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.     

Early recognition of surgically correctable causes of excessive mediastinal bleeding after coronary artery bypass graft surgery

In an attempt to establish criteria to enable recognition of patients with surgically correctable causes of excessive mediastinal bleeding, 250 patients undergoing coronary artery bypass graft surgery were reviewed. Ten (4 percent) required reexploration for excessive postoperative mediastinal bleeding and were compared with 95 consecutive control patients. There were no statistically significant differences in preoperative coagulation studies, use of aspirin or warfarin, number of vessels bypassed or bypass time. Mean mediastinal blood loss was statistically greater (p <0.001) in the reexploration group for the first 8 hours of the postoperative period than in the control group. Mean heterologous blood transfusion was 8.4 units in the reexploration group compared with 1.3 units in the control group.Based on analysis of the differences in mediastinal bleeding rates in the control and reexploration groups, we conclude that after coronary artery bypass graft surgery postoperative mediastinal bleeding of greater than 300 ml in the 1st hour, greater than 250 ml in the 2nd hour, and greater than 150 ml/hour thereafter suggests the presence of a surgically correctable lesion.     

A prospective study of aspirin's effect on red blood cell loss in cardiac surgery

The effect of aspirin on red blood cell (RBC) loss and blood transfusions was evaluated prospectively in 100 consecutive patients, with normal bleeding times, undergoing elective coronary artery bypass (CABG) surgery. Patients taking 85-325 mgm of aspirin daily up to or within 48 hours of surgery (the "aspirin" group) were compared to patients not taking aspirin or those who had discontinued aspirin at least 4 days before surgery (the "no-aspirin" group). RBC loss was determined by measuring preoperative and postoperative RBC volume using RISA and 51Cr techniques. There were no significant differences, respectively, between the aspirin and no-aspirin groups for: RBC loss (1158 +/- 67 ml vs 1129 +/- 47 ml, p = 0.737), chest tube drainage (925 +/- 31 ml vs 844 +/- 70 ml, p = 0.553), and gm% discharge Hemoglobin (Hgb) (9.94 +/- 0.32 vs 9.49 +/- 1.4, p = 0.0148). Strict criteria for blood transfusions were employed: (1) intraoperative hematocrit of less than 21%, (2) postoperative Hgb of less than 7 gm% for patients less than 70 years old and (3) postoperative Hgb of less than 8 gm% for patients greater than 70 years old. There were no significant differences, respectively, between the aspirin and no-aspirin groups for units of blood transfused (1.32 +/- vs 1.21 +/- 0.20, p = 0.843) and patients not receiving transfusions during the entire hospitalization (44% vs 50%). Patients taking 85-325 mgm of aspirin with a normal bleeding time undergoing elective CABG did not have increased RBC loss or increased transfusion requirements. These results indicate it is not necessary to delay elective CABG surgery for the purpose of discontinuing aspirin.     

Aggressive blood conservation in coronary artery surgery: impact on patient care

Data on 100 consecutive non-emergency coronary artery bypass (CABG) patients were analyzed retrospectively. Sixty-nine patients received no homologous blood (Group I). Thirty-one patients received a total of 118 units of blood products averaging 2.23 units of red cells (Group II). The average red cell transfusion rate for all patients was 0.7 units per patient. The median age for Group I was 61 and Group II was 68 years (p less than 0.05). The average number of grafts was the same for both (3 per patient) with 75% of Group I and 58% of Group II receiving internal mammary artery (IMA) grafts (p less than 0.05). Twelve of the Group II patients who received intraoperative transfusions on cardiopulmonary bypass to maintain adequate hemoglobin levels were older and had lower admission hematocrits: 36 +/- 0.8% compared to 41 +/- 0.5% for all other patients (p less than 0.05). Average postoperative blood loss was 889 +/- 38 ml for Group I and 1077 +/- 104 ml for Group II (p less than 0.05). Increased hemorrhage was correlated with bypass time and IMA use but not with preoperative heparin administration, pre-existing risk factors (diabetes, hypertension, etc.), bleeding time, post-bypass clotting time, age or number of grafts. Two patients in Group II and none in Group I required exploration for excessive postoperative hemorrhage. Mortality rate was 2% (both in Group II, neither transfusion related). Discharge hematocrits were the same for all at 29.4 +/- 0.4%. Among anemia-related postoperative symptoms, only sinus tachycardia was significantly higher in Group I (20%) compared to Group II (6.5%).(ABSTRACT TRUNCATED AT 250 WORDS)     

