Off-pump Patients Research Articles

Comparative hemodynamic effects of vasopressin and norepinephrine after milrinone-induced hypotension in off-pump coronary artery bypass surgical patients

Phosphodiesterase inhibitor is essential to the pharmacologic management of decompensated heart failure because it increases contractility and decreases afterload of right ventricle. It also improves hemodynamics and increases blood flow of the grafted internal mammary arteries and middle cerebral arteries during coronary artery bypass surgery. However, it induces vasodilation and necessitates the use of vasoconstrictors, such as norepinephrine. We hypothesized that vasopressin could recover hypotension induced by milrinone with less effect on pulmonary vascular resistance (PVR) compared to norepinephrine. Fifty patients, undergoing coronary artery bypass graft (CABG) surgery, were assigned randomly in a double-blind manner to receive either vasopressin or norepinephrine. After baseline hemodynamic measurements, a loading dose of milrinone 50 microg/kg was infused slowly for 20 min followed by continuous infusion of 0.5 microg/(kg min). Immediately after the loading dose of milrinone, hemodynamic variables were measured, and vasopressin (VP group) or norepinephrine (NE groups) was infused. After being titrated until the mean arterial pressure was increased by 20%, hemodynamic variables were measured again. Milrinone infusion reduced both systemic vascular resistance (SVR, 1218+/-299 dynes/cm5 vs 838+/-209 dynes/cm5, 1345+/-299 dynes/cm5 vs 1011+/-195 dynes/cm5) and PVR (95+/-34 dynes/cm5 vs 72+/-30 dynes/cm5, 119+/-85 dynes/cm5 vs 87+/-33 dynes/cm5) in the VP and NE groups, respectively. Vasopressin and norepinephrine infusion increased both SVR (838+/-209 dynes/cm5 vs 1100+/-244 dynes/cm5, 1011+/-195 dynes/cm5 vs 1446+/-681 dynes/cm5, respectively) and PVR (72+/-30 dynes/cm5 vs 84+/-18 dynes/cm5, 87+/-33 dynes/cm5 vs 139+/-97 dynes/cm5, respectively). The PRV/SVR ratio was decreased after vasopressin infusion (0.10+/-0.03 vs 0.08+/-0.03), while no changes were found after norepinephrine infusion (0.09+/-0.02 vs 0.09+/-0.02). In the patients undergoing CABG surgery, both norepinephrine and low dose vasopressin were effective in restoring milrinone-induced decrease of SVR. However, only low-dose vasopressin decreased the PVR/SVR ratio that was increased by milrinone. Considering the importance of maintaining systemic perfusion pressure as well as reducing right heart afterload, milrinone-vasopressin may provide better hemodynamics than milrinone-norephinephrine during the management of right heart failure.

Combined Off-Pump Coronary Artery Bypass Grafting Surgery and Ablative Therapy for Atrial Fibrillation: Early and Mid-Term Results

The aim of this study was to evaluate the feasibility of off-pump coronary artery bypass grafting combined with radiofrequency ablation and to compare outcomes between patients with permanent and paroxysmal atrial fibrillation (AF) in terms of restoring sinus rhythm. Thirty-three patients underwent the combined procedure. Mean age was 62.34 +/- 8.20 years; there were 12 female and 21 male patients. Twenty-one patients were diagnosed as permanent AF (group A) and 12 had paroxysmal AF (group B). After the off-pump revascularization patients underwent pulmonary vein ablation. Rhythm was evaluated at discharge and at 6 and 12 months' follow-up. Patients in stable sinus rhythm underwent transthoracic echocardiographic examination to evaluate atrial contractility at 6 and 12 months. There was no operative mortality or major complications. The mean ablation time was 11 +/- 3.4 minutes, including multiple applications. At the end of the procedure 84.5% of patients were free of AF. Sinus rhythm was established in 56% (group A, 52%; group B, 58.3%), 70.5% (group A, 58%; group B, 83.3%), and 71% (group A, 59%; group B, 83.3%) of patients at discharge and at 6 and 12 months, respectively (p = 0.249). Biatrial contractility was detected in 71% of group A and 76% of group B patients at 6 months' follow-up. More patients in group A returned to AF during follow-up when compared with group B (p = 0.016). Female sex (odds ratio, 2.1), chronic lung disease (odds ratio, 1.40), left ventricular disfunction (p = 0.016), and hypertension (odds ratio, 2.57) emerged as risk factors for AF recurrence after ablation. Concomitant off-pump coronary artery bypass grafting and bipolar radiofrequency ablation was safe and effective. These patients should be considered for adjunctive treatment at the time of off-pump revascularization.

