Reduced Blood Loss and Fewer Transfusions

Clinical studies have consistently demonstrated that OPCAB is an effective technique for significantly reducing the blood loss and transfusion requirements often associated with CPB.^{1,3,4,5,12,15,18,21,22,23} In two prospective, randomized studies by Puskas et al. and Ascione et al., the number of OPCAB patients requiring transfusions was reduced by 41% and 56%, respectively, compared to patients who underwent CABG with CPB.^5,21 Related to lower transfusion rates, the amount of blood products required for OPCAB patients has been as much as 30% to 70% less than the amount needed for patients subjected to CPB.^{4,5,15,21,22,23}

The reduction in blood loss and transfusion requirements with OPCAB contributes to reducing the complications associated with blood transfusions, conserving hospital blood supply, and decreasing resource utilization.

1. Systematic off-pump coronary artery revascularization in multivessel disease: experience of three hundred cases

Cartier R, Brann S, Dagenais F, Martineau R, Couturier A.

Department of Cardiac Surgery, Montreal Heart Institute, Quebec, Canada.

OBJECTIVE: We sought to report our recent experience with off-pump coronary artery revascularization in multivessel disease.

METHODS: Between October 1996 and December 1998, 300 off-pump beating heart operations were performed at the Montreal Heart Institute by a single surgeon, representing 94% of all procedures undertaken during this same time frame (97% for 1998). This cohort of patients was compared with 1870 patients operated on with cardiopulmonary bypass from 1995 to 1996.

RESULTS: Mean age, sex distribution, and preoperative risk factors were comparable for the two groups. On average, 2.92 + 0.8 and 2.84 + 0.6 grafts per patient were completed in the beating heart and cardiopulmonary bypass groups, respectively. A majority of patients (70%) had either a triple or quadruple bypass. Coronary anastomoses were achieved with myocardial mechanical stabilization and heart "verticalization." Ischemic time was shorter in the beating heart group (29.8 + 0.9 vs 45 + 0.4 minutes, P<.05). Similarly, the need for transfusion was significantly less in the beating heart group (beating heart operations, 34%; cardiopulmonary bypass, 66%; P<.005). Reduced use of postoperative intra-aortic counterpulsation, as well as a lower rise in creatine kinase MB isoenzyme, was observed in the beating heart group. Operative mortality rates (beating heart operations, 1.3%; cardiopulmonary bypass, 2%) and perioperative myocardial infarction (beating heart operations, 3.6%; cardiopulmonary bypass, 4.2%) were comparable for the two groups.

CONCLUSION: In a majority of patients, off-pump complete coronary artery revascularization is an acceptable alternative to conventional operations, yielding good results given progressive experience, rigorous technique, and adequate coronary artery stabilization.

Journal of Thoracic and Cardiovascular Surgery. 2000 Feb;119(2):221-9.

2. Clinical outcomes and resource usage in 100 consecutive patients after off-pump coronary bypass procedures

Lee JH, Abdelhady K, Capdeville M.

Departments of Surgery and Anesthesiology, University Hospitals Heart Institute, University Hospitals of Cleveland, Cleveland, Ohio.

BACKGROUND: Cardiopulmonary bypass initiates a cascade of inflammatory processes that may result in end-organ damage, leading to the increased prevalence of noncardiac complications.

Therefore, off-pump coronary artery bypass graft (OPCAB) procedures have recently been introduced into clinical practice.

METHODS: This study was a case-controlled study that compared the outcomes and cost of 100 consecutive OPCAB procedures with a control group of 100 contemporary matched conventional coronary artery bypass grafting procedures. All operations were performed by a single surgeon (J.H.L.) and complete revascularization that used off-pump techniques was achieved with the use of innovative exposure techniques to the lateral and posterior wall vessels.

RESULTS: An average of 3.1 grafts per patient were performed in the OPCAB group (range, 1-5). The incidence of conversion to conventional coronary artery bypass grafting was 1%. The overall mortality rate was 2.0%. There were no instances of stroke, renal failure, or sternal infections in the OPCAB group. Thus, the OPCAB group had a shorter length of stay (6.1 + 2.5 versus 7.1 + 3.3 d; P=.003), with a corresponding reduction in variable direct cost per case of 29% (P<.001).

CONCLUSION: Our experience suggests that OPCAB procedures are feasible for most patients who currently require complete revascularization. It is associated with very a low morbidity rate and may represent the ideal revascularization strategy for patients at high risk for undergoing cardiopulmonary bypass.

