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
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
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
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.
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
A case of severe hypokalaemia with stupor, skeletal muscle and heart muscle damage is reported. An initial infusion of glucose-insulin and potassium (GIK) produced a temporary clinical improvement with reduction of creatine kinase (CKMB) and elevation of serum K+. On the 4th day of treatment, neuromuscular and cardiovascular deterioration occurred accompanied by a further rise of CKMB. This deterioration was coincident with a serum phosphate of 0.26 mmol/l. The impaired left ventricular (LV) function was measured using echocardiography and detecting the ejection fraction (EF). GIK was stopped and a potassium phosphate infusion commenced. As the phosphate and potassium deficiencies were corrected, the neuromuscular and cardiac abnormalities resolved, CKMB fell to normal and LVEF rose from 40% to 72%. We suggest that additional cardiac damage due to hypophosphataemia may have occurred in this patient, who already had cardiac impairment as a result of profound hypokalaemia. Possible mechanisms are discussed.
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
Patients undergoing coronary artery bypass grafting (CABG) experience a reduction in right ventricular long axis velocities post surgery.
We tested whether the phenomenon of right ventricular (RV) long axis velocity decline depends on the chest being opened fully by mid-line sternotomy, pericardial incision, or on the type of operation performed.
By intraoperative transoesophageal echocardiography (TEE) we recorded serial right ventricular (RV) systolic pulse-wave tissue Doppler velocities during 6 types of elective procedure: 53 CABG surgery, 15 robotic-assisted minimally-invasive CABG (RCABG), 28 aortic valve replacement (AVR), 8 minimally-invasive aortic valve replacement (mini-AVR), 5 mediastinal mass excision, and 1 left atrial myxoma excision. Pre and post operative transthoracic echocardiography (TTE) were also conducted.
Surgery without substantial opening of the pericardium did not significantly reduce RV systolic velocities (RCABG 13 ± 1.8 versus 12.4 ± 2.7 cm/s post; mini-AVR 11.9 ± 2.3 versus 11.1 ± 2.3 cm/s; mediastinal mass excision 13.9 ± 3.1 versus 13.8 ± 4 cm/s). In contrast, within 5 min of pericardial incision those whose surgery involved full opening of the pericardium had large reductions in RV velocities: 54 ± 11% decline with CABG (11.3 ± 1.9 to 5.1 ± 1.6 cm/s, p < 0.0001), 54 ± 5% with AVR (12.6 ± 1.4 to 5.7 ± 0.6 cm/s, p < 0.001) and 49% with left atrial myxoma excision (11.3 to 15.8 cm/s). This persisted immediately after pericardial opening to the end of surgery (61 ± 11%, p < 0.0001; 58 ± 7%, p < 0.0001; 59% respectively).
It is full opening of the pericardium, and not cardiac surgery in general, which causes RV long axis decline following cardiac surgery. The impact is immediate (within 5 min) and persistent.
RV function; Pericardium; Cardiac surgery; Pulsed-wave tissue Doppler echocardiography
To review the currently available data to investigate the clinical benefit of high- and low-dose glucose-insulin-potassium (GIK) in patients with ST-segment elevation acute myocardial infarction (STEMI).
Quantitative analysis of all randomised trials on GIK in patients with STEMI. Electronic and manual searches for randomised controlled trials of GIK in STEMI were performed with regard to inclusion criteria, dose of GIK and additional use of reperfusion therapy, and a meta-analysis with the primary endpoint 30-day mortality was performed.
Data from 16 randomised trials, involving 26,273 patients, were included.
Studies were conducted between 1962 and 2005. Overall, hospital mortality was 9.6% after GIK compared with 10.2% in controls (p=0.088). GIK infusion was not associated with an increase in major adverse events.