A single nucleotide polymorphism of macrophage migration inhibitory factor is related to inflammatory response in coronary bypass surgery using cardiopulmonary bypass

Cardiac surgery causes induction and release of inflammatory mediators that may be regulated by genetic background. Macrophage migration inhibitory factor (MIF) is a proinflammatory mediator that is known to be up-regulated in patients undergoing cardiac operations. Here we analyzed genotype distribution and allele frequency of the MIF-173*G/C single nucleotide polymorphism (SNP) and MIF plasma levels in patients undergoing surgical revascularization with (on-pump, n=45) and without (off-pump, n=34) cardiopulmonary bypass (CPB). Genotyping was performed using a real-time PCR-based system with a hybridization probe system specific for the MIF-173*G/C SNP. In on-pump patients, blood samples were drawn before start of CPB, after termination of CPB and 12h postoperatively. In off-pump patients, blood samples were collected before stabilizer placement, after removal of the stabilizer and 12h postoperatively. MIF levels were measured using ELISA technique. Genotype distribution and allele frequencies were comparable between on-pump and off-pump patients. When comparing patients according to MIF genotype, a significant increase of MIF plasma levels after completed coronary bypass grafting using CPB was found in patients heterozygous for the MIF-173*G/C SNP (p<0.05). Moreover, on-pump patients showed significantly decreased MIF plasma levels after 12h postoperatively (p<0.05). In off-pump patients, MIF plasma levels were not significantly different over the time-course and were independent of the genotype. Patients carrying the C-allele showed significantly increased levels of the proinflammatory cytokine MIF compared to G/G homozygous when revascularization was carried out using CPB. The G/C genotype may be associated with a severe inflammatory reaction and therefore preoperative screening could be beneficial for patients undergoing cardiac surgery using CPB.

Endothelial apoptosis and circulating endothelial cells after bypass grafting with and without cardiopulmonary bypass☆

We compared profiles of the numbers of circulating endothelial cells (CEC) and the apoptosis-inducing capacity of serum samples on human endothelial cells (hEC) in on-pump and off-pump coronary artery bypass grafting (CABG) patients. Blood samples from 30 patients undergoing CABG (randomly assigned to two groups: 15 patients off-pump and 15 on-pump (cardiopulmonary bypass, CPB)) were collected after induction of anesthesia (preoperatively), at weaning from CPB/end of bypass grafting (0 h), and 1, 6, 12, 24, and 48 h afterwards. CEC were isolated with immunomagnetic anti-CD146-coated Dynabeads, and counted in a Nageotte chamber. The apoptosis-inducing activity of serum samples on hEC was examined by a tissue culture assay system. Apoptotic and normal cells were identified using phase contrast/fluorescence microscopy after DNA dye staining. CEC numbers and proportions of apoptotic hEC were significantly elevated during and after surgery in both groups (p<0.01). Compared with the on-pump group, CEC and proportions of apoptotic hEC were significantly lower (p=0.04 and p=0.03, respectively) in patients having CABG performed off-pump. Starting at comparable baseline levels, the mean CEC-number was highest at 6h postoperatively with 81.9 ml(-1) (range, 44-141) for on-pump patients and 63.3 ml(-1) (range, 48-105) for off-pump patients. hEC apoptosis peaked also at T4: 16.5+/-2.8% versus 11.3+/-2.2%. In both groups, CEC numbers and proportions of endothelial apoptosis were still elevated at 48 h after surgery. The number of circulating endothelial cells and apoptotic endothelial cell death are markers of endothelial activation and damage during CABG. This study provides evidence that CABG with the use of CPB in comparison to OPCAB surgery is associated with a significantly more pronounced endothelial response in the immediate postoperative period.

