Although single dose and short-term glucose-insulin-potassium (GIK) infusions are known to have positive cardiac effects, the effects of repeated and long-term GIK infusion on left ventricular (LV) systolic function and brain natriuretic peptide (BNP) levels are unknown.
To investigate the effects of repeated and long-term GIK infusion on LV systolic function and BNP levels.
Thirty-three patients diagnosed with ischemic cardiomyopathy were included in the study. Patients were divided into two groups: the GIK group (n=19) and the control group (n=14). GIK solutions (1000 mL 20% dextrose, 60 U insulin and 50 mmol/L KCl) were administered at 1 mL/kg/h for 24 h on the first, third and fifth days. The patients were examined by echocardiography at 24 h, one week and one month after the start of treatment. BNP levels were measured before and after GIK infusion.
In the GIK group, baseline ejection fraction (EF) was 29.2±10.3%. After one week, EF elevated to 40.8±10.8% (P=0.001). The EF after one month (37.1±10.9%) was less than the EF in the first week, but it was significantly higher than baseline in the GIK group (P=0.01). However, no significant changes in EF were observed after one week and one month in the control group (P=0.1 and P=0.2, respectively). BNP levels after GIK infusion was significantly lower than baseline level in the GIK group (P=0.01).
Intermittent and long-term GIK infusion has beneficial effects on LV systolic function in a short and intermediate amount of time. Decrease in BNP levels may indicate effective GIK treatment. Intermittent and long-term GIK infusion could be a promising treatment option in patients with systolic heart failure.
BNP; Cardiomyopathy; GIK infusion; Systolic functions
Favorable clinical outcomes have been observed with glucose-insulin-potassium infusion (GIK) in acute myocardial infarction (MI). The mechanisms of this beneficial effect have not been delineated clearly. GIK has metabolic, anti-inflammatory and profibrinolytic effects and it may preserve the ischemic myocardium. We sought to assess the effect of GIK infusion on infarct size and left ventricular function, as part of a randomized controlled trial.
Patients (n = 940) treated for acute MI by primary percutaneous coronary intervention (PCI) were randomized to GIK infusion or no infusion. Endpoints were the creatinine kinase MB-fraction (CK-MB) and left ventricular ejection fraction (LVEF). CK-MB levels were determined 0, 2, 4, 6, 24, 48, 72 and 96 hours after admission and the LVEF was measured before discharge.
There were no differences between the two groups in the time course or magnitude of CK-MB release: the peak CK-MB level was 249 ± 228 U/L in the GIK group and 240 ± 200 U/L in the control group (NS). The mean LVEF was 43.7 ± 11.0 % in the GIK group and 42.4 ± 11.7% in the control group (P = 0.12). A LVEF ≤ 30% was observed in 18% in the controls and in 12% of the GIK group (P = 0.01).
Treatment with GIK has no effect on myocardial function as determined by LVEF and by the pattern or magnitude of enzyme release. However, left ventricular function was preserved in GIK treated patients.
Glucose-insulin infusions (with potassium [GIK] or without [GI]) have been advocated in the setting of coronary artery bypass graft (CABG) surgery to optimize myocardial glucose use and to minimize ischemic injury.
To conduct a meta-analysis assessing whether the use of GIK/GI infusions perioperatively reduce in-hospital mortality or atrial fibrillation (AF) after CABG surgery.
Electronic databases (Medline, EMBASE and Cochrane Central Register of Controlled Trials [CENTRAL]) and references of retrieved articles were searched for randomized controlled trials that evaluated the effects of GIK or GI infusions, before or during CABG surgery, on in-hospital mortality and/or postoperative AF. Pooled ORs and 95% CIs were calculated for each outcome.
Twenty trials were identified and eligible for review. The summary OR for in-hospital mortality was 0.88 (95% CI 0.56 to 1.40), based on 44 deaths among 2326 patients. While postoperative AF was a more frequent outcome (occurring in 519 of 1540 patients in the 10 trials reporting this outcome), the overall pooled estimate of effect was nonsignificant (OR 0.79, 95% CI 0.54 to 1.15). This latter finding needs to be interpreted cautiously because it is accompanied by significant heterogeneity across trials.
Perioperative use of GIK/GI does not significantly reduce mortality or atrial fibrillation in patients undergoing CABG surgery. Unless future trial data in support of GIK/GI infusions become available, the routine use of these treatments in patients undergoing CABG surgery should be discouraged because the safety of these infusions has not been systematically examined.
