Comparison of hydroxyl radical generation in patients undergoing coronary artery bypass grafting with and without cardiopulmonary bypass

We measured the hydroxyl radical (√OH) generation in fourteen patients undergoing coronary artery bypass grafting (CABG), of whom seven patients underwent on-pump CABG with cardiopulmonary bypass (CPB) and seven patients underwent off-pump CABG without CPB. To detect √OH generation, we measured the urinary excretion of √OH products of creatinine (Cr), creatol (CTL; 5-hydroxycreatinine) and methylguanidine (MG) with HPLC using the one point sampling and collected urine during and after the operation. The urinary CTL value corrected urinary Cr value of on-pump CABG significantly increased about 3-5 times from the beginning of CPB to 4 h after operation compared to the baseline value before CPB in both the collected urine and the one point sampling urine. The urinary MG/Cr value in both groups did not change significantly. Significantly increased √OH generation was found during and soon after on-pump CABG.     

Perioperative kinetics of endocan in patients undergoing cardiac surgery with and without cardiopulmonary bypass

IntroductionEndothelial Specific Molecule-1 or endocan is a novel biomarker associated with the development of acute lung injury (ALI) in response to a systemic inflammatory state such as trauma. Acute Respiratory Distress syndrome (ARDS), a severe form of ALI is a devastating complication that can occur following cardiac surgery due to risk factors such as the use of cardiopulmonary bypass (CPB) during surgery. In this study we examine the kinetics of endocan in the perioperative period in cardiac surgical patients.MethodsAfter ethics approval, we obtained informed consent from 21 patients undergoing elective cardiac surgery (3 groups with seven patients in each group: coronary artery bypass grafting (CABG) with the use of CPB, off-pump CABG and complex cardiac surgery). Serial blood samples for endocan levels were taken in the perioperative period (T0: baseline prior to induction, T1: at the time of heparin administration, T2: at the time of protamine, T2, T3, T4 and T5 at 1, 2, 4 and 6 h following protamine administration respectively). Endocan samples were analysed using the enzyme-linked immunosorbent assay (ELISA) method. Statistical analysis incorporated the use of test for normality.ResultsOur results reveal that an initial rise in the levels of serum endocan from baseline in all patients after induction of anaesthesia. Patients undergoing off-pump surgery have lower endocan concentrations in the perioperative period than those undergoing CPB. Endocan levels decrease following separation from CPB, which may be attributed to haemodilution following CPB. Following administration of protamine, endocan concentrations steadily increased in all patients, reaching a steady state between 2 and 6 h. The baseline endocan concentrations were elevated in patients with hypertension and severe coronary artery disease.ConclusionBaseline endocan concentrations are higher in hypertensive patients with critical coronary artery stenosis. Endocan concentrations increased after induction of anaesthesia and decreased four hours after separation from CPB. Systemic inflammation may be responsible for the rise in endocan levels following CPB.     

Sutureless aortic valve with supracoronary ascending aortic replacement as an alternative strategy for composite graft replacement in elderly patients

Netherlands Heart Journal - Aortic valve disease is frequently associated with ascending aorta dilatation and can be treated either by separate replacement of the aortic valve and ascending aorta...     

Relationship between cerebral injury and inflammatory responses in patients undergoing cardiac surgery with cardiopulmonary bypass

This study was performed to evaluate whether cytokines, adhesion molecules, ghrelin and S-100B are useful markers in predicting the cerebral infarction after cardiac surgery with cardioplumomary bypass (CPB). The patients (n=20) were classified into two groups; group A (n=4) showed postoperative organized cerebral damage, while group B (n=16) consisted of patients without occurrence of postoperative strokes. Before CPB, serum levels of S-100B in both groups A and B were low (<0.5 ng/mL), while ghrelin concentrations in group A (all patients had history of strokes) were much higher than those in group B. After CPB, when serum levels of S-100B in group A at 24h were higher than those in group B, ghrelin in group A at same time point showed high levels in comparison to group B. At 12 and 24h after CPB, levels of tumor necrosis factor (TNF)-alpha, interleukin-10 and soluble TNF-receptor I in group A were significantly higher than those in group B. In conclusion, it is considered that ghrelin as well as S-100B can be a useful marker for the prediction of stoke after CPB. Increase of TNF-alpha, interleukin-10 and soluble TNF-receptor I after CPB may be involved in the pathogenesis of stroke after CPB.     

