Effect of glutamate infusion on NT-proBNP after coronary artery bypass grafting in high-risk patients (GLUTAMICS II): A randomized controlled trial.

BACKGROUND: Animal and human data suggest that glutamate can enhance recovery of myocardial metabolism and function after ischemia. N-terminal pro-brain natriuretic peptide (NT-proBNP) reflects myocardial dysfunction after coronary artery bypass surgery (CABG). We investigated whether glutamate infusion can reduce rises of NT-proBNP in moderate- to high-risk patients after CABG. METHODS AND FINDINGS: A prospective, randomized, double-blind study enrolled patients from November 15, 2015 to September 30, 2020, with a 30-day follow-up at 4 academic cardiac surgery centers in Sweden. Patients underwent CABG ± valve procedure and had left ventricular ejection fraction ≤0.30 or EuroSCORE II ≥3.0. Intravenous infusion of 0.125 M L-glutamic acid or saline at 1.65 mL/kg/h started 10 to 20 minutes before releasing the aortic cross-clamp, then continued for another 150 minutes. Patients, staff, and investigators were blinded to the treatment. The primary endpoint was the difference between preoperative and day-3 postoperative NT-proBNP levels. Analysis was intention to treat. We studied 303 patients (age 74 ± 7 years; females 26%, diabetes 47%), 148 receiving glutamate group and 155 controls. There was no significant difference in the primary endpoint associated with glutamate administration (5,390 ± 5,396 ng/L versus 6,452 ± 5,215 ng/L; p = 0.086). One patient died ≤30 days in the glutamate group compared to 6 controls (0.7% versus 3.9%; p = 0.12). No adverse events linked to glutamate were observed. A significant interaction between glutamate and diabetes was found (p = 0.03). Among patients without diabetes the primary endpoint (mean 4,503 ± 4,846 ng/L versus 6,824 ± 5,671 ng/L; p = 0.007), and the incidence of acute kidney injury (11% versus 29%; p = 0.005) was reduced in the glutamate group. These associations remained significant after adjusting for differences in baseline data. The main limitations of the study are: (i) it relies on a surrogate marker for heart failure; and (ii) the proportion of patients with diabetes had almost doubled compared to the cohort used for the sample size estimation. CONCLUSIONS: Infusion of glutamate did not significantly reduce postoperative rises of NT-proBNP. Diverging results in patients with and without diabetes agree with previous observations and suggest that the concept of enhancing postischemic myocardial recovery with glutamate merits further evaluation. TRIAL REGISTRATION: ClinicalTrials.gov https://clinicaltrials.gov/ct2/show/NCT02592824. European Union Drug Regulating Authorities Clinical Trials Database (Eudra CT number 2011-006241-15).

The impact of glutamate infusion on postoperative NT-proBNP in patients undergoing coronary artery bypass surgery: a randomized study.

BACKGROUND: Glutamate, a key intermediate in myocardial metabolism, may enhance myocardial recovery after ischemia and possibly reduce the incidence and severity of postoperative heart failure in coronary artery bypass surgery (CABG). N-terminal pro-B-type natriuretic peptide (NT-proBNP) can be used to assess postoperative heart failure (PHF) after CABG. Our hypothesis was that glutamate enhances myocardial recovery in post-ischemic heart failure and, therefore, will be accompanied by a mitigated postoperative increase of NT-proBNP. METHODS: Substudy of the GLUTAmate for Metabolic Intervention in Coronary Surgery (GLUTAMICS) trial (ClinicalTrials.gov Identifier: NCT00489827) a prospective triple-center double-blind randomized clinical trial on 399 patients undergoing CABG with or without concomitant procedure for acute coronary syndrome at three Swedish Cardiac Surgery centres (Linköping, Örebro, and Karlskrona) from May 30, 2007 to November 12, 2009. Patients were randomly assigned to intravenous infusion of 0.125 M L-glutamic acid or saline (1.65 mL/kg of body weight per hour) intraoperatively and postoperatively. Plasma NT-proBNP was measured preoperatively, the first (POD1) and third postoperative morning (POD3). A Clinical Endpoints Committee, blinded to both intervention and NT-proBNP used prespecified criteria to diagnose PHF. The primary endpoints were the absolute levels of postoperative NT-proBNP and the difference between preoperative and postoperative levels of NT-proBNP. RESULTS: Overall no significant difference was detected in postoperative NT-proBNP levels between groups. However, in high-risk patients (upper quartile of EuroSCORE II ≥ 4.15; glutamate group n = 56; control group n = 45) glutamate was associated with significantly lower postoperative increase of NT-proBNP (POD3-Pre: 3900 [2995-6260] vs. 6745 [3455-12,687] ng•L-1, p = 0.012) and lower NT-proBNP POD3 (POD3: 4845 [3426-7423] vs. 8430 [5370-14,100] ng•L-1, p = 0.001). After adjusting for significant differences in preoperative demographics, NT-proBNP POD3 in the glutamate group was 0.62 times of that in the control group (p = 0.002). Patients in the glutamate group also had shorter ICU stay (21 [19-26] vs. 25 [22-46] h, p = 0.025) and less signs of myocardial injury (Troponin T POD3 (300 [170-500] vs. 560 [210-910] ng•L-1, p = 0.025). CONCLUSIONS: Post hoc analysis of postoperative NT-proBNP suggests that intravenous infusion of glutamate may prevent or mitigate myocardial dysfunction in high-risk patients undergoing CABG. Further studies are necessary to confirm these findings. Trial registration Swedish Medical Products Agency 151:2003/70403 (prospectively registered with amendment about this substudy filed March 17, 2007). ClinicalTrials.gov Identifier: NCT00489827 (retrospectively registered) https://clinicaltrials.gov/ct2/show/NCT00489827?term=glutamics&draw=1&rank=1.