Does Coronary Artery Bypass Graft Surgery Improve Survival Among Patients With End-Stage Renal Disease?

Cardiovascular disease remains the most frequent cause of death for patients with end-stage renal disease. To determine the long-term benefit of surgical revascularization in this high-risk population, we studied our patients with ESRD having coronary artery bypass graft surgery (CABG), comparing the results of off-pump to on-pump revascularization. As a baseline reference group, we used dialysis patients with a diagnosis of coronary artery disease who did not have surgical revascularization or percutaneous coronary interventions. The control group data set was obtained from the United States Renal Data System. From January 1995 through July 2003, 158 patients with end-stage renal disease who were on hemodialysis (excluding those in cardiogenic shock, needing resuscitation, and with emergent or salvage status) underwent CABG. Fifty-nine patients (37.3%) had off-pump revascularization, and 99 patients (62.7%) had bypass grafting utilizing extracorporeal circulation. Preoperative risk factors and operative results were analyzed, and longitudinal survival data obtained. The mean follow-up time was 39.1 months (median, 33.1) for the on-pump patients and 18.3 months (median, 14.7) for off-pump. The total number of anastomoses per off-pump patient was 2.4 +/- 1.0, and with cardiopulmonary bypass (CPB), it was 3.3 +/- 0.9 (p < 0.001). Patients revascularized off-pump had an operative mortality rate of 1.7%, whereas patients grafted using CPB had an operative mortality of 17.2% (p = 0.003). The predicted risk of mortality for the off-pump group (9.3% +/- 7.4%) was not statistically different from the on-pump cohort (9.1% +/- 7.7%, p = not significant). Logistic regression analysis indicates that CPB use was an independent risk factor for early death (p = 0.01, odds ratio = 13.6, 95% confidence interval: 1.7 to 110). Long-term follow-up demonstrated that the patients revascularized using CPB had improved survival compared with the off-pump patients and the control population. Off-pump CABG improves early mortality rate when compared with conventional revascularization. Despite a greater operative mortality, however, long-term survival is improved in the patients revascularized with CPB as compared with the off-pump cohort, suggesting possible advantages from a more complete revascularization in this population.

Predictors of Mid-Term Symptom Recurrence, Adverse Cardiac Events and Mortality in 591 Unselected Off-Pump Coronary Artery Bypass Graft Patients

Off-pump coronary artery bypass (OPCAB) grafting is gaining popularity; however, decreased mid-term graft patency and increased coronary reintervention rates are reported. Five hundred and ninety-one consecutive unselected patients underwent OPCAB grafting from February 2000 to April 2004 (mean follow-up 38.54 +/- 0.54 months). One hundred and thirteen patients had < or =2 grafts, and four hundred and seventy-eight had > or =3 grafts. At least one radial artery graft was present in 398 patients, 328 received postoperative Clopidogrel, and 391 received postoperative statins. History of at least one percutaneous coronary intervention (PCI) was present in 192 patients. Twenty-nine patients developed recurrent angina, nine had myocardial infraction, and twenty underwent coronary reintervention. Five patients died of sudden cardiac death. Overall mortality was 4.9% during follow-up (29 patients). Postoperative Clopidogrel and statins as well as intraoperative shunt use significantly decreased symptom recurrence and adverse cardiac events. Diabetes, chronic obstructive pulmonary disease, prior history of PCI, and utilization of radial artery grafts were positive predictors of symptom recurrence and adverse cardiac events. Utilization of radial artery grafts, history of PCI as well as low preoperative ejection fraction increased mortality. Number of bypass grafts, type of conduit, grafted territory, hyperlipidemia, or prior coronary artery bypass graft surgery (CABG) did not influence symptom recurrence, adverse cardiac events or mortality. OPCAB grafting can be performed with low symptom recurrence, adverse cardiac events, and mortality rates. Modification of intra- and postoperative management strategies may improve outcomes.