Coronary artery bypass graft surgery; GIK; Insulin; Meta-analysis
Objectives: Levosimendan (LS) is a new inotropic drug which belongs to the group of drugs known as calcium sensitizers. It is different from other inotropic agents by its inotropic and vasodilatory actions without an increase in myocardial oxygen consumption and considered as a good choice in high-risk patients undergoing cardiac surgery. We aimed to investigate the proper time of the administration and the effect of prophylactic usage of LS in patients with low left ventricular ejection fraction (LVEF) undergoing coronary artery bypass grafting (CABG). Methods: Forty patients who underwent isolated CABG with LVEF) less than 30% were evaluated retrospectively. Patients were divided into 3 groups according to the induction time of LS during different phases of the operation and compared to a non-LS control group. LS infusion (0.2 μg/kg/min) was applied 12 hours before the operation in Group 1 (G1) (n=10), after the induction of anaesthesia in Group 2 (G2) (n=10) and during the pump removal period in Group 3 (G3) (n=10) and non-LS control group 4 (G4) (n=10). Demographic data, operative characteristics, hemodynamic parameters and serum lactate, troponin, creatinine levels were compared between groups before and after LS treatment during pre and postoperative period. Data were evaluated by Fisher exact, Kruskal-Wallis, Mann-Whitney U, Chi-square and Wilcoxon rank tests. Results: We found that the duration of tracheal intubation, the intensive care unit stay and the hospital stay were significantly decreased in G1 and G2 when compared to the patients in G3 and G4. During postoperative period, in G1 and G2 one (10%) patient from each required intraaortic balloon pump (IABP), while in G3 two (20%) patients and in G4 five (50%) patients required IABP. Cardiac index (CI) was significantly increased in all groups from baseline to intensive care unit (ICU)1h and ICU24h. When groups compared each other significant increase was found in G1-G4 (p=0.001) and G2-G4 (p=0.007) at ICU1h. There was a significant increase in % EF especially in G1-G4 (p=0.011) and G2-G4 (p=0.007) at ICU1h. Systemic vascular resistance index significantly decreased in G1 and G2 in comparison to G3 and G4. However there was no significant decrease in pulmonary capillary wedge pressure of all 4 groups before and after LS. There was a significant decrease in mean pulmonary arterial pressure in G1 and G2 according to G4. Compared with the other groups preoperatively LS-treated patients (G1 and G2) had lower postoperative troponin I, serum lactate and creatinine concentrations. Conclusions: Our study shows that the elective preoperative initiation of LS especially 12 hours before the operation onset is associated with better improvement on cardiac functions as well as with lower mortality and complication rates, lower use of additional inotropic and vasopressor drugs, less need for intra-aortic balloon pump support and shorter length of stay in the ICU in patients with high perioperative risk or compromised left ventricular function. As a result, patients who received an infusion of LS 12 hours before surgery showed an evidence of less myocardial damage which suggested the preconditioning effect of the drug.
Levosimendan; cardiac surgery; low cardiac output; preoperative usage
Background: Glucose–insulin–potassium (GIK) infusion improves cardiac function and outcome during acute ischaemia.
Objective: To determine whether GIK infusion benefits patients with chronic ischaemic left ventricular dysfunction, and if so whether this is related to the presence and nature of viable myocardium.
Methods: 30 patients with chronic ischaemic left ventricular dysfunction had dobutamine echocardiography and were given a four hour infusion of GIK. Segmental responses were quantified by improvement in wall motion score index (WMSI) and peak systolic velocity using tissue Doppler. Global responses were assessed by left ventricular volume and ejection fraction, measured using a three dimensional reconstruction. Myocardial perfusion was determined in 15 patients using contrast echocardiography.
Results: WMSI (mean (SD)) improved with dobutamine (from 1.8 (0.4) to 1.6 (0.4), p < 0.001) and with GIK (from 1.8 (0.4) to 1.7 (0.4), p < 0.001); there was a similar increment for both. Improvement in wall motion score with GIK was observed in 55% of the 62 segments classed as viable by dobutamine echocardiography, and in 5% of 162 classed as non-viable. There was an increment in peak systolic velocity after both dobutamine echocardiography (from 2.5 (1.8) to 3.2 (2.2) cm/s, p < 0.01) and GIK (from 3.0 (1.6) to 3.5 (1.7) cm/s, p < 0.001). The GIK effects were not mediated by changes in pulse, mean arterial pressure, lactate, or catecholamines, nor did they correlate with myocardial perfusion. End systolic volume improved after GIK (p = 0.03), but only in 25 patients who had viable myocardium on dobutamine echocardiography.
Conclusions: In patients with viable myocardium and chronic left ventricular dysfunction, GIK improves wall motion score, myocardial velocity, and end systolic volume, independent of effects on haemodynamics or catecholamines. The response to GIK is observed in areas of normal and abnormal perfusion assessed by contrast echocardiography.
ischaemic heart disease; glucose-insulin-potassium infusion; dobutamine echocardiography
Clinical and experimental studies have suggested benefit of treatment with intravenous glucose-insulin-potassium (GIK) in acute myocardial infarction. However, patients hospitalized with acute coronary syndromes often experience recurrent myocardial ischemia without infarction that may cause progressive left ventricular (LV) dysfunction. This study tested the hypothesis that anticipatory treatment with GIK attenuates both systolic and diastolic LV dysfunction resulting from ischemia and reperfusion without infarction in vivo. Open-chest, anesthetized pigs underwent 90 min of moderate regional ischemia (mean subendocardial blood flow 0.3 ml·g−1·min−1) and 90 min reperfusion. Eight pigs were treated with GIK (300 g/l glucose, 50 U/l insulin, and 80 meq/l KCl; infused at 2 ml·kg−1·h−1) beginning 30 min before ischemia and continuing through reperfusion. Eight untreated pigs comprised the control group. Regional LV wall area was measured with orthogonal pairs of sonomicrometry crystals. GIK significantly increased myocardial glucose uptake and lactate release during ischemia. After reperfusion, indexes of regional systolic function (external work and fractional systolic wall area reduction), regional diastolic function (maximum rate of diastolic wall area expansion), and global LV function (LV positive and negative maximum rate of change in pressure with respect to time) recovered to a significantly greater extent in GIK-treated pigs than in control pigs (all P < 0.05). The findings suggest that the clinical utility of GIK may extend beyond treatment of acute myocardial infarction to anticipatory metabolic protection of myocardium in patients at risk for recurrent episodes of ischemia.
ventricular function; energy metabolism; substrates
To evaluate the effects of high-dose glucose–insulin–potassium (GIK) solution on hemodynamics and cardiac remodeling in patients with acute myocardial infarction (AMI) treated with primary percutaneous coronary intervention (PCI).