Perioperative intraperitoneal metabolic markers in patients undergoing cardiac surgery with cardiopulmonary bypass: an exploratory pilot study.

BACKGROUND: Cardiopulmonary bypass and postoperative cardiac dysfunction cause splanchnic hypoperfusion resulting in intra-abdominal anaerobic metabolism and risk for gastrointestinal complications. The intra-abdominal metabolism can be monitored by intraperitoneal measurement of relevant metabolites using microdialysis. The aim of this study was to investigate the intraperitoneal metabolism using microdialysis during and after cardiopulmonary bypass at 34°C. METHODS: In six patients undergoing elective coronary artery bypass grafting or aortic valve replacement under cardiopulmonary bypass, microdialysis was used to measure intraperitoneal and subcutaneous glucose, lactate, pyruvate, glycerol and glutamate concentrations, intraoperatively and up to 36 hours postoperatively. Arterial and central venous blood gases were analysed as were haemodynamics and the development of complications. RESULTS: All patients had an ordinary perioperative course and did not develop gastrointestinal complications. The arterial, intraperitoneal and subcutaneous lactate concentrations changed during the perioperative course with differences between compartments. The highest median (interquartile range) concentration was recorded in the intraperitoneal compartment at 1 hour after the end of cardiopulmonary bypass (2.1 (1.9-2.5) mM compared to 1.3 (1.2-1.7) mM and 1.5 (1.0-2.2) mM in the arterial and subcutaneous compartments, respectively). In parallel with the peak increase in lactate concentration, the intraperitoneal lactate/pyruvate ratio was elevated to 33.4 (12.9-54.1). CONCLUSION: In cardiac surgery, intraperitoneal microdialysis detected changes in the abdominal metabolic state, which were more pronounced than could be shown by arterial blood gas analysis. Despite an uneventful perioperative course, patients undergoing low-risk surgery under cardiopulmonary bypass might be subjected to a limited and subclinical intra-abdominal anaerobic state.

Post hoc analysis of the glutamics-trial: intravenous glutamate infusion and use of inotropic drugs after cabg.

BACKGROUND: Intravenous glutamate reduced the risk of developing severe circulatory failure after isolated coronary artery bypass graft surgery (CABG) for acute coronary syndrome (ACS) in a double-blind randomised clinical trial (GLUTAMICS-ClinicalTrials.gov Identifier: NCT00489827 ). Here our aim was to study if glutamate was associated with reduced the use of inotropes. METHODS: Post-hoc analysis of 824 patients undergoing isolated CABG for ACS in the GLUTAMICS-trial. ICU-records were retrospectively scrutinised including hourly registration of inotropic drug infusion, dosage and total duration during the operation and postoperatively. RESULTS: ICU-records were found for 171 out of 177 patients who received inotropes perioperatively. Only one fourth of the patients treated with inotropes fulfilled study criteria for postoperative heart failure at weaning from cardiopulmonary bypass (CPB) or later in the ICU. Inotropes were mainly given preemptively to facilitate weaning from CPB or to treat postoperative circulatory instability (bleeding, hypovolaemia). Except for a significantly lower use of epinephrine there were only trends towards lower need of other inotropes overall in the glutamate group. In patients treated with inotropes (glutamate n = 17; placebo n = 13) who fulfilled study criteria for left ventricular failure at weaning from CPB the average duration of inotropic treatment (34 ± 20 v 80 ± 77 h; p = 0.014) and the number of inotropes used (1.35 ± 0.6 v 1.85 ± 0.7; p = 0.047) were lower in the glutamate group. CONCLUSIONS: Intravenous glutamate was associated with a minor influence on inotrope use overall in patients undergoing CABG for ACS whereas a considerable and significant reduction was observed in patients with heart failure at weaning from CPB.

