Pulmonary vascular resistance index during coronary artery bypass surgery with aprotinin.

Low pulmonary vascular resistance index (PVRI) reflects favorable redundant pulmonary circulation following coronary artery bypass grafting with cardiopulmonary bypass surgery (CPB). This randomized study investigated whether aprotinin given in different modalities impacts PVRI after coronary artery bypass grafting. A total of 40 patients undergoing coronary artery bypass grafting were randomized to four groups according to aprotinin dose: (1) high dose, (2) early low dose, (3) late low dose, and (4) without aprotinin. Oxygenation index, pulmonary shunt, alveolar-arterial oxygen gradient and PVRI were determined. PVRI was calculated as the transpulmonary pressure gradient divided by cardiac index multiplied by 80. The results showed that PVRI remained relative low in all patients provided aprotinin regardless of treatment dosage; PVRI increased at 4 h after restarting ventilation after CPB in patients without aprotinin as compared with aprotinin (266 ± 137, 266 ± 115, 244 ± 86 vs. 386 ± 121, dynes-s-cm-5, respectively, p = .047). Elevated postoperative PVRI was predictive for patients without aprotinin (AUC 0.668; SE 0.40; p < .0001; CI 0.590-0.746). There were no statistical differences in oxygenation index, pulmonary shunt or alveolar-arterial oxygen gradient between the groups. In conclusion, aprotinin maintains a low PVRI in elective patients with healthy lungs during CPB. We suggest that aprotinin maintains pulmonary arterial endothelial integrity.

Symptoms of Sternal Nonunion Late after Cardiac Surgery.

Background A cohort of patients having symptoms of sternal nonunion late after sternotomy was studied to find out whether the complaints were related to true sternal nonunion or decreased bone density. Methods A survey was mailed to 2,053 cardiac surgical patients operated in our institution between July 2007 and June 2010. The patients were requested about symptoms referring to sternal instability. A group of symptomatic individuals as well as 1:1 age- and time-matched asymptomatic controls were examined with sternal palpation, ultrasound during standardized sternal pressure provocation, and computed tomography (CT). Results The number of patients replied in the survey was 1,918 (93.4%); 2.3% (44 patients) reported sensation of movement or clicking in sternum during body movements and during coughing. Symptomatic patients living within 200 km to the hospital (21) and their asymptomatic controls (21) were selected for further clinical and imaging studies. Mean period between the initial operation and the examinations was 36 (22-56) months. Sternal palpation pain was significantly associated with reported symptoms suggestive of sternal nonunion (odds ratio [OR] 22.0; 95% confidence interval [CI] 2.5-195); however, none of the patients had clinically unstable sternum or nonunion in the sternal imaging. The symptoms of sternal instability were more frequent in patients whose bone mineralization rate (as measured with T-scores) was higher. Conclusion Symptoms suggestive of sternal nonunion were experienced by 2.3%. However, their symptoms did not correlate with CT scans or provocation ultrasound although palpation pain was evident. Thus the pain is derived from nonmechanical etiologies. Higher bone mineralization rate correlated with abnormal symptoms of sternal wound.

Associations of metabolic syndrome and diabetes mellitus with 16-year survival after CABG.

