Operative mortality after conventional versus coronary revascularization without cardiopulmonary bypass.

OBJECTIVE: Off-pump coronary artery bypass (CABG) is a safe revascularization option with comparable or superior results to the conventional on-pump CABG. However, comparative analysis of the type of surgical approach on the mortality rate is largely unknown. This study sought to investigate whether CABG without cardiopulmonary bypass (off-pump CABG) is associated with lower operative mortality than the conventional on-cardiopulmonary bypass (on-pump) approach. METHODS: From October 1998 to June 2001, off-pump CABG was performed on 2477 patients and on-pump CABG was performed on 3077 patients. The patients undergoing off-pump CABG were randomly matched to on-pump patients via propensity score. Seventy-four percent of the off-pump CABG patients were matched with on-pump patients via propensity scores. A logistic regression model was used to test the difference in the postoperative mortality rate between off-pump CABG and on-pump CABG, controlling the correlation between matched sets. A multiple logistic regression model predicting the risk of mortality adjusted by risk factors of mortality and operation type was computed. RESULTS: Results from the general estimating equation showed that patients who had on-pump CABG were 1.6 (95% confidence intervals (CI)=1.2-2.0, P<0.01) times more likely to die during the first 30 days after surgery than patients who had off-pump CABG. Independent predictors of 30-day mortality identified from the multiple logistic model included on-pump CABG (versus off-pump CABG), advanced age, female gender, carotid artery disease, chronic renal failure, depressed ejection fraction, reoperative CABG, preoperative intraaortic balloon counterpulsation, and recent myocardial infarction. CONCLUSION: Excellent clinical results and a lower operative mortality rate can be achieved with the off-pump CABG technique compared with the conventional on-pump approach.     

Beating heart versus conventional cardiopulmonary bypass: the octopus experience: a randomized comparison of 281 patients undergoing coronary artery bypass surgery with or without cardiopulmonary bypass

In the Octopus Study, 281 coronary artery bypass surgery patients were randomized to surgery with or without cardiopulmonary bypass. The primary objective was to compare cognitive outcome between off-pump and on-pump coronary artery bypass surgery. Before and after surgery, psychologists administered a battery of 10 neuropsychological tests to the patients. Cognitive decline was defined as a decrease in an individual's performance of at least 20% from baseline, in at least 20% of the main variables. According to this definition, cognitive decline was present in 21% in the off-pump group and 29% in the on-pump group, 3 months after the procedure (P = .15). At 12 months, cognitive decline was present in 31% in the off-pump group and 34% in the on-pump group (P = .69). These results indicated that patients undergoing coronary artery bypass surgery without cardiopulmonary bypass had improved cognitive outcomes 3 months after the procedure, but the effects were limited and became negligible at 12 months. The same definition of cognitive decline was also applied to 112 volunteers not undergoing surgery. The definition labeled 28% of the control subjects as suffering from cognitive decline, 3 months after their first assessment. This suggests that the natural fluctuations in performance during repeated neuropsychological testing should be included in the statistical analysis of cognitive decline. Using an alternative definition of cognitive decline that takes these natural fluctuations in performance into account, the proportions of coronary artery bypass surgery patients displaying cognitive decline were substantially lower. This indicates that the incidence of cognitive decline after coronary artery bypass surgery has been overestimated.     

Troponin as a marker of myocardial damage during coronary surgery with and without cardiopulmonary bypass

BACKGROUND: The use of coronary surgery without cardiopulmonary bypass (CBP) has been growing during the last years. In order to compare myocardial damage during coronary surgery with and without CBP, perioperative Troponin T determinations were done. METHODS: Experimental design and setting: prospective, comparative. Cardiovascular surgery department. Patients, interventions and measures: 29 prospective patients who underwent elective coronary surgery were enrolled. Troponin T determinations (ng/ml) were done before surgical procedure, after a 2-hour and after a 12-hour postoperative. Population was divided in two groups: group 1, with CBP (17 patients); group 2, without CBP (12 patients). Variables in relation with population characteristics, myocardial damage and immediate postoperative haemodynamic results were all analyzed. RESULTS: Population characteristics and basal Troponin levels were similar for the two groups. Troponin T average levels at 2-hour postoperative period was 0.729 ng/ml and 0.067 ng/ml for group 1 and 2, respectively (p<0.00002). At 12 hours postoperative period Troponin T was 1.047 ng/ml and 0.183 ng/ml for group land 2 (p<0.0002). Haemodynamic performance was better in the group without CBP. CONCLUSIONS: Troponin T levels were significantly elevated in group 1, showing that surgical procedures without CBP caused less myocardial damage.     