Patients and Methods:
We observed the changes in the hemodynamic parameters in 26 patients with AMI. All patients received primary PCI before entering the study. All patients in the study were randomized into the GIK group (n = 14) or the control group (n = 12). Patients in the GIK group received high-dose GIK solution (25% glucose, 80 mmol/L KCl and 50 IU/L insulin; 1.5 ml/kg/h) over 24 h. Patients in the control group received standard therapy. We monitored the hemodynamic parameters at baseline and after 6 h, 12 h, 18 h and 24 h, respectively. Then, we followed-up the cardiac function with echocardiography after 7 days, 1 month and 6 months.
The basic clinical data was similar between the groups. Primary PCI was performed successfully in 25 patients. The two groups were indistinguishable in all factors measured. GIK solution did not have a deleterious effect on the hemodynamic parameters. The pulmonary capillary wedge pressure increased during the first 12-h period and then decreased smoothly (F = 3.75, P = 0.02). The trends were similar between the two groups. The system vascular resistance index (SVRI) and pulmonary vascular resistance index (PVRI) decreased during the first 12 h in the GIK group but increased in the control group. The GIK solution significantly influenced SVRI (F = 4.71, P = 0.02). GIK solution improved the cardiac function measured by stroke volume (F = 4.11, P = 0.03) and cardiac index (F = 4.40, P = 0.02). In the 6-month follow-up, GIK improved cardiac remodeling (left ventricular diastolic diameter: 49.2 ± 2.89 vs. 53.9 ± 2.48, P < 0.001; left ventricular systolic diameter: 32.9 ± 2.24 vs. 35.9 ± 2.78, P < 0.01).
High-dose GIK solution had no adverse effects on the hemodynamics in AMI patients treated with primary PCI. It can improve cardiac function by lowering SVRI. In the 6-month follow-up, it improved cardiac remodeling.
Acute myocardial infarction; glucose–insulin–potassium; reperfusion therapy
Background: Erythropoietin (EPO) is known as a regulating hormone for the production of red blood cells, called erythropoiesis. Some studies have shown that EPO exerts some non-hematopoietic protective effects on ischemia-reperfusion injuries in myocytes. Using echocardiography, we evaluated the effect of EPO infusion on reducing ischemia-reperfusion injuries and improvement of the cardiac function shortly after coronary artery bypass graft surgery (CABG).
Methods: Forty-three patients were recruited in this study and randomly divided into two groups: the EPO group, receiving standard medication and CABG surgery plus EPO (700 IU/kg), and the control group, receiving standard medication and CABG surgery plus normal saline (10 cc) as placebo. The cardiac function was assessed through echocardiography before as well as at 4 and 30 days after CABG.
Results: Echocardiography indicated that the ejection fraction had no differences between the EPO and control groups at 4 days (47.05±6.29 vs. 45.90±4.97; P=0.334) and 30 days after surgery (47.27±28 vs. 46.62±5.7; P=0.69). There were no differences between the EPO and control groups in the wall motion score index at 4 (P=0.83) and 30 days after surgery (P=0.902). In the EPO group, there was a reduction in left ventricular end-systolic and end-diastolic diameters (LVESD and LVEDD, respectively), as compared to the control group.
Conclusion: Our results indicated that perioperative exogenous EPO infusion could not improve the ventricular function and wall motion index in the immediate post-CABG weeks. Nevertheless, a reduction in LVEDD and LVESD at 4 days and 30 days after CABG in the EPO group, by comparison with the control group, suggested that EPO correlated with a reduction in the remodeling of myocytes and reperfusion injuries early after CABG.
Trial Registration Number: 138809102799N1
Erythropoietin; Ischemia; Reperfusion injury; Coronary artery bypass graft
Coronary artery bypass graft (CABG) surgery is one of the most commonly performed surgical procedures worldwide, and it may be accompanied by postoperative neurocognitive impairment. Although this complication has been attributed to the use of cardiopulmonary bypass, it is still a matter of debate whether the switch from on-pump to off-pump technique affects the cognitive function.
The aim of this study was to compare the impact of the on-pump and off-pump techniques on neurocognitive impairment in low-risk CABG surgery groups.
In a descriptive and analytic study, 201 CABG patients with left-ventricular ejection fraction >30%, and without cardiac arrhythmia were enrolled. Before the elective operation, all patients underwent neurological examination and neurocognitive test, Mini-Mental State Examination (MMSE). Two months following the operation, both on- and off-pump, the patients were re-examined by MMSE to detect any neurocognitive impairment.
Out of 154 patients included in the study, 95 (61.6%) and 59 (38.3%) patients were in off-pump and on-pump groups, respectively. Mean age of the patients was 57.17 ± 9.82 years. A 2-month postoperative neurocognitive impairment was detected among 17 patients of on-pump group (28.8%) and in 28 cases of off-pump group (29.4%) (P = 0.54). The mean postoperative MMSE scores were not comparable between groups (25.01 ± 4.49 in off-pump group versus 23.73 ± 4.88 in on-pump group, P = 0.09).
The present study revealed that in low-risk patients undergoing CABG surgery, either the techniques of on-pump or off-pump did not differ regarding the neurocognitive outcome 2 months after the procedure.
neurocognitive impairment; off-pump; on-pump; coronary artery bypass graft surgery
Atrial fibrillation (AF) is the most common complication of cardiac surgery. Although it is managed easily, it can cause critical hemodynamic instabilities for intensive care patients. This observational study investigated the predictive power of P-wave dispersion (PWD) for the incidence of post cardiac surgery AF.
