Immediate coronary artery bypass surgery after platelet inhibition with eptifibatide: results from PURSUIT. Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrelin Therapy

BACKGROUND: The platelet GP IIb/IIIa inhibitor eptifibatide improves outcomes in patients with acute coronary syndromes. Patients requiring emergent coronary artery bypass grafting, however, may be at increased risk for bleeding if exposed to eptifibatide. Data from the PURSUIT trial were reviewed to assess this risk in patients undergoing coronary surgery immediately after exposure to eptifibatide. METHODS: In PURSUIT, 10,948 patients who presented with non-ST segment elevation acute coronary syndromes were prospectively randomized to receive eptifibatide (180 microg/kg bolus plus 2 microg/kg/min infusion) or placebo. A total of 78 patients underwent immediate coronary artery bypass surgery within 2 hours of cessation of study drug (placebo, n = 46; eptifibatide, n = 32). Clinical outcome, bleeding, and transfusion requirements within this subset were examined. RESULTS: Major bleeding was not different between groups, occurring in 64% of patients receiving placebo and 63% of patients receiving eptifibatide. The incidence of blood transfusion was similar as well (57% vs 59%). Postoperative thrombocytopenia occurred less often after eptifibatide exposure. Perioperative myocardial infarction was significantly reduced in patients who received eptifibatide (46% vs 22%, p < 0.05). There was no difference in perioperative stroke (2.2% vs 6.3%) or mortality (6.3% vs 6.5%). CONCLUSIONS: Patients may safely undergo coronary artery bypass surgery within 2 hours of discontinuation of eptifibatide. Eptifibatide infusion in the immediate preoperative period had no adverse clinical effects, but did significantly decrease the incidence of perioperative myocardial infarction. Additionally, platelet counts after surgery were higher in the group of patients who received eptifibatide, perhaps indicative of a platelet-sparing effect during cardiopulmonary bypass.     

Pulmonary abnormalities after coronary arterial bypass grafting operation: cardiopulmonary bypass versus mechanical stabilization

BACKGROUND: Cardiopulmonary bypass has been implicated in causing poor pulmonary gas exchange postoperatively in patients undergoing coronary artery bypass grafting procedures. This randomized prospective study was conducted to determine whether patients undergoing coronary artery bypass grafting operations using cardiac stabilization and thereby avoiding cardiopulmonary bypass will have improved pulmonary function postoperatively. METHODS: Fifty-eight patients were randomized to one of two groups: coronary artery bypass grafting operation with stabilization or coronary artery bypass grafting operation with cardiopulmonary bypass. Preoperative and postoperative pulmonary gas exchange measurements were performed on intubated patients, including the arterial partial pressure of oxygen on 100% inspired oxygen, the alveolar-arterial oxygen gradient, and pulmonary shunt. Static and dynamic lung compliance measurements were performed postoperatively. Hemodynamic variables (including creatine kinase-MB and troponin levels), intubation time, postoperative bleeding, and blood transfusions were compared. RESULTS: Both study groups had a large decrease in arterial partial pressure of oxygen on 100% inspired oxygen (p < 0.0001) and a significant postoperative increase in the alveolar-arterial oxygen gradient (p < 0.0001). There was no statistical difference in the postoperative gas exchange between the two groups; however, the postoperative pulmonary shunt was significantly better in the stabilization group (24% versus 31%, p = 0.03). The patients were extubated in the intensive care unit earlier in the stabilization group (8.2 hours versus 9.2 hours, not significant). The mean static and dynamic lung compliance postoperatively was lower in the stabilization group, although not statistically significant (p = 0.06). CONCLUSIONS: Coronary artery bypass grafting operation using cardiac stabilization technique is safe and avoids the risk of cardiopulmonary bypass. The pulmonary gas exchange postoperatively is comparable to standard cardiopulmonary bypass procedures, but a reduced postoperative pulmonary shunt was seen in the stabilization group.     