Endotoxemia in coronary artery bypass surgery: a comparison of the off-pump technique and conventional cardiopulmonary bypass

OBJECTIVES: The endotoxemia associated with cardiac surgery is thought to be dominantly influenced by the use of cardiopulmonary bypass. The objectives of this study were to assess the relative contribution of cardiopulmonary bypass on endotoxemia apart from cardiac surgical access and to improve our understanding of the potential benefits of off-pump procedures. METHODS: Thirty patients undergoing coronary artery bypass grafting were followed up prospectively. The patients were divided into 2 equal groups: those who underwent bypass grafting through a sternotomy incision without cardiopulmonary bypass (off-pump group) and those who underwent bypass grafting through a sternotomy incision with cardiopulmonary bypass (CPB group). Blood sampling for endotoxin, lactate, and cardiac index measurements were performed during the following time points: (1) after sternotomy; (2) during the coronary occlusion period in the off-pump group and during aortic clamping in the CPB group; (3) after removal of the coronary occlusion sutures in the off-pump group and after removal of the aortic clamp in the CPB group; (4) 30 minutes after the completion of all distal anastomoses in the off-pump group and immediately after weaning from cardiopulmonary bypass in the CPB group; (5) 1 hour postoperatively; and (6) 12 hours postoperatively. RESULTS: Endotoxin and lactate levels were significantly (P <.05) lower in the off-pump group at all sampling time points, except after sternotomy. CONCLUSIONS: In conclusion, this study has shown that endotoxemia during coronary artery bypass surgery seems mainly to be associated with cardiopulmonary bypass procedure. The relatively lower endotoxin levels observed in off-pump surgery might contribute to improved postoperative recovery.     

Influence of intraoperative fluid volume on cardiopulmonary bypass hematocrit and blood transfusions in coronary artery bypass surgery

A hematocrit (Hct) of less than 25% during cardiopulmonary bypass (CPB) and transfusion of homologous packed red blood cells (PRBC) are each associated with an increased probability of adverse events in cardiac surgery. Although the CPB circuit is a major contributor to hemodilution intravenous (IV) fluid volume may also significantly influence the level of hemodilution. The objective of this study was to explore the influence of asanguinous IV fluid volume on CPB Hct and intraoperative PRBC transfusion. After Institutional Review Board approval, a retrospective chart review of 90 adult patients that had undergone an elective, isolated CABG with CPB was conducted. Regression analysis was used to determine if pre-CPB fluid volume was associated with the lowest CPB Hct and the incidence of an intraoperative PRBC transfusion. In separate multivariate analyses, higher pre-CPB fluid volume was associated with lower minimum CPB Hct (p < .0001), and higher minimum CPB Hct was associated with a decreased probability of PRBC transfusion (p < .0001). Compared to patients that received <1600 mL (n = 55) of pre-CPB fluid, those that received >1600 mL (n = 35) had a decreased mean low CPB Hct (22.4% vs 25.6%, p < .0001), an increased incidence of a CPB Hct <25% (74% vs. 38%, p = .0008) and PRBC transfusion (60% vs. 16%, p < .0001), and increased median PRBC units transfused (2.0 vs 1.0, p = .1446) despite no significant difference in gender, age, patient size, baseline Hct, or CPB prime volume. Patients that received a PRBC transfusion (n = 30) received a significantly higher volume of pre-CPB fluid than nontransfused patients (1800 vs. 1350 mL, p = .0039). These findings suggest that pre-CPB fluid volume can significantly contribute to hemodilutional anemia in cardiac surgery. Optimizing pre-CPB volume may preserve baseline Hct and help limit intraoperative hemodilution.     