Right ventricular lead perforation with iatrogenic injury to an intercostal artery causing haemothorax after pacemaker implant.

A woman in her 80s experienced a life-threatening complication of pacemaker implant consisting of subacute right ventricular lead perforation causing iatrogenic injury to an intercostal artery, resulting in a large haemothorax. A CT scan confirmed active bleeding from the fourth intercostal artery. The patient underwent cardiothoracic surgery via a median sternotomy approach, during which the source of the bleeding was sealed, a new epicardial lead was positioned, and the original lead was extracted. This case emphasises the potentially severe consequences of pacemaker lead perforation and secondary injury to adjacent structures. It underscores the importance of early recognition and timely intervention, preferably in a tertiary specialist unit equipped for cardiothoracic surgery and confirms the value of pacemaker interrogation and CT scans for diagnosis.

Health-related quality of life after Nuss procedure for pectus excavatum: a cross-sectional study.

OBJECTIVES: Pectus excavatum (PE) can cause both physical and psychosocial symptoms and affect patients' health-related quality of life. Previous international studies have shown that the Nuss procedure increases both self-esteem and body image. The aim of the study was to evaluate the health-related quality of life in patients who have undergone the Nuss procedure for PE. METHODS: The study had a cross-sectional multicentre design. All patients (N = 420) who underwent the Nuss procedure for PE in 3 cardiothoracic departments in Sweden from 2000 to 2019 were invited to answer the RAND-36 and Nuss Questionnaire modified for adults. Genders were compared using the Mann-Whitney U-test. Patients were divided into groups based on age at time of surgery (<20, 20-30 or >30 years) and analysed by the Kruskal-Wallis H-test with post-hoc analyses. RESULTS: A total of 236 patients returned the questionnaires; 82.2% were males. Men scored significantly better on the modified Nuss Questionnaire total (P = 0.01) and psychosocial (P = 0.02) subscales. Patients who had surgery at <20 years of age had significantly better scores on the same scales (P = 0.007 and 0.006, respectively) compared to patients aged 20-30 years at the time of surgery. However, no significant difference was seen in comparison with patients >30 years. Patients who had their bar removed had significantly better values on both scales. CONCLUSIONS: Male gender, young age at surgery and bar removal seem to be associated with better health-related quality of life after the Nuss procedure for PE.

Utility of NT-proBNP as an objective marker of postoperative heart failure after coronary artery bypass surgery: a prospective observational study.

BACKGROUND: Postoperative heart failure (PHF) is the main cause for mortality after cardiac surgery but unbiased evaluation of PHF is difficult. We investigated the utility of postoperative NT-proBNP as an objective marker of PHF after coronary artery bypass surgery (CABG). METHODS: Prospective study on 382 patients undergoing isolated CABG for acute coronary syndrome. NT-proBNP was measured preoperatively, the first (POD1) and third postoperative morning (POD3). A blinded Endpoints Committee used prespecified criteria for PHF. Use of circulatory support was scrutinized. RESULTS: After adjusting for confounders PHF was associated with 1.46 times higher NT-proBNP on POD1 (p = 0.002), 1.54 times higher on POD3 (p < 0.0001). In severe PHF, NT-proBNP was 2.18 times higher on POD1 (p = 0.001) and 1.81 times higher on POD3 (p = 0.019). Postoperative change of NT-proBNP was independently associated with PHF (OR 5.12, 95% CI 1.86-14.10, p = 0.002). The use of inotropes and ICU resources increased with incremental quartiles of postoperative NT-proBNP. CONCLUSIONS: Postoperative NT-proBNP can serve as an objective marker of the severity of postoperative myocardial dysfunction. Due to overlap in individuals, NT-proBNP is useful mainly for comparisons at cohort level. As such, it provides a tool for study purposes when an unbiased assessment of prevention or treatment of PHF is desirable. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00489827 https://clinicaltrials.gov/ct2/show/NCT00489827?term=glutamics&draw=2&rank=1 .