Prediction of the excessive perioperative bleeding in patients undergoing coronary artery bypass grafting: role of aspirin and platelet glycoprotein IIIa polymorphism

OBJECTIVE: The presence of the glycoprotein IIIa allele PlA2 is associated with enhanced thrombin formation and an impaired antithrombotic action of aspirin, which could favor coronary thrombosis. We wondered whether PlA1/A2 genetic polymorphism could affect the postoperative bleeding in patients undergoing coronary artery bypass grafting. We also aimed to assess the effects of aspirin pretreatment and to ascertain the value of platelet function studies as predictors of postoperative bleeding. METHODS: In a randomized, double-blind study, patients undergoing coronary artery bypass grafting were pretreated with a 150-mg dose of aspirin orally 12 and 3 hours before surgery (n = 51, 41 elective) or with placebo (n = 51, 43 elective). The hemostasis was monitored by Simplate (bioMérieux, Inc, Durham, NC) bleeding time and capillary closure time (platelet function analyzer PFA 100; Sysmex UK Ltd, Milton Keynes, United Kingdom). Postoperative bleeding and blood products transfusions were recorded. The glycoprotein IIIa polymorphism was analyzed. RESULTS: Bleeding was significantly greater in PlA1 homozygotes from control group. Blood loss was significantly greater (by 25%) in aspirin group. The volume of blood products transfusions in aspirin patients was significantly larger (by 137%). When subjects were stratified accordingly to blood platelet glycoprotein IIb/IIIa genotype, in the aspirin group PlA2 carriers had greater blood loss than PlA1 homozygotes (1858 +/- 932 mL vs 1216 +/- 525 mL, P < .05). CONCLUSION: PlA1 homozygotes normally had a greater risk of perioperative bleeding. Capillary closure time had no advantage relative to Simplate bleeding time in predicting postoperative blood loss. Aspirin pretreatment revealed no beneficial effects and resulted in increased postoperative bleeding and requirement for blood product transfusions after coronary artery bypass grafting in patients with stable angina. It was most unfavorable for PlA2 carriers.     

Desmopressin acetate in uncomplicated coronary artery bypass surgery: a prospective randomized clinical trial

Bleeding in coronary artery bypass procedures increases morbidity and exposes patients to the risks associated with blood transfusion. Desmopressin acetate (DDAVP), a synthetic vasopressin analogue, may limit bleeding during cardiac surgery. In a prospective randomized trial, the authors evaluated the ability of DDAVP to reduce perioperative bleeding during uncomplicated coronary bypass operations. Sixty-two patients who underwent coronary artery bypass grafting were randomized to receive intraoperatively either a placebo or DDAVP. Both groups were similar with respect to operative characteristics and preoperative hematologic profiles, von Willebrand factor levels increased postoperatively in both placebo (2.77 +/- 1.06 versus 2.17 +/- 1.51 U) and DDAVP groups (2.75 +/- 0.94 versus 1.80 +/- 0.88 U). Only the increase in the DDAVP groups was significant (p less than 0.001). There was no difference in total blood loss between the placebo (1826 +/- 849 ml) and DDAVP groups (1716 +/- 688 ml). Total red cell transfusions were similar in placebo (3.4 +/- 1.3 units of blood) and DDAVP groups (3.6 +/- 0.8 units). These results do not support the intraoperative use of DDAVP to reduce perioperative bleeding in routine coronary artery bypass surgery.     

Bilateral internal thoracic artery use for dialysis patients: does it increase operative risk?

BACKGROUND: The efficacy and risk of using the bilateral internal thoracic artery (BITA) for coronary artery bypass grafting in dialysis patients is virtually unknown. METHODS: Twenty-five patients on dialysis who underwent coronary artery bypass grafting using the BITA were retrospectively studied (BITA group). For comparison purposes, 52 patients on dialysis who underwent coronary artery bypass grafting using the left ITA were selected (LITA group). RESULTS: No wound healing problems occurred in the BITA group. Mean postoperative bleeding volume was 1,427 +/- 808 mL and 800 +/- 508 mL in the BITA and LITA groups, respectively (p = 0.00009). Blood transfusions for the BITA and LITA groups required an average of 6.8 and 6.2 units of packed red blood cells, respectively, with no significant difference. Five patients in the BITA group (20%) showed severe atherosclerotic deterioration of the ascending aorta, precluding clamping. Hospital mortality was 4% (1 of 25 patients) in the BITA group and 7.7% (4 of 52 patients) in the LITA group, with no significant difference (p = 0.49). CONCLUSIONS: In patients on dialysis, especially those with severe atherosclerotic or calcified deterioration of the ascending aorta, coronary artery bypass grafting using BITA grafting (arterial in situ conduits) may offer the easiest and most suitable solution without increased operative risk.     