BACKGROUND: The associations of metabolic syndrome (MetS) or diabetes mellitus (DM) on long-term survival after coronary artery bypass grafting (CABG) have not been extensively evaluated. The aim of the present study was to assess the impact of MetS and DM on the 16-year survival after CABG. METHODS: Diabetic and metabolic status together with relevant cardiovascular data was established in 910 CABG patients operated in 1993-94. They were divided in three groups as follows: neither DM nor MetS (375 patients), MetS alone (279 patients) and DM with or without MetS (256 patients). The 16-year follow-up of patient survival was carried out using national health databases. The relative survival rates were analyzed using the Life Table method comparing the observed survival rates of three patient groups to the rates based on age-, sex- and time-specific life tables for the whole population in Finland. To study the independent significance of MetS and DM for clinical outcome, multivariate analysis was made using an optimizing stepwise procedure based on the Bayesian approach. RESULTS: Bayesian multivariate analysis revealed together six variables to predict clinical outcome (2 months to 16 years) in relation to the national background population, i.e. age, diabetes, left ventricular ejection fraction, BMI, perfusion time during the CABG and peripheral arterial disease. Our principal finding was that after postoperative period the 16-year prognosis of patients with neither DM nor MetS was better than that of the age-, sex-and time-matched background population (relative survival against background population 1.037, p < 0.0001). The overall survival of MetS patients resembled that of the matched background population (relative survival 0.998, NS). DM was associated with significantly increased mortality (relative survival 0.86, p < 0.0001). Additionally, mortality was even higher in patients receiving insulin treatment than in those without. Excess death rate of DM patients was predominantly caused by cardiovascular causes. CONCLUSION: In this long-term follow-up study patient groups without diabetes had at least equal 16 years' survival after CABG than their matched background populations. Survival of DM patients started to deteriorate already few years after the operation.

Cardiopulmonary bypass decreases pulmonary vascular resistance index after coronary artery bypass surgery.

BACKGROUND: Decreased pulmonary vascular resistance index (PVRI) reflects favorable postoperative pulmonary circulation after coronary artery bypass grafting. This randomized study investigated whether cardiopulmonary bypass (CPB) impacts PVRI after coronary artery bypass grafting. MATERIAL AND METHODS: A total of 47 patients undergoing coronary artery bypass grafting were randomized into four groups according to the ventilation and surgical technique: (1) No ventilation group, with intubation tube detached from the ventilator, (2) low tidal volume group, with continuous low tidal volume ventilation, (3) continuous 10 cm H2O positive airway pressure (CPAP) group, and (4) randomly selected patients undergoing surgery without CPB. Oxygenation index, pulmonary shunt, alveolar-arterial oxygen gradient and PVRI were determined. PVRI was calculated as the transpulmonary pressure gradient divided by cardiac index multiplied by 80. RESULTS: During the first postoperative morning there were no statistical differences in oxygenation index, pulmonary shunt or alveolar-arterial oxygen gradient between the groups, while PVRI remained elevated in patients without CPB as compared with patients with CPB (263 ± 98 vs. 122 ± 84, dyne-s-cm(-5), respectively, p < 0.001). PVRI decreased in all patients with CPB regardless of ventilation technique. In contrast, elevated postoperative PVRI values were predictive for patients without CPB (AUC 0.786; SE 0.043; p < 0.001; 95% CI. 0.701-0.870). CONCLUSIONS: Modified ventilation does not affect PVRI in elective patients with healthy lungs during CPB. Instead, CPB per se may have an important role on diminished PVRI. We suggest that CPB preserves pulmonary arterial endothelial integrity.

Confined ischemia may improve remote myocardial outcome after rat cardiac arrest.

BACKGROUND: Confined ongoing ischemia after ischemia-reperfusion injury (IRI) may alter myocardial recovery. We evaluated in a rat cardiac transplantation model whether distal persistent myocardial ischemia (dMI) and remote preconditioning (RPreC) have a remote myocardial impact after IRI. MATERIAL AND METHODS: Syngeneic heterotopic cardiac transplantation was performed on 29 Fischer344 rats to induce IRI, including nine rats which underwent distal ligation of the left anterior coronary artery (LAD) to yield distal MI (IRI+ dMI). RPreC was applied by occluding the left renal artery 5 min prior to reperfusion in six rats with IRI (IRI+ RPreC) as well as in seven with distal MI (IRI+ dMI+ RPreC). Microdialysis, histology and qRT-PCR for inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) were performed after graft harvesting. RESULTS: In contrast to IRI + dMI + RPreC (39 ± 7 µmol), glutamate decreased in IRI + RPreC and IRI + dMI as compared with IRI (26 ± 3 and 31 ± 8 vs 91 ± 20, µmol respectively, p < 0.007). The relative number of vacuolated intramyocardial artery nuclei decreased in IRI + dMI as compared with IRI (0.02 ± 0.01, range 0-12 vs. 0.42 ± 0.31, range 0-3.25 PSU respectively, p < 0.04). iNOS expression decreased in IRI + RPreC as compared with IRI (p < 0.04), and eNOS expression decreased in IRI + dMI + RPreC as compared with IRI + dMI (p < 0.006) along with increased glycerol release. CONCLUSIONS: dMI after IRI has a potentially beneficial myocardial impact after cardiac arrest, which is hampered by RPreC.