Low-dose postoperative aprotinin reduces mediastinal drainage and blood product use in patients undergoing primary coronary artery bypass grafting who are taking aspirin: a prospective, randomized, double-blind, placebo-controlled trial

BACKGROUND: Although low-dose aprotinin administered after cardiopulmonary bypass has been reported to reduce mediastinal blood loss and blood product requirements in patients not taking aspirin, it is unknown whether low-dose postoperative aprotinin has any beneficial effects in patients undergoing coronary artery bypass operations who are at high risk of excessive postoperative bleeding and increased transfusion requirements because of aspirin use until just before the operation. METHODS: Fifty-five patients undergoing primary coronary artery operations with cardiopulmonary bypass who continued taking aspirin (150 mg/d) until the day before the operation were enrolled in a prospective, randomized, double-blind trial to receive a single dose of either placebo (n = 29) or 2 x 10(6) kallikrein inhibiting units of aprotinin (n = 26) at the time of sternal skin closure. RESULTS: Patients in the aprotinin group had a lower rate (28 +/- 18 vs 43 +/- 21 mL/h [mean +/- standard deviation], P <.005) and total volume of mediastinal drainage (955 +/- 615 vs 1570 +/- 955 mL, P <.007), as well as a shorter duration of mediastinal drain tube insertion (24.4 +/- 13.8 vs 31.3 +/- 16.5 hours, P <.05). In addition, a smaller proportion of patients receiving aprotinin required a blood product (31% vs 62%, P =.03), resulting in a reduction in the use of packed cells by 47% (P =.05), platelets by 77% (P =.01), fresh frozen plasma by 88% (P =.03), and total blood products by 68% (P =.01) in this group. CONCLUSIONS: These results suggest that postoperative administration of low-dose aprotinin in patients taking aspirin until just before primary coronary artery operations with cardiopulmonary bypass not only reduces the rate and total amount of postoperative mediastinal blood loss but also lowers postoperative blood product use.     

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.     

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

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 < or = 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.     

Perfusion-assisted direct coronary artery bypass provides early reperfusion of ischemic myocardium and facilitates complete revascularization

BACKGROUND: Perfusion-assisted direct coronary artery bypass (PADCAB) was developed to initiate early reperfusion of grafted coronary artery segments during off-pump operations to resolve episodes of myocardial ischemia and avoid its sequelae. This case series outlines intraoperative findings and clinical outcomes of our first year clinical experience with PADCAB. METHODS: From November 1999 to November 2000, 169 PADCAB and 358 off-pump coronary artery bypass procedures were performed at the Emory University Hospitals. The decision to use PADCAB was predicated on surgeon preference. Perfusion pressure and flow, amount of intracoronary nitroglycerin, and total perfusion time and volume were recorded at the time of operation. RESULTS: One off-pump coronary artery bypass patient required emergent conversion to cardiopulmonary bypass. Two PADCAB patients had ischemic ventricular arrhythmias during target vessel occlusion that resolved once active perfusion had begun. Perfusion pressure in PADCAB grafts was on average 44% higher than mean arterial pressure (p < 0.001). Nitroglycerin, infused locally by PADCAB, was used in 67 patients to resolve ischemic episodes and increase initial coronary flows. The mean number of diseased coronary territories and grafts placed was 2.8 +/- 0.5 and 3.4 +/- 0.7, respectively, in the PADCAB group, and 2.3 +/- 0.8 and 2.7 +/- 1.0, respectively, in the off-pump coronary artery bypass group (p < 0.001 for both comparisons). More PADCAB patients received lateral wall grafts than off-pump coronary artery bypass patients (83.4% vs 59.4%; p < 0.001). Hospital death and postoperative myocardial infarction were not different between groups. CONCLUSIONS: PADCAB can provide suprasystemic perfusion pressures and a means to add vasoactive drugs to target coronary vessels. PADCAB provides early reperfusion of ischemic myocardium and facilitates complete revascularization of severe multivessel coronary artery disease.     

The role of desmopressin acetate in patients undergoing coronary artery bypass surgery. A controlled clinical trial with thromboelastographic risk stratification.