Among patients undergoing isolated coronary artery bypass grafting surgery (CABG), 52 patients were selected randomly. Before the operation, ejection fraction, regional wall motion abnormality, and mitral regurgitation were determined by echocardiography. Angiographic data provided information about stenosed vessels. PWD was measured before and after CABG. The incidence of post-CABG AF was determined by rhythm monitoring.
There were no significant differences in age, sex, stenosed vessels, maximum P-wave duration, the prevalence of hypertension, smoking, mitral regurgitation, and regional wall motion abnormality between post-CABG AF and non-AF groups (P > 0.05). The mean prevalence of diabetes mellitus in post-CABG AF group was more than non-AF group (P = 0.036). The mean ejection fraction in post-CABG AF group was lower than non-AF group (P < 0.005). The mean PWD in AF group vs. non-AF group before CABG was 47.5 vs. 23.7 ms. The mean values of post-surgical PWD in AF and non-AF groups were 48.10 and 24.4 ms, respectively. Before CABG, the mean ejection fraction value and minimum P-wave duration in AF group were lower than non-AF group (P < 0.005). A reverse relation was present between minimum P wave duration and PWD (P < 0.001). There was a negative association between high ejection fraction values and decreased PWD (P = 0.002).
Our data suggested minimum P wave duration, PWD, and low ejection fraction are as good predictors of AF in patients undergoing isolated CABG. The absence of differences in age, sex, smoking, hypertension, mitral regurgitation, and regional wall motion abnormality in our study was in contrast with other reports. On the other hand, increased rate of post-CABG AF in our diabetic patients with lower ejection fraction supports other studies. Overall, minimum P wave duration, PWD, and low ejection fraction can be used for patient risk stratification of AF after CABG.
Atrial Fibrillation; Coronary Artery Bypass Grafting; P-Wave Dispersion; Predictor
Repeat coronary artery bypass grafting (redo‐CABG) in patients with ischaemic cardiomyopathy is associated with high perioperative risk and worse long‐term outcome compared with patients undergoing their first CABG.
To assess whether patients with viable myocardium undergoing redo‐CABG have a better outcome.
18 patients with ischaemic cardiomyopathy underwent redo‐CABG and 34 underwent their first CABG; all had substantial viability (⩾25% of the left ventricle) on dobutamine stress echocardiography (DSE). Left ventricular ejection fraction (LVEF) and heart failure symptoms were assessed before and 9–12 months after revascularisation. Cardiac event rate was assessed during the follow‐up period (median 4 years, 25–75th centile 2.8–4.9 years).
The extent of viable myocardium on DSE was comparable in the two groups (11.3 (3.9) segments in patients who underwent redo‐CABG v 12.8 (3.0) in patients who underwent their first CABG; p = NS). LVEF improved from 32% (9%) to 39% (12%); p = 0.01, in patients who underwent redo‐CABG and from 30% (7%) to 36% (7%); p<0.01, in those who underwent their first CABG; New York Heart Association class improved from 2.5 (1.1) to 1.9 (0.8); p = 0.03, and from 2.7 (1.0) to 1.8 (0.70); p<0.01, respectively. In patients who underwent redo‐CABG, the perioperative mortality was 0, post‐surgery inotropic support was needed in 11% of the patients and mid‐term (4‐year) survival was 100%, with a total event rate of 28%. All these variables were not statistically different from patients who underwent their first CABG (p = 0.50, 0.90, 0.08 and 0.81, respectively).
Patients with ischaemic cardiomyopathy and substantial viability undergoing redo‐CABG benefit from revascularisation in terms of improvement in LVEF, heart failure symptoms, angina and mid‐term prognosis.
Chronic obstructive pulmonary disease (COPD) has traditionally been recognised as a predictor of poorer early outcomes in patients undergoing coronary artery bypass grafting (CABG). The aim of this study was to analyse the impact of different COPD stages, as defined by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) spirometric criteria, on the early surgical outcomes in patients undergoing primary isolated non-emergency CABG
Between January 2008 and April 2012, 1 737 consecutive patients underwent isolated CABG in the Department of Cardiovascular Surgery of Gulhane Military Academy of Medicine; 127 patients with the diagnosis of moderate-risk COPD were operated on. Only 104 patients with available pulmonary function tests and no missing data were included in the study. Two different treatment protocols had been used before and after 2010. Before 2010, no treatment was applied to patients with moderate COPD before the CABG procedure. After 2010, a pre-treatment protocol was initiated. Patients who had undergone surgery between 2008 and 2010 were placed in group 1 (no pre-treatment, n = 51) and patients who had undergone surgery between 2010 and 2012 comprised group 2 (pre-treatment group, n = 53). These two groups were compared according to the postoperative morbidity and mortality rates retrospectively, from medical reports.