High-throughput quantification of circulating metabolites improves prediction of subclinical atherosclerosis.

AIMS: High-throughput metabolite quantification holds promise for cardiovascular risk assessment. Here, we evaluated whether metabolite quantification by nuclear magnetic resonance (NMR) improves prediction of subclinical atherosclerosis in comparison to conventional lipid testing. METHODS AND RESULTS: Circulating lipids, lipoprotein subclasses, and small molecules were assayed by NMR for 1595 individuals aged 24-39 years from the population-based Cardiovascular Risk in Young Finns Study. Carotid intima-media thickness (IMT), a marker of subclinical atherosclerosis, was measured in 2001 and 2007. Baseline conventional risk factors and systemic metabolites were used to predict 6-year incidence of high IMT (≥ 90 th percentile) or plaque. The best prediction of high intima-media thickness was achieved when total and HDL cholesterol were replaced by NMR-determined LDL cholesterol and medium HDL, docosahexaenoic acid, and tyrosine in prediction models with risk factors from the Framingham risk score. The extended prediction model improved risk stratification beyond established risk factors alone; area under the receiver operating characteristic curve 0.764 vs. 0.737, P =0.02, and net reclassification index 17.6%, P =0.0008. Higher docosahexaenoic acid levels were associated with decreased risk for incident high IMT (odds ratio: 0.74; 95% confidence interval: 0.67-0.98; P = 0.007). Tyrosine (1.33; 1.10-1.60; P = 0.003) and glutamine (1.38; 1.13-1.68; P = 0.001) levels were associated with 6-year incident high IMT independent of lipid measures. Furthermore, these amino acids were cross-sectionally associated with carotid IMT and the presence of angiographically ascertained coronary artery disease in independent populations. CONCLUSION: High-throughput metabolite quantification, with new systemic biomarkers, improved risk stratification for subclinical atherosclerosis in comparison to conventional lipids and could potentially be useful for early cardiovascular risk assessment.

Lack of C4d deposition may reveal susceptibility for ascending aortic dissection.

OBJECTIVES: Complement activation as evidenced by C4d deposition indicates immunological tissue reactivity. We sought to study the vascular reactivity of the aortic wall by characterizing C4d deposits. DESIGN: Aortic wall histology and immunohistochemistry for C4d, leukocytes, T- and B-lymphocytes, plasma cells, macrophages, endothelial cells, smooth muscle cells, cell proliferation, elastase, and Van-Gieson-staining were performed to 91 consecutive patients that underwent surgery for ascending aorta, and the samples were grouped according to presence of C4d deposits. RESULTS: Fifty-three out of 91 patients had C4d deposits mainly within the adventitia (C4d +), whereas 38 patients lacked C4d deposits (C4d-) including decreased staining of intra-aortic vessels (p < 0.005). Intimal thickness and cellularity, together with inflammation consisting of plasma cells were increased in C4d- as compared with C4d + (p < 0.05). Receiver operating characteristic curve (ROC) analysis showed that C4d was associated with stabile nondissecting ascending aorta (AUC 0.792; SE 0.053; p = 0.000; 95% CI 0.688-0.895), but not with presence of aortitis per se (AUC 0.523; SE 0.069; p = 0.752; 95 % CI 0.388-0.658). CONCLUSIONS: Lack of C4d may indicate active remodeling of the aortic wall leading to aortic dissection (AD). Immunologic complement factors may be amenable to diagnosis of instability after aortic surgery.

Diazoxide may protect endothelial glycocalyx integrity during coronary artery bypass grafting.