Effects of tranexamic acid on postoperative bleeding and related hematochemical variables in coronary surgery: Comparison between on-pump and off-pump techniques

OBJECTIVES: Bleeding and inflammation are major complications of extracorporeal circulation. Off-pump coronary artery bypass grafting may reduce the rate of complications, but it can only be applied in selected cases. Pilot studies have shown a potential benefit from the use of antifibrinolytic drugs, but efficacy in randomized double-blind studies evaluating off- and on-pump coronary artery bypass grafting has not been proved. METHODS: We enrolled 102 patients scheduled for on-pump (n = 51) or off-pump (n = 51) coronary artery bypass grafting. Patients were separately double-blind randomly assigned to treatment with tranexamic acid (1 g as 20-minute bolus before skin incision, followed by continuous infusion of 400 mg/h, with 500 mg added to priming in patients undergoing on-pump coronary artery bypass grafting) or placebo (saline solution of equivalent volume). Bleeding in the first 24 postoperative hours was the primary outcome. Requirement for allogeneic transfusions, thrombotic complications, outcomes, and monitoring of coagulation, fibrinolysis, and inflammation were also recorded. RESULTS: Tranexamic acid reduced total postoperative bleeding by 43% in patients undergoing on-pump coronary artery bypass grafting and by 27% in those undergoing off-pump coronary artery bypass grafting (P <.0001), with 80% reduction in bleeding exceeding 600 mL (P <.001), 58% reduction in the requirement for all allogeneic transfusions (P =.07), and no apparent effect on thrombotic complications or outcome. This was associated with a reduction in plasma D-dimer levels (P <.0001), to a greater degree in patients undergoing on-pump coronary artery bypass grafting (P <.0001), and interleukin 6 levels (P <.0001), to a greater degree in patients undergoing off-pump coronary artery bypass grafting (P <.001). CONCLUSIONS: By affecting fibrinolysis, tranexamic acid significantly reduces bleeding both in off- and on-pump coronary artery bypass grafting and may modulate inflammation in these surgical settings.     

The effect of desmopressin acetate on postoperative hemorrhage in patients receiving aspirin therapy before coronary artery bypass operations.

It has been suggested that desmopressin acetate has been effective in reducing hemorrhage after coronary artery bypass grafting in patients receiving aspirin before operation. We conducted a prospective, randomized, placebo-controlled, double-blind trial to determine the effectiveness and safety of desmopressin in these patients. Sixty-five patients pretreated with aspirin within 7 days before their scheduled elective coronary artery bypass grafting were randomized to receive desmopressin (0.3 micrograms/kg) or placebo after cessation of bypass and reversal of heparin with protamine. The demographic characteristics and last dose of aspirin were similar in both groups. There was a significant reduction in postoperative blood loss noted between groups for both chest tube blood loss (833 +/- 311 ml for the 1-desamino-8-D-arginine vasopressin [desmopressin] group versus 1176 +/- 674 ml for the placebo group; p = 0.016) and total blood loss (1215 +/- 381 ml for the desmopressin group versus 1637 +/- 761 ml for the placebo group; p = 0.0097). Despite the differences in blood loss between the two groups, the red cell transfusions were not significantly different, but the use of platelets was less in the desmopressin group and almost achieved statistical significance (p = 0.053). Neither was there a difference in the occurrence of thrombotic complications between groups. It appears that desmopressin in this specific subgroup of patients receiving preoperative aspirin is effective as a prophylactic agent for reduction of postsurgical hemorrhage.     

