Preoperative aspirin administration improves oxygenation in patients undergoing coronary artery bypass grafting

OBJECTIVES: Release of thromboxane (Tx) A(2) by platelets may be one of multiple factors that are responsible for lung injury after cardiopulmonary bypass, leading to pulmonary vasoconstriction and impaired oxygenation. In experimental models, the inhibition of Tx receptor or its production improved lung function. The use of aspirin, which is used widely in the treatment of ischemic heart disease because of its antiplatelet activity, is usually discontinued a week before the patient undergoes the operation to restore normal platelet hemostatic function. The purpose of this study was to determine the relationship between the time of cessation of aspirin before coronary artery bypass surgery, and postoperative oxygenation and bleeding. DESIGN: A prospective clinical study comparing the effect of aspirin on postoperative oxygenation in patients who had been treated or had not been treated with aspirin. SETTING: Tx levels in the pericardial fluid, oxygenation, and bleeding were compared between the two groups. PATIENTS: Thirty-two patients with coronary artery disease who were undergoing coronary artery bypass grafting. Fourteen of these patients received aspirin until the day of the operation, whereas 18 patients stopped receiving aspirin at least 1 week before undergoing the operation.Main results: Mean (+/- SD) Tx levels in the pericardial fluid were significantly lower in the aspirin group (117 +/- 47 pg/mL) compared to those in the control group (1,306 +/- 2,048 pg/mL; p = 0.02). The duration of ventilation after the operation was significantly longer in the nonaspirin group (9.6 +/- 5.6 h vs 3.8 +/- 1.4 h, respectively; p = 0.0004). Po(2) reached a higher level while patients breathed 100% O(2) in the aspirin group (235 +/- 54 mm Hg vs 176 +/- 27 mm Hg, respectively; p = 0.001). The mean amount of bleeding during the first 24 h after surgery was increased in the aspirin group (710 +/- 202 mL) compared with the nonaspirin group (539 +/- 143 mL; p = 0.01), but these patients did not require more transfusions. CONCLUSIONS: The administration of aspirin until the operation may improve oxygenation with only a slight increase in bleeding. This improvement is probably mediated by antiplatelet activity and Tx inhibition by aspirin.     

Starting aspirin therapy after operation. Effects on early graft patency. Department of Veterans Affairs Cooperative Study Group.

BACKGROUND. Although aspirin therapy started before operation improves vein graft patency after coronary artery bypass grafting, it also causes bleeding. The objective of this prospective, centrally directed, randomized, double-blind, placebo-controlled trial was to compare the effects of aspirin therapy started before operation with aspirin started 6 hours after operation on early (7-10-day) graft patency. METHODS AND RESULTS. Patients were randomized to receive either aspirin 325 mg or placebo the night before surgery; after operation, all patients received aspirin 325 mg daily, with the first dose administered through the nasogastric tube 6 hours after operation. Angiography was performed in 72% of the analyzed patients an average of 8 days after operation, and the primary end point was saphenous vein graft patency in 351 patients. Internal mammary artery graft patency was also assessed in 246 patients because many individuals received both internal mammary artery and vein grafts. In the patients given preoperative aspirin, the vein graft occlusion rate was 7.4 +/- 1.3% compared with 7.8 +/- 1.5% in those who received preoperative placebo (p = 0.871). In the subgroup of patients receiving Y grafts, 0.0% of the grafts were occluded in the preoperative aspirin group compared with 7.0 +/- 3.6% in the preoperative placebo group (p = 0.066). The internal mammary artery occlusion rate was 0.0% (0 of 131) in the aspirin group compared with 2.4 +/- 1.4% (three of 125) in the placebo group (p = 0.081). Patients in the aspirin group received more transfusions than those in the placebo group (median, 900 versus 725 ml, p = 0.006). The reoperation rate for bleeding in the aspirin group was 6.3% compared with 2.4% in the placebo group (p = 0.036). Median chest tube drainage within the first 6 hours after operation was 500 ml in the aspirin group compared with 448 ml in the placebo group (p = 0.011). CONCLUSIONS. Thus, preoperative aspirin is associated with increased bleeding complications and offers no additional benefit in early vein graft patency compared with starting aspirin therapy 6 hours after operation. There was a trend, although not significant, toward improved early patency for Y grafts and internal mammary artery grafts with preoperative aspirin.     