The role of desmopressin acetate in attenuating blood loss and reducing homologous blood component therapy after cardiopulmonary bypass is unclear. The purpose of this investigation was to identify a subgroup of patients that may benefit from desmopressin acetate therapy. One hundred fifteen patients completed a prospective randomized double-blind, placebo-controlled trial designed to evaluate the effect of desmopressin acetate (0.3 microgram.kg-1) on mediastinal chest tube drainage after elective coronary artery bypass grafting surgery in patients with normal and abnormal platelet-fibrinogen function as diagnosed by the maximal amplitude (MA) on thromboelastographic (TEG) evaluation. The 115 patients evaluated were divided into two groups based on the MA of the post-cardiopulmonary bypass TEG tracing. Group 1 (TEG:MA greater than 50 mm) consisted of 86 patients, of whom 44 received desmopressin and 42 received placebo. Twenty-nine patients had abnormal platelet function (TEG:MA less than 50 mm) and were designated as group 2. In group 2, 13 received desmopressin and 16 placebo. During the first 24 h after cardiopulmonary bypass, the placebo-treated patients in group 2 had significantly greater mediastinal chest tube drainage when compared to placebo patients in group 1 (1,352.6 +/- 773.1 ml vs. 865.3 +/- 384.4 ml, P = 0.002). In addition to increases in blood loss, group 2 placebo patients also were administered an increased number of blood products (P less than 0.05). The desmopressin-treated patients in group 2 neither experienced increased mediastinal chest tube drainage nor received increased amounts of homologous blood products when compared to those in group 1.(ABSTRACT TRUNCATED AT 250 WORDS)     

Coronary bypass surgery early after thrombolytic therapy for acute myocardial infarction

The safety of coronary bypass operations after coronary reperfusion with streptokinase for acute myocardial infarction is not well documented. Therefore we studied 23 consecutive patients (mean age, 59.5 years; 22 men) undergoing bypass operations a median of 5 days (range, 1 to 23 days) after thrombolysis (streptokinase). The control group consisted of 169 concurrent patients of similar mean age (58.8 years) having bypass operations for standard indications. The preoperative angiographic ejection fraction was 68 +/- 14% in the control patients and 61 +/- 14% in the streptokinase group (p less than 0.05). The number of diseased vessels (70% stenosis or greater) averaged 2.6 in control and 2.3 in streptokinase patients. A previous myocardial infarction had occurred in 42% of the controls and all of the streptokinase patients. Aortic cross-clamp times did not differ between the two groups (80 +/- 35 minutes for the controls and 68 +/- 25 minutes for the streptokinase group). Cardiopulmonary bypass times were similar: 108 +/- 45 minutes in the controls versus 109 +/- 28 minutes in the streptokinase group. Grafts per patient averaged 3.7 +/- 1.5 for the controls versus 2.8 +/- 1.1 for the streptokinase patients (p less than 0.01). Difficult operative hemostasis was noted in 4% of both groups. Inotropic support was given postoperatively to 11% of the control and 13% of the streptokinase patients (p = not significant). Measured blood loss during the first 48 hours postoperatively was similar, averaging 809 ml in controls and 776 ml in the streptokinase group. Blood product replacement was also comparable: mean, 713 ml in the control group versus 759 ml in the streptokinase group.(ABSTRACT TRUNCATED AT 250 WORDS)     

Should obese patients not undergo coronary artery surgery?

To assess the effect of obesity on the patient's recovery from coronary artery bypass surgery, a prospective study was performed on 200 patients. Group 1 comprised 101 nonobese patients and group 2, 99 obese patients. The mean percentage over the ideal weight was 8.2% in group 1 and 33.4% in group 2 (p less than 0.001). Preoperative assessment revealed no difference in age, sex, height, incidence of diabetes, family history or smoking habits between the two groups. Group 2 had a higher incidence of hypertension (p less than 0.01) and hyperlipidemia (p less than 0.02). The average number of grafts placed per patient was 3.4 +/- 0.8 in group 1 and 3.5 +/- 0.08 in group 2. Operative mortality was 2.9% and 2.0% in groups 1 and 2 respectively. Obesity was a predictive factor in postoperative hypertension (p less than 0.025), in the development of wound infection (p less than 0.01) and in an increased requirement of bronchodilators (p less than 0.01). The postoperative progression of physical activity and length of hospital stay was similar, being 10.9 +/- 5.8 days and 9.7 +/- 9.5 days in groups 1 and 2 respectively. The authors conclude that bypass grafting is an acceptable therapeutic option for obese patients with coronary artery disease.     