This quantitative analysis of GIK in patients with STEMI did not show a beneficial or detrimental effect of GIK infusion on 30-day mortality. GIK infusion should not be part of the standard therapy for patients with STEMI.
glucose-insulin-potassium; GIPS; myocardial infarction; reperfusion
Diabetes negatively affects the outcome of patients undergoing percutaneous transluminal coronary angioplasty (PTCA) or coronary surgery. However, data are lacking with respect to the impact of arterial revascularization in the diabetic population.
Between 1999 and 2003, 100 of 491 diabetics underwent coronary artery bypass graft surgery (CABG) with total arterial grafting (Group 1, G1); these patients were compared with 100 diabetics undergoing conventional CABG with saphenous veins (Group 2, G2), who were matched for Euroscore and other risk factors such as age, obesity, hypertension, left ventricular ejection fraction (LVEF), previous myocardial infarction and chronic obstructive pulmonary disease (COPD).
Both groups had a similar number of diseased coronary vessels (G1=2.6 vs G2= 2.7) and received a similar degree of myocardial revascularization (grafted vessels: G1=2.2 vs G2=2.4). Early outcome was comparable between the groups in terms of ventilatory support (G1=10.8±6 vs G2=10.4±5 hours), intensive care unit (ICU) stay (G1=24±12 vs G2=25±14 hours) and major post-operative complications such as atrial fibrillation (G1=26% vs G2=28%), peri-operative myocardial infarction (G1=1% vs G2=2%)and prolonged ventilatory support (G1=6% vs G2=5%). Hospital mortality was 2% in G1 and 3% in G2. Angiography was performed at a mean follow-up of 34 months in 65.9% and 71.1% of hospital survivors of G1 and G2 respectively: patients of G1 showed a significantly higher patency rate (G1=96% vs G2=83.6%, p=0.02). Additionally, patients of G1 showed a significantly lower incidence of recurrent myocardial ischemia (G1=7 pts. vs G2=18 pts., p=0.03), late myocardial infarction (G1=2 pts. vs G2=10 pts., p=0.03) and need for coronary reintervention (G1=1 pt. vs G2=12 pts, p=0.004).
Total arterial grafting in diabetic patients significantly improved the benefits of coronary surgery providing at mid term a higher graft patency rate with a lower incidence of cardiac related events.
Coronary surgery; Diabetes; Arterial conduits; Composite grafts
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
Coronary artery bypass graft (CABG) surgery is the standard of care for the management of patients with severe three-vessel and left main coronary artery disease (CAD). However, the optimal strategy for management of patients with CAD and severe left ventricular (LV) dysfunction [ejection fraction (EF) ≤35%] is not clear. A meta-analysis of observational studies was performed to determine the operative mortality and long-term (5-year actuarial survival) outcomes among patients with severe LV dysfunction undergoing CABG.
Methods and results
A systematic computerized literature search was performed and observational studies consisting of patients undergoing isolated CABG for CAD and severe LV dysfunction were included. Studies that did not report operative mortality, long-term (≥1 year) survival data, or pre-operative EF and multiple studies from the same group were excluded. In total, 4119 patients from 26 observational clinical studies were included. The estimated mean age was 63.9 years and 82.4% of patients were men. The mean (estimate) pre-operative EF was 24.7% (95% CI 22.5–27.0%). The operative mortality among patients (26 studies, n= 3621) who underwent on-pump CABG was 5.4%, n= 189 (95% CI 4.5–6.4%). The 5-year actuarial survival among patients (13 studies, n= 1980) who underwent on-pump CABG was 73.4%, n= 1483 (95% CI 68.7–77.7%). Patients who underwent off-pump CABG (7 studies, n= 498) tended to have reduced operative mortality of 4.4%, n= 20 (95% CI 2.8–6.4%). The mean (estimate) post-operative EF was 35.19% (95% CI 31.95–38.43%).
The present meta-analysis demonstrates that based on data from available observational clinical studies, CABG can be performed with acceptable operative mortality and 5-year actuarial survival in patients with severe LV dysfunction.