Aspirin and clopidogrel taken until 2 days prior to coronary artery bypass graft surgery is associated with increased postoperative drainage loss

OBJECTIVE: Platelet aggregation inhibitors, such as aspirin and clopidogrel, are associated with increased bleeding in patients undergoing cardiac surgery with cardiopulmonary bypass. We investigated the impact of time between the last intake of aspirin and clopidogrel before CABG surgery and drainage loss, transfusion requirements and rate of reoperation. PATIENTS AND METHODS: The records of patients who had coronary artery bypass graft surgery (CABG) were reviewed for intake of aspirin and clopidogrel within 7 days prior to surgery. Drainage loss, transfusion requirements and rate of reoperation for bleeding within 5 days after the operation, were recorded. RESULTS: Out of 261 analysed patients, 225 patients (86.2 %) had no anti-platelet medication and 36 patients (13.8 %) were on aspirin and clopidogrel. Aspirin and clopidogrel, taken all until 2 days prior to operation, were associated with a significantly higher postoperative blood loss (1840 mL [1230 - 3710] vs. 280 mL [185 - 765], p = 0.005 for one day and 850 mL [345 - 1725] vs. 277 mL [165 - 778], p = 0.026, for 2 days prior to surgery). The trend showed that patients in the study group received more platelet concentrates (PC: 5.3 % vs. 13.9 %, p = 0.067). The rate of reoperation for bleeding was not different ( p = 0.25). CONCLUSION: Aspirin and clopidogrel up to 2 days prior to CABG were associated with a significantly higher postoperative drainage loss.     

The effect of pre-operative aspirin on bleeding, transfusion, myocardial infarction, and mortality in coronary artery bypass surgery: a systematic review of randomized and observational studies.

AIMS: To obtain estimates of the efficacy and safety of pre-operative aspirin in patients undergoing coronary artery bypass grafting (CABG). METHODS AND RESULTS: Eligible studies included randomized controlled trials (RCTs) and observational studies of patients undergoing CABG, comparing pre-operative aspirin with no aspirin/placebo, and reporting at least one of our primary outcomes. In eight RCTs (n = 805), pre-operative aspirin increased post-operative bleeding [Mean difference (MD), 104.9 mL; 95% confidence interval (CI), 19.2-190.6; P = 0.016] and reoperation [odds ratio (OR), 2.52; 95% CI, 1.18-5.38; P = 0.017), but not transfusion requirements (MD, 0.62 units; 95% CI, -0.06-1.30; P = 0.072). Subgroup analysis suggested that bleeding was increased with aspirin doses > or =325 mg/day, but not with lower doses. In 14 observational studies (n = 4485), pre-operative aspirin increased post-operative bleeding (MD, 113.6 mL; 95% CI, 45.2-182.0; P = 0.001) and transfusion requirements (MD, 0.34; 95% CI, 0.12-0.56 units; P = 0.002), but not reoperation (OR, 1.12; 95% CI, 0.69-1.83; P = 0.647). Neither analysis detected a significant effect on myocardial infarction or death. CONCLUSION: Pre-operative aspirin increases post-operative bleeding, but this may be avoided by the use of aspirin doses <325 mg/day. Most of the RCTs are old and the meta-analysis was underpowered for efficacy outcomes. A large randomized trial is necessary to determine the safety and efficacy of pre-operative aspirin in the setting of contemporary cardiac surgical practice.     

Effect of timing of chronic preoperative aspirin discontinuation on morbidity and mortality in patients having combined coronary artery bypass grafting and valve surgery

The objective of this study was to determine if late use of aspirin before coronary artery bypass grafting (CABG) with valve surgery affects bleeding events and major adverse cardiovascular events. Aspirin has been shown to decrease postoperative CABG mortality and ischemic events. There are no data on the time of aspirin discontinuation and its effect on CABG with valve surgery and bleeding complications. From January 1, 2002 to January 31, 2008, 1,963 patients undergoing nonurgent plus valve surgery at the Cleveland Clinic were on preoperative aspirin; 1,404 (72%) discontinued aspirin ≥ 6 days before surgery (early discontinuation) and 559 (28%) continued aspirin within 5 days of surgery (late use). Propensity-score analysis and matching were employed for fair comparison of outcomes. There was no difference between early-discontinuation and late-use groups in the composite outcome of in-hospital mortality, myocardial infarction, and stroke (5.3% in the 2 groups). More patients in the late-use group received postoperative transfusions (49% vs 42%, p = 0.02). There was a trend toward increased reoperation for bleeding (6.1% vs 3.7%, p = 0.08) in the late-use group. In conclusion, in patients undergoing CABG with valve surgery, there was an increased use of postoperative red blood cell transfusion and a trend toward increased reoperation for bleeding in the late-use group. There was no difference in major adverse cardiac events between groups. Late use of aspirin in CABG with valve surgery must be weighed against an increased risk of bleeding.     