Preoperative aspirin ingestion increases operative blood loss after coronary artery bypass grafting

Thirty-four patients were entered into a non-blinded, randomized study to test the effect of preoperative aspirin ingestion on postoperative blood loss and transfusion requirements after coronary artery bypass grafting. Sixteen patients in the aspirin-treated group had significantly increased chest-tube blood loss 12 hours after operation (1,513 +/- 978 versus 916 +/- 482 ml; p = 0.038). In addition, aspirin users had significantly increased requirements for postoperative packed red blood cells (4.4 +/- 3.5 versus 1.8 +/- 1.3 units; p = 0.014), platelets (1.3 +/- 1.3 versus 0.2 +/- 0.4 six-donor units, p = 0.0049), and fresh-frozen plasma (3.6 +/- 5.0 versus 0.78 +/- 1.6 units; p = 0.042) transfusions. The only patients requiring reoperation for bleeding were in the aspirin-treated group (2 patients). Six patients were not entered into the randomized part of the study because of excessively prolonged post-aspirin bleeding times (greater than 10 minutes). This finding suggests that a subset of patients are particularly sensitive to aspirin and have significantly prolonged bleeding times after aspirin ingestion. We conclude that aspirin ingestion increases postoperative blood loss and transfusion requirements, and we recommend discontinuation of aspirin therapy before cardiac procedures.     

Low-dose aspirin protects against lipid accumulation in primate vein bypass grafts

Platelet inhibition with high-dose aspirin combined with dipyridamole reduces lipid accumulation and improves early patency of coronary artery bypass grafts. However, recent evidence suggests that platelet inhibition can be achieved with substantially lower aspirin doses than have been conventionally prescribed. To evaluate whether low-dose aspirin protects against lipid accumulation in bypass grafts, we studied 15 stump-tailed macaque monkeys in which autologous cephalic veins were grafted into the femoral arteries. A control group received no treatment, a second group was treated with a low, single daily dose of aspirin (12 mg), and a third group was given a higher dosage of aspirin (80 mg/day) combined with dipyridamole (50 mg/day) divided into two daily doses. A special diet was fed that resulted in plasma cholesterol levels (224 +/- 50 mg/dl, mean +/- standard deviation) and plasma lipoprotein distributions that mimic the profile in humans. Cholesterol concentration in grafts removed 3 months after insertion was 0.47 +/- 0.12 mg/100 mg tissue in the control group; it was reduced to 0.23 +/- 0.04 mg/100 mg (p less than 0.001) by low-dose aspirin and to 0.17 +/- 0.05 mg/100 mg (p less than 0.001) by combined aspirin and dipyridamole therapy. Graft apolipoprotein B concentration was 66 +/- 19 micrograms/100 mg in control group; it was reduced to 40 +/- 8 micrograms/100 mg (p less than 0.05) by low-dose aspirin and to 23 +/- 7 micrograms/100 mg (p less than 0.001) with the combination treatment. There were no differences between groups in either cholesterol concentration (0.09 +/- 0.02 mg/100 mg) or apolipoprotein B concentration (10 +/- 3 micrograms/100 mg) in normal ungrafted vein. Platelet function tests demonstrated platelet aggregation in all control monkeys, in none of the combined therapy group, and in two of five monkeys receiving low-dose aspirin. This study indicates that low-dose aspirin is protective against graft lipid accumulation in monkeys. The mechanism of this antilipid effect and its relation to any antithrombotic effect remain to be elucidated.     