Short-term and long-term cognitive function and cerebral perfusion in off-pump and on-pump coronary artery bypass patients

The aim of this study was to evaluate cognitive function, as measured by serial neuropsychological testing, and cerebral perfusion, as measured by brain SPECT scanning in patients with coronary artery diseases (CAD) following off-pump and on-pump coronary artery bypass graft surgery. Besides, the relationship between cerebral blood flow, cognitive functions, surgery parameters, and cardiac function in these patients were estimated. Also, brain-protective effects of instenon were studied. Brain SPECT and comprehensive neuropsychological testing were performed 1 day before, 10-14 days and 6 months after coronary artery bypass graft surgery (CABG). The study involved 65 patients (62 males and 3 females, mean age 55+/-2) who underwent CABG with cardiopulmonary bypass (CPB) (43 pts) and off-pump coronary revascularization (OPCAB) using the Octopus stabilization system (22 pts). In 21 cases employing CPB, for prevention of the impairments of cerebral perfusion and cognitive deficit instenon was administered. CABG with the use of extracorporeal circulation is complicated by short-term and long-term neurocognitive dysfunction (in 96 and 55% cases, correspondingly). Also, in the early period after CABG, in 68% patients, decrease in regional cerebral blood flow (rCBF) was found, and after 6 months brain perfusion was lower than the baseline in 55% cases. Relationship between postoperative rCBF changes and the dynamics of cognitive function was found in early period and after 6 months following CABG. The coronary revascularization on beating heart or preventive administration of instenon in CPB patients helps significantly to diminish the risk of cerebrovascular complication.

Incomplete Revascularization During OPCAB Surgery is Associated With Reduced Mid-Term Event-Free Survival

The aim of this study was to compare early and mid-term outcome in patients undergoing off-pump coronary artery bypass surgery who have had complete revascularizations and incomplete revascularizations (IRs). Patient and operative data were collected prospectively for all patients who had off-pump coronary artery bypass surgery. Patients with multivessel disease were classified as having IR if the number of diseased coronary systems (left anterior descending coronary artery, circumflex and right coronary artery) exceeded the number of distal anastomoses. In-hospital outcomes, survival, and event-free survival were compared between patients with complete revascularization and IR using propensity scores to take account of differences in prognostic factors. There were 1,479 off-pump coronary artery bypass surgery patients between April 1996 and December 2002 (30% of all coronary artery bypass graft patients), and 16.0% (237 patients) had IRs. Patients with IRs tended to be older and were female, had more extensive disease, worse dyspnea, a higher Parsonnet score, poorer ejection fraction, congestive cardiac failure, asthma or chronic obstructive airways disease, and previous cardiac surgery. The adjusted hazard ratio for patient survival with IRs versus complete revascularizations was 1.56 (95% confidence interval, 1.19 to 2.06; p = 0.001). Analyses for multiple time periods confirmed that IRs had a significantly increased risk of death, but also that the risk disappeared after the first 4 to 6 months of follow-up (p < 0.0001). Compared with off-pump coronary artery bypass surgery patients with complete revascularizations, those with IRs have reduced survival, but only in the first 4 to 6 months after surgery. Patients' preoperative condition, rather than IR itself, may explain these findings because IRs should have mid-term as well as early effects.

Renal Dysfunction in High-Risk Patients After On-Pump and Off-Pump Coronary Artery Bypass Surgery: A Propensity Score Analysis