Saphenous vein graft patency 1 year after coronary artery bypass surgery and effects of antiplatelet therapy. Results of a Veterans Administration Cooperative Study

To determine whether antiplatelet therapies improve saphenous vein graft patency after coronary artery bypass grafting, we compared 1) aspirin (325 mg once daily), 2) aspirin (325 mg three times daily), 3) aspirin and dipyridamole (325 mg and 75 mg, respectively, three times daily), 4) sulfinpyrazone (267 mg three times daily), and 5) placebo (three times daily). Therapy with dipyridamole and sulfinpyrazone was started 48 hours before bypass graft surgery, and aspirin treatment was begun 12 hours before surgery as a single 325-mg dose. Postoperative treatment was started 6 hours after surgery and continued for 1 year. Graft patency data were obtained early (median, 9 days) and late (median, 367 days) after surgery. The early graft occlusion rate was decreased with all aspirin treatment regimens compared with that of the placebo regimen. At 1 year, in 406 patients with 1,315 grafts, the graft occlusion rate in all of the aspirin groups combined was 15.8% compared with 22.6% for the placebo group (p = 0.029). The patients taking aspirin once daily had a lower occlusion rate (13.2%) compared with the patients receiving placebo (p = 0.050). At 1 year, in the vein grafts placed to vessels less than or equal to 2.0 mm in diameter (804 distal sites), the graft occlusion rate in all of the aspirin groups was 20.1% compared with 32.3% for the placebo group (p = 0.008). In the vein grafts placed to vessels greater than 2.0 mm in diameter (511 distal sites), there was no difference in the occlusion rates between aspirin and the placebo group at 1 year (8.7% vs. 9.0%, p = 0.918).(ABSTRACT TRUNCATED AT 250 WORDS)     

Long term clinical outcome of coronary surgery and assessment of the benefit obtained with postoperative aspirin and dipyridamole.

Three hundred and twenty patients originally entered into a randomised study to assess the effect of aspirin and dipyridamole on the patency of coronary bypass grafts one year after operation were clinically reassessed a mean of 6.6 years (range 4.3-8.6) after operation. Patients were recruited between 1978 and 1982 after the present policy of total revascularisation had been adopted. During the follow up period there were 25 deaths of which 17 were due to cardiac causes (average annual cardiac mortality 0.8%). Of 280 patients available for contact, 250 (89.3%) attended an outpatient interview. Ninety four (37.6%) patients complained of recurrent angina but in only 23 (9.2%) was this severe. Two hundred and eleven (84.4%) of the 250 patients underwent exercise stress testing. There were 73 (34.6%) abnormal tests of which 52 were in the group of 94 patients with recurrent angina. Myocardial infarction occurred in nine of the 250 patients during the follow up period. Twenty six patients (10.4%) had reinvestigation for symptoms. This group had a graft occlusion rate of 52%. Half these patients have required reoperation and 20 of 22 occluded or severely stenosed grafts were replaced. In only two instances were vein grafts inserted into vessels with new disease. Half of the original group were given aspirin (330 mg three times a day) plus dipyridamole (75 mg three times a day). Of the 250 patients interviewed, 122 took aspirin and dipyridamole from the second postoperative day for a mean of 25 months, with warfarin for three months. The other 128 patients took placebo for a mean of 23 months together with warfarin for three months. This long term treatment with aspirin plus dipyridamole conferred no significant benefit for all clinical outcomes measured at a mean of 6.6 years.     

Long term clinical outcome of coronary surgery and assessment of the benefit obtained with postoperative aspirin and dipyridamole