Surgery. 2000 Oct;128(4):548-55.

3. Multivessel off-pump coronary artery bypass surgery in the elderly

Demers P, Cartier R. Department of Surgery, Montreal Heart Institute, Research Center, Montreal, Quebec, Canada.

OBJECTIVE: Coronary artery bypass grafting in the elderly patient is associated with increased perioperative morbidity and mortality. The avoidance of cardiopulmonary bypass (CPB) in this population is potentially beneficial. We examined our initial experience with off-pump multivessel coronary artery revascularization in patients aged 70 years and older.

METHODS: In a consecutive series of 300 off-pump coronary artery bypass (OPCAB) operations performed by a single surgeon between 1996 and 1999, 98 patients were aged 70 years and older. These patients were compared with a consecutive cohort of 497 patients aged 70 years and older operated on with CPB in the same institution from 1995 to 1996, period where OPCAB surgery was not performed in our institution.

RESULTS: Patients in the beating heart group were older (75 + 4 vs. 74 + 3 years; P=0.001). Gender distribution and other preoperative risk factors were comparable for the two groups. On average, 3.0 + 0.8 and 2.8 + 0.7 grafts per patient were completed in the OPCAB and the CPB groups, respectively (P=0.007). Perioperative mortality rates (OPCAB group, 3.1%; CPB group, 3.6%), perioperative myocardial infarction (OPCAB, 2.0%; CPB, 5.1%) and neurologic events (OPCAB, 1.0%; CPB, 3.2%) were comparable for the two groups. The incidence of postoperative atrial fibrillation was lower in the OPCAB group (42 vs. 54%; P=0.05). The need for allogenic blood transfusions was significantly less in the OPCAB group (53 vs. 82%; P=0.001).

CONCLUSIONS: In patients aged 70 years and older, multivessel OPCAB surgery is associated with lower rates of postoperative atrial fibrillation and reduced transfusion requirements. Multivessel OPCAB in the elderly patient is an acceptable alternative to procedures performed with CPB.

European Journal of Cardio-Thoracic Surgery. 2001 Nov;20(5):908-12.

4. Off-pump multivessel coronary artery surgery in high-risk patients

Meharwal ZS, Mishra YK, Kohli V, Bapna R, Singh S, Trehan N.

Department of Cardiovascular Surgery, Escorts Heart Institute and Research Centre, New Delhi, India.

BACKGROUND: Coronary artery bypass surgery on cardiopulmonary bypass is associated with significant morbidity and mortality, which may be more marked in high-risk patients. We evaluated our results of off-pump coronary artery bypass (OPCAB) in high-risk patients with multivessel coronary artery disease and compared them with results in similar patients who underwent operation on cardiopulmonary bypass.

METHODS: A total of 1,075 patients who underwent OPCAB between October 1996 and June 2001 and who had one or more of the following risk factors were included in the study: poor left ventricular function (EF < 30%), advanced age (> 70 years), left main stenosis, acute myocardial infarction, and redo coronary artery surgery. These patients were compared with 2,312 similar patients who underwent coronary artery bypass grafting on cardiopulmonary bypass during the same period. Preoperative risk factors, intraoperative variables, and postoperative results were analyzed and compared between two groups.

RESULTS: The average number of grafts was 3.0 + 0.4 and 3.2 + 0.3 in the off-pump (OPCAB) and on-pump (CCAB) groups, respectively. Hospital mortality was 3.2% and 4.5% in OPCAB and CCAB groups respectively (p = 0.109). Perioperative myocardial infarction, requirement of inotropic agents, stroke, and renal dysfunction were comparable in two groups. Intubation time (19 + 5 vs 24 + 6 hours, p < 0.001), mean blood loss (362 + 53 vs 580 + 66 mL, p < 0.001), atrial fibrillation (14.3 vs 19.7%, p < 0.001), and prolonged ventilation (4.6 vs 7.6%, p = 0.002) were less in OPCAB group. Intensive care unit stay (20 + 8 hours) and hospital stay (6 + 3 days) were significantly less in the OPCAB group (p < 0.001).

CONCLUSIONS: Off-pump coronary artery surgery can be safely performed in high-risk patients with multivessel coronary artery disease. Operative mortality is comparable to that associated with on-pump surgery, and avoidance of cardiopulmonary bypass is associated with reduced postoperative morbidity in these patients. Annals of Thoracic Surgery. 2002 Oct;74(4):S1353-7.