Cardiopulmonary bypass may be a causal factor in the development of renal impairment after cardiac surgery. When acute renal failure requiring dialysis occurs after cardiac surgery, it is associated with high mortality. We attempted to determine whether off-pump coronary artery bypass grafting surgery prevents postoperative renal dysfunction in patients at high risk for renal failure. Retrospective analysis identified 2,869 patients who had preexisting renal dysfunction (preoperative creatinine clearance less than 60 mL/min) and who underwent isolated coronary artery bypass grafting between 1995 and 2003. Patients who required preoperative dialysis were excluded. Propensity scores were computed to match off-pump coronary artery bypass surgery patients 3:1 with those who underwent conventional coronary artery bypass grafting surgery, and the independent predictors of postoperative renal dysfunction were determined. Two thousand seven hundred eleven patients with preexisting renal dysfunction underwent conventional coronary artery bypass grafting surgery, and 158 patients underwent coronary artery bypass grafting surgery without cardiopulmonary bypass (off-pump coronary artery bypass grafting surgery group). The matched groups showed no differences in any of the preoperative or postoperative variables examined. Diabetes (odds ratio, 1.96; p = 0.01), peripheral vascular disease (odds ratio, 2.50; p < 0.001), and reduced preoperative creatinine clearance (odds ratio, 1.02; p = 0.02) were independent risk factors for the development of postoperative renal dysfunction. Off-pump coronary artery bypass grafting surgery was not associated with a decreased risk of renal dysfunction by univariate or multivariable analysis. Off-pump coronary artery bypass grafting surgery did not reduce the risk of postoperative renal dysfunction in this large, unselected, sequential series of patients at high risk for renal failure after coronary artery bypass grafting surgery. Our results suggest that renal function should not be a deciding factor when determining whether or not a patient undergoes off-pump coronary artery bypass grafting surgery.

Off-Pump Coronary Artery Bypass Attenuates Transient Hepatocellular Damage After Myocardial Revascularization

Cardiopulmonary bypass (CPB) affects hepatocellular integrity and occasionally results in liver dysfunction after cardiac surgery. Performing coronary artery bypass graft surgery without CPB may help to reduce the risk of this complication and better preserve perioperative liver function. This study compared perioperative hepatocellular damage in patients undergoing on-pump and off-pump bypass surgery. Prospective study. University hospital. Patients scheduled for elective on-pump (n = 21) and off-pump (n = 17) coronary artery bypass surgery. Liver function was assessed by serum levels of alcohol dehydrogenase (AD) and alpha-glutathione S-transferase (alpha-GST), which serve as more sensitive indices of hepatocellular injury than do conventional transaminases. Arterial blood was sampled at 6 stages: after induction of anesthesia (baseline); at the end of CPB in the on-pump group or on completion of the last distal anastomosis in the off-pump group; at the end of surgery; and 6 hours, 12 hours, and 24 hours after the end of anesthesia. The off-pump patients showed significantly lower increases in serum AD and alpha-GST levels than did the on-pump group. AD and alpha-GST values increased in the on-pump patients after the initiation of CPB and peaked at the end of surgery, with a return to baseline at 12 hours and 24 hours after the end of anesthesia. No clinically relevant liver dysfunction was observed in either group. CPB induced transient subclinical hepatocellular damage, whereas off-pump revascularization attenuated this damage.

Serum S-100 β Protein During Coronary Artery Bypass Graft Surgery With or Without Cardiopulmonary Bypass

Brain damage is a serious complication of cardiac anesthesia. The purpose of this study was to detect brain damage at different surgical stages during coronary artery bypass graft with or without cardiopulmonary bypass. We conducted a prospective, longitudinal study to evaluate serum S-100 beta protein, an early marker of brain injury, in patients electively undergoing off-pump (n = 30) or traditional coronary artery bypass graft (n = 60). Blood was sampled immediately before anesthesia, before and after cardiopulmonary bypass, and on the day after surgery. Serum S-100 beta protein was lowest immediately before induction of anesthesia and significantly increased before and after cardiopulmonary bypass, then declined by the first postoperative day in both groups. Peak values were highest in the traditional group directly after coronary artery bypass graft. On the day after surgery, S-100 beta protein levels were similar between groups, but were higher than baseline within each group. Significant increase in serum S-100 beta protein was also observed even before cardiopulmonary bypass in cardiopulmonary bypass patients, or before manipulation of the heart and aorta in off-pump patients. These reflect the possibility that brain damage may occur before major manipulation (cardiopulmonary bypass or manipulating heart and aorta). Moreover, S-100 beta levels did not return to normal on the day after the operation. This prospective study has shown that serum S-100 beta protein was not only higher than baseline both after cardiopulmonary bypass and on the day after surgery in both groups of patients but it was also significantly increased before cardiopulmonary bypass or manipulation of the heart or aorta. These findings may have implications for anesthesiologic care during the total course of cardiac surgery.