OBJECTIVES: Plasma hyaluronan and syndecan-1 levels represent shedding of the endothelium glycocalyx during ischemia and edema. Diazoxide, a K(ATP)-channel opener, has been shown to decrease myocardial edema during coronary artery bypass grafting (CABG). We evaluated whether diazoxide exerts an impact on plasma hyaluronan and syndecan-1 levels during CABG. DESIGN: Representative blood samples for hyaluronan and syndecan-1, before, during and after surgery, were obtained in 13 out of 16 patients that had a history of stable coronary artery disease undergoing CABG with or without diazoxide. Electron microscopy from biopsies procured from the right atrium in 9 patients was performed to confirm ultrastructural differences among patients before and during CABG. RESULTS: Ultrastructural differences were apparent between individual patients already before operation at base line reflecting differences in the severity of myocardial ischemia and edema. A significant decrease of hyaluronan and syndecan-1 values was observed in patients with diazoxide after surgery (p < 0.04). Significant correlation of plasma hyaluronan and syndecan-1 levels was observed in patients with diazoxide but not in controls (p < 0.005, Spearman rank rho). CONCLUSION: Diazoxide may have an impact on levels of peripheral plasma hyaluronan and syndecan-1 after CABG, suggesting decreased shedding of the endothelial glycocalyx layer.

Inflammatory Glycoprotein YKL-40 Is Elevated after Coronary Artery Bypass Surgery and Correlates with Leukocyte Chemotaxis and Myocardial Injury, a Pilot Study.

The aim of the present study was to investigate the levels of YKL-40 during and after coronary artery bypass grafting surgery (CABG) and to establish possible connections between YKL-40 and markers of oxidative stress, inflammation, and myocardial injury. Patients undergoing elective CABG utilizing cardiopulmonary bypass (CPB) were recruited into the study. Blood samples were collected at the onset of anesthesia, during surgery and post-operatively. Levels of YKL-40, 8-isoprostane, interleukin-8 (IL-8), monocyte chemotactic protein-1 (MCP-1) and troponin T (TnT) were measured by immunoassay. YKL-40 levels increased significantly 24 h after CPB. Positive correlation was seen between post-operative TnT and YKL-40 levels (r = 0.457, p = 0.016) and, interestingly, baseline YKL-40 predicted post-operative TnT increase (r = 0.374, p = 0.050). There was also a clear association between YKL-40 and the chemotactic factors MCP-1 (r = 0.440, p = 0.028) and IL-8 (r = 0.484, p = 0.011) linking YKL-40 to cardiac inflammation and fibrosis following CABG. The present results show, for the first time, that YKL-40 is associated with myocardial injury and leukocyte-activating factors following coronary artery bypass surgery. YKL-40 may be a factor and/or biomarker of myocardial inflammation and injury and subsequent fibrosis following heart surgery.

European multicenter study with the Soprano valve for aortic valve replacement: one-year clinical experience and hemodynamic data.