Coronary artery bypass surgery; Revascularization; Coronary artery disease; Meta-analysis; Observational studies
In the present study, patients with severely compromized left ventricular function underwent magnetic resonance imaging (MRI) before and after coronary artery bypass grafting (CABG). Although improvement of global myocardial contractile function has been shown before, we sought to evaluate whether a functional contractile improvement may be determinable on a myocardial segmental basis after CABG surgery.
Thirty-three CABG patients with left ventricular ejection fraction (LVEF) ≤30% prospectively underwent MRI to compare pre- and postoperative functional data. At follow-up, all survivors underwent clinical assessment. In 16 patients (three patients died perioperatively, 13 could were lost to MRI follow-up because of cardiac resynchronization therapy and other reasons) postoperative MRI scanning was performed.
In-hospital mortality was 9%. At 20 ± 2 months after surgery, New York Heart Association class improved from 3.0 ± 0.1 to 2.2 ± 0.2 (p < 0.01). Left ventricular end-diastolic volumes decreased significantly from 229 ± 14 mL to 189 ± 19 mL (p < 0.05). LV end-systolic volumes decreased significantly from 163 ± 13 mL to 126 ± 17 mL (p < 0.05). LVEF improved from 30 ± 2% to 36 ± 3% (p < 0.05). On a segmental basis, 42 out of 875 segments (4.8%) had normal function before surgery, at follow-up, 177 segments (20.4%) had normal regional function (p < 0.05).
Patients who undergo CABG surgery with severely compromized left ventricular function, postoperative MRI shows improved global and segmental cardiac function at mid-term follow-up. At the same time there is considerable clinical improvement.
coronary artery bypass grafting; magnetic resonance imaging; left ventricular function; outcomes
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
Surgical ventricular reconstruction is a specific procedure designed to reduce left ventricular volume in patients with heart failure caused by coronary artery disease. We conducted a trial to address the question of whether surgical ventricular reconstruction added to coronary-artery bypass grafting (CABG) would decrease the rate of death or hospitalization for cardiac causes, as compared with CABG alone.
Between September 2002 and January 2006, a total of 1000 patients with an ejection fraction of 35% or less, coronary artery disease that was amenable to CABG, and dominant anterior left ventricular dysfunction that was amenable to surgical ventricular reconstruction were randomly assigned to undergo either CABG alone (499 patients) or CABG with surgical ventricular reconstruction (501 patients). The primary outcome was a composite of death from any cause and hospitalization for cardiac causes. The median follow-up was 48 months.
Surgical ventricular reconstruction reduced the end-systolic volume index by 19%, as compared with a reduction of 6% with CABG alone. Cardiac symptoms and exercise tolerance improved from baseline to a similar degree in the two study groups. However, no significant difference was observed in the primary outcome, which occurred in 292 patients (59%) who were assigned to undergo CABG alone and in 289 patients (58%) who were assigned to undergo CABG with surgical ventricular reconstruction (hazard ratio for the combined approach, 0.99; 95% confidence interval, 0.84 to 1.17; P = 0.90).
Adding surgical ventricular reconstruction to CABG reduced the left ventricular volume, as compared with CABG alone. However, this anatomical change was not associated with a greater improvement in symptoms or exercise tolerance or with a reduction in the rate of death or hospitalization for cardiac causes. (ClinicalTrials.gov number, NCT00023595.)