5. Off-pump coronary artery bypass grafting provides complete revascularization with reduced myocardial injury, transfusion requirements, and length of stay: a prospective randomized comparison of two hundred unselected patients undergoing off-pump versus conventional coronary artery bypass grafting

Puskas JD, Williams WH, Duke PG, Staples JR, Glas KE, Marshall JJ, Leimbach M, Huber

P, Garas S, Sammons BH, McCall SA, Petersen RJ, Bailey DE, Chu H, Mahoney EM, Weintraub WS, Guyton RA.

Division of Cardiothoracic Surgery, Emory University School of Medicine, and the Emory Center for Outcomes Research, Crawford Long Hospital, Atlanta, GA.

OBJECTIVE: Retrospective comparisons of selected patients undergoing off-pump versus conventional on-pump coronary artery bypass grafting have yielded inconsistent results and raised concerns about completeness of revascularization in off-pump coronary artery bypass grafting.

METHODS: Two hundred unselected patients referred for elective primary coronary artery bypass grafting were randomly assigned to undergo off-pump coronary artery bypass grafting with an Octopus tissue stabilizer (Medtronic, Inc, Minneapolis, Minn) or conventional coronary artery bypass grafting with cardiopulmonary bypass by a single surgeon. Revascularization intent determined before random assignment was compared with the revascularization performed. All management followed strict, unbiased, criteria-driven protocols. Patients and nonoperative care providers were blinded to surgical group.

RESULTS: Baseline characteristics were similar. The number of grafts performed per patient (mean + SD 3.39 + 1.04 for off-pump coronary artery bypass grafting, 3.40 + 1.08 for conventional coronary artery bypass grafting) and the index of completeness of revascularization (number of grafts performed/number of grafts intended, 1.00 + 0.18 for off-pump coronary artery bypass grafting, 1.01 + 0.09 for conventional coronary artery bypass grafting) were similar. Likewise, the index of completeness of revascularization was similar between groups for the lateral wall. Combined hospital and 30-day mortalities and stroke rates were similar. Postoperative myocardial serum enzyme measures were significantly lower after off-pump coronary artery bypass grafting, suggesting less myocardial injury. Adjusted postoperative thromboelastogram indices, fibrinogen, international normalized ratio, and platelet levels all showed significantly less coagulopathy after off-pump coronary artery bypass grafting. Patients undergoing off-pump coronary artery bypass grafting received fewer units of blood, were more likely to avoid transfusion altogether, and had a higher hematocrit at discharge. Cardiopulmonary bypass was an independent predictor of transfusion (odds ratio 2.42, P =.0073) by multivariate analysis. More patients undergoing off-pump coronary artery bypass grafting were extubated in the operating room and within 4 hours. Postoperative length of stay (in days) was shorter for off-pump coronary artery bypass grafting (5.1 + 6.5 for off-pump coronary artery bypass grafting, 6.1 + 8.2 for conventional coronary artery bypass grafting, P =.005 by Wilcoxon test). One patient (in the conventional coronary artery bypass grafting group) required angioplasty for graft closure within 30 days.

CONCLUSIONS: When compared with conventional coronary artery bypass grafting with cardiopulmonary bypass, off-pump coronary artery bypass grafting achieved similar completeness

of revascularization, similar in-hospital and 30-day outcomes, shorter length of stay, reduced transfusion requirement, and less myocardial injury. Journal of Thoracic and Cardiovascular Surgery. 2003 Apr;125(4):797-808.

12. Comparison of coronary bypass surgery with and without cardiopulmonary bypass in patients with multivessel disease

Mack MJ, Pfister A, Bachand D, Emery R, Magee MJ, Connolly M, Subramanian V.

Cardiopulmonary Research Science and Technology Institute, Medical City Dallas Hospital, TX, USA.

BACKGROUND: Coronary artery bypass grafting can now be performed with or without cardiopulmonary bypass. Our objective was to determine whether off-pump coronary artery bypass grafting is associated with better early outcomes compared with conventional coronary artery bypass grafting.

METHODS: In 4 centers with off-pump coronary surgery experience, a retrospective analysis of all coronary artery bypass grafting in a 3-year period was performed. Groups were compared to determine selection criteria, mortality, and morbidity, then computer-matched by propensity score to control for selection bias. Multivariate logistic regression identified risk factors predictive of mortality. Specific subgroups most likely to benefit were identified.