Long-term outcomes of isolated aortic valve replacement and concomitant AVR and coronary artery bypass grafting

Background

It is well established that concomitant aortic valve replacement (AVR) and coronary artery bypass grafting (CABG) has a higher operative mortality rate than isolated AVR. However, studies report conflicting results on the long-term mortality. The aim of this prospective study was to explore and compare the outcomes and risk factors of isolated AVR and concomitant AVR and CABG in a consecutive Dutch patient population.

Methods

From January 2001 through January 2010, 332 consecutive patients underwent AVR with or without CABG at a single institution (197 isolated AVR and 135 concomitant AVR and CABG). A multivariate Cox proportional hazard analysis was performed to determine the independent risk factors for long-term mortality after aortic valve replacement.

Results

All 332 consecutive, referred patients who underwent aortic valve surgery were followed for up to 10 years. Median follow-up length was 48 months. The population had a median age of 73 years (IQR 65–78) and predominantly consisted of males (62%). Patients in the combined AVR and CABG group were older, had worse cardiac risk profiles and had worse preoperative cardiac statuses than those receiving isolated AVR. Five-year survival was 85% in AVR and 73% in AVR-CABG (p-value 0.012). Independent risk factors for mortality were higher creatinine values, previous CABG and increasing age.

Conclusion

Unselected, consecutive patients who underwent aortic valve replacement surgery and who received concomitant bypass surgery between 2001–2010 had higher 5-year mortality than their counterparts without CABG. Prior CABG, renal function, age but not concomitant CABG remained independently associated with increased mortality. Finally, the observed mortality rate in this consecutive patient group compared favourably with preoperative risk assessment using the EuroSCORE.     

The effect of aortic valve replacement on quality of life in symptomatic patients with severe aortic stenosis

Background

Although symptomatic patients with severe aortic stenosis have a high disease burden and guidelines recommend aortic valve replacement, many are treated conservatively. This study describes to what extent quality of life is changed by aortic valve replacement relative to conservative treatment.

Methods

This observational study followed 132 symptomatic patients with severe aortic stenosis who were subjected to an SF-36v2TM Health Survey.

Results

At baseline 84 patients were treated conservatively, 48 were referred for aortic valve replacement. In the conservatively treated group 15 patients died during a mean follow-up of 18 months (Kaplan-Meier survival was 85 % and 72 % at one and 2 years respectively) and 22 patients crossed over to the surgical group. Of the resulting 70 patients in the surgical group 3 patients died during a mean follow-up of 11 months (survival 95 % at 1 year). Physical functioning, vitality and general health improved significantly 1 year after aortic valve replacement. In conservatively treated patients physical quality of life deteriorated over time while general health, vitality and social functioning showed a declining trend. Mental health remained stable in both groups.

Conclusions

Aortic valve replacement improves physical quality of life, general health and vitality in patients with symptomatic severe aortic stenosis. Besides having a low life expectancy, conservatively treated patients experience deterioration of physical quality of life. Health surveys such as the SF-36v2TM can be valuable tools in monitoring the burden of disease for an individual patient and offer additional help in treatment decisions.     

Successful aortic valve replacement in a patient with AIDS

In trying to assess the benefit of cardiac surgery in AIDS patients, the question arises whether a patient with a deficient immune system can tolerate open heart surgery well enough to make the operation worthwhile. Surgical procedures and cardiopulmonary bypass have been noted to alter immune function (Diettrich et al., Ide et al.). Therefore, the presence of clinical AIDS is often still regarded as a contraindication to cardiac surgery. In this report we describe an AIDS patient who developed endocarditis of the native aortic valve. The endocarditis was successfully treated with antibiotic drugs, but the patient was left with damaged valves. Over the months he developed a massive aortic insufficiency and underwent aortic valve replacement. The patient did well after surgery, and is alive and well 18 months after the operation, suggesting that cardiac surgery might be a good and valuable treatment option in AIDS patients.     