Effects of off-pump versus on-pump coronary artery bypass grafting on function and viability of circulating endothelial progenitor cells

Off-pump coronary artery bypass grafting may result in fewer myocardial and vascular complications than on-pump. Although differences in aortic manipulations likely play a role, the systemic responses of endothelial progenitor cells to both types of operations have not been examined. We sought to examine endothelial progenitor cell characteristics after off-pump versus on-pump coronary artery bypass grafting. Twenty patients undergoing off-pump or on-pump coronary artery bypass grafting were prospectively enrolled and had endothelial progenitor cells isolated and cultured from their peripheral blood before and 24 hours after surgery. Endothelial progenitor cells were identified by fluorescent dual lectin/low-density lipoprotein binding. Their number, phenotype characteristics, proliferation, migratory function, and viability were determined in a blinded fashion. Patient characteristics and numbers of grafts were equivalent. Endothelial progenitor cells had similar phenotypes between groups before and after surgery. Off-pump and on-pump coronary artery bypass grafting resulted in similar increases in endothelial progenitor cell numbers and showed equivalent proliferation activity. However, endothelial progenitor cell migratory function was higher in off-pump patients (25.3 +/- 5.0 vs 5.0 +/- 1.0 cells per high-powered field for off-pump vs on-pump coronary artery bypass grafting, respectively; P = .04). Postoperative endothelial progenitor cell viability adjusted for preoperative baseline was also higher after off-pump than on-pump coronary artery bypass grafting by 72.4% +/- 14.6% (P = .01). Endothelial progenitor cells of on-pump patients were less viable after surgery than before surgery, whereas the reverse was observed in off-pump patients. Both on-pump and off-pump coronary artery bypass grafting elicit mobilization of endothelial progenitor cells into the peripheral blood. On-pump coronary artery bypass grafting, however, impairs the migratory function and viability of these vascular repair cells, which are conversely preserved after off-pump surgery. Further work is necessary to determine whether the function and viability of endothelial progenitor cells correlate with vascular outcomes and whether their therapeutic modulation may one day benefit coronary artery bypass grafting patients.

Aborted Off-Pump Coronary Artery Bypass Patients Have Much Worse Outcomes Than On-Pump or Successful Off-Pump Patients

Off-pump coronary artery bypass graft (CABG) surgery is purported to reduce perioperative mortality and morbidity compared with on-pump coronary bypass graft surgery. However, the outcomes of patients for whom an off-pump strategy must be changed to an on-pump procedure during surgery have not been extensively studied. The Merged Cardiac Registry (Health Data Research, Inc) contains 70 514 isolated CABG performed from January 1998 to March 2004 in 40 facilities. Among them, 62 634 patients begun and completed on-pump bypass (CPB); 7880 patients begun off-pump, of which 7424 (94.2%) completed off-pump coronary artery bypass (OPCAB), whereas 456 (5.8%) were converted to on-pump (CONVERT). CONVERT patients were more severely ill. The observed mortality of CONVERT, CPB, and OPCAB was 9.9%, 3.0%, and 1.6%, respectively, and the observed-to-predicted ratio was 2.77, 1.20, and 0.74, respectively. CONVERT also had more morbidity than either OPCAB or CPB. Finally, a risk model was created to identify patients who might be at risk for conversion from off-pump to on-pump CABG. Patients who are intended for an off-pump strategy and then require conversion to on-pump have significantly higher operative mortality and morbidity than either completed OPCAB or CPB patients. In addition, the operative mortality and morbidity are far in excess of that predicted preoperatively. Based on these results, strong consideration should be given for a planned strategy of CPB for those patients with preoperative hemodynamic instability requiring a salvage CABG operation, left ventricular hypertrophy, or previous CABG.