Inflammatory response to cardiac surgery: cardiopulmonary bypass versus non-cardiopulmonary bypass surgery

Cardiac surgery has been routinely performed using cardiopulmonary bypass (CPB) ever since its clinical introduction during the 1950s. CPB is, however, associated with an intense inflammatory response because of conversion to laminar flow, blood contact with the artificial bypass surface, cold cardiac ischaemia and hypothermia. The inflammatory reaction can intensify to a systemic inflammatory response syndrome (SIRS) associated with serious morbidity and mortality. Strategies to suppress inflammation had some success but fell short of controlling SIRS. The development of cardiac immobilization techniques allowing complete revascularization has caused a renaissance of coronary artery bypass grafting surgery on the beating heart (OPCAB). This strategy avoids all inflammation caused by CPB and reduces the pro-inflammatory stimulus to sternotomy and the revascularization procedure itself. This review summarises the pathophysiological features of the inflammatory response to CPB, revisits therapeutic anti-inflammatory strategies designed to suppress CPB-induced inflammation and balances the clinical evidence available comparing off-pump and on-pump revascularization.     

Minimised versus conventional cardiopulmonary bypass: outcome of high-risk patients

Background: Coronary artery bypass grafting (CABG) with extracorporeal circulation (ECC) is the gold standard for surgical coronary re-vascularisation. Recently, minimised extracorporeal circulation system (MECC) has been postulated a safe and advantageous alternative for multi-vessel CABG. Method: Between January 2004 and December 2007, 244 high-risk patients (logistic EuroScore (ES) > 10%) underwent CABG in our institution. ECC was used in 139 (57%) and MECC in 105 (43%) patients. Demographic data including age (MECC: 73.4 ± 7.4 years; ECC: 73.3 ± 6.4 years), ES (MECC: 19.2 ± 9.8%; ECC: 21.4 ± 11.9%), left-ventricular ejection fraction (MECC: 45.6 ± 16.1%; ECC: 43.1 ± 15.3%), diabetes mellitus (MECC: 14.3%; ECC: 15.1%) and COPD (MECC: 6.7%; ECC: 7.9%) did not differ between the two groups. Preoperative end-stage renal failure was an exclusion criterion. The clinical course and serological/haematological parameters in the ECC and MECC patients were compared in a retrospective manner. Results: Although the numbers of distal anastomoses did not differ between the two groups (MECC: 3.0 ± 0.9; ECC: 2.9 ± 0.9), ECC time was significantly shorter in the MECC group (MECC: 96 ± 33 min; ECC: 120 ± 50 min, p < 0.01). Creatinine kinase (CK) levels were significantly lower 6 h after surgery in the MECC group (MECC: 681 ± 1505 U l⁻¹; ECC: 1086 ± 1338 U l⁻¹, p < 0.05) and the need of red blood cell transfusion was significantly less after MECC surgery (MECC: 3 [range: 1–6]; ECC: 5 [range: 2–9] p < 0.05). Moreover, 30-day mortality was significantly lower in the MECC group as compared to the ECC group (MECC: 12.4%; ECC: 26.6, p < 0.01). Discussion: MECC is a safe alternative for CABG surgery. A lower 30-day mortality, lower transfusion requirements and less renal and myocardial damage encourage the use of MECC systems, especially in high-risk patients.     

Off pump coronary artery bypass graft surgery versus conventional coronary artery bypass graft surgery: a systematic review of the literature

The recent development of off-pump coronary artery bypass (OPCAB) graft surgical techniques has led to numerous observational and several randomized trials that have investigated outcomes compared with the current gold standard of conventional on-pump coronary bypass (CCAB) graft surgery. This systematic review assesses the current randomized trials that compare OPCAB and CCAB. Numerous end points were investigated, including mortality, stroke, myocardial infarction, atrial fibrillation, blood transfusions, wound infections, and renal failure. In addition to these important outcomes, resource utilization markers were also examined such as hospital length of stay, intensive care unit length of stay, and duration of intubation/ventilation. Finally, when level I evidence from randomized trials was unavailable, level II evidence was examined. This was done for subgroup analysis, where currently no randomized trials exist, looking at OPCAB in high-risk patients. Recommendations were made as to who should receive OPCAB and the potential benefits in this patient population.     

Reoperative coronary surgery with and without cardiopulmonary bypass.