The mean ages of the patients in both groups were 62.1 ± 7.6 and 64.5 ± 6.4 years, respectively. Thirty-nine of the patients in group 1 and 38 in group 2 were male. There were similar numbers of risk factors such as diabetes, hypertension, renal disease (two patients in each group), previous stroke and myocardial infarction in both groups. The mean ejection fractions of the patients were 53.3 ± 11.5% and 50.2 ± 10.8%, respectively. Mean EuroSCOREs of the patients were 5.5 ± 2.3 and 5.9 ± 2.5, respectively in the groups. The average numbers of the grafts were 3.1 ± 1.0 and 2.9 ± 0.9. Mean extubation times were 8.52 ± 1.3 hours in group 1 and 6.34 ± 1.0 hours in group 2. The numbers of patients who needed pharmacological inotropic support were 12 in group 1 and five in group 2. Duration of hospital stay of the patients was shorter in group 2. While there were 14 patients with post-operative atrial fibrillation (PAF) in group 1, the number of patients with PAF in group 2 was five. Whereas there were seven patients who had pleural effusions requiring drainage in group 1, there were only two in group 2. There were three mortalities in group 1, and one in group 2. There were no sternal infections and sternal dehiscences in either group.
Pre-treatment in moderate-risk COPD patients improved post-operative outcomes while decreasing adverse events and complications. Therefore for patients undergoing elective CABG, we recommend the use of medical treatment.
cardiac surgery; complication; EuroSCORE; morbidity; risk factors
High-dose glucose-insulin-potassium infusion (GIK) has been suggested to be beneficial in acute myocardial infarction (MI). Recently new large trials have shown no effect of GIK on mortality. To investigate whether metabolic derangement could have negated the potential beneficial effect, we studied the relation between systemic glucose and potassium levels and outcome.
Patients with signs and symptoms of ST-segment-elevation MI and treated with primary percutaneous coronary intervention (PCI) were randomised to no infusion or high-dose GIK, i.e. 80 mmol potassium chloride in 500 ml 20% glucose at a rate of 3 ml/kg/hour and 50 units short-acting insulin in 50 ml 0.9% sodium chloride for 12 hours.
A total of 6991 glucose values and 7198 potassium values were obtained in 476 GIK patients and 464 controls. Mean serum glucose was significantly higher in the GIK group (9.3±4.5 mmol/l vs. 8.4±2.9 mmol/l, p<0.001). Mean potassium level was significantly higher in the GIK group (4.2±0.5 mmol/l vs. 3.9±0.4 mmol/l, p<0.001). Incidence of hyperglycaemia (glucose >11.0 mmol/l) occurred in 70.8% of GIK patients and 33.8% of controls (p<0.001). Hypokalaemia was less common in the GIK group (23.5 vs. 41.2%, p<0.001). Incidence of hyperkalaemia and hypoglycaemia did not differ significantly between the two groups. In multivariate analysis age, previous cardiovascular disease, Killip class >1, unsuccessful PCI and mean glucose after admission were associated with increased one-year mortality.
In ST-segment-elevation MI patients treated with primary PCI, high-dose GIK induced hyperglycaemia and prevented hypokalaemia. Derangement of the glucose metabolism was related to one-year mortality.
glucose; insulin; potassium; infusion; myocardial infarction; hyperglycaemia
Background: During induction of anesthesia and intubation, hemodynamic changes are very important; especially in patients with coronary artery disease (CAD) and left ventricular dysfunction. A little information is available on the hemodynamic effects of a combination of ketamine-thiopental for induction of anesthesia in patients undergoing coronary artery bypass graft (CABG) surgery, with impaired ventricular function.
Aim: The aim of this study was to compare the hemodynamic responses to etomidate versus ketamine-thiopental sodium combination for anesthetic induction in CABG surgery patients with low ejection fraction (EF<45%).
Materials and Methods: In a double blind randomized clinical trial, a total of 100 patients, scheduled for elective CABG surgery were randomly assigned into two groups. These patients received either etomidate or ketamine-thiopental sodium combination at induction of anesthesia. Hemodynamics variable were measured and recorded at baseline, immediately before and after laryngoscopy and intubation, one, two and three minutes after intubation. Also, muscle twitching incidence among patients in two groups was evaluated.
Results: No significant differences between the two groups regarding the changes of hemodynamic variables including systolic and diastolic arterial blood pressure, mean arterial pressure and heart rate, were notice (p>0.05). Muscle twitching was not observed in the two groups.
Conclusion: Hemodynamic stability after administration of ketamine-thiopental sodium combination for induction of anesthesia in patients undergoing CABG surgery, with impaired ventricular function, supports the clinical impression that this combination is safe in CABG surgery patients with low EF.
Anesthesia; CABG; Etomidate; Hemodynamic; Thiopental sodium
Secondary prevention is needed following coronary artery bypass graft (CABG) surgery to reduce the subsequent risk of unstable angina, myocardial infarction and death. However, little research exists on the use of cardiovascular medical therapy in CABG surgery patients. The objective of the present study is to describe the use of cardiovascular medical therapy among patients discharged after CABG surgery.
The use of acetylsalicylic acid, clopidogrel, warfarin, antilipid agents, beta-blockers, calcium channel blockers, nitrates and angiotensin-converting enzyme (ACE) inhibitors was examined among 320 patients enrolled in the Routine versus Selective Exercise Treadmill Testing After Coronary Artery Bypass Graft Surgery (ROSETTA-CABG) Registry. Logistic regression identified the determinants of medication use at 12 months following CABG surgery.
Most patients were male, hyperlipidemic and underwent CABG surgery for relief of angina symptoms. At admission, discharge and at 12 months, acetylsalicylic acid was used in 71%, 92% and 87% of cases, respectively, and some form of antiplatelet agent was used in 74%, 94% and 89% of cases, respectively. The use of antilipid agents remained constant, from 55% at admission to 57% at discharge. However, 24% of patients were not receiving antilipid agents at 12 months. The use of beta-blockers was 57% at admission, 71% at discharge and 64% at 12 months. The use of calcium channel blockers and nitrates decreased modestly from admission to discharge and remained stable at approximately 20% and 22%, respectively, at 12 months. ACE inhibitor use remained stable, from 33% at admission to 38% at 12-months. Hyperlipidemia, hypertension, obesity and pre-CABG surgery left ventricular ejection fraction less than 40% were all found to be important determinants of 12-month medication use. Importantly, the use at discharge was an important determinant of 12-month use of for each medication examined in the present study.