Clopidogrel and Bleeding After Coronary Artery Bypass Graft Surgery

There is evidence that clopidogrel (with or without aspirin) confers superior outcomes in patients with coronary artery disease. The purpose of this study is to review the effect of preoperative clopidogrel administration on clinical outcome, bleeding complications and resource utilization after coronary artery bypass graft surgery. Patient data were prospectively collected from 919 patients who had isolated coronary surgery during the period 2000 to 2003. Outcome comparisons were studied, firstly between patients who received preoperative clopidogrel with those who did not, and secondly between patients on clopidogrel only, aspirin only, both or neither medications. Twenty-four patients (2.6%) were on clopidogrel only, 598 (65.1%) were on aspirin only, 61 (6.6%) were on both, and 236 (25.7%) were on neither. Clopidogrel (n = 85) versus no clopidogrel (n = 834): there were no significant differences in the off-pump patients. In the on-pump patients, the clopidogrel group had significantly increased bleeding (p = 0.02), blood transfused (p = 0.01), intensive care (p = 0.03), and hospital stays (p = 0.03). There were no significant differences in surgical reexploration, perioperative myocardial infarction, intraoperative balloon pump use, inotropic support or 30-day mortality. Clopidogrel versus aspirin versus both versus neither: patients on both clopidogrel and aspirin had significantly more postoperative bleeding than patients on aspirin alone or on neither medication. The preoperative use of clopidogrel in patients undergoing coronary artery bypass graft surgery showed limited clinical benefits; however, its use significantly increased the risk of bleeding, blood transfusion, and resource utilization.

Is there cognitive decline 1 year after CABG?

It is widely assumed that decline in cognition after coronary artery bypass grafting (CABG) is related to use of the cardiopulmonary bypass pump. Because most studies have not included comparable control groups, it remains unclear whether postoperative cognitive changes are specific to cardiopulmonary bypass, general aspects of surgery, or vascular pathologies of the aging brain. This nonrandomized study included four groups: CABG patients (n = 140); off-pump coronary surgery (n = 72); nonsurgical cardiac controls (NSCC) with diagnosed coronary artery disease but no surgery (n = 99); and heart healthy controls (HHC) with no cardiac risk factors (n = 69). Subjects were evaluated at baseline (preoperatively), 3 months, and 12 months. Eight cognitive domains and a global cognitive score, as well as depressive and subjective symptoms were analyzed. At baseline, patients with coronary artery disease (CABG, off-pump, and NSCC) had lower performance than the HHC group in several cognitive domains. By 3 months, all groups had improved. From 3 to 12 months, there were minimal intrasubject changes for all groups. No consistent differences between the CABG and off-pump patients were observed. Compared with heart healthy controls (HHC), the groups with coronary artery disease had lower cognitive test scores at baseline. There was no evidence that the cognitive test performance of coronary artery bypass grafting (CABG) patients differed from that of control groups with coronary artery disease over a 1-year period. This study emphasizes the need for appropriate control groups for interpreting longitudinal changes in cognitive performance after CABG.

Postoperative Hyperthermia Following Off-Pump Versus On-Pump Coronary Artery Bypass Surgery

Hyperthermia is common in the first 24 hours following coronary artery bypass graft surgery (CABG) with cardiopulmonary bypass (CPB). An inflammatory response to CPB is often implicated in the pathophysiology of this fever. Unlike CABG with CPB, the temperature pattern after off-pump CABG (OPCAB), where CPB is avoided, has not yet been described. The purpose of this study was to describe the postoperative temperature pattern following OPCAB and to compare it with that following on-pump cardiac surgery. Retrospective, observational study. Tertiary care university hospital. Consenting patients undergoing CABG or OPCAB procedures. Observational. Of the CABG patients, 89% had temperature elevations above 38 degrees C, versus 44% of the OPCAB patients (P = 0.04). Peak body temperature was higher in the on-pump patients (CABG 38.5 degrees C +/- 0.4 degrees C versus OPCAB 37.9 degrees C +/- 0.5 degrees C; P = 0.002), as was the area under the curve for temperatures greater than 38 degrees C (CABG 1.6 +/- 1.7 degrees C/hr versus OPCAB 0.4 +/- 1.2 degrees C/hr; P = 0.02). Off-pump CABG surgery patients experience less hyperthermia compared with on-pump CABG patients. The reasons for a lower incidence and severity of hyperthermia after OPCAB surgery are not known, but may be related to a reduced inflammatory response.