Blood levels of corticosteroid-binding globulin, total cortisol and unbound cortisol in patients undergoing coronary artery bypass grafting surgery with cardiopulmonary bypass

Previous studies have demonstrated a persistent rise in serum cortisol concentrations after cardiac surgery. To further investigate this finding and to evaluate the effect of hemodilution that occurs with the onset of cardiopulmonary bypass (CPB), concentrations of cortisol-binding globulin (CBG), total and unbound cortisol, and packed cell volume (PCV) were studied in 28 patients undergoing coronary artery bypass graft surgery. All patients received a standardized general anesthetic using a balanced technique with sufentanil, isoflurane, and midazolam. Blood was collected preoperatively, intraoperatively during CPB, and postoperatively in the evenings on the day of surgery and on the first and second postoperative day. Cortisol and CBG concentrations were measured by radioimmunoassay and were used to calculate the fraction of unbound cortisol. Serum CBG and cortisol concentrations corrected for hemodilution were significantly higher than non-corrected values. Perioperatively, CBG measurements were significantly intercorrelated. Intraoperatively, total and unbound cortisol concentrations were not significantly increased compared to preoperative values. Postoperatively up to the end of the study period serum concentrations of total and unbound cortisol were significantly increased compared to baseline values. Our results suggest that hemodilution occurs in all patients during cardiac surgery and continues up to the second postoperative day. This may lead to an underestimation of serum cortisol and CBG concentrations in patients undergoing heart surgery with CPB. Intraoperatively, concentrations of total and unbound cortisol were not significantly elevated. The postoperative rise in serum total cortisol concentration was accompanied by an increase in unbound cortisol concentration. The postoperative increase of unbound cortisol concentrations in patients undergoing cardiac surgery with CPB was largely due to an increase in cortisol secretion.     

Oxidative stress precedes peak systemic inflammatory response in pediatric patients undergoing cardiopulmonary bypass operation

Oxidative stress seems to contribute to cardiopulmonary bypass (CPB)-related postoperative complications. Pediatric patients are particularly prone to these complications. With this in mind, we measured oxidative stress markers in blood plasma of 20 children undergoing elective heart surgery before, during, and up to 48 h after cessation of CPB, along with inflammatory parameters and full analysis of iron status. Ascorbate levels were decreased by approximately 50% (P < 0.001) at the time of aorta cross-clamp removal (or pump switch-off in 4 patients with partial CPB), and associated with corresponding increases in dehydroascorbate (P < 0.001, r = -0.80) and malondialdehyde (P < 0.01, r = -0.59). In contrast to the immediate oxidative response, peak levels of IL-6 and IL-8 were not observed until 3-12 h after CPB cessation. The early loss of ascorbate correlated with duration of CPB (P < 0.002, r = 0.72), plasma hemoglobin after cross-clamp removal (P < 0.001, r = 0.70), and IL-6 and IL-8 levels at 24 and 48 h after CPB (P < 0.01), but not with postoperative lactate levels, strongly suggesting that hemolysis, and not inflammation or ischemia, was the main cause of early oxidative stress. The correlation of ventilation time with early changes in ascorbate (P < 0.02, r = 0.55), plasma hemoglobin (P < 0.01, r = 0.60), and malondialdehyde (P < 0.02, r = 0.54) suggests that hemolysis-induced oxidative stress may be an underlying cause of CPB-associated pulmonary dysfunction. Optimization of surgical procedures or therapeutic intervention that minimize hemolysis (e.g., off-pump surgery) or the resultant oxidative stress (e.g., antioxidant treatment) should be considered as possible strategies to lower the rate of postoperative complications in pediatric CPB.     

Trace element changes in sclerotic heart valves from patients undergoing aortic valve surgery