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
Cardiopulmonary bypass is known to cause alterations in insulin secretion and resistance, resulting in profound hyperglycemia. Aggressive treatment of the resulting hyperglycemia intra-operatively could result in a severe degree of post-operative hypoglycemia. We undertook this prospective non-randomized clinical study to compare the alterations in glucose homeostasis in diabetic (group A, n=50) and non-diabetic (Group B, n=50) patients undergoing moderate hypothermic (30°C) cardiopulmonary bypass for coronary artery bypass grafting (CABG). All patients had a fasting blood sugar level done on the morning of surgery. Blood sugars were monitored intra-operatively and post-operatively at fixed time intervals. Intra-operative hyperglycemia was treated aggressively by a continuous, infusion of injecting plain insulin. Both the groups experienced similar significant increase in blood glucose levels during bypass (‘p’=0.00003). However, the mean blood glucose level upon arrival in the intensive care unit was significantly decreased in group B compared to group A (p=0.0002). 60% of group B and 10% of group A patients required treatment for post-operative hypoglycemia (blood glucose level <60mg/dl). This clinical study reveals that attempting to maintain normoglycemia in this setting with Insulin may initiate post-operative hypoglycemia.
Insulin; blood glucose levels; cardiopulmonary bypass
OBJECTIVE--To compare the cardioprotective efficacy of cold crystalloid cardioplegia and intermittent ischaemic arrest in patients undergoing elective coronary artery surgery. DESIGN--Prospective randomised trial. SETTING--London teaching hospital. SUBJECTS--20 patients with at least moderately good left ventricular function undergoing elective coronary artery surgery by one experienced surgeon and needing at least two bypass grafts. INTERVENTIONS--Patients were randomised to cold crystalloid cardioplegia or intermittent ischaemic arrest. MAIN OUTCOME MEASURES--The primary determinant of the efficacy of myocardial protection was serial measurement (before and at 1, 6, 24, and 72 hours after the end of cardiopulmonary bypass) of cardiac troponin T (cTnT), a highly sensitive and specific marker of myocardial damage. RESULTS--There was no significant difference in age, ejection fraction, number of grafts, bypass times, or cross clamp times between the two groups. One patient in the cardioplegia group had a perioperative infarct and was excluded from further study. In both groups there was a significant increase in cTnT, with peak concentrations being reached 6 hours after the end of cardiopulmonary bypass and remaining significantly high at 72 hours. At 6 hours the median (75% interquartile range) concentrations of cTnT were similar in both groups (1.8 (1.0-3.6) micrograms/l for cardioplegia v 1.9 (1.0-3.5) micrograms/l for intermittent ischaemic arrest). CONCLUSION--This trial shows that intermittent ischaemic arrest, even without systemic cooling or venting of the left ventricle, provides a similar level of myocardial protection to cardioplegia in patients with moderate left ventricular function and short ischaemic times.
Non-Insulin Dependent Diabetes Mellitus (NIDDM) is a common disease entity in patients with Coronary Artery Disease (CAD). Diabetic Ketoacidosis (DKA) is not only one of the major complications of Diabetes Mellitus but also a significant challenging clinical entity for the patients undergoing any elective or emergency surgery. Coronary Artery Bypass Grafting (CABG) being done in a patient with DKA has not been reported. We are presenting a rare case with DKA in whom CABG was carried out in a hospital devoted exclusively to cardiac cases. Insulin was given in very large doses as a part of therapeutic regimen and the outcome was favorable. This report concludes that if a patient undergoing urgent cardiac surgery incidentally develops DKA after induction of anesthesia, then the operation can be carried out provided DKA is managed aggressively. Also, major stress factors like cardio pulmonary bypass (CPB) and hypothermia should be avoided and care should be taken to avoid cerebral edema.
Coronary Artery Bypass Grafting; Diabetes Mellitus; Diabetic Ketoacidosis; Insulin
The aim of this retrospective study was to evaluate the clinical outcome of three different minimally invasive surgical techniques for left anterior descending (LAD) coronary artery bypass grafting (CABG): Port-Access surgery (PA-CABG), minimally invasive direct CABG (MIDCAB) and off-pump totally endoscopic CABG (TECAB).
Over a decade, 160 eligible patients for elective LAD bypass were referred to one of the three techniques: 48 PA-CABG, 53 MIDCAB and 59 TECAB. In MIDCAB group, Euroscore was higher and target vessel quality was worse. In TECAB group, early patency was systematically evaluated using coronary CT scan. During follow-up (mean 2.7 ± 0.1 years, cumulated 438 years) symptom-based angiography was performed.