A prospective, randomized study of the effects of prostacyclin on platelets and blood loss during coronary bypass operations

A randomized, double-blind study was designed to evaluate the therapeutic effect and safety of prostacyclin (epoprostenol) in patients undergoing cardiopulmonary bypass. One hundred patients having isolated coronary bypass grafting received 300 units/kg of heparin and then either prostacyclin (12.5 ng/kg/min from heparinization until cardiopulmonary bypass, 25 ng/kg/min during bypass) or buffer/diluent in a similar manner. Standardized anesthetic, perfusion, and surgical techniques were used. Drug and placebo groups were similar in demographic data and bypass times, and there were no deaths. Activated coagulation time and platelet count were significantly higher during cardiopulmonary bypass in patients receiving prostacyclin. Platelet count remained significantly higher 24 hours after bypass in the active drug group. Immediately after operation, there was significantly less prolongation of bleeding time (1.3 versus 2.9 minutes; p = 0.009) in the patients receiving prostacyclin. Blood loss was significantly reduced during the first 4 hours postoperatively in the prostacyclin group (261 +/- 159 versus 347 +/- 197 ml; p = 0.02). There was no significant difference between the groups when total blood loss was compared (710 +/- 351 versus 869 +/- 498 ml; p = 0.07). Patients receiving prostacyclin required an average of 257 ml less blood transfused in the intensive care unit (p = 0.02). We conclude that the clinical impact of prostacyclin in patients undergoing coronary artery operations was demonstrable, but small. Prostacyclin may provide clinical benefits in patients undergoing cardiopulmonary bypass when there are contraindications to or other difficulties with blood transfusion. With prostacyclin, reduced heparin dose is possible and therefore reduced protamine requirement would offer a potential benefit of less cardiovascular depression immediately after bypass. However, the advantages offered by prostacyclin are not sufficient to recommend its routine use during cardiopulmonary bypass.     

Amelioration of the bleeding tendency of preoperative aspirin after aortocoronary bypass grafting

BACKGROUND: Aspirin therapy is widely used in the treatment of cardiac disease. It has been recognized as a causative factor for increased bleeding and blood loss after open heart operations. METHODS: To determine whether high-dose aprotinin maintained its efficacy in reducing blood loss in the presence of aspirin pretreatment in patients undergoing aortocoronary bypass, we performed a double blind study on 60 adult patients. Half received high-dose aprotinin (Trasylol) and half placebo. RESULTS: Total hemoglobin loss, the primary efficacy variable was reduced from 36.1 +/- 31.4 g (mean +/- SD) to 14.1 +/- 16.0 g (p = 0.002). Blood loss was reduced intraoperatively and total loss was reduced from 837.3 mL +/- 404.9 mL to 368.7 mL +/- 164.3 mL (p < 0.001). The number of patients who did not receive any donor blood products was significantly higher in the aprotinin-treated patients (56.7% versus 23.3%, p = 0.008). Activation of the clotting cascade was significantly less in the treated patients toward the end of cardiopulmonary bypass both by measurement of thrombin-antithrombin III complex (p < 0.0001) and prothrombin fragment 1 + 2 (p < 0.0001). D-Dimer generation was significantly less from the onset of bypass and after reversal of heparin in the aprotinin-treated patients (p < 0.0001). CONCLUSIONS: High-dose aprotinin was highly effective in reducing bleeding in this high-risk group of patients. Biochemical analyses suggest the mechanism by which aspirin increases blood loss after cardiopulmonary bypass is different from the blood-preserving effects of aprotinin, which is acting as an antifibrinolytic agent.     

Reoperative coronary surgery. Comparative analysis of 6591 patients undergoing primary bypass and 508 patients undergoing reoperative coronary artery bypass

During an 18-year period a consecutive series of 6591 patients underwent primary coronary bypass grafting and 508 patients underwent reoperative bypass. The mean patient age for the reoperative group was identical to that of the primary group, 59.8 years, but the mean age at initial operation for the reoperative group was 55.2 years. Mammary grafts were done at initial operation in 59% of patients who have had one operation versus only 46% of patients who subsequently required reoperation (p less than 0.001). The overall operative mortality rate was 2.0% (134/6591) for primary coronary bypass versus 6.9% (35/508) for reoperations (p less than 0.001). Patients with a reoperative interval of 1 to 10 years had a 6.0% (18/312) mortality rate, compared with 17.6% (13/74) for those in whom the interval between operations was greater than 10 years (p less than 0.01). Ventricular arrhythmias, excessive bleeding, prolonged ventilatory support, intraaortic balloon pump insertion (all p less than 0.05), and perioperative myocardial infarction (p less than 0.001) were all more prevalent after reoperations. Including perioperative mortality, the actuarial survival rate at 5 years was 80% for reoperations versus 90% for primary operations. The corresponding figures at 10 years were 65% and 75%. The probability of undergoing reoperation within 5 and 10 years was 0.034 +/- 0.003 and 0.055 +/- 0.005, respectively. Ten years postoperatively, 36% of patients having the initial operation had recurrent angina whereas 58% of the reoperative group had significant recurrent angina. Ten years after reoperation, 30% of operative survivors were free of heart-related morbidity and mortality compared with 50% of patients having a primary operation. Univariate analysis of factors increasing the probability of reoperation include the absence of a mammary graft and younger age at operation. Patients undergoing a second bypass operation represent a substantially higher risk subgroup than patients undergoing initial operation in terms of perioperative morbidity, mortality, decreased long-term survival, and decreased relief of recurrent cardiac morbidity.     