RESULTS: In all, 17,401 isolated coronary artery bypass grafts were performed, 7,283 (41.9%) off-pump coronary artery bypass grafts and 10,118 (58.1%) conventional coronary artery bypass with cardiopulmonary bypass. Factors determining selection of patients for off-pump coronary artery bypass grafting included female gender (55.5% vs 44.5%), preexisting renal failure (57.0% vs 43.0%), and reoperations (52.6% vs 47.4%). Operative mortality was 2.8%; off-pump coronary artery bypass grafting versus conventional coronary artery bypass with cardiopulmonary bypass (1.9% vs 3.5%, P <.001) had the same predicted risk. Of the patients with multivessel disease, 11,548 were matched by propensity scoring. Mortality was significantly less in the off-pump coronary artery bypass grafting group (2.8% vs 3.7%, P <.001). By multivariate logistic regression analysis of the matched sample, predictors for mortality were female gender (odds ratio 1.83, confidence interval 1.37-2.44), preexisting renal failure (odds ratio 2.85, confidence interval 2.64- 4.95), history of stroke (odds ratio 1.74, confidence interval 1.08-2.80), previous coronary artery bypass grafting surgery (odds ratio 4.22, confidence interval 2.92-6.09), use of cardiopulmonary bypass (odds ratio 2.08, confidence interval 1.52-2.83), and recent myocardial infarction (odds ratio 2.31, confidence interval 1.68-3.22). Cardiopulmonary bypass was predictive of mortality in reoperations, female patients, and patients aged > 75 years. Off-pump coronary artery bypass grafting was associated with less morbidity, including reductions in blood transfusion (32.6% vs 40.6%, P <.001), stroke (1.4% vs 2.1%, P =.002), renal failure (2.6% vs 5.2%, P <.001), pulmonary complications (4.1% vs 9.5%, P <.001), reoperation (1.7% vs 3.2%, P <.001), atrial fibrillation (21.1% vs 24.99%, P <.001), and gastrointestinal complications (3.6% vs 4.8%, P =.02).

CONCLUSION: In 4 centers with beating-heart operation experience, there is an overall early benefit in off-pump surgery, especially in patients traditionally considered at high risk for coronary artery bypass grafting.

Journal of Thoracic and Cardiovascular Surgery. 2004 Jan;127(1):167-73.

13. Propensity case-matched analysis of off-pump coronary artery bypass grafting in patients with atheromatous aortic disease

Sharony R, Grossi EA, Saunders PC, Galloway AC, Applebaum R, Ribakove GH, Culliford

AT, Kanchuger M, Kronzon I, Colvin SB.

Department of Surgery, New York University School of Medicine, New York, USA.

OBJECTIVE: Atheromatous aortic disease is a risk factor for excessive mortality and stroke in patients undergoing coronary artery bypass grafting. Outcomes of off-pump coronary artery bypass grafting and coronary artery bypass grafting with cardiopulmonary bypass in patients with severe atheromatous aortic disease were compared by propensity case-match methods.

METHODS: Routine intraoperative transesophageal echocardiography identified 985 patients undergoing isolated coronary artery bypass grafting with severe atheromatous disease in the aortic arch or ascending aorta. Off-pump coronary artery bypass grafting was performed in 281 patients (28.5%). Propensity matched-pairs analysis was used to match patients undergoing off-pump coronary artery bypass grafting (n = 245) with patients undergoing coronary artery bypass grafting with cardiopulmonary bypass.

RESULTS: Univariate analysis revealed decreased hospital mortality (16/245, 6.5% vs 28/245, 11.4%; P =.058) and stroke prevalence (4/245, 1.6% vs 14/245, 5.7%; P =.03) in off-pump coronary artery bypass grafting compared with coronary artery bypass grafting with cardiopulmonary bypass. Freedom from any postoperative complication was higher in off-pump coronary artery bypass grafting compared with coronary artery bypass grafting with cardiopulmonary bypass (226/245, 92.2% vs 196/245, 80.0%; P <.001). Multivariable analysis of preoperative risk factors showed that increased hospital mortality was associated with coronary artery bypass grafting with cardiopulmonary bypass (odds ratio = 2.7; P =.01), fewer grafts (P =.05), acute myocardial infarction (odds ratio = 11.5; P <.001), chronic obstructive pulmonary disease (odds ratio = 2.4; P =.03), previous cardiac surgery (odds ratio = 10.2, P =.05), and peripheral vascular disease (odds ratio = 2.1; P =.05). Cardiopulmonary bypass was the only independent risk factor for stroke (odds ratio = 3.6, P =.03). At 36 months' follow-up, comparable survival was observed in the off-pump coronary artery bypass grafting and coronary artery bypass grafting with cardiopulmonary bypass groups (74% vs 72%). Multivariable analysis revealed that renal disease (P <.001), advanced age (P <.001), previous myocardial infarction (P =.03), and lower number of grafts (P =.02) were independent risks for late mortality.