There was no conversion from off-pump to on-pump procedure or to sternotomy approach. In TECAB group, there was one hospital cardiac death (1.7%), reoperation for bleeding was higher (8.5% vs 3.7% in MIDCAB and 2% in PA-CABG) and 3-month LAD reintervention was significantly higher (10% vs 1.8% in MIDCAB and 0% in PA-CABG). There was no difference between MIDCAB and PA-CABG groups. During follow-up, symptom-based angiography (n = 12) demonstrated a good patency of LAD bypass in all groups and 4 patients underwent a no LAD reintervention. At 3 years, there was no difference in survival; 3-year angina-free survival and reintervention-free survival were significantly lower in TECAB group (TECAB, 85 ± 12%, 88 ± 8%; MIDCAB, 100%, 98 ± 5%; PA-CABG, 94 ± 8%, 100%; respectively).
Our study confirmed that minimally invasive LAD grafting was safe and effective. TECAB is associated with a higher rate of early bypass failure and reintervention. MIDCAB is still the most reliable surgical technique for isolated LAD grafting and the least cost effective.
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
In the current stent era, aggressive repeated percutaneous coronary intervention (PCI) has become more common. The aim of this study was to investigate the impact of previous repeated PCI on the subsequent coronary artery bypass grafting (CABG).
Between January 1990 and January 2008, a total of 894 patients underwent first-time isolated elective CABG. Among the 894 patients, 515 patients had had no PCI (group A), 179 patients had had single PCI (Group B), and 200 patients had had multiple PCI (2-15 times, mean 3.6 ± 2.3 times) (group C) before CABG. These groups were compared in terms of early and late clinical results.
Preoperative left ventricular ejection fraction was significantly higher in group A (group A;58 ± 13%, group B;54 ± 12%, and group C;54 ± 12%). Number of bypass grafts was significantly smaller in group C (A:3.3 ± 1.0, B 3.4 ± 0.9, C 3.1 ± 1.0). Although there was no statistically significant difference among the groups, in-hospital mortality in group C was higher than that in group A and B (A:1.6%, B:1.1%, C:3.5%, p = 0.16). Survival analysis by Kaplan-Meier method (mean follow-up: 58 ± 43 methods) revealed that freedom from all-cause death and cardiac death was significantly lower in group C in comparison with group A. Freedom from cardiac event was significantly higher in group C than that in group A. Multivariate analysis identified a number of previous PCI as an independent risk factor for cardiac death.
Repeated PCI increased risk for long-term prognosis of subsequent CABG.
coronary artery bypass grafting; coronary stent; prognosis
We sought to evaluate retrospectively the outcomes of patients at our hospital who had moderate ischemic mitral regurgitation and who underwent coronary artery bypass grafting (CABG) alone or with concomitant mitral valve repair (CABG+MVr).
A total of 83 patients had a reduced left ventricular ejection fraction and moderate mitral regurgitation: 28 patients underwent CABG+MVr, and 55 underwent CABG alone. Changes in mitral regurgitation, functional class, and left ventricular ejection fraction were compared in both groups.
The mean follow-up was 5.1 ± 3.6 years (range, 0.1–15.1 yr). Reduction of 2 mitral-regurgitation grades was found in 85% of CABG+MVr patients versus 14% of CABG-only patients (P < 0.0001) at 1 year, and in 56% versus 14% at 5 years, respectively (P = 0.1), as well as improvements in left ventricular ejection fraction and functional class. One- and 5-year survival rates were similar in the CABG+MVr and CABG-only groups: 96% ± 3% versus 96% ± 4%, and 87% ± 5% versus 81% ± 8%, respectively (P = NS). Propensity analysis showed similar results. Recurrent (3+ or 4+) mitral regurgitation was found in 22% and 47% at late follow-up, respectively.