BACKGROUND: Reoperative coronary surgery without cardiopulmonary bypass (CPB) was analyzed to evaluate the technical profile of the patients studied and the benefit from this technique. MATERIAL AND METHODS: From November 21, 1994 to May 20, 1999, 166 patients had reoperative coronary surgery, 112 patients (Group A) with and 54 patients (Group B) without CPB. Median sternotomy was used in all the patients in Group A and in 13 patients in Group B. The remaining had a LAST (37 patients) or a posterolateral thoracotomy (4 patients). RESULTS: Anastomoses per patient were 2.4 +/- 0.8 in Group A and 1.1 +/- 0.4 in Group B (p < 0.001). When a single graft was needed, CPB was not used in 82.8% of the cases. However, when more than one graft was required, CPB was not used in only 5.6% of the cases. When a single territory had to be grafted, CPB was not used in 76.6% of the patients. If two territories were grafted, only 6.8% of the patients were in Group B, whereas no patient who needed a graft in all the three territories was in Group B. Overall mortality was 3.6% cerebrovascular accident (CVA) and acute myocardial infarction (AMI) incidence were 0.6% and 1.8%, respectively, and were similar in both groups. Incidence of early major events (overall 8.4%) was not different between groups. CONCLUSIONS: The primary endpoints (mortality, CVA rate, and AMI) were similar in both groups, but patients in Group B were less complicated. However, patients in the two groups were not the same, as the technical profile was quite different. As our results were similar to those obtained in the first operation, we think that consideration of different surgical possibilities, depending on territory to be grafted, will improve the results of redo coronary surgery, making them similar to those obtained in the first operation.     

Reoperative coronary bypass surgery using normothermic cardiopulmonary bypass: comparison with first-time procedures.

Redo coronary artery bypass grafting (CABG) is characterized by increased patient risk compared with first-time CABG. The reason for higher risk is not completely understood but it is logically related to inadequate myocardial preservation evidenced by the higher incidence of postoperative low-output syndrome. We compared normothermic cardiopulmonary bypass with cold blood maintenance cardioplegia in both first-time and redo CABGs to determine whether this single approach is appropriate for both instances. Five hundred seventeen consecutive CABG patients were retrospectively reviewed. Four hundred fifty-four first-time CABG procedures were compared with 44 redo procedures. All aspects of the operation were identical including myocardial preservation. Retrospective univariant analysis of both groups followed. Three clinical features distinguished first-time versus redo CABG. These were previous percutaneous transluminal coronary angioplasty (first-time 19% vs redo 71%; P < 0.001), preoperative intra-aortic balloon pump (first-time 38% vs redo 71%; P < 0.001), and Parsonnet risk score (first-time 11.7+/-8.2 vs redo 19.2+/-8.8; P < 0.001). Operative mortality for redo CABG was higher than in first-time procedures (3.4% vs 6.4%; P = not significant), although small sample size limited statistical significance. The length of stay was statistically longer in redo patients (8.7+/-10.8 vs 6.0+/-5.1 days; P < 0.01) and is related to a higher Parsonnet score, increased postoperative pneumonia, and failed percutaneous transluminal coronary angioplasty before redo CABG. We conclude that redo CABG is a different operation from first-time procedures and requires enhanced myocardial preservation. Normothermic cardiopulmonary bypass with cold blood maintenance cardioplegia does not appear to achieve this goal.     

Risk factors for hemorrhage-related reexploration and blood transfusion after conventional versus coronary revascularization without cardiopulmonary bypass.

OBJECTIVE: The premise of coronary revascularization without cardiopulmonary bypass (off-pump CABG) proposes that patient morbidity and, potentially, mortality can be reduced without compromising the excellent results of conventional revascularization techniques (on-pump CABG). It is unknown, however, whether coronary artery bypass without cardiopulmonary bypass (off-pump CABG) is associated with similar hemorrhage related reexploration rates and blood transfusion requirements compared to the on-pump approach. METHODS: Between January 1998 and June 2002, 3646 patients underwent off-pump CABG and were compared with a contemporaneous control group of 5197 on-pump CABG patients. A logistic regression model was used to test the difference in the postoperative hemorrhage related reexploration rates and need for postoperative blood transfusions between the groups, controlling for preoperative risk factors. The patients undergoing off-pump CABG were matched to on-pump patients by propensity score. RESULTS: Hemorrhage related reexploration rates were comparable between the 2 groups (odds-ratio [OR]=0.80, 95% confidence intervals [CI]=0.55-1.09, P=0.15). Off-pump CABG was associated with a lower need for single and multiple unit postoperative blood transfusions (OR=0.30, CI=0.24-0.31, P<0.01 and OR=0.4, CI=0.36-0.51, P<0.01, respectively) compared to on-pump CABG patients. CONCLUSIONS: Off-pump CABG eliminates the risks of cardiopulmonary bypass and the systemic inflammatory response it elicits. A substantially lower need for postoperative blood transfusions and a comparable hemorrhage-related reexploration rate suggests that off-pump CABG may avoid the morbidity and mortality associated with excessive postoperative blood loss.     