CONCLUSIONS: Patients with severe atherosclerotic aortic disease who undergo off-pump coronary artery bypass grafting have a significantly lower prevalence of hospital mortality, perioperative stroke, and overall complications than matched patients who underwent coronary artery bypass grafting with cardiopulmonary bypass. Routine intraoperative transesophageal echocardiography identifies severe atheromatous aortic disease and directs the choice of surgical technique.

Journal of Thoracic and Cardiovascular Surgery. 2004 Feb;127(2):406-13.

14. Neuromonitoring and neurocognitive outcome in off-pump versus conventional coronary bypass operation

Diegeler A, Hirsch R, Schneider F, Schilling LO, Falk V, Rauch T, Mohr FW.

Department of Cardiac Surgery, Herzzentrum, Universitat Leipzig, Germany.

BACKGROUND: Cardiopulmonary bypass seems to be a major cause for both intraoperative microemboli and cerebral hypoperfusion. This study investigates high intensive transient signals (HITS) in transcranial Doppler ultrasound (TCD) and serum levels of the neurobiochemical marker protein S-100 in patients who underwent coronary artery bypass operation without cardiopulmonary bypass (off-pump CABG) in comparison with the conventional procedure using cardiopulmonary bypass (CPB). The results are related to the neuropsychologic outcome in both surgical groups.

METHODS: Forty patients were randomized in 2 groups (20 conventional and 20 off-pump CABG). Neurocognitive status was assessed preoperatively and postoperatively. Venous serum levels of S-100 protein were measured before and after coronary operation, HITS were measured in the middle cerebral artery during the operation.

RESULTS: The median value of HITS was 394.5 (0 to 2217) in the conventional versus 11 (0 to 50) in the off-pump group, p less than 0.0001. Postoperative S-100 serum levels were: 3.76 (0.13 to 11.2) microg/L (conventional) versus 0.13 (0.04 to 1.01) microg/L (off-pump), p less than 0.0001. Postoperative cognitive testing showed significantly different results with a postoperative impairment of 90% of the patients in the conventional group versus no impairment in the off-pump group.

CONCLUSIONS: Cognitive impairment seems to be strongly associated to CPB and the occurrence of micro-emboli. The off-pump technique appears to be promising in order to eliminate the source of these neuropyschologic impairments following CABG operation.

Annals of Thoracic Surgery. 2000 Apr;69(4):1162-6.

15. Benefits of off-pump bypass on neurologic and clinical morbidity: a prospective randomized trial

Lee JD, Lee SJ, Tsushima WT, Yamauchi H, Lau WT, Popper J, Stein A, Johnson D, Lee D, Petrovitch H, Dang CR.

Department of Surgery, University of Hawaii School of Medicine, Honolulu, Hawaii, USA.

BACKGROUND: Neurologic and clinical morbidity after coronary artery bypass grafting (CABG) can be significant. By avoiding cardiopulmonary bypass, off-pump CABG (OPCAB) may reduce morbidity.

METHODS: Sixty patients (30 CABG and 30 OPCAB) were prospectively randomized. Neurocognitive testing was performed before the operation and 2 weeks and 1 year after the operation. Neurologic testing to detect stroke and (99m)Tc-HMPAO whole-brain single photon emission computed tomography scanning to assess cerebral perfusion were performed before the operation and 3 days afterward. Bilateral middle cerebral artery transcranial Doppler scanning was performed intraoperatively to detect cerebral microemboli. All examiners were blinded to treatment group. Clinical morbidity and costs were compared.