Emergency coronary artery bypass graft surgery in abciximab-treated patients

BACKGROUND: Although the platelet antiaggregant abciximab is frequently used with percutaneous coronary interventions, results of emergency coronary artery bypass graft operations in patients recently treated with abciximab are poorly characterized. METHODS: During a 29-month period, 12 patients required emergency coronary artery bypass grafting within 12 hours (mean, 1.9 hours) of abciximab therapy. Our full standard heparin dose regimen was used (mean heparin dose, 53,000 U per patient). Each patient received a single platelet transfusion dose after protamine administration, and further blood products were transfused as necessary. Clinical outcome and transfusion requirements were compared with predicted results based on risk-adjusted historical patients. RESULTS: No patients died and none were returned to the operating room for coagulopathy-related bleeding. Per patient transfusion requirements were as follows: red blood cells, 3.6 units; apheresis platelets, 1.4 units; and fresh frozen plasma, 1.5 units. As compared with predicted values, there was no excessive incidence of mortality, stroke, or red blood cell transfusion requirements. CONCLUSIONS: Emergency coronary artery bypass graft operations using full-dose heparin can be performed successfully in acutely ischemic abciximab-treated patients. Prophylactic transfusion of platelets after protamine administration appears to be useful.     

Ultra-low dose aprotinin decreases transfusion requirements and is cost effective in coronary operations

BACKGROUND: The recommended dose of aprotinin has been shown to reduce blood loss and need for blood transfusions, but the cost precludes its routine use. This study was designed to determine whether a less expensive, ultra-low dose of aprotinin is effective when used in coronary artery bypass grafting with left internal mammary artery. METHODS: Patients (n = 202) were randomized to receive either placebo or aprotinin, 0.5 million KIU before incision and 0.5 million KIU during initiation of cardiopulmonary bypass. Differences in quantity of blood transfused were analyzed. Further groups were analyzed to account for the effect of aspirin. Multivariable analysis was performed to determine risk factors for transfusion. Direct costs of blood products and aprotinin were tabulated for each group. RESULTS: There was an important reduction in the proportion of patients transfused, and number of blood units transfused when aprotinin was given before coronary artery bypass grafting. These differences were even more important in patients on aspirin preoperatively. Independent predictors for increased number of transfusions were aspirin continued before operation, smaller body surface area, and the use of placebo instead of ultra-low dose aprotinin. There was no difference in morbidity between treatment groups. There was a reduction in direct costs associated with the use of aprotinin. CONCLUSIONS: These data support the routine use of aprotinin 1 million KIU in coronary artery bypass grafting with left internal mammary artery to reduce cost and transfusion requirements.     

A double-blind, placebo-controlled trial of epsilon-aminocaproic acid for reducing blood loss in coronary artery bypass grafting surgery

BACKGROUND: Epsilon-aminocaproic acid is a plasmin inhibitor that potentially reduces perioperative bleeding when administered prophylactically to cardiac surgery patients. To evaluate the efficacy of epsilon-aminocaproic acid, a prospective placebo-controlled trial was conducted in patients undergoing primary coronary artery bypass grafting surgery. STUDY DESIGN: One hundred patients were randomly assigned to receive either epsilon-aminocaproic acid (100 mg/kg before skin incision followed by 1 g/hour continuous infusion until chest closure, 10 g in cardiopulmonary bypass circuit) or placebo, and the efficacy of epsilon-aminocaproic acid was evaluated by the reduction in postoperative thoracic-drainage volume and in donor-blood transfusion up to postoperative day 12. RESULTS: Postoperative thoracic-drainage volume was significantly lower in the epsilon-aminocaproic acid group compared with the placebo group (epsilon-aminocaproic acid, 649 +/- 261 mL; versus placebo, 940 +/- 626 mL; p=0.003). There were no significant differences between the epsilon-aminocaproic acid and placebo groups in the percentage of patients requiring donor red blood cell transfusions (epsilon-aminocaproic acid, 24%; versus placebo, 18%; p=0.62) or in the number of units of donor red blood cells transfused (epsilon-aminocaproic acid, 2.2 +/- 0.8 U; versus placebo, 1.9 +/- 0.8 U; p=0.29). Epsilon-aminocaproic acid did not reduce the risk of donor red blood cell transfusions compared with placebo (odds ratio: 1.2, 95% confidence interval; 0.4 to 3.2, p=0.63). CONCLUSIONS: Prophylactic administration of epsilon-aminocaproic acid reduces postoperative thoracic-drainage volume by 30%, but it may not be potent enough to reduce the requirement and the risk for donor blood transfusion in cardiac surgery patients. This information is useful for deciding on a therapy for hemostasis in cardiac surgery.     