The use of antilipid agents, beta-blockers and ACE inhibitors was found to be too low among post-CABG surgery patients, who are known to benefit from their use, and the use of nitrates was too high. Discharge from hospital provides a unique opportunity for physicians to modify the use of cardiovascular medical therapy among patients undergoing CABG surgery.
Cardiovascular medical therapy; Coronary artery bypass graft; Discharge; Secondary prevention
Atrial fibrillation (AF) is the most common type of arrhythmia following elective off-pump coronary bypass graft (CABG) surgery, occurring on the 2nd or 3rd postoperative day. Postoperative atrial fibrillation and early complications may be the cause of long term morbidity and mortality after hospital discharge. High sensitive C-reactive protein (hsCRP) seems to be most significantly associated with cardiovascular disorders. This study was designed to evaluate whether preoperative hsCRP (≥3 mg/dl) can predict post-elective off-pump CABG, AF, and early complications in patients with severe left ventricle dysfunction (Ejection Fraction (EF)<30%).
This study was conducted on 104 patients with severe left ventriclar dysfunction (EF < 30%), undergoing elective off-pump CABG surgery during April to September 2011 at the Afshar Cardiovascular Center in Yazd, Iran. Patients undergoing emergency surgery and those with unstable angina, creatinine higher than 2.0 mg/dl, malignancy, or immunosuppressive disease were excluded from the study. The subjects were divided into two groups: Group I with preoperative increased hsCRP (>3 mg/dl) (n=51) and group N with preoperative normal hsCRP (<3 mg/dl) (n=53). We evaluated post-CABG variables including incidence, duration, and frequency of AF, early morbidity (bleeding, infection, vomiting, renal and respiratory dysfunctions), ICU or hospital stay and early mortality. Data were then analyzed by Analysis of Variance (ANOVA), Chi-square and Fisher exact test for quantitative and qualitative variables.
The average age of the patients was 62.5 years, 75 cases (72.1%) were male, and 39 (37.5%) were female. Postoperative AF occurred in 19 cases (18.2%); 17 cases (33.3%) had hsCRP≥3 mg/dl and 2 cases (3.8%) had hsCRP≤3 mg/dl (P=0.03). Postoperative midsternotomy infection, respiratory dysfunction, and hospital stay were significantly higher in group I compared with group N (P<0.05). No statistical significant differences were identified between the two groups concerning other postoperative complications (bleeding, vomiting, renal dysfunction and ICU stay) (P>0.05).
Preoperative hsCRP ≥3 mg/dl can predict incidence of postoperative atrial fibrillation and early complications such as midsternotomy infection, respiratory dysfunction, and hospital stay following elective off-pump CABG.
Atrial fibrillation; C-reactive protein; early complications; elective off-pump CABG
We evaluated the short-term and mid-term differences in perfusion and function after off-pump and on-pump coronary artery bypass grafting (CABG) using gated myocardial single photon emission computed tomography.
Materials and Methods
A total of 70 patients with coronary artery disease who underwent CABG were included based on the propensity score matching results from 165 patients. Thirty-five patients underwent off-pump and 35 patients on-pump CABG. Rest 201Tl/dipyridamole stress 99 mTc-methoxyisobutylisonitrile gated single photon emission computed tomographies were performed preoperatively and postoperatively at short-term (103 ± 23 days after surgery) and mid-term follow-up (502 ± 111 days after surgery). Changes in left ventricular ejection fraction, end systolic volume, stress and rest segmental perfusion, and segmental wall thickening were compared between the two groups. The segments with preoperative rest 201Tl uptake under 60% of maximum uptake were included in the segmental analysis.
Left ventricular ejection fraction (P = 0.001) and end systolic volume (P = 0.008) showed significant improvement in both groups. There were no significant short-term and mid-term differences between the two groups in terms of left ventricular ejection fraction (P = 0.309) and end systolic volume (P = 0.938). Likewise, segmental rest (P = 0.178) and stress perfusion (P = 0.071), and systolic wall thickening (P = 0.241) showed significant improvement in both groups with similar time courses.
Off-pump CABG resulted in significant improvements in left ventricular ejection fraction, end systolic volume, and regional myocardial perfusion and function that are comparable to on-pump CABG at short-term and mid-term. Gated myocardial SPECT successfully revealed that off-pump CABG is as good as on-pump CABG from the viewpoint of myocardial perfusion and function.
Gated myocardial single photon emission computed tomography; Off-pump coronary artery bypass grafting; Cardiopulmonary bypass; Coronary artery disease
Experimental studies suggest that metabolic myocardial support by intravenous (IV) glucose, insulin, and potassium (GIK) reduces ischemia-induced arrhythmias, cardiac arrest, mortality, progression from unstable angina pectoris (UAP) to acute myocardial infarction (AMI), and MI size. However, trials of hospital administration of IV GIK to patients with ST elevation MI (STEMI) have generally not shown favorable effects, possibly due to the GIK intervention taking place many hours after ischemic symptom onset. A trial of GIK used in the very first hours of ischemia has been needed, consistent with the timing of benefit seen in experimental studies.