RESULTS: Coronary artery bypass grafting was associated with more cerebral microemboli (575 + 278.5 CABG versus 16.0 + 19.5 OPCAB (median + semiinterquartile range) and significantly reduced cerebral perfusion after the operation to the bilateral occipital, cerebellar, precunei, thalami, and left temporal lobes (p < 0.01). Cerebral perfusion with OPCAB was unchanged. Compared with base line, OPCAB patients performed better on the Rey Auditory Verbal Learning Test (total and recognition scores) at both 2 weeks and at 1 year (p < 0.05), whereas CABG performance was statistically unchanged for all cognitive measures. Patients who underwent CABG had more chest tube drainage (1389 + 1256 mL CABG versus 789 + 586 mL OPCAB, p = 0.02) and required more blood (3.9 + 5.8 U CABG versus 1.2 + 2.2 U OPCAB, p = 0.02), fresh frozen plasma (3.0 + 6.0 U CABG versus 0.5 + 2.2 U OPCAB, p = 0.03), and hours of postoperative use of dopamine (16.3 + 21.2 hours CABG versus 7.3 + 9.7 hours OPCAB, p = 0.04). These differences culminated in higher costs for CABG ($23,053 + $5,320 CABG versus $17,780 + $4,390 OPCAB, p < 0.0001). One stroke occurred with CABG, compared with none with OPCAB (p = NS). One OPCAB patient died because of a pulmonary embolus (p = NS).

CONCLUSIONS: Compared with CABG, OPCAB may reduce neurologic and clinical morbidity as well as cost.

Annals of Thoracic Surgery. 2003 Jul;76(1):18-25; discussion 25-6.

18. Minimally invasive coronary revascularization in women: A safe approach for a high-risk group

Petro KR, Dullum MK, Garcia JM, Pfister AJ, Qazi AG, Boyce SW, Bafi AS, Stamou SC, Corso PJ.

Division of Cardiac Surgery, Department of Surgery, Washington Hospital Center, Medstar Research Institute, Washington, DC 20010, USA.

PURPOSE: Female gender has been shown to be an independent risk factor for mortality in coronary artery bypass graft (CABG) surgery. This report analyzes our early outcomes in 304 women who underwent off-pump coronary artery bypass (OPCAB) surgery at the Washington Hospital Center (Washington, DC) over the last 3 years to determine whether this is a safe approach for coronary bypass in women.

METHODS: A retrospective review of 5528 cases of CABG bypass (on-pump) and 840 cases of OPCAB surgery, from June 1996 to July 1999, was performed. Women accounted for 1527 (27.6%) of the on-pump bypass cases and 304 (36.2%) of the OPCABs. All cases without cardiopulmonary bypass were included, with the majority of the most recent cases being multivessel revascularization. The data for analysis were obtained from our cardiac surgery database and included cases from all surgeons operating at the Washington Hospital Center, although the majority of off-pump cases were performed by only a few of these surgeons.

RESULTS: The two groups were similar with respect to urgent cases, redos, and other comorbities including preoperative congestive heart failure, peripheral vascular disease, transient ischemic attack (TIA), cerebral vascular accident, and previous myocardial infarction. The mean age for the two groups was similar, 67 years for the off-pump group and 66 years for the on-pump group. The absolute number of all off-pump cases increased each year (from 175 to a total of 373), representing a corresponding increase in percentage of all coronary artery bypass procedures (from 9% to 16%). Of the total number of patients undergoing CABG, the percentage of women who underwent OPCAB doubled from 3% to 6% over the time period analyzed. The percentage of single-vessel cases in the off-pump group fell from 88% to 41% as multivessel bypasses became more routine However, the percentage of patients aged > 75 years was greater for the off-pump group (30%) than for the on-pump group (24%). Otherwise, the two groups differed only in diabetic disease (36% off-pump compared with 46% on-pump; p = 0.001) and previous transcatheter therapy (38% off-pump compared with 29% on-pump; p = 0.003). Patients who had OPCABs received fewer postoperative transfusions (40%) than the on-pump group (59%; p < 0.001). The off-pump group also had fewer neurological complications in the form of TIAs or strokes (0.3%) compared with the on-pump group (3.5%; p = 0.001). The mortality rate was 2.3% off -pump versus 4.1% on pump but did not reach statistical significance in this study (p =.12).

CONCLUSION: Myocardial revascularization in women can be performed safely without cardiopulmonary bypass. In our series, the mortality for women receiving off-pump revascularization was lower than the on-pump cohorts despite an older age and higher incidence of diabetes. Although the absolute mortality rates did not reach statistical significance, we were encouraged that the mortality rate for women operated on without CPB dropped to the mortality rate typically seen in men. We also observed a favorable tendency in the off-pump group for a shorter length of stay and a lower incidences of transient ischemic attacks, strokes, post-op bleeding, and blood transfusions. A larger series of patients with multivariate analysis and/or a prospective trial will need to be analyzed in order to confirm our findings.