Redo coronary artery bypass grafting on the beating heart and transfusion needs

AIM: Reoperative coronary artery bypass grafting is associated with significant morbidity and a difficult perioperative management; in particular, important bleeding is observed. Off pump technique may give specific advantages in redo coronary operations since it is associated to decreased interactions of blood with foreign surfaces. We investigated our 5-year database to evaluate the role of off pump technique in reducing transfusion needs. METHODS: The present single centre case control study was carried out in a university tertiary care hospital on 132 consecutive patients undergoing reoperative coronary artery bypass grafting off pump (OP group, 41 patients) or with cardiopulmonary bypass (CPB group, 91 patients). Univariate and multivariate analysis were performed. RESULTS: There was no preoperative difference between the 2 groups; mean number of grafts per patient differed between groups (OP: 1.4+/-0.7, CPB: 2.5+/-1.0). The frequency of patients transfused with blood products was significantly (P=0.004) higher in the CPB group (47.3%) than in the OP group (19.5%). The only independent predictors of transfusions, determined by stepwise multivariate logistic regression analysis, was the use of cardiopulmonary bypass (OR: 4.1, CI: 1.6 - 10.1), and female gender (OR: 7.0, CI: 2.1 - 16.1). CONCLUSION: In our centre, off pump coronary surgery is associated with reduced transfusion of blood products.     

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

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.     

Tranexamic acid and early saphenous vein graft patency in conventional coronary artery bypass graft surgery: a prospective randomized controlled clinical trial

OBJECTIVE: Use of antifibrinolytic agents reduces the risk of bleeding and decreases the need for blood product use in patients undergoing cardiac surgery. The purpose of this study was to determine whether perioperative use of tranexamic acid decreases the rate of saphenous vein graft patency in the early postoperative period after conventional coronary artery bypass grafting surgery. METHODS: A total of 312 patients scheduled for elective coronary artery bypass grafting surgery with cardiopulmonary bypass were randomized to receive either tranexamic acid 100 mg/kg (n = 147) or placebo (n = 165) in a double-blinded fashion before the initiation of cardiopulmonary bypass. Saphenous vein graft patency was assessed with magnetic resonance imaging 5 to 30 days after surgery. RESULTS: Both groups were comparable with respect to baseline demographic data and surgical characteristics. A total of 237 (76%) patients underwent magnetic resonance imaging assessment. A total of 297 saphenous vein grafts were performed and 253 (85.2%; 95% confidence interval, 83.5%-86.9%) were seen in the tranexamic acid group, and 265 saphenous vein grafts were performed and 231 (87.2%; 95% confidence interval, 85.5%-88.9%) were seen in the placebo group (P = .4969). The blood loss and blood product transfusion rates in the tranexamic acid group were significantly lower than in the placebo group. There was no difference between groups with respect to postoperative morbidity and mortality. CONCLUSIONS: The administration of tranexamic acid before cardiopulmonary bypass did not seem to compromise early venous graft patency rates but reduced perioperative blood product transfusion rates. Consequently, tranexamic acid could be advocated for routine use in patients undergoing conventional coronary artery bypass grafting surgery.     

Perioperative use of tirofiban hydrochloride (Aggrastat) does not increase surgical bleeding after emergency or urgent coronary artery bypass grafting.