BACKGROUND AND AIM OF THE STUDY: During recent years, pericardial bioprostheses have gained widespread acceptance as cardiac valve substitutes. The study aim was to evaluate the early clinical and hemodynamic performance of the Sorin SopranoTM supra-annular aortic bioprosthesis, as used for aortic valve replacement (AVR). METHODS: Between January 2004 and August 2006, a total of 501 patients (55% males; mean age 75 +/- 6.4 years) was prospectively enrolled into the study, which involved 10 European institutions. The indications for AVR were aortic stenosis in 91% of patients, aortic incompetence in 8%, and redo surgery in 1%. Preoperatively, 62% of the patients were in NYHA class III, and 12% in class IV. The mean prosthesis size was 21.4 +/- 1.8 mm. A non-everting technique was used in 88% of patients. Concomitant procedures were performed in 52% of cases (mainly coronary artery bypass grafts; 41%). The mean cross-clamp and cardiopulmonary bypass times were 70 +/- 27.2 min and 99 +/- 39.7 min, respectively. Doppler echocardiography performed at one and 12 months after surgery was evaluated by an independent core laboratory. RESULTS: Postoperatively, there were 25 early deaths (5%) and 13 late deaths, with an overall survival at one year of 92.9% (95% CI: 90.2-94.8) and freedom from valve-related death of 98.6% (95% CI: 97.5-99.6). After 12 months, most patients (87%) were in NYHA classes I-II. Actuarial freedoms from thromboembolism, bleeding, endocarditis and paraprosthetic leak at one year were 97.1% (CI: 95.1-98.2), 98.9% (CI: 97.4-99.5), 99.1% (CI: 97.7-99.7), and 99.6% (CI: 98.3-99.9), respectively. No events of thrombosis and structural valve deterioration (SVD) were observed. Subsequent echocardiographic evaluation showed low mean (11.1 +/- 5.1 mmHg at one year) and peak (19.5 +/- 8.9 mmHg at one year) transvalvular gradients, and a significant reduction in left ventricular mass, from 211 +/- 78.5 g at one month to 185 +/- 64.7 g at 12 months (p <0.0001). CONCLUSION: After 12 months, the clinical outcome with the Soprano bioprosthesis, when used for AVR, was excellent. The bioprosthesis also showed good hemodynamic performance, with a significant reduction of left ventricular hypertrophy.

The human heart releases cardiotrophin-1 after coronary artery bypass grafting with cardiopulmonary bypass.

OBJECTIVES: Cardiotrophin-1 (CT-1) is closely linked to many cardiovascular diseases, such as myocardial infarction and heart failure, and exhibits cardioprotective effect in ischemia-reperfusion injury. The present study was designed to investigate the course of CT-1 in patients undergoing on-pump coronary artery bypass grafting (CABG), and to evaluate the relationship between plasma CT-1 levels and postoperative cardiac function. METHODS: Twenty-four patients undergoing elective CABG were studied. Radial artery blood samples were collected before cardiopulmonary bypass (CPB), 5 min and 20 min after reperfusion, and 1 h, 6 h, 12 h and 24 h after CPB. Coronary sinus blood samples were collected before CPB, 5 min and 20 min after reperfusion. Plasma CT-1 levels were measured using the ELISA method. Hemodynamic data were collected. RESULTS: Peripheral CT-1 levels did not change significantly postoperatively. Trans-myocardial CT-1 levels increased significantly 5 min and 20 minutes after reperfusion as compared to baseline. A weak positive correlation (r = 0.408, p = 0.048) was found between trans-myocardial CT-1 levels at 20 min after reperfusion and CI at 12 h after CPB. CONCLUSIONS: The heart secretes CT-1 after ischemic injury. The precise effect of CT-1 in CABG needs further investigation.

Aquaporin-7 expression during coronary artery bypass grafting with diazoxide.

OBJECTIVES: Aquaporin-7 is a water-channel protein that controls tissue glycerol supply after ischemia. A burden of experimental studies suggests that diazoxide, a mitochondrial K(ATP)-channel opener, may decrease myocardial edema during coronary artery bypass grafting (CABG). We evaluated whether diazoxide has an impact on atrial aquaporin-7 expression during CABG. DESIGN: Sixteen patients with a history of stable coronary artery disease were enrolled in the study. Eight patients were treated during cardiopulmonary bypass with diazoxide, while the rest eight patients remained as controls. Histopathology was evaluated from biopsies procured before and during CABG from the right atrium. From fresh atrial tissue biopsies, Aquaporin-7 was quantified by RT-PCR. RESULTS: Histological differences were apparent between individual patients already before operation at base line reflecting differences in severity of myocardial ischemia. As compared with fold change values before operation, Aquaporin-7 expression after operation was positive in all but one control, whereas aquaporin-7 expression was positive in only two patients receiving diazoxide. The relative aquaporin-7 expression was significantly lower in patients treated with diazoxide as compared with controls (p < 0.05). CONCLUSIONS: Diazoxide may have an impact on myocardial water balance and glycerol energy supply by decreasing relative aquaporin-7 expression during CABG.