Early bypass grafting following intracoronary thrombolysis with streptokinase

Early bypass grafting following intracoronary thrombolysis with streptokinase may be indicated in patients with acute coronary artery thrombosis and severe coronary disease. To evaluate this approach, we prospectively studied 41 patients (32 men and nine women, mean age 53 years) with acute infarction. Emergency cardiac catheterization was performed within 18 hours after onset of chest pain and intracoronary streptokinase was given. All patients underwent bypass 3 to 10 days later (mean 7 days). Serial gated radionuclide left ventricular angiograms to determine ejection fraction were obtained on hospital admission, preoperatively, and 3 to 6 months later. Thirty-four patients had complete occlusion of the artery supplying the infarcted segment. In 30 patients (88%) reperfusion was not successful. In seven patients the artery was not totally thrombosed. Thirty-two patients (78%) had multivessel disease. An average of 2.8 grafts per patient were placed with an operative mortality of 2% (one patient). Serial measurements of ejection fraction were obtained in 23 patients in whom the admission ejection fraction was less than 50%. There was a significant increase in ejection fraction from admission (33% +/- 11%) to the preoperative measurement (41% +/- 9%, p less than 0.001), and this improvement persisted at follow-up (40% +/- 14%). Intracoronary streptokinase has been shown to restore blood flow to infarcting myocardium and to improve left ventricular performance. In patients with significant organic stenosis, the risk of bypass grafting 3 to 10 days after intracoronary streptokinase infusion appears to be no different from the risk of elective operation performed at a time remote from an acute infarction.     

Platelet-leukocyte plasmapheresis attenuates the deleterious effects of cardiopulmonary bypass.

A method of harvesting a high yield of concentrated platelet- and leukocyte-rich plasma was developed with the goal of attenuating some of the deleterious effects of cardiopulmonary bypass. The study involved 32 patients who underwent coronary artery bypass grafting with plasmapheresis before cardiopulmonary bypass and a control group of 32 patients who did not have plasmapheresis. A volume of 857 +/- 359 mL of platelet- and leukocyte-rich plasma was concentrated from 4.6 +/- 1.5 L of blood, and red cells and plasma were returned to the patient. The platelet- and leukocyte-rich plasma contained yields of 3.5 +/- 1.4 x 10(11) platelets and 3.4 +/- 1.9 x 10(9) leukocytes. There were no differences in age, sex, duration of cardiopulmonary bypass, and major risk factors between groups. However, total mediastinal chest tube drainage was 788 +/- 542 mL in the controls and 425 +/- 207 mL in the plasmapheresis group (p less than 0.01). Homologous units transfused were 3.9 +/- 2 in controls and 1.6 +/- 2 in the plasmapheresis group (p less than 0.01). Arterial oxygen tension on extubation was 94 +/- 32 mm Hg in controls and 119 +/- 25 mm Hg in the plasmapheresis group (p less than 0.01). This technique of platelet and leukocyte protection results in reduced postoperative bleeding, a decreased need for homologous blood products, and improved pulmonary function.     

Reduction and elimination of systemic heparinization during cardiopulmonary bypass.