The Immediate Myocardial Metabolic Enhancement During Initial Assessment and Treatment in Emergency care (IMMEDIATE) Trial tested whether, if given very early, GIK could have the impact seen in experimental studies. Accordingly, distinct from prior trials, IMMEDIATE tested the impact of GIK 1) in patients with acute coronary syndromes (ACS), rather than only AMI or STEMI, and 2) administered in prehospital emergency medical service (EMS) settings, rather than later, in hospitals, following emergency department evaluation.
IMMEDIATE was an EMS-based randomized placebo-controlled clinical effectiveness trial conducted in 13 cities across the US which enrolled 911 participants. Eligible were patients age 30 or older for whom a paramedic performed a 12-lead electrocardiogram (ECG)to evaluate chest pain or other symptoms suggestive of ACS for whom electrocardiograph-based ACI-TIPI (acute cardiac ischemia time-insensitive predictive instrument) indicated a > 75% probability of ACS, and/or the TPI (thrombolytic predictive instrument) indicated presence of a STEMI, or if local criteria for STEMI notification of receiving hospitals were met. Prehospital IV GIK or placebo was started immediately.
Pre-specified were the primary endpoint of progression of ACS to infarction, and as major secondary endpoints, the composite of cardiac arrest or in-hospital mortality; 30-day mortality; and the composite of cardiac arrest, 30-day mortality or hospitalization for heart failure (HF). Analyses were planned on an intent-to-treat basis, on a modified intent-to-treat group who were confirmed in emergency departments to have ACS, and for participants presenting with STEMI.
The IMMEDIATE Trial tested whether GIK, when administered as early as possible in the course of ACS by paramedics using ACI-TIPI and TPI decision support, would reduce progression to AMI, mortality, cardiac arrest, and HF. It also tested whether it would provide clinical and pathophysiological information on GIK’s biological mechanisms.
Over the last two decades, many studies have shown better long-term patency rates and survival in patients undergoing coronary artery bypass grafting (CABG) with left internal mammary artery (LIMA) to the left anterior descending artery (LAD). World-wide, LIMA is accepted as the ‘gold standard’ for surgical revascularisation and its usage has been steadily increasing.
PATIENTS AND METHODS
Between April 1997 and September 2001, a total of 4406 consecutive patients underwent coronary artery bypass grafting with revascularisation to the left anterior descending artery.
Of the study group, 4047 (91.8%) patients received LIMA to LAD, leaving 359 (8.2%) who did not. Six sub-groups of patients in whom LIMA usage was significantly less were the elderly (> 70 years of age), females, diabetics, patients having emergency CABG, poor left ventricular (LV) function (ejection fraction [EF] < 30%) and patients with respiratory disease.
Although the current focus in the UK is on mortality rates, we believe that it will not be long before this will also include the incidence of major morbidity after CABG such as stroke, myocardial infarction (MI), renal failure and sternal wound problems. We also believe that we should now consider LIMA usage as a marker of quality control after CABG.
LIMA; CABG; Quality control
Dexmedetomidine, an alpha2-adrenoceptor agonist, has been evaluated as an adjunct to anesthesia and for the delivery of sedation and perioperative hemodynamic stability. It provokes dose-dependent and centrally-mediated sympatholysis. Coronary artery bypass grafting (CABG) with extracorporeal circulation is a stressful procedure increasing sympathetic nervous system activity which could attenuate renal function due the interrelation of sympathetic nervous system, hemodynamics and renal function. We tested the hypothesis that dexmetomidine would improve kidney function in patients undergoing elective CABG during the first two postoperative days.
This was a double-blind, randomized, parallel-group study. Patients with normal renal function and scheduled for elective CABG were randomized to placebo or to infusion of dexmedetomidine to achieve a pseudo steady-state plasma concentration of 0.60 ng/ml. The infusion was started after anesthesia induction and continued until 4 h after surgery. The primary endpoint was creatinine clearance. Other variables included urinary creatinine and output, fractional sodium and potassium excretion, urinary potassium, sodium and glucose, serum and urinary osmolality and plasma catecholamine concentrations. The data were analyzed with repeated-measures ANOVA or Cochran-Mantel-Haenszel test.
Sixty-six of 87 randomized patients were evaluable for analysis. No significant between-group differences were recorded for any indices of renal function except for a mean 74% increase in urinary output with dexmedetomidine in the first 4 h after insertion of a urinary catheter (p < 0.001). Confidence interval examination revealed that the sample size was large enough for the no-difference statement for creatinine clearance.
Use of intravenous dexmedetomidine did not alter renal function in this cohort of relatively low-risk elective CABG patients but was associated with an increase in urinary output.
This study was carried out in 1994-1997 and was thus not registered.
Objectives: To quantify the incidence of major adverse events (AEs) occurring in hospital or within 30 days after surgery in patients undergoing coronary artery bypass graft (CABG) surgery and to identify risk factors for these AEs.
Methods: Systematic review and analysis of studies published in English since 1990. Studies of isolated standard CABG reporting postoperative incidence of myocardial infarction (MI), stroke, gastrointestinal bleeding, renal failure, or death in hospital or within 30 days were eligible for inclusion. Incidence of these events was calculated overall and for selected patient groups defined by all elective CABG versus mixed (some non-elective); mean ejection fraction ⩽ 50% versus > 50%; mean age ⩽ 60 versus > 60 years; primary CABG versus some reoperations; randomised controlled trials versus cohort studies; and single centre versus multicentre studies. Odds ratios of selected AEs were computed according to group risk factors.