Myocardial infarction induces early increased remote ADAM8 expression of rat hearts after cardiac arrest.

BACKGROUND: A disintegrin and metalloproteinase-8 (ADAM8) is a potential surrogate of inflammation which has recently been associated with myocardial infarction. We evaluated in a rat cardiac transplantation model whether ischemia-reperfusion injury alone (IRI) or with early regional myocardial infarction (MI) would suffice to induce inflammatory myocardial remodeling and ADAM8 expression. MATERIAL AND METHODS: Isogenic heterotopic cardiac transplantation after cardiac arrest was performed to 48 Fischer 344 rats to induce ischemia-reperfusion injury (IRI), of which 27 rats also underwent ligation of the left anterior coronary artery (LAD) of the heart to yield MI. Histology was performed at 0.5, 24 and 48 h after transplantation. ADAM8 was evaluated by qRT-PCR after graft harvesting. RESULTS: After 0.5 and 48 h respectively, edematous intramyocardial artery nuclei and periadventitial inflammation were more prominent in MI after transplantation, as compared with IRI alone and Controls (57.0 vs 40.0 and 5.0; 1.9 vs 1.1 and 0.9, point score units, p < 0.05, respectively). The expression of ADAM-8 was increased in MI as compared with Controls (1.9 vs 1.0, 1.9 fold increase) at 48 h. In grafts with MI, ADAM8 was localized using immunohistochemistry to the vicinity of the area corresponding to the developing infarction as well as in intramyocardial arteries remote to the infarction area. CONCLUSIONS: Remote histopathological changes of ischemic cardiac grafts are associated with increased expression of ADAM8 thus emphasizing a global myocardial impact of MI.

A disintegrin and metalloprotease -8 and -15 and susceptibility for ascending aortic dissection.

BACKGROUND. Dilatation of the ascending aorta (AA) is affected by extra-cellular matrix modifications and inflammation. A disintegrin and metalloproteases (ADAMs) may reveal differences between AA and ascending aortic dissection (AD). We characterized the inflammatory histology of AD and AA and examined the role of ADAM8 and -15 in these diseases. MATERIAL AND METHODS. Aortic wall histology and immunohistochemistry for leukocytes, T- and B-lymphocytes, plasma cells, macrophages, endothelial cells, smooth muscle cells, cell proliferation, elastase and Van-Gieson-staining were performed to 40 consecutive patients that underwent surgery for AA or AD. The expressions of ADAM8 and -15 mRNA and proteins were evaluated using QRT-PCR and immunohistochemistry. RESULTS. Thirty-four patients were enrolled, of which 29 had AA and five had AD of the ascending aorta. B-cells throughout the aortic wall and intimal plasma cells were more numerous during AD as compared with AA (p < 0.05). The gene expressions for ADAM8 and -15 were notably lower in AA as compared with AD. The median for down-regulation of ADAM8 and -15 in AA was -2.7 and -1.8, respectively. ADAM8 and -15 were mainly found in the media layer in patients with AD. Two of the patients with AA and increased ADAMs developed AD of the remaining aorta. CONCLUSIONS. The involvement of ADAM8 and -15 together with inflammation consisting of B-cells may indicate active remodelling of the aortic wall leading to AD.

External validation of modified EuroSCORE.