After extensive experimental evaluation, heparin-coated perfusion equipment was clinically evaluated with low or no systemic heparinization in three different groups of patients (n = 47). In group 1, resection of descending thoracic aortic aneurysms (n = 24) was performed with heparin-coated equipment used for left heart bypass (n = 12) or partial cardiopulmonary bypass (n = 12) for proximal unloading and distal protection (heparin 5000 IU, autotransfusion). All devices remained functional throughout the procedures and no systemic emboli were detected. The sole death (1 of 24, 4%) occurred in a patient with ruptured thoracoabdominal aortic aneurysm requiring operation in extremis. Paraparesis with spontaneous recovery occurred in one patient (1 of 24, 4%). In group 2, coronary artery revascularization randomized for low (activated clotting time greater than 180 seconds) versus full (activated clotting time greater than 480 seconds) systemic heparinization was prospectively analyzed in 22 patients. All patients recovered without sequelae, and no myocardial infarction was diagnosed. Low dose of heparin (8041 +/- 1270 IU versus 52,500 +/- 17,100 IU; p less than 0.0005) resulted in reduced protamine requirements (7875 +/- 1918 IU versus 31,400 +/- 14,000 IU; p less than 0.0005), reduced blood loss (831 +/- 373 ml versus 2345 +/- 1815 ml; p less than 0.01), reduced transfusion requirements of homologous blood products (281 +/- 415 ml versus 2731 +/- 2258 ml; p less than 0.001), and less patients transfused (5 of 12 versus 10 of 10; p less than 0.05). Lower D-dimer levels in the group perfused with low systemic heparinization (0.50 +/- 0.43 mg/L versus 1.08 +/- 0.59 mg/L; p less than 0.05) were attributed to the absence of cardiotomy suction in this group. In group 3, rewarming in accidental hypothermia by cardiopulmonary bypass was successfully performed without systemic heparinization in a patient with hypothermic cardiac arrest (23.3 degrees C) and intracranial trauma. We conclude that systemic heparinization for clinical cardiopulmonary bypass can be reduced and eliminated in selected patients if perfusion equipment with improved biocompatibility is used. Bypass-induced morbidity can be reduced.     

Effects of pulsatile perfusion on plasma catecholamine levels and hemodynamics during and after cardiac operations with cardiopulmonary bypass

Thirty patients scheduled for elective coronary artery bypass grafting were studied in two groups. Group A had standard cardiopulmonary bypass with nonpulsatile perfusion and group B had pulsatile perfusion. Measurements of plasma epinephrine, norepinephrine, granulocyte elastase, and hemodynamic parameters including mean arterial pressure total peripheral resistance, cardiac index, and pulmonary capillary wedge pressure were made before and after anesthesia induction, after surgical incision, during cardiopulmonary bypass, and 2, 4, and 24 hours after the operation. The venous compliance of the total body venous bed was measured at the end of the operation. In all patients the total net fluid balance was determined during bypass and in the postoperative period. In both groups plasma catecholamine levels increased 5 minutes after institution of bypass (epinephrine 176 +/- 56 to 611 +/- 108 pg/ml and norepinephrine 231 +/- 48 to 518 +/- 100 pg/ml in group A; epinephrine 168 +/- 40 to 444 +/- 100 pg/ml and norepinephrine 162 +/- 44 to 267 +/- 52 pg/ml in group B). The maximum catecholamine level was measured between the end of bypass and 2 hours after the end of bypass (epinephrine 1489 +/- 169 pg/ml and norepinephrine 1542 +/- 108 pg/ml in group A; epinephrine 990 +/- 134 pg/ml and norepinephrine 934 +/- 197 pg/ml in group B). During the same period mean arterial pressure and total peripheral resistance were also significantly higher in group A than in group B mean arterial pressure, 61.4 +/- 3 versus 53.6 +/- 3, p less than 0.06; total peripheral resistance, 1055 +/- 60 versus 899 +/- 45, p less than 0.01). The venous compliance was significantly higher in group A than in group B (2.4 +/- 0.3 versus 1.2 +/- 0.3 ml/mm Hg/kg body weight). The intraoperative and perioperative net fluid balance were significantly higher in group A than in group B (p less than 0.005). The average postoperative tracheal intubation time was also significantly longer in group A than in group B (4.6 +/- 1.2 hours versus 2.7 +/- 0.8 hours, p less than 0.001). No significant difference was detected in either hemoglobin or plasma free hemoglobin content between the two groups postoperatively. The results suggest that pulsatile perfusion, when compared with nonpulsatile perfusion, can attenuate the catecholamine stress response to cardiopulmonary bypass, reduce the fluid overloading of patients, and improve the postoperative recovery period as evaluated by tracheal intubation time.