Translation and psychometric evaluation of the Swedish versions of the Nuss Questionnaire modified for Adults and the Single Step Questionnaire.

BACKGROUND: Pectus excavatum (PE) is the most common congenital chest wall deformity. Most individuals with PE suffer from psychosocial problems, with low self-esteem and poor body image. Correctional surgery for PE is available, the most widely used is the Nuss procedure. The Nuss procedure has previously been reported to improve self-esteem, body image and health-related quality of life (HRQoL). To assess HRQoL among individuals with PE, the Nuss Questionnaire modified for Adults (NQ-mA) and Single Step Questionnaire (SSQ) has been developed. The aim of the current study was to translate and culturally adapt NQ-mA and SSQ to fit a Swedish context, and to evaluate the psychometric properties, and validate the culturally adapted versions. METHODS: Individuals who had undergone the Nuss procedure for pectus excavatum were invited to participate in a multicentre study with cross-sectional design. HRQoL was assessed by NQ-mA, SSQ and RAND-36. Psychometric properties for NQ-mA and SSQ were evaluated by content validity index and construct validity (exploratory factor analysis, confirmatory factor analysis, and inter-scale correlations). Known-groups validity, as well as floor and ceiling effects, were evaluated. Internal consistency reliability was examined using Cronbach's alpha. RESULTS: In total 236 individuals participated in the study. Content validity index for NQ-mA showed satisfactory results, except for two items. Factor analysis for NQ-mA suggested a two-factor model, with exclusion of two items. Subscales correlated adequately with RAND-36's domains. Known-groups validity for NQ-mA demonstrated high sensitivity for between-group differences. Ceiling effects were present in several items. Cronbach's alpha for NQ-mA was .89. Confirmatory factor analysis for SSQ resulted in a three-factor model, with exclusion of five items. However, this model was shown to be unstable through further exploratory factor analysis testing, and no further psychometric tests were conducted for SSQ. CONCLUSION: The 10-item Swedish version of NQ-mA was shown to be valid for research and clinical assessment of HRQoL in individuals with pectus excavatum. The Swedish version of SSQ requires revision of items before further validation can be performed.

A metabolic protective strategy could improve long-term survival in patients with LV-dysfunction undergoing CABG.

OBJECTIVE: Adverse outcome after CABG is closely related to postoperative heart failure precipitated by ischemia and myocardial infarction. Restrictive use of inotropes is therefore desirable. Patients with preoperative left ventricular dysfunction are a high-risk group in this respect. To reduce myocardial oxygen expenditure we evolved a metabolic strategy for perioperative care. DESIGN: Observational study on 104 consecutive patients with severe left ventricular dysfunction undergoing CABG. The metabolic strategy implied physiological measures to minimize myocardial oxygen expenditure including restrictive use of inotropes and specific measures such as extended CPB and metabolic support to facilitate myocardial recovery. Hemodynamic state was primarily assessed by mixed venous oxygen saturation (SvO(2)). Follow-up averaged 9.7+/-1.4 years. RESULTS: LVEF was 0.30+/-0.05 (range 0.20-0.37) and 3.5+/-1.3 vessels were bypassed. Inotropes were used in 6.7% for weaning from CPB. Increase of s-creatinine by > or =50% compared to preoperative values was observed in 2.9%. Logistic EuroSCORE was 8.3% whereas observed 30-day mortality was 1.0%. Crude 5-year survival was 89.4%. CONCLUSIONS: The metabolic strategy allowed restrictive use of inotropes and was associated with encouraging long-term survival. Renal function was well preserved suggesting that SvO(2) served as an adequate marker of circulation. Randomized trials with metabolic support are warranted.

In-Hospital Physiotherapy and Physical Recovery 3 Months After Lung Cancer Surgery: A Randomized Controlled Trial.