The effects of conventional extracorporeal circulation versus miniaturized extracorporeal circulation on microcirculation during cardiopulmonary bypass-assisted coronary artery bypass graft surgery

OBJECTIVES To reduce the complications associated with cardiopulmonary bypass (CPB) during cardiac surgery, many modifications have been made to conventional extracorporeal circulation systems. This trend has led to the development of miniaturized extracorporeal circulation systems. Cardiac surgery using conventional extracorporeal circulation systems has been associated with significantly reduced microcirculatory perfusion, but it remains unknown whether this could be prevented by an mECC system. Here, we aimed to test the hypothesis that microcirculatory perfusion decreases with the use of a conventional extracorporeal circulation system and would be preserved with the use of an miniaturized extracorporeal circulation system. METHODS Microcirculatory density and perfusion were assessed using sublingual side stream dark-field imaging in patients undergoing on-pump coronary artery bypass graft (CABG) surgery before, during and after the use of either a conventional extracorporeal circulation system (n?=?10) or a miniaturized extracorporeal circulation system (n?=?10). In addition, plasma neutrophil gelatinase-associated lipocalin and creatinine levels and creatinine clearance were assessed up to 5 days post-surgery to monitor renal function. RESULTS At the end of the CPB, one patient in the miniaturized extracorporeal circulation-treated group and five patients in the conventional extracorporeal circulation-treated group received one bag of packed red blood cells (300?ml). During the CPB, the haematocrit and haemoglobin levels were slightly higher in the miniaturized extracorporeal circulation-treated patients compared with the conventional extracorporeal circulation-treated patients (27.7?±?3.3 vs 24.7?±?2.0%; P?=?0.03; and 6.42?±?0.75 vs 5.41?±?0.64?mmol/l; P?相似文献   

Postoperative atrial tachyarrhythmias in patients undergoing coronary artery bypass graft surgery without cardiopulmonary bypass: a role for intraoperative magnesium supplementation

OBJECTIVE: To determine if intraoperative magnesium supplementation would be associated with a reduction in postoperative atrial tachyarrhythmias (POAT) in patients undergoing coronary artery bypass grafting (CABG) surgery without cardiopulmonary bypass (off-pump CABG surgery). DESIGN: Retrospective study. SETTING: University Medical Center. PARTICIPANTS: Patients who had undergone off-pump CABG surgery (n = 124). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The charts of 124 patients who had undergone off-pump CABG surgery (64 by anterior thoracotomy and 60 by median sternotomy) were retrospectively reviewed. Demographic data and perioperative care were recorded and compared among patients who did and did not experience POAT and among patients who did and did not receive intraoperative magnesium supplementation. Logistic regression analysis was used to assess the association between magnesium supplementation and incidence of POAT, controlling for other covariables. Of the 124 patients, 16 had a prior history of atrial or ventricular arrhythmias and/or were receiving antiarrhythmic medications. Medical records of the remaining 108 patients were reviewed. Twenty-four patients (22%) had POAT. Forty-two patients (39%) received intraoperative magnesium. In patients receiving intraoperative magnesium, the incidence of POAT was significantly decreased (12% v 29%; p = 0.03). In these patients, initial postoperative serum magnesium was significantly higher (2.37 mEq/L v 1.86 mEq/L; p < 0.01). In patients not receiving intraoperative magnesium, 35% had hypomagnesemia (serum magnesium < 1.8 mEq/L) compared with 9% of patients receiving magnesium (p < 0.01). Patients who received intraoperative magnesium and beta-adrenergic blockers had a lower incidence of POAT (5%) than patients who received only one (19%) or neither (33%) (p < 0.05). CONCLUSIONS: Intraoperative magnesium supplementation is associated with a decrease in POAT after off-pump CABG surgery. The combination of a beta-blocker and magnesium may reduce POAT further. It is recommended that intraoperative magnesium supplementation be part of the care of patients undergoing off-pump CABG surgery.     