Efficacy and Safety of Heparinase I versus Protamine in Patients Undergoing Coronary Artery Bypass Grafting with and without Cardiopulmonary Bypass

Hemodynamic protamine reactions with heparin reversal during cardiac surgery are common and associated with adverse outcomes. As an alternative to protamine, the authors examined heparinase I reversal of heparin after aortocoronary bypass graft surgery. In a randomized, double-blind, double-dummy trial, 167 on- and off-pump aortocoronary bypass graft surgery patients received either heparinase I (maximum 35 microg/kg) or protamine (maximum 650 mg) for heparin reversal, monitored by activated clotting time values and clinical assessment. Hemodynamic parameters were recorded electronically; safety evaluation was to 30 days postoperatively. Noninferiority was predefined as 400 ml or less median 12-h chest tube drainage from intensive care unit arrival for heparinase I patients, after risk adjustment. Hemodynamic instability was defined as systemic hypotension (> or = 30 mmHg decrease) and/or pulmonary hypertension (> or = 40 mmHg with an increase > or = 10 mmHg) within 30 min of heparin reversal initiation. Patient enrollment was terminated on advisement of the Data Safety Monitoring Board. Although heparinase I was noninferior for 12-h chest tube drainage, protamine had a superior safety profile. Overall, heparinase I subjects had longer hospital stays (P = 0.04), were more likely to experience a serious adverse event (P = 0.01), and were less likely to avoid transfusion (P = 0.006). A composite morbidity score was not different (P = 0.24), and similar rates of hemodynamic instability were observed between groups. Findings were consistent in analyses stratified by on- and off-pump surgery. Heparinase I reverses heparin anticoagulation after aortocoronary bypass graft surgery but is not equivalent to protamine because of its inferior safety profile.

This Month in Anesthesiology

This Month in Anesthesiology

On-Pump Versus Off-Pump Surgical Revascularization for Left Main Stem Stenosis: Risk Adjusted Outcomes

Recent publications have shown coronary surgery is safe and effective in patients with critical left main stem stenosis when using off-pump coronary surgery techniques. However, these studies were small and did not adjust for differences in case mix. Between April 1997 and March 2003, 1,197 consecutive patients with critical left main stem stenosis (> 50%) underwent coronary surgery. Two hundred and fifty-nine (21.6%) of these patients had off-pump coronary surgery, while 938 (78.4%) received on-pump coronary surgery. Multivariate logistic regression and Cox proportional hazards analysis were used to assess the effect of off-pump coronary surgery on outcomes, while adjusting for patient characteristics (treatment selection bias). Treatment selection bias was controlled by constructing a propensity score from core patient characteristics. The propensity score was the probability of receiving off-pump coronary surgery and was included along with the comparison variable in the multivariable analyses of outcome. After adjusting for the propensity score, the requirement for inotropic support (22.4% versus 35.3%; p < 0.001) or a prolonged length of stay (5.3% versus 9.3%; p = 0.034) were significantly reduced after receiving off-pump coronary surgery. There was a trend to suggest that off-pump patients had a lower incidence of stroke and chest infection. The adjusted freedom from death in off-pump patients at 2 years was 94.6% compared with 93.6% for on-pump patients (p = 0.54). After risk adjustment, patients with critical left main stem stenosis can undergo off-pump coronary surgery safely, with results comparable with on-pump coronary surgery.

Routine Immediate Extubation After Off-Pump Coronary Artery Bypass Surgery: 514 Consecutive Patients

The purpose of this study was to evaluate the feasibility of routine immediate extubation in patients undergoing off-pump coronary artery bypass surgery. Case series. Private hospital. Five hundred forty-eight consecutive patients undergoing off-pump coronary bypass surgery, representing 5 years of a single anesthesiologist's practice, were evaluated for routine immediate extubation. Thirty-four patients were excluded because they were already intubated, in preoperative cardiogenic shock, or converted to on-pump during the procedure. Patients received general anesthesia or general anesthesia plus thoracic epidural analgesia (25%) and underwent off-pump coronary bypass surgery. All 514 patients who were intended to be immediately extubated were expeditiously extubated in the operating room. The numbers of reintubations, morbidity, and mortality were low. Routine immediate extubation of most off-pump coronary artery bypass patients appears feasible and most probably safe.