Background. Lung cancer is the most frequently diagnosed cancer and one of the leading causes of cancer deaths. Surgery is the primary approach for curative treatment. Postoperative complications are common, and physiotherapy is often routinely provided for their prevention and treatment, even though the evidence is limited. The aim of this study was to examine the effect of in-hospital physiotherapy on postoperative physical capacity, physical activity, and lung function among patients undergoing lung cancer surgery. Methods. A total of 107 patients undergoing elective thoracic surgery were included in a single-blinded randomized controlled trial, and randomized to a study group, receiving in-hospital physiotherapy treatment, or a control group, not receiving in-hospital physiotherapy treatment. The patients were assessed preoperatively and 3 months after surgery. The in-hospital physiotherapy treatment consisted of early mobilization, ambulation, breathing exercises, and thoracic range of motion exercises. Physical capacity was assessed with the 6-minute walk test. Level of physical activity was objectively assessed with an accelerometer and subjectively assessed with the International Physical Activity Questionnaire Modified for the Elderly. Results. Physical capacity for the whole sample was significantly decreased 3 months postoperatively compared with preoperative values (P = .047). There were no statistically significant differences between the groups regarding physical capacity, physical activity, spirometric values, or dyspnea. However, patients in the study group increased their level of self-reported physical activity from preoperatively to 3 months postoperatively, while the patients in the control group did not. Conclusions. No difference in physical capacity, physical activity, or lung function was found 3 months postoperatively in lung cancer surgery patients receiving in-hospital physiotherapy compared with control patients.

In-hospital physiotherapy improves physical activity level after lung cancer surgery: a randomized controlled trial.

OBJECTIVES: Patients undergoing lung cancer surgery are routinely offered physiotherapy. Despite its routine use, effects on postoperative physical recovery have yet not been demonstrated. The aim of this study was to investigate whether physiotherapy could improve postoperative in-hospital physical activity level and physical capacity. DESIGN: Single-blind randomized controlled trial. SETTING: Thoracic surgery department at a University Hospital. PARTICIPANTS: Patients undergoing elective thoracic surgery (n=94) for confirmed or suspected lung cancer were assessed during hospital stay. INTERVENTION: Daily physiotherapy, consisting of mobilization, ambulation, shoulder exercises and breathing exercises. The control group received no physiotherapy treatment. OUTCOMES: In-hospital physical activity assessed with the Actigraph GT3X+ accelerometer, six-minute walk test, spirometry and dyspnea scores. RESULTS: The treatment group reached significantly more accelerometer counts (2010 (1508) vs 1629 (1146), mean difference 495 [95% CI 44 to 1109]), and steps per hour (49 (47) vs 37 (34), mean difference 14 [95% CI 3 to 30]), compared to the control group, during the first three postoperative days. No significant differences in six-minute walk test (percent of preoperative 71% vs 79%, P=0.13), spirometry (FEV1 percent of preoperative 69% vs 69%, P=0.83) or dyspnoea (M-MRC 2 vs 2, P=0.74) between the groups were found. CONCLUSIONS: Patients receiving in-hospital physiotherapy showed increased level of physical activity during the first days after lung cancer surgery, compared to an untreated control group. However, no effects on the six-minute walk test or spirometric values were found. The clinical importance of an increased physical activity level during the early postoperative period needs to be further evaluated. CLINICAL TRIAL REGISTRATION NUMBER: NCT01961700.

EndoVascular and Hybrid Trauma Management (EVTM) for Blunt Innominate Artery Injury with Ongoing Extravasation.

Innominate artery (IA) traumatic injuries are rare but life-threatening, with high mortality and morbidity. Open surgical repair is the treatment of choice but is technically demanding. We describe a case of blunt trauma to the IA with ongoing bleeding, treated successfully by combined (hybrid) endovascular and open surgery. The case demonstrates the immediate usage of modern endovascular and surgical tools as part of endovascular and hybrid trauma management.

Preoperative NT-proBNP independently predicts outcome in patients with acute coronary syndrome undergoing CABG.

OBJECTIVES: The predictive value of preoperative N-terminal pro-B-type natriuretic peptide (NT-proBNP) was evaluated in patients with acute coronary syndrome undergoing coronary artery bypass grafting (CABG). DESIGN: As a substudy to a clinical trial 383 patients with acute coronary syndrome undergoing CABG were studied. 17 patients had a concomitant procedure. NT-proBNP was measured immediately preoperatively and evaluated with regard to in-hospital mortality, and severe circulatory failure postoperatively according to prespecified criteria. Follow-up was 3.2 ± 0.9 years. RESULTS: In patients with isolated CABG, receiver operating characteristics (ROC) analysis showed an area under the curve (AUC) of 0.82 for in-hospital mortality and 0.87 for severe circulatory failure respectively with a best cut-off for preoperative NT-proBNP of 1028 ng/L. This cut-off level independently predicted severe circulatory failure. Patients with NT-proBNP < 1028 ng/L had significantly better long-term survival (p = 0.004). Preoperative NT-proBNP was higher in patients with concomitant procedure than isolated CABG (2146 ± 1858 v 887 ± 1635 ng/L; p = 0.0005). In patients with concomitant procedure ROC analysis showed an AUC of 0.93 for severe circulatory failure with a best cut-off for preoperative NT-proBNP of 3145 ng/L. CONCLUSIONS: Preoperative NT-proBNP predicted in-hospital mortality, severe circulatory failure postoperatively and long-term survival in patients undergoing surgery for acute coronary syndrome but a higher threshold was found in patients having concomitant procedures.