BACKGROUND: EuroSCORE is an adult cardiac surgery risk scoring method that is used worldwide, which has been shown to significantly overestimate the operative risk. We derived a new risk scoring method by modifying some of the risk factors included in the EuroSCORE algorithm and we validated it in an external database. METHODS: This study included 4,014 patients who underwent adult cardiac surgery at the Heart Centre, Tampere University Hospital, Finland. Operative risk was estimated by EuroSCORE and its modified version. RESULTS: In-hospital postoperative mortality rate was 3.2%. EuroSCORE (AUC for logistic EuroSCORE 0.82; 95% confidence interval (CI), 0.79-0.85) and modified score (AUC for logistic modified score 0.79; 95% CI, 0.75-0.83) performed well in predicting in-hospital mortality in this series. The mean logistic EuroSCORE was 8%, and the mean logistic modified score was 2.2%. Thus, the observed to expected ratio for in-hospital mortality was 0.4 for logistic EuroSCORE and 1.5 for logistic modified score. The difference between observed and predicted mortality rate matched correctly for increasing additive modified score, but not for EuroSCORE. The observed to predicted ratio in high-risk patients (within the 90th percentile of each risk algorithm) was 0.36 (13.2%/36.2% in 402 patients) for logistic EuroSCORE and 0.99 (14.7%/14.9% in 395 patients) for logistic modified score. CONCLUSIONS: This modified and simplified score, which includes most of EuroSCORE variables, seems to provide a more realistic estimation of postoperative mortality risk of patients undergoing any adult cardiac surgery.

Glutamate release predicts ongoing myocardial ischemia of rat hearts.

BACKGROUND: Glutamate metabolism is associated with myocardial ischemia-reperfusion, but it is not clear whether glutamate reveals ongoing ischemia (OI). We evaluated whether microdialysis would detect OI induced by coronary artery ligation in a rat cardiac transplantation model. MATERIAL AND METHODS: A total of 24 Fischer 344 rats underwent syngeneic heterotopic cardiac transplantation. Of these, 16 rats underwent ligation of the left anterior coronary artery (LAD) of the heart to induce ongoing ischemia (OI), of which eight grafts received intra-aortally Gabapentin (12 mg/graft), a glutamate-release inhibitor and eight grafts with transplantation only served as the control. With a microdialysis catheter samples for glucose, lactate, pyruvate, glutamate, and glycerol were analysed spectrophotometrically. Histology and aquaporin 7 evaluations were performed after graft harvesting. RESULTS: Glutamate was elevated after 15 min of reperfusion in OI as compared with Control (14.31 +/- 5.03 microM vs 6.75 +/- 2.21 microM, p = 0.05), respectively. Glycerol remained high in OI (61.89 +/- 46.13 microM to 15.84 +/- 0.85 microM, p = ns) and low in Control (12.33 +/- 3.36 microM to 5.52 +/- 0.25 microM, p = ns). Gabapentin decreased glutamate release from 7.32 +/- 1.57 microM to 2.71 +/- 0.64 microM, (p < 0.05) and resulted in decrease of glycerol levels from 24.64 +/- 4.03 microM to 10.43 +/- 2.49 microM, (p < 0.05) in OI. The expression of aquaporin 7 and histology confirmed OI. CONCLUSIONS: We suggest that glutamate release may be used as an early indicator of OI after cardiac arrest.

Pulmonary function and immediate outcome of patients undergoing aortic valve replacement.

BACKGROUND AND AIM OF THE STUDY: The study aim was to evaluate whether pulmonary function, as assessed by spirometry, affects immediate outcome after aortic valve replacement (AVR). METHODS: Data relating to the preoperative percentages of predicted forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) were retrieved from a series of 453 patients who underwent AVR, with or without coronary artery bypass surgery. RESULTS: The percentage of predictive FVC (odds ratio (OR) 0.952; 95% CI 0.914-0.990; AUC 0.749; p = 0.019), but not of predicted FEV1, nor any history of pulmonary disease, proved to be independent predictors of in-hospital mortality, even when adjusted for the logistic EuroSCORE. A percentage predictive FVC of < 80% proved to be the best cut-off (in-hospital mortality 6.3% versus 1.3%; p = 0.005; OR 5.100; 95% CI 1.544-16.849; specificity 69%, sensitivity 69%). The percentage of predictive FVC was found to be an independent predictor of stroke (OR 0.956; 95% CI 0.923-0.989; p = 0.009). Patients with a percentage of predictive FVC < 80% had a risk of postoperative stroke of 6.9% versus 1.9% among those patients with better FVC values (OR 3.769; 95% CI 1.342-10.581; p = 0.012). Patients with a percentage of predictive FVC < 80% (10.4% versus 4.2%; OR 2.648; 95% CI 1.225-5.724; p = 0.011) and a history of pulmonary disease (13.1% versus 5.1%; OR 2.808; 95% CI 1.117-6.694; p = 0.016) had a significantly higher risk of an intensive care unit stay of five or more days. Postoperative pneumonia was not associated with either spirometric parameters, nor with any history of pulmonary disease. CONCLUSION: Pulmonary disease, as indicated by decreased preoperative values of FVC and FEV1, is an important comorbidity factor in patients undergoing AVR surgery. Further studies are required to demonstrate whether the identification and treatment of these patients could improve their outcome after AVR.