Three hundred and twenty patients originally entered into a randomised study to assess the effect of aspirin and dipyridamole on the patency of coronary bypass grafts one year after operation were clinically reassessed a mean of 6.6 years (range 4.3-8.6) after operation. Patients were recruited between 1978 and 1982 after the present policy of total revascularisation had been adopted. During the follow up period there were 25 deaths of which 17 were due to cardiac causes (average annual cardiac mortality 0.8%). Of 280 patients available for contact, 250 (89.3%) attended an outpatient interview. Ninety four (37.6%) patients complained of recurrent angina but in only 23 (9.2%) was this severe. Two hundred and eleven (84.4%) of the 250 patients underwent exercise stress testing. There were 73 (34.6%) abnormal tests of which 52 were in the group of 94 patients with recurrent angina. Myocardial infarction occurred in nine of the 250 patients during the follow up period. Twenty six patients (10.4%) had reinvestigation for symptoms. This group had a graft occlusion rate of 52%. Half these patients have required reoperation and 20 of 22 occluded or severely stenosed grafts were replaced. In only two instances were vein grafts inserted into vessels with new disease. Half of the original group were given aspirin (330 mg three times a day) plus dipyridamole (75 mg three times a day). Of the 250 patients interviewed, 122 took aspirin and dipyridamole from the second postoperative day for a mean of 25 months, with warfarin for three months. The other 128 patients took placebo for a mean of 23 months together with warfarin for three months. This long term treatment with aspirin plus dipyridamole conferred no significant benefit for all clinical outcomes measured at a mean of 6.6 years.     

Impact of intraoperative echocardiography on surgical management of congenital heart disease

Intraoperative echocardiography was performed by epicardial, 2-dimensional, low- and high-pulsed repetition frequency, continuous-wave Doppler and color flow mapping in 50 patients. Forty studies were performed before and 44 studies after cardiopulmonary bypass. Studies before cardiopulmonary bypass agreed with preoperative evaluation. After cardiopulmonary bypass, studies revealed that 11 of 25 patients who underwent repair of ventricular septal defects had residual ventricular septal defects, and 1 of 25 patients who underwent atrial septal repair had 1 residual atrial communication. One patient with a "Swiss cheese" ventricular septum underwent repeat cardiopulmonary bypass to close residual ventricular septal defects. The patient with a residual atrial communication required immediate reoperation because of a right to left shunt after a modified Fontan procedure. Eight of 10 remaining residual ventricular septal defects spontaneously closed 1 to 41 days after operation. Assessment of postcardiopulmonary bypass and postoperative valvular regurgitation in 21 valves revealed good correlation (p less than 0.01). However, 1 patient required reoperation for mitral valve replacement on the sixth postoperative day. The correlation was fair between postcardiopulmonary bypass and postoperative residual stenotic pressure gradients in 12 surgically repaired stenotic lesions. This study shows that little additional information is added to a comprehensive preoperative evaluation by precardiopulmonary bypass intraoperative echocardiography. Postcardiopulmonary bypass intraoperative echocardiography is useful in identifying residual shunts. Assessment of stenotic gradients and valvular regurgitation must be interpreted in light of a changing hemodynamic state.     

Clinical effects of different protamine doses after cardiopulmonary bypass

The optimal dose of protamine needed to reverse the anticoagulant effect of heparin after cardiopulmonary bypass is still not known. In this retrospective cohort study, we investigated 3 different dose regimes in 300 patients undergoing coronary artery bypass grafting. Group A patients (n = 100) were given protamine in the ratio of 1.3 mg to 1 mg heparin, group B patients (n = 100) were given 0.75 mg protamine to 1 mg heparin, and group C patients (n = 100) were given protamine in fractionated doses of 1 mg + 0.15 mg + 0.15 mg to 1 mg heparin. The groups were comparable in all major clinical and operative variables. The heparin dose was almost identical in the groups. The rate of red cell transfusion was significantly higher in group B than in the other groups. A similar but nonsignificant trend was observed in the incidence of resternotomy for postoperative bleeding, mediastinal drainage, and postoperative hemoglobin loss. The study demonstrates that a single bolus dose of 1.3 mg protamine to 1 mg heparin is safe and efficient for neutralizing heparin after cardiopulmonary bypass.     

Beneficial effect of aspirin on renal function post-cardiopulmonary bypass

Urine thromboxane, plasma creatinine, and creatinine clearance were determined perioperatively in 20 patients undergoing coronary bypass surgery. Ten patients took aspirin until the day of surgery, and 10 discontinued aspirin at least one week before surgery. A significant increase in urine thromboxane following establishment of cardiopulmonary bypass was observed only in the control group. Plasma creatinine increased in the control group on the 1st postoperative day (from 81.9 +/- 13.2 to 97.6 +/- 13.2 micromol.L(-1), p = 0.02) and decreased next day to the preoperative level (82.7 +/- 9 micromol.L(-1), p = 0.03). In the aspirin group, creatinine remained unchanged on the 1st postoperative day (89.4 +/- 14.2 vs. 87.2 +/- 7.7 micromol.L(-1), p = 0.6), and increased significantly on the 2nd day (101.4 +/- 8.5 micromol.L(-1), p = 0.01). The aspirin group had higher creatinine levels (p < 0.0001) and lower creatinine clearance (60.2 +/- 16.5 vs. 82 +/- 25.7 mL.min(-1), p < 0.0001) than the control group on the 2nd postoperative day. A significant positive correlation was seen between urine thromboxane and creatinine on day 2 in both groups (r = 0.6). Aspirin administrated before coronary surgery may have a beneficial effect on renal function, probably mediated by its antiplatelet activity and thromboxane inhibition.     