GLUTAMICS--a randomized clinical trial on glutamate infusion in 861 patients undergoing surgery for acute coronary syndrome.

OBJECTIVE: Glutamate has been claimed to protect the heart from ischemia and to facilitate metabolic and hemodynamic recovery after ischemia. The GLUTAmate for Metabolic Intervention in Coronary Surgery trial investigated whether an intravenous glutamate infusion given in association with surgery for acute coronary syndrome could reduce mortality and prevent or mitigate myocardial injury and postoperative heart failure. METHODS: In the present prospective, triple-center, double-blind study, 861 patients undergoing surgery for acute coronary syndrome were randomly assigned to an intravenous infusion of glutamate (n = 428) or saline (n = 433) perioperatively. RESULTS: The incidence of the primary endpoint--a composite of 30-day mortality, perioperative myocardial infarction, and left ventricular heart failure at weaning from cardiopulmonary bypass-was 7.3% versus 5.8% (P = .41) in the glutamate and control groups, respectively. Patients with left ventricular failure at weaning from cardiopulmonary bypass had a shorter median intensive care unit stay (25 vs 92 hours; P = .02) if they were treated with glutamate. In patients with unstable angina (Canadian Cardiovascular Society class IV) undergoing isolated coronary artery bypass grafting (n = 458), the incidence of severe circulatory failure according to the prespecified criteria was significantly lower in the glutamate group (1.3% vs 6.9%; P = .004). On multivariate analysis, glutamate infusion was associated with a reduced risk of developing severe circulatory failure (odds ratio, 0.17; 95% confidence interval, 0.04-0.72; P = .02). A relative risk reduction exceeding 50% for developing severe circulatory failure was seen in most risk groups undergoing isolated coronary artery bypass grafting, with those with diabetes a notable exception. CONCLUSIONS: The primary endpoint did not differ significantly between the groups. The secondary outcomes and post hoc analyses warrant additional studies with regard to the potential beneficial effect of glutamate on postischemic myocardial recovery.

The S-100B substudy of the GLUTAMICS trial: glutamate infusion not associated with sustained elevation of plasma S-100B after coronary surgery.

BACKGROUND & AIMS: Concerns have been raised about potential neurological injury related to exogenous glutamate. In cardiac surgery glutamate has been administered as a putative cardioprotective agent by cardioplegia or intravenous infusion. In the GLUTAMICS trial, in addition to surveillance of clinical neurological injuries, a prespecified subgroup was analyzed with regard to postoperative S-100B levels to detect potential subclinical neurological injury related to glutamate infusion. METHODS: Sixty-nine patients operated on for unstable coronary syndrome were randomized to intravenous infusion of glutamate (n=35) or saline (n=34) perioperatively. Plasma levels of S-100B were obtained on the third postoperative day. RESULTS: S-100B in the glutamate group and the control group were 0.079+/-0.034microg/L and 0.090+/-0.042microg/L respectively (p=0.245). There were no patients with stroke or mortality. Three patients in the control group and two in the glutamate group had postoperative confusion. These patients had significantly elevated S-100B compared with those without confusion (0.132+/-0.047vs 0.081+/-0.036microg/L; p=0.003). Overall, 21 patients had S-100B above reference level (> or =0.10microg/L) and these patients had significantly more calcifications in the ascending aorta on epiaortic scanning. CONCLUSIONS: Intravenous glutamate infusion during surgery for unstable coronary artery disease did not initiate a sustained elevation of plasma S-100B. Thus, no evidence for subclinical neurological injury related to glutamate infusion was found. In contrast, postoperative elevation of plasma S-100B was linked to calcification of the ascending aorta and postoperative confusion.