BACKGROUND: The platelet glycoprotein IIb/IIIa inhibitor tirofiban hydrochloride improves outcome in patients with acute coronary syndrome. Nevertheless, a considerable number of patients require emergency or urgent coronary artery bypass grafting and may be at increased risk of postoperative bleeding after treatment with this molecule. The aim of this study is to evaluate the incidence of bleeding complications among patients undergoing bypass grafting after treatment with tirofiban. METHODS: We investigated the influence of the molecule on postoperative bleeding after cardiac surgery, comparing 2 groups of patients undergoing emergency or urgent coronary artery bypass grafting: group A (n = 20) received tirofiban, and group B (n = 68) received conventional therapy with intravenous heparin up until the operation. A total of 88 patients underwent coronary artery bypass surgery within 2 hours of ceasing the hemodynamic study. Clinical outcome, chest tube outputs, bleeding complications, transfusion requirements, platelet and hemoglobin counts, and clinical complications were examined. RESULTS: Bleeding differences were noted between the 2 groups at 8, 16, and 24 hours postoperatively. The incidence of blood, platelet, and fresh frozen plasma transfusions was higher in the control group. Postoperative thrombocytopenia was preserved in group A (199.5 +/- 70.4 vs 150.6 +/- 33.4 10(3)/mL, P <.01). No significant differences were noted between the 2 groups in the incidence of perioperative myocardial infarction, but significant differences were noted in enzyme levels, length of stay in the intensive care unit, and length of stay in the hospital. No deaths were observed. Hospital morbidity was increased in group B because of factors that were not apparently linked with tirofiban infusion. CONCLUSIONS: Patients may safely undergo coronary artery bypass surgery after treatment with tirofiban hydrochloride. This molecule, administered in the immediate preoperative period, has no adverse clinical effects and does not seem to negatively influence the incidence of perioperative myocardial infarction. Although extracorporeal circulation can modify platelet numbers and function, our ongoing data could show significant reduction in the loss of platelets induced by cardiopulmonary bypass, minor postoperative bleeding, and a minor transfusion requirement in general.     

Tranexamic acid reduces bleeding and the need for blood transfusion in primary myocardial revascularization

BACKGROUND: The objective of this study was to study the effect of low-dose tranexamic acid (TA) on postoperative bleeding and coagulation variables after coronary artery bypass grafting operation. METHODS: Fifty patients undergoing primary coronary artery bypass grafting were randomly assigned to receive either placebo (0.9% NaCl; n = 25) or 10 mg/kg TA followed by infusion of 1 mg/kg per hour during the operation (n = 25). Data measured included blood loss, transfusion, reoperation, fibrinogen level, fibrinogen split products, platelet size, and platelet function. Measurements were made after induction of anesthesia, after heparin administration, during patient warming, after skin closure, and 24 hours after operation. RESULTS: Patients in the TA study group weighed less. Other demographic characteristics were similar between groups. Postoperative bleeding was less in the TA group (194 +/- 135 mL versus 488 +/- 238 mL, p < 0.001), whereas blood requirement was higher in the control group (1.68 +/- 1 versus 0.52 +/- 0.9 U of packed cells per patient, p < 0.001). The percent of patients exposed to blood products was significantly less in the TA group (36% versus 100%, p < 0.001). Fibrinogen split products were lower in the TA group during bypass (p < 0.001). Fibrinogen levels fell in both groups during cardiopulmonary bypass. Platelet number and function were reduced equally in both groups by cardiopulmonary bypass. Other test results were not different between groups. CONCLUSIONS: The use of low-dose TA during coronary artery bypass grafting significantly reduced the coagulopathy-induced postoperative bleeding and allogeneic blood products requirement. The low levels of fibrinogen split products during bypass in the study group reflect the inhibiting effect of TA in fibrinolysis. Tranexamic acid had no effect on platelet function during cardiopulmonary bypass.     

Single-dose tranexamic acid reduces postoperative bleeding after coronary surgery in patients treated with aspirin until surgery