Results: 176 studies (205 717 patients) met all inclusion criteria. The average incidence of major AEs occurring in-hospital was death (1.7%); non-fatal MI (2.4%); non-fatal stroke (1.3%); gastrointestinal bleeding (1.5%); and renal failure (0.8%). Thirty day mortality was 2.1%. Meta-analyses show that age > 70, female sex, low ejection fraction, history of stroke, MI, or heart surgery, and presence of diabetes or hypertension are all associated with increased 30 day mortality after CABG.
Conclusion: The incidence of major AEs in patients after CABG varies widely across studies and patient populations, and this heterogeneity must be controlled when using the literature to benchmark safety.
CABG; coronary artery bypass graft surgery; adverse events; mortality; meta-analysis
To investigate the effect of glucose-insulin-potassium (GIK) infusion on erythrocyte antioxidant enzyme activity levels during therapy and post-therapy in patients with dilated cardiomyopathy (DCM).
Forty-one patients with DCM were enrolled in the present study. GIK solution (50 U of insulin in 500 mL of 30% glucose, plus 60 mmol/L KCl), in addition to the standard treatment, was administered by 24 h infusion in 28 patients (GIK group). In the remaining 13 patients (control group), 0.9% NaCl solution was administered. Venous blood samples from all patients were collected at baseline, during therapy (2 h, 8 h, 12 h and 24 h after baseline) and after therapy (48 h after baseline). The activity levels of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSHP) were measured.
In the GIK group, SOD values showed a significant increase at 24 h and 48 h compared with baseline and 2 h values (P<0.05). An increasing trend in CAT activity was observed during and after GIK infusion compared with baseline (0 h) values. However, these differences were not statistically significant (P>0.05). With regard to GSHP activity, no significant change was found in the GIK group during follow-up (P>0.05). In the control group, SOD, CAT and GSHP activity levels measured during and after therapy were found to be similar to those measured at baseline (P>0.05).
Administration of GIK solution, in addition to standard therapy, in patients with DCM may improve the metabolic scope of the disease by reducing myocardial oxidative stress.
Cardiomyopathy; Glucose; Insulin; Oxidative stress; Potassium
The impact of admission serum glucose (SG) level on outcomes in coronary artery bypass grafting (CABG) surgery is unknown. The present study sought to determine whether elevated admission SG level is associated with adverse outcomes following CABG surgery.
Patients undergoing CABG surgery between January 2000 and December 2005 at a single centre were identified (n=2856). Admission SG levels of less than 9.2 mmol/L and 9.2 mmol/L or greater were chosen to divide patients into two groups based on the 75th percentile of SG distribution. A logistic regression model was generated to determine the impact of admission SG level on a composite outcome of any one or more of in-hospital mortality, stroke, perioperative myocardial infarction, sepsis, deep sternal wound infection, renal failure, requirement for postoperative inotropes and prolonged ventilation.
In total, 76.3% of patients had an admission SG level of less than 9.2 mmol/L (group A) and 23.7% had an admission SG level of 9.2 mmol/L or greater (group B). Group B patients were more likely to be female, have diabetes, have preoperative renal failure, have an ejection fraction of less than 40%, experience myocardial infarction within 21 days before surgery, and have triple vessel or left main disease (P<0.05). Univariate analysis revealed no difference in in-hospital mortality between group A (2.2%) and group B (3.2%) (P=0.12); however, the composite outcome was more likely to occur in group B (40.8%) versus group A (27.9%) (P=0.0001). After multivariable adjustment, admission SG level of 9.2 mmol/L or greater remained an independent predictor of composite outcome (OR=1.3, 95% CI 1.0 to 1.7, P=0.02, receiver operating characteristic = 78%).
Admission SG level of 9.2 mmol/L or greater is associated with significant morbidity in patients undergoing CABG surgery.
Admission glucose; Bypass surgery; Diabetes; Outcome
Cardiovascular events are common in patients with diabetes mellitus (DM), which make coronary artery bypass graft (CABG) a highly demanded surgery in this population. Tight control of blood glucose in patients with DM is beneficial in reducing postoperative complications; however, the adequate range has not been determined yet.
This study aimed to investigate the effect of semi-tight (moderate) control of DM on complications and serum glucose levels during and after CABG.
Patients and Methods:
In this prospective clinical trial, 18 and 31 patients with and without DM, respectively, who were referred to Shahid Chamran Hospital, Isfahan, Iran, for elective CABG surgery, were enrolled. For DM group, patients with controlled DM (i.e. glycosylated hemoglobin levels [HgA1C] ≤ 7%) were recruited. Blood glucose level (blood sugar, BS) was measured after anesthesia, during pumping, warming, off pumping, six and 12 hours after Intensive Care Unit (ICU) admission, and at discharging from the hospital. The hemodynamic state of the patients, bleeding, need of blood transfusion, infection, and duration of hospitalization were also monitored and recorded.
None of the BS measurements (FBS, after anesthesia, on-pump, warming, off pump, six and 12 hours after ICU admission, and at discharge) were significantly different between study groups (P > 0.05). Frequency of surgery site bleeding and blood transfusion need were not significantly different between these groups (P > 0.05).
Semi-tight control of DM with insulin infusion during operation did not led to any difference in the type and rate of CABG complications between patients with well-controlled and those without DM; however, BS levels in patients with well-controlled DM could be more easily controlled.
Insulin; Coronary Artery Bypass Graft; Glucose; Surgery
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.
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.
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.
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.
Coronary artery bypass grafting; Diabetes mellitus; Metabolic syndrome; Follow-up; Mortality