1.70 for mortality (95% CI, 1.35 to 2.12; p < 0.001). After controlling for covariates, hypothermia was not significantly associated with infectious complications or organ dysfunction, except for arrhythmia (adjusted odds ratio, 1.40; CI, 1.03 to 1.90; p = 0.031). Hypothermia was not associated with a difference in ICU (p = 0.310) or ventilator (p = 0.144) LOS. But a slight increase in hospital days was noted in the hypothermic patient (hazards ratio, 0.890 for discharge; 95% CI, 0.838 to 0.946; p < 0.001).

CONCLUSIONS

Hypothermia is a common problem at admission in a rural trauma center. It is associated with an increase in hospitalized days but not with increased ICU or ventilator days among survivors. Other than arrhythmias, it was not significantly associated with other National Trauma Registry of the American College of Surgeons infectious or organ dysfunction complications. Hypothermia is an independent risk factor for mortality in the rural trauma patient.

Cognitive decline after invasive intervention in cardiovascular disease: is it drug related?

OBJECTIVE

To identify drugs used to treat cardiovascular disease (CVD) after an invasive intervention that may adversely affect cognitive function.

SETTING

Ambulatory care setting.

PRACTICE DESCRIPTION

A pharmacy faculty member serves as an ambulatory care preceptor for students at a cardiac rehabilitation and wellness center on the campus of St. Joseph's Hospital, Atlanta, Georgia. Pharmacy services include patient case reviews, consultations, patient education, and therapeutic recommendations.

PRACTICE INNOVATION

As part of the advanced practice experience, students are responsible for monitoring drug therapy regimens and conducting medication reconciliations. A literature review of primary sources and education databases was conducted to report cognitive adverse drug reactions associated with cardiac drugs in selective electronic tertiary sources.

MAIN OUTCOMES

Documentation of cognitive dysfunction associated with drugs used to treat CVD.

RESULTS

Drugs used to treat CVD may be associated with adverse drug effects including short-term memory loss, amnesia, confusion, decreased mental acuity, and impaired concentration.

CONCLUSION

Pharmacists providing consultation in the cardiac rehabilitation setting can provide insight into medications that can contribute to cognitive dysfunction.

Prognostic value of the Syntax score in patients undergoing coronary artery bypass grafting for three-vessel coronary artery disease

BACKGROUND

The Syntax score prognostic value has recently been highlighted in patients undergoing percutaneous coronary intervention (PCI) for multivessel coronary artery disease (CAD), however its prognostic value in patients undergoing coronary artery bypass grafting (CABG) for multivessel CAD is still unknown. The aim of this study was to evaluate the prognostic value of the Syntax score in patients undergoing CABG for 3-vessel CAD.

METHODS

A cohort of 320 consecutive patients with multivessel (3-vessel) CAD who were subjected for CABG were included in this study and divided into tertiles according to the Syntax score (<24.5, 24.5-34, and >34). During the 1-year follow-up, cardiovascular events including death, myocardial infarction (MI), and stroke were systematically indexed. The primary end point was the composite criteria death/MI/stroke.

RESULTS

The Syntax score ranged from 11-74 with a mean of 31.2 +/- 12.6 and a median of 28.5 [22-38]. Baseline clinical characteristics were similar among the tertiles. No statistical difference was found for the composite criteria death/MI/stroke: 9.4% versus 7.5% versus 10.4% in the groups with a Syntax score <24.5, 24.5-34, and >34, respectively (P = 0.754).

CONCLUSION

Unlike for PCI, the Syntax score has a poor prognostic value for severe cardiovascular events in patients undergoing CABG for 3-vessel CAD. Other risk scores should be used to predict the outcome of this population.

ARTA: AT1-receptor blocker therapy in patients undergoing coronary artery bypass grafting

BACKGROUND

Decline in renal and cognitive function may complicate early recovery after coronary-artery bypass grafting. AT(1)-receptor antagonists have been demonstrated to be neuro- and renoprotective. Aim of ARTA, a prospective, double-blind, randomised and placebo controlled study, was to detect whether preoperative treatment with candesartan influences postoperative cognitive and renal function.

STUDY PROTOCOL

One hundred and five patients eligible for coronary artery bypass graft surgery (65-85 years old, all suffering from hypertension and coronary artery disease, with stable kidney function) were randomized to candesartan (8 mg od) or placebo for between 8 and 11 days prior to surgery. Existing ACE-inhibitor/angiotensin receptor antagonist-therapy had to be stopped prior to the study. Validated cognitive function tests (trail making, Horn's perfomance III und VI, divided attention and change of reaction, memory - immediate and delayed recall, digit span) were performed preoperatively, 1 week and 3 months after surgery. Renal function was assessed by creatinine clearance on the day before, 1 week and 3 months after surgery.

RESULTS

Eighty-seven patients (n = 43 Candesartan, n = 44 placebo) were included in the ITT-population for analysis. Drug treatment had no adverse effect on perioperative blood pressure. Only five patients experienced a period of hypotension during introduction of anaesthesia (Candesartan 1/44, placebo 4/44). One week as well as three months after surgery, there were no differences in relevant cognitive function parameters compared to the status prior to surgery, independent from treatment. Creatinine clearance showed a clear decrease one week after surgery with a minor further reduction observed 3 months after surgery, but there was no difference between Candesartan and placebo treated patients. Between both groups, there were no significant differences in the number of adverse events and number of patients with adverse events nor in the incidence of renal failure with consecutive dialysis and cerebral strokes (candesartan 2, placebo 5) and possibly drug related severe adverse events.

CONCLUSION

This randomised placebo-controlled and prospective study in elderly patients does not support previous reports suggesting a substantial impairment of cognitive function after coronary artery bypass graft surgery. Preservation of cognitive and renal function was independent of pre-surgical administration of candesartan.

Interpreting studies of cognitive function following cardiac surgery: a guide for surgical teams

Patients with coronary disease and related health care providers are faced with confusing and often conflicting information with regards to the neurocognitive impact of different strategies for coronary revascularization. Studies involving the measurement of postoperative cognitive deficit (POCD) have significant limitations that may ultimately impact on their interpretation and clinical relevance. In this review, we have described the origin of these tests and delineated the rationale for the design of testing that is commonly used in cardiac surgery patients. In general, neurocognitive tests assess domains of memory/new learning, psychomotor speed/dexterity and attentional capacity/mental control. Pre- and post-intervention tests in each domain can be evaluated either by the measurement of mean change scores (Group Comparison Model) for the entire group as continuous data, or by using categorical or continuous data to examine patterns of individual decline (Individual Comparison Model). This latter approach requires a specific definition of what constitutes a decline, which can be criticized as being arbitrary. There are limitations to each of these approaches that necessitate that critical information in trial design is available to the reviewer to facilitate interpretation. For example, the impact of factors such as test/re-test reliability and practice effect can be mitigated by the use of an appropriately chosen control population. Liberal parlance of neurocognitive outcome as a rationale for therapeutic choice must be tempered by wise interpretation of these tests. It is only through the understanding of their limitations and the implications of trial design that we can translate these results to provide the best therapeutic options for our patients in unbiased manner.