Prediction of neurological damage after cardiopulmonary bypass surgery

Sixty-five patients who had coronary artery graft surgery were subjected to detailed neuropsychometric assessment before operation and twice again within 7 days after operation. They were monitored continuously with a cerebral function analysing monitor during the operation. The results of the peroperative cerebral monitoring were compared on completion of the study with the neuropsychometric assessments. Seventy-six percent of the patients with a significant neuropsychometric deficit after operation also showed significant peroperative changes on the analysing monitor; the majority occurred immediately after the start of perfusion. Twenty-eight patients failed to demonstrate any evidence of neuropsychometric deficit and six (21%) of these also showed significant peroperative changes. All patients whose traces demonstrated more than one significant change during the peroperative course had a significant neuropsychometric deficit afterwards.     

Prospective randomized trial of normothermic versus hypothermic cardiopulmonary bypass on cognitive function after coronary artery bypass graft surgery.

BACKGROUND: Despite significant advances in cardiopulmonary bypass (CPB) technology, surgical techniques, and anesthetic management, central nervous system complications occur in a large percentage of patients undergoing surgery requiring CPB. Many centers are switching to normothermic CPB because of shorter CPB and operating room times and improved myocardial protection. The authors hypothesized that, compared with normothermia, hypothermic CPB would result in superior neurologic and neurocognitive function after coronary artery bypass graft surgery. METHODS: Three hundred patients undergoing elective coronary artery bypass graft surgery were prospectively enrolled and randomly assigned to either normothermic (35.5-36.5 degrees C) or hypothermic (28-30 degrees C) CPB. A battery of neurocognitive tests was performed preoperatively and at 6 weeks after surgery. Four distinct cognitive domains were identified and standardized using factor analysis and were then compared on a continuous scale. RESULTS: Two hundred twenty-seven patients participated in 6-week follow-up testing. There were no differences in neurologic or neurocognitive outcomes between normothermic and hypothermic groups in multivariable models, adjusting for covariable effects of baseline cognitive function, age, and years of education, as well as interaction of these with temperature treatment. CONCLUSIONS: Hypothermic CPB does not provide additional central nervous system protection in adult cardiac surgical patients who were maintained at either 30 or 35 degrees C during CPB.     

Moderate hypothermic versus normothermic total cardiopulmonary bypass for coronary artery surgery: a retrospective study

A retrospective analysis of 200 patients who underwent coronary artery bypass surgery between 1987 and 1990 was performed to ascertain whether there was any difference in morbidity or mortality with normothermic versus moderate hypothermic perfusion. Total cardiopulmonary bypass was used in all patients. 100 patients (Group H) were perfused using moderate (28-32 degrees C) hypothermia and the remaining 100 patients (Group N) were perfused at normothermia (37 degrees C). Both groups were comparable for age, weight, BSA, and perfusion time (Group H-mean 64 years, 82 Kg., 1.92 m2, 94 minutes; Group N-mean 63 years, 82 Kg., 1.90 m2, 90 minutes). Mean perfusate temperature in Group H was 31 degrees C, while the normothermic group was maintained at 37 degrees C. Both groups were perfused to maintain a venous oxygen saturation between 65-70 percent and arterial pressure between 60-70 mmHg. The cardiac index during bypass for Group H was lower (2.32 +/- .19 L/m2/min) than Group N (2.55 +/- .11 L/m2/min) (p less than 0.001). Mean arterial pressure for Group H was 69 +/- 12.4 mmHg and for Group N was 63 +/- 7.8 mmHg (p less than 0.001). Oxygen transfer for Group N (159 +/- 43 cc/min) was higher than Group H (113 + 31cc/min) (p less than .001). Metabolic acidosis was not observed in either group. Group H required vasodilators while Group N required vasoconstriction to maintain pressures on total bypass between 60-70 mmHg.(ABSTRACT TRUNCATED AT 250 WORDS)