Heart Surgery Forum. 2000;3(1):41-6

20. Off-pump myocardial revascularization is associated with less incidence of stroke in elderly patients

Athanasiou T, Al-Ruzzeh S, Kumar P, Crossman MC, Amrani M, Pepper JR, Del Stanbridge R, Casula R, Glenville B.

Department of Cardiothoracic Surgery, The National Heart and Lung Institute, Imperial College of Science, Technology and Medicine, St. Mary's Hospital, London, United Kingdom.

Several recent studies have highlighted the potential benefits of using off-pump coronary artery bypass (OPCAB) surgery, particularly in high-risk patients. The aim of this meta-analysis is to assess the effect of OPCAB on the incidence of stroke compared with coronary artery bypass grafting using cardiopulmonary bypass (CPB) in elderly patients. We performed a meta-analysis of all observational studies, published in MEDLINE between 1999 and 2002 and a comparison between the OPCAB and CPB techniques in elderly patients was performed with the outcome of interest being the incidence of stroke. Elderly patients were defined as those aged 70 years or older. Nine studies are included in the meta-analysis. The total number of subjects included was 4,475 patients, of which, 1,253 underwent OPCAB (28%) and 3,222 (72%) underwent CPB. The meta-analysis showed that the OPCAB technique was associated with significantly lower incidence of stroke in elderly patients compared with the CPB technique (1% vs 3%), with an odds ratio of 0.38% to 95% (CI, 0.22 to 0.65). We did not identify any significant heterogeneity and funnel plot asymmetry between the studies included in the meta-analysis. Meta-regression analysis including variables predicting stroke, mortality, and study characteristics did not show any associations affecting the calculated odds ratio of stroke. Despite the fact that this is a meta-analysis of observational studies and adjustment for differences in baseline risk factors between OPCAB and CPB patients was not possible, we believe that this study suggests that the OPCAB technique might be associated with reduced incidence of stroke in the elderly patients undergoing coronary artery bypass grafting.

21. Reduced postoperative blood loss and transfusion requirement after beating-heart coronary operations: a prospective randomized study

Ascione R, Williams S, Lloyd CT, Sundaramoorthi T, Pitsis AA, Angelini GD.

Bristol Heart Institute, Bristol Royal Infirmary, Bristol BS2 8HW, United Kingdom.

OBJECTIVE: Coronary artery bypass grafting on the beating heart through median sternotomy is a relatively new treatment, which allows multiple revascularization without the use of cardiopulmonary bypass. A prospective randomized study was designed to investigate the effect of coronary bypass with or without cardiopulmonary bypass on postoperative blood loss and transfusion requirement.

METHODS: Two hundred patients with coronary artery disease were prospectively randomized to (1) on-pump treatment with conventional cardiopulmonary bypass and cardioplegic arrest and (2) off-pump treatment on the beating heart. Postoperative blood loss identified as total chest tube drainage, transfusion requirement, and related costs together with hematologic indices and clotting profiles were analyzed.

RESULTS: There was no difference between the groups with respect to preoperative and intraoperative patient variables. The mean ratio of postoperative blood loss and 95% confidence interval between groups was 1.64 and 1.39 to 1.94, respectively, suggesting on average a postoperative blood loss 1.6 times higher in the on-pump group compared with the off-pump group. Seventy-seven patients in the off-pump group required no blood transfusion compared with only 48 in the on-pump group (P <.01). Furthermore, less than 5% of patients in the on-pump group required fresh frozen plasma and platelet transfusion compared with 30% and 25%, respectively, in the on-pump group (both P <.05). Mean transfusion cost per patient was higher in the on-pump compared with that in the off-pump group ($184.8 + $35.2 vs $21.47 + $6.9, P <.01).

CONCLUSIONS: Coronary artery bypass grafting on the beating heart is associated with a significant reduction in postoperative blood loss, transfusion requirement, and transfusion-related cost when compared with conventional revascularization with cardiopulmonary bypass and cardioplegic arrest.

Journal of Thoracic and Cardiovascular Surgery. 2001 Apr;121(4):689-96.

22. Blood use in patients undergoing coronary artery bypass surgery: impact of cardiopulmonary bypass pump, hematocrit, gender, age, and body weight

Scott BH, Seifert FC, Glass PS, Grimson R.

Department of Anesthesiology, State University of New York at Stony Brook, 11794-8480, USA.