Tranexamic acid reduces postoperative bleeding after coronary artery bypass grafting. We evaluated the effects of a single dose of tranexamic acid given immediately before cardiopulmonary bypass (CPB) in patients treated with aspirin until the day before surgery. The study was a prospective, randomized, double-blinded, placebo-controlled, parallel-group trial. Eighty patients were included and divided into two groups: one group received tranexamic acid 30 mg/kg, and one group received placebo (0.9% NaCl) as a bolus injection before CPB. Postoperative blood loss was recorded for 16 h. Transfusions of blood products were recorded for the whole hospital stay. Transfusions of packed red cells were given when the hematocrit value was less than 20% during CPB and less than 25% after surgery. The patients in the tranexamic acid group had significantly less postoperative bleeding compared with the patients in the placebo group (mean [SD]) (475 [274] mL versus 713 [243] mL; P < 0.001). An effective inhibition of fibrinolysis was found in patients receiving tranexamic acid. Tranexamic acid reduces postoperative bleeding in coronary artery bypass grafting patients treated with aspirin until the day before surgery. IMPLICATIONS: Continuation of aspirin medication until the day before coronary artery bypass grafting may increase postoperative bleeding. The administration of a single dose of tranexamic acid (30 mg/kg) immediately before cardiopulmonary bypass significantly reduced postoperative bleeding and inhibited fibrinolysis in these patients.     

Thromboelastography-Based Transfusion Algorithm Reduces Blood Product Use after Elective CABG: A Prospective Randomized Study

Abstract   Objective: Bleeding and allogeneic transfusion remain constant problems in cardiac surgical procedures. In this study, we aimed to test the role of a routine thromboelastography (TEG)-based algorithm on bleeding and transfusions in patients undergoing elective coronary artery bypass grafting (CABG). Methods: Patients (n = 224) undergoing elective CABG with cardiopulmonary bypass were prospectively randomized into two groups according to transfusion strategy: in group 1 (clinician-directed transfusion, n = 110) need for blood transfusion was based on clinician's discretion and standard coagulation tests and in group 2 (TEG algorithm group, n = 114) kaolin-activated (k) TEG-based algorithm-guided perioperative transfusion management. Transfusion, blood loss, and outcome data were recorded.  Results: There were no differences in consumption of packed cell units, blood loss, re-exploration for bleeding, and early clinical outcome between the groups. Patients in the TEG group had significantly lower median units of fresh frozen plasma and platelets compared with the other group (p = 0.001). The median number of total allogeneic units transfused (packed cells and blood products) was significantly reduced in the TEG group compared with the other group (median 2, range 1–3 units vs. median 3, range 2–4 units, respectively, p = 0.001). The need for tranexamic acid was significantly diminished in the TEG group compared with the other group (10.3% vs. 19%, respectively, p = 0.007). Conclusion: Our results show that routine use of a kTEG-guided algorithm reduces the consumption of blood products in patients undergoing elective CABG. Adopting such an algorithm into routine management of these patients may help to improve clinical outcome and reduce the potential risks of transfusion-related complications and total costs after CABG.     

The effect of prophylactic epsilon-aminocaproic acid on bleeding, transfusions, platelet function, and fibrinolysis during coronary artery bypass grafting.

BACKGROUND: Antifibrinolytic medications administered before skin incision decrease bleeding after cardiac surgery. Numerous case reports indicate thrombus formation with administration of epsilon-aminocaproic acid (epsilon-ACA). The purpose of this study was to examine the efficacy of epsilon-ACA administered after heparinization but before cardiopulmonary bypass in reducing bleeding and transfusion requirements after primary coronary artery bypass surgery. METHODS: Seventy-four adult patients undergoing primary coronary artery bypass surgery were randomized to receive 125 mg/kg epsilon-ACA followed by an infusion of 12.5 mg x kg(-1) x h(-1) or an equivalent volume of saline. Coagulation studies, thromboelastography, and platelet aggregation tests were performed preoperatively, after bypass, and on the first postoperative day. Mediastinal drainage was recorded during the 24 h after surgery. Homologous blood transfusion triggers were predefined and transfusion amounts were recorded. RESULTS: One patient was excluded for surgical bleeding and five patients were excluded for transfusion against predefined criteria One patient died from a dysrhythmia 2 h postoperatively. Among the remaining 67, the epsilon-ACA group had less mediastinal blood loss during the 24 h after surgery, 529+/-241 ml versus 691+/-286 ml (mean +/- SD), P < 0.05, despite longer cardiopulmonary bypass times and lower platelet counts, P < 0.05. Platelet aggregation was reduced in both groups following cardiopulmonary bypass but did not differ between groups. Homologous blood transfusion was similar between both groups. CONCLUSIONS: Prophylactic administration of epsilon-ACA after heparinization but before cardiopulmonary bypass is of minimal benefit for reducing blood loss postoperatively in patients undergoing primary coronary artery bypass grafting.     