In patients with moderate ischemic mitral regurgitation, either surgical approach led to an improvement in functional class. Early and intermediate-term mortality rates were low with either CABG or CABG+MVr. However, an increased rate of late recurrent mitral regurgitation in the CABG+MVr group was observed.
Cardiac surgical procedures; coronary artery bypass; coronary disease/complications/surgery; disease-free survival/trends; matched-pair analysis; mitral valve insufficiency/physiopathology/surgery; multivariate analysis; myocardial ischemia/complications/surgery; myocardial revascularization/methods/statistics & numerical data; postoperative period; recurrence; risk assessment
The objective of the present study was to compare postoperative cardiac troponin I (cTnI) release and the thresholds of cTnI that predict adverse outcome after elective coronary artery bypass graft (CABG), after valve surgery, and after combined cardiac surgery.
Six hundred and seventy-five adult patients undergoing conventional cardiac surgery with cardiopulmonary bypass were retrospectively analyzed. Patients in the CABG (n = 225) and valve surgery groups (n = 225) were selected after matching (age, sex) with those in the combined surgery group (n = 225). cTnI was measured preoperatively and 24 hours after the end of surgery. The main endpoint was a severe postoperative cardiac event (sustained ventricular arrhythmias requiring treatment, need for inotropic support or intraaortic balloon pump for at least 24 hours, postoperative myocardial infarction) and/or death. Data are presented as the median and the odds ratio (95% confidence interval).
Postoperative cTnI levels were significantly different among the three groups (combined surgery, 11.0 (9.5–13.1) ng/ml versus CABG, 5.2 (4.7–5.7) ng/ml and valve surgery, 7.8 (7.6–8.0) ng/ml; P < 0.05). The thresholds of cTnI predicting severe cardiac event and/or death were also significantly different among the three groups (combined surgery, 11.8 (11.5–14.8) ng/ml versus CABG, 7.8 (6.7–8.8) ng/ml and valve surgery, 9.3 (8.0–14.0) ng/ml; P < 0.05). An elevated cTnI above the threshold in each group was significantly associated with a severe cardiac event and/or death (odds ratio, 4.33 (2.82–6.64)).
The magnitude of postoperative cTnI release is related to the type of cardiac surgical procedure. Different thresholds of cTnI must be considered according to the procedure type to predict early an adverse postoperative outcome.
Surgical ventricular reconstruction (SVR) is used in conjunction with coronary artery bypass graft surgery (CABG) to improve left ventricular function and clinical outcomes in selected patients with ischemic heart failure. The impact of SVR on quality of life and medical costs is unknown.
We compared CABG plus SVR with CABG alone in 1000 patients with ischemic heart failure, a large anterior wall scar, and a left ventricular ejection fraction ≤ 0.35. In 991 (99% of eligible), we collected a battery of quality of life (QOL) instruments. The principal, pre-specified QOL measure was the Kansas City Cardiomyopathy Questionnaire (KCCQ), which evaluates the effects of heart failure symptoms on QOL using a scale from 0 to 100 with higher scores indicating better QOL. Structured QOL interviews were conducted at baseline, 4, 12, 24, and 36 months post randomization and were ≥ 92% complete. Cost data were collected on 196 of 200 (98%) patients enrolled in the United States.
Heart-failure-related QOL outcomes did not differ between the two treatment strategies out to 3 years (median KCCQ scores for CABG alone and CABG plus SVR, respectively: baseline 53 versus 54, p=0.53; 3 years 85 versus 84, p=0.89). There were no treatment-related differences in other QOL measures. In the US patients, total index hospitalization costs averaged over $14,500 higher for CABG plus SVR (P=0.004) due primarily to 4.2 extra post-operative high-intensity care days in the hospital.
Addition of SVR to CABG in patients with ischemic heart failure did not improve quality of life but significantly increased health care costs.
Heart failure; coronary artery bypass graft surgery; quality of life; cost; surgical ventricular reconstruction