Return to work after coronary artery bypass surgery. A 10-year follow-up study.

OBJECTIVES: To establish which factors influence patients' return to work and how well they remain at work after coronary artery bypass grafting (CABG). DESIGN: Five hundred and sixty nine consecutive CABG patients aged less than 65 years were followed for 10 years. Data were collected from patient records and by questionnaires supplemented with information from Finnish national archives. RESULTS: Multivariate analysis showed the best predictors for return to work to be younger age, preoperative working, as well as absence of diabetes or perioperative cardiac damage. Almost half of the patients aged less than 60 and preoperatively not retired were working one year after CABG. Five years postoperatively, 85% of patients younger than 60 years and once returned to work were still working. Correspondingly, of subjects remaining under 60 years during a 10-year follow-up, 75% continued working. CONCLUSIONS: Younger age and preoperative employment were the most important predictors of successful return to work. Once returned after CABG, patients' staying at work was comparable with that in the general population.

Forearm vessel atherosclerosis. A harbinger of carotid disease?

OBJECTIVES: Atherosclerosis is a systemic disease affecting several vessels of the body. Coronary artery patients requiring bypass surgery have increased prevalence of carotid artery atherosclerosis which is known to increase operative risk in coronary artery bypass surgery (CABG). Radial artery is often screened for grafting purposes preoperatively. Our aim was to find out whether atherosclerotic changes in forearm vessels are correlated and could reveal risk to carotid artery disease. DESIGN: Eighty-five patients planned for elective CABG were examined with ultrasonography preoperatively. Biplane ultrasonographic scanning was performed on forearm arteries and both carotid arteries. RESULTS: Eleven patients had pathologic changes in the wall of forearm vessels. Carotid artery disease was found on 19 patients. Forearm vessel pathology was found to have correlation to carotid artery disease. When forearm arteries show atherosclerotic pathology the risk of having carotid disease is at least five-fold, in subgroups even higher. CONCLUSIONS: Forearm arterial pathology is correlated to carotid artery disease. When forearm vessel pathology is evident in preoperative examination, scanning of the carotid vessels should be considered.

The anti-inflammatory effect of bradykinin preconditioning in coronary artery bypass grafting (bradykinin and preconditioning).

OBJECTIVE: The present study was designed to investigate the cardioprotective effect of exogenous administration of bradykinin (BK) in cardiac surgery. METHODS: Forty-one patients who were scheduled for isolated coronary artery bypass grafting (CABG) were randomized into Control group and BK group. BK patients received 25 microg bradykinin infusion for 7 minutes before the cardiopulmonary bypass (CPB). Release of cardiac specific troponin I (TnI) and creatine kinase cardiac isoenzyme (CK-MB) was recorded. Perioperative circulating cytokine interleukin (IL)-6, 8 and 10 were measured. RESULTS: There was no significant difference in TnI between groups. However, BK patients released significantly less CK-MB than the controls (p =0.043). Systemic plasma levels of IL-6, IL-8 and IL-10 increased significantly after reperfusion in both groups as compared with baseline (p <0.05). The ratio of IL-8 to IL-10 was significantly lower in BK groups than in controls (p =0.03). CONCLUSIONS: We conclude that exogenous administration of BK prior to CPB in CABG patients attenuates ischemic myocardial injury. It also shifts the circulating inflammatory cytokine balance towards the anti-inflammatory direction.