A randomized double-blind study of the effect of triiodothyronine on cardiac function and morbidity after coronary bypass surgery.

BACKGROUND: Although triiodothyronine deficiency has been described after cardiopulmonary bypass, data supporting its use have been conflicting. A double-blind, randomized, placebo-controlled study was undertaken to further define the effect of triiodothyronine on hemodynamics and outcome after coronary artery bypass grafting. METHODS: A total of 170 patients undergoing elective coronary artery bypass grafting were enrolled and completed the study from November 1996 through March 1998. On removal of the aortic crossclamp, patients were randomized to receive either intravenous triiodothyronine (0.4 microgram/kg bolus plus 0.1 microgram/kg infusion administered over a 6-hour period, n = 81) or placebo (n = 89). Outcome variables included hemodynamic profile and inotropic drug/pressor requirements at several time points (mean +/- standard error of the mean), perioperative morbidity (arrhythmia/ischemia/infarction), and mortality. RESULTS: Despite similar baseline characteristics, patients randomized to triiodothyronine had a higher cardiac index and lower inotropic requirements after the operation. Subjects receiving triiodothyronine demonstrated a significantly lower incidence of postoperative myocardial ischemia (4% vs 18%, P =.007) and pacemaker dependence (14% vs 25%, P =.013). Seven patients in the placebo group required postoperative mechanical assistance (intra-aortic balloon pump, n = 4; left ventricular assist device, n = 3), compared with none in the triiodothyronine group (P =.01). There were 2 deaths in the placebo group and no deaths in the triiodothyronine group. CONCLUSIONS: Parenteral triiodothyronine given after crossclamp removal during elective coronary artery bypass grafting significantly improved postoperative ventricular function, reduced the need for treatment with inotropic agents and mechanical devices, and decreased the incidence of myocardial ischemia. The incidence of atrial fibrillation was slightly decreased, and the need for postoperative pacemaker support was reduced.     

A phase II dose-response study of hemoglobin raffimer (Hemolink) in elective coronary artery bypass surgery

BACKGROUND: We performed this study to determine the dose-response of hemoglobin raffimer administered in conjunction with intraoperative autologous donation in patients undergoing coronary artery bypass grafting surgery. A secondary objective was to evaluate hemoglobin raffimer for reducing the incidence of allogeneic red blood cell transfusions. METHODS: This was a phase II, single-blind, multicenter, placebo-controlled, open-label study. Patients undergoing coronary artery bypass grafting with cardiopulmonary bypass and intraoperative autologous donation were randomized to receive a single dose of hemoglobin raffimer or control (10% pentastarch). Patients were sequentially enrolled in a dose block of 250, 500, 750, and 1000 mL. RESULTS: Sixty patients received hemoglobin raffimer (n = 30) or control (n = 30). Hemoglobin raffimer was well tolerated. Most (98%) adverse events were mild or moderate in severity. There was an expected dose-dependent increase in the incidence of blood pressure increases and jaundice in hemoglobin raffimer-treated patients. In a dose-pooled analysis of hemoglobin raffimer versus control, increased blood pressure (43% vs 17%), nausea (37% vs 33%), and atrial fibrillation (37% vs 17%) were the most frequently reported adverse events. All serious adverse events were considered unrelated or unlikely to be related to study drug. No hemoglobin raffimer-treated patient required an intraoperative allogeneic red blood cell transfusion, compared with 5 (17%) pentastarch-treated patients (P =.052). This advantage of hemoglobin raffimer was maintained at 24 hours after surgery (7% vs 37%; P =.010) and up to 5 days after surgery (10% vs 47%; P =.0034). CONCLUSIONS: Hemoglobin raffimer was not associated with any serious adverse events in patients undergoing primary coronary artery bypass grafting with cardiopulmonary bypass and intraoperative autologous donation in a dose-response study up to 1000 mL. Hemoglobin raffimer was effective in facilitating decreased exposure or avoidance of allogeneic red blood cell transfusions when used in conjunction with intraoperative autologous donation.