We investigated the impact of cardiopulmonary bypass pump (CPB), hematocrit, gender, age, and body weight on blood use in patients undergoing coronary artery bypass graft surgery at a major university hospital. Participants were 1235 consecutive patients undergoing primary coronary artery surgery over a period of 2 yr (1999 and 2000); 681 patients underwent coronary surgery with use of CPB, and 554 patients underwent off-pump coronary artery bypass surgery using a median sternotomy incision. There were 881 males and 354 females. Average packed red blood cells (PRBC) transfusion for patients on CPB was 3.4 U compared with 1.6 U for the off-pump group (P < 0.001). Patients on CPB received more frequent PRBC transfusion (72.5%) compared with 45.7% of off-pump patients (P < 0.001). Average PRBC transfusion for males was 2.2 U compared with 3.6 U for females (P < 0.001). A lower percentage of males (52.6%) than females (79.4%) received transfusion (P < 0.001). The impact of CPB, off-pump status, preoperative hematocrit < 35%, gender, age > 65 yr, and weight < 83 kilograms using median values as cut points, on blood use was examined using logistic regression models. Use of CPB, preoperative hematocrit, (<35%) female gender, increasing age, and decreased body weight were significant predictors of transfusion (P < 0.001). Preoperative hematocrit <35% and use of CPB were the strongest predictors of PRBC transfusion.

IMPLICATIONS: We examined the impact of cardiopulmonary bypass, preoperative hematocrit, gender, age, and body weight on blood use in patients undergoing primary coronary artery bypass surgery at a tertiary care institution. We found that all five of these variables are significant predictors of blood use in patients undergoing coronary artery bypass surgery.

Anesthesia & Analgesia. 2003 Oct;97(4):958-63, table of contents.

23. Influence of diabetes on mortality and morbidity: off-pump coronary artery bypass grafting versus coronary artery bypass grafting with cardiopulmonary bypass

Magee MJ, Dewey TM, Acuff T, Edgerton JR, Hebeler JF, Prince SL, Mack MJ.

Cardiopulmonary Research Science and Technology Institute, Dallas, Texas, USA.

BACKGROUND: Myocardial revascularization in diabetic patients is challenging with no established optimum treatment strategy. We reviewed our coronary artery bypass grafting experience to determine the impact of eliminating cardiopulmonary bypass on outcomes in diabetic patients relative to nondiabetic patients.

METHODS: From January 1995 through December 1999, 9,965 patients, of whom 2,891 (29%) had diabetes, underwent isolated coronary artery bypass grafting. Diabetic and nondiabetic patients were further divided into groups on the basis of cardiopulmonary bypass use. Twelve percent (346 of 2,891) of diabetic patients and 12% (829 of 7,074) of nondiabetic patients underwent coronary artery bypass grafting without cardiopulmonary bypass; the remainder had coronary artery bypass grafting with cardiopulmonary bypass. Nineteen preoperative variables were compared among treatment groups by univariate analysis.

RESULTS: Patients undergoing coronary artery bypass grafting without cardiopulmonary bypass compared with those having coronary artery bypass grafting with cardiopulmonary bypass had higher mean predicted mortalities (diabetic, 3.96% versus 3.72%, p = 0.83; nondiabetic, 3.03% versus 2.86%, p = 0.79). In nondiabetic patients, coronary artery bypass grafting without cardiopulmonary bypass provides an actual and risk-adjusted survival advantage over coronary artery bypass grafting with cardiopulmonary bypass (1.81% versus 3.44%, p = 0.0127; risk-adjusted mortality, 1.79% versus 3.61%, p = 0.007). This survival benefit of coronary artery bypass grafting without cardiopulmonary bypass was not seen in diabetic patients (2.89% versus 3.69%, p = 0.452; risk-adjusted mortality, 2.19% versus 2.98%, p = 0.42). Diabetic patients undergoing coronary artery bypass grafting without cardiopulmonary bypass had fewer complications, including decreased blood product use (34.39% versus 58.4%, p = 0.001), and reduced incidence of prolonged ventilation (6.94% versus 12.10%, p = 0.005), atrial fibrillation (15.90% versus 23.26%, p = 0.002), and renal failure requiring dialysis (0.87% versus 2.75%, p = 0.036).

CONCLUSIONS: The survival advantage in nondiabetic patients treated with coronary artery bypass grafting without cardiopulmonary bypass is not apparent in diabetic patients. Coronary artery bypass grafting without cardiopulmonary bypass in diabetic patients is nevertheless associated with a significant reduction in morbidity.

Annals of Thoracic Surgery. 2001 Sep;72(3):776-80; discussion 780-1

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