Several trace elements are essential nutrients for an optimal functioning of organs and tissues, including the immune system and the heart. The pathogenesis of some heart diseases has been associated with changes in the balance of certain trace elements. The etiology of nonrheumatic aortic valve sclerosis is unknown, however. A prospective study was performed on trace element changes in the sclerotic valves of 46 patients undergoing surgical aortic valve replacement because of aortic stenosis. Valves from 15 individual forensic cases without known cardiac disease served as controls. The contents of 15 trace elements (Al, As, Cd, Ca, Co, Cu, Fe, Pb, Mg, Mn, Hg, Se, Ag, V, and Zn) were measured by inductively coupled plasma — mass spectrometry (ICP-MS) of aortic valve tissue from both patients and forensic autopsy controls. Some trace elements showed similar concentrations in sclerotic and control valves (Al, Ag, Hg, Mn), whereas a few were moderately changed in the sclerotic as compared with the control valves, including an increase in Cd by 52% (p<0.05) and decreases in Se by 14% (p<0.05), in V by 42% (p<0,001), and in Cu by 45% (p<0.001). However, there were pronounced increases (p<0.001) in the concentrations of As (5-fold), Ca (70-fold), Co(10-fold), Fe (20-fold), Pb (8-fold), Mg (20-fold), and Zn (10-fold) in the sclerotic valves. Thus, sclerotic aortic valve disease is associated with a pronounced imbalance in several trace elements of well-known importance for cardiovascular and immune function as well as in trace elements with hitherto unknown significance.     

Increases in leukocyte cluster of differentiation antigen expression during cardiopulmonary bypass in patients undergoing heart transplantation

Cardiopulmonary bypass (CPB) is essential in heart transplantation surgery. It is also used in coronary artery grafting surgery where it has been associated with a postoperative inflammatory response. This manifests as an increase in pro-inflammatory proteins like interleukin-8 and tumour necrosis factor alpha accompanied by increases in neutrophil populations and increased expression of cluster of differentiation (CD) antigens. The latter have been investigated using flow cytometry, which is limited to the measurement of three to four CD antigens simultaneously. We have developed a novel antibody array that can simultaneously measure the expression of 72 different CD antigens. The purpose of this study was to use this technology to measure CD antigen expression in patients undergoing CPB during heart transplantation. Twelve patients undergoing this operation were studied. A preoperative sample acted as an internal control while a second sample taken during CPB was the comparator. No previous studies have examined changes in CD antigen expression during heart transplantation. We report an increase in the expression of 10 different CD antigens across all patients between the two time points.     

Report on outcomes of valve-in-valve transcatheter aortic valve implantation and redo surgical aortic valve replacement in the Netherlands

Netherlands Heart Journal - We sought to investigate real-world outcomes of patients with degenerated biological aortic valve prostheses who had undergone valve-in-valve transcatheter aortic valve...     

Defect in oxidative phosphorylation in LV papillary muscle mitochondria of patients undergoing mitral valve replacement

Mitochondria play a pivotal role in cellular metabolism, especially in energy production. Myocardial function depends on adenosine triphosphate (ATP) supplied by oxidation of several substrates. In the adult heart, this energy is obtained primarily from fatty acid oxidation through oxidative phosphorylation (OXPHOS). With this in view, we studied OXPHOS, Total-ATPase and cytochrome content in the mitochondria of the left ventricular (LV) papillary muscles in excised mitral valves of patients who underwent mitral valve replacement (MVR). The mitochondrial OXPHOS, cytochrome content and ATPase activity were studied in 70 patients (ranging from 22 to 40 years) operated on for mitral valve disease. Control study includes 25 normal mitral valves removed at necropsy from patients who died of extracardiac causes. In the presence of glutamate and succinate as substrates, the rate of mitochondrial oxygen consumption was significantly lower in LV papillary muscles of pathological mitral valves (P<0.001) by using with and without addition of ADP. The ADP/O ratio indices for glutamate and succinate were not significantly affected. Using glutamate as substrate, respiratory control index was significantly raised (P<0.05) as compared with control. A significant reduction of total cytochrome content and ATPase activity (P<0.001) was noted in LV papillary muscles of patients operated for mitral valve disease. Our results showed that OXPHOS, cytochromes 'a', 'b', 'c+c(1)' and ATP activity are significantly impaired in LV papillary muscles in patients with pathological mitral valve. Cardiac mitochondrial oxygen consumption is a very valuable tool to investigate the regulation of cardiac mitochondrial energy metabolism. There is increasing evidence that mitochondrial diseases, such as mitochondrial cardiomyopathy, valvular disease and some myopathies, can be responsive to treatment with metabolic intermediates such as coenzyme Q(10), thiamine, prednisone, and vitamin therapy.