In vivo measurement of thromboxane B2 and 6-keto-prostaglandin F1 alpha in humans in response to a standardized vascular injury and the influence of aspirin

The effects of smoking, aspirin ingestion, and sex differences on bleeding times and bleeding time thromboxane B2 and 6-keto-prostaglandin (PG)F1 alpha production were examined. Nonsmoking men produced more thromboxane B2 (3.99 +/- 0.76 ng/ml) than nonsmoking women (2.13 +/- 0.24 ng/ml). Female smokers produced more thromboxane B2 (5.01 +/- 0.97 ng/ml) than nonsmoking women. Twenty-four hours after a single dose of 600 mg aspirin, in vitro production of thromboxane B2 in response to collagen fell by 95%, whereas in vivo production of thromboxane B2 and 6-keto-PGF1 alpha in bleeding time blood fell by 87% and 66%, respectively. Subjects with the lowest absolute levels of thromboxane B2 24 hours after aspirin were also those with the longest postaspirin bleeding times. Recovery of 6-keto-PGF1 alpha production was faster than recovery of thromboxane B2 production, but 6-keto-PGF1 alpha production for most subjects was still below basal 72 hours after aspirin. The influence of two different doses of long-term aspirin (80 mg every other day and 325 mg daily) on the in vivo production of thromboxane B2 and 6-keto-PGF1 alpha was studied in normals and diabetics. After 14 days of 80 mg aspirin every other day, thromboxane B2 and 6-keto-PGF1 alpha production were both substantially inhibited (93% and 78%, respectively). After 14 days of 325 mg aspirin daily, thromboxane B2 production was similarly substantially inhibited (93%), whereas 6-keto-PGF1 alpha was significantly less affected (only 45% inhibition). Study of a second group of five normal subjects confirmed that 6-keto-PGF1 alpha production was significantly inhibited 24 hours after the first dose of 325 mg aspirin but was not significantly less than basal after 14 days of 325 mg aspirin. The results suggest that 325 mg aspirin daily is more antithrombotic compared with 80 mg every other day due to the superior preservation of prostacyclin production.     

Reduction of Blood Loss and Transfusion Requirements After Coronary Artery Bypass Grafting: Similar Efficacy of Tranexamic Acid and Aprotinin in Aspirin-treated Patients

Abstract Background: In patients with coronary artery disease, continuation of aspirin may reduce the incidence of unstable angina and preoperative myocardial infarction before surgery, but the risk of perioperative bleeding may be increased.
Methods: The efficacy of aprotinin and tranexamic acid (TXA) was examined in a prospective, randomized, double-blind trial involving 56 patients scheduled for coronary artery bypass grafting and who received aspirin 100 mg/day until the day of the operation. Group I received high-dose aprotinin whereas group II received 10 g of tranexamic acid (TXA) over 20 minutes before sternotomy. Heparinization during cardiopul-monary bypass was controlled with HDTT (high-dose thrombin time) to eliminate interference of aprotinin on ACT (celite activated clotting time). Postoperative blood loss and transfusion requirements were registered during the first 24 hours.
Results: The demographics, coagulation, and intraoperative parameters were similar in both groups. Postoperative blood loss (aprotinin 840 mL /24 hours, TXA 880 mL/24 hours, p = 0.481). and transfusion requirements (2.18 units/patient in the aprotinin group, 2.11 units/patient in the TXA group) were not remarkably different between the two regimen protocols. No perioperative myocardial infarction, pulmonary embolism, cerebrovascular event, or other thrombotic events were observed.
Conclusions: In this trial, we were not able to demonstrate any difference in postoperative bleeding in patients pre-treated with aspirin after high-dose aprotinin or TXA. From a practical point of view, TXA is safe, less expensive than aprotinin, and easy to handle, and can be recommended in patients pre-treated with aspirin to improve postoperative hemostasis.     

The incidence of awareness,and amnesia for perioperative events,after cardiac surgery with lorazepam and fentanyl anesthesia

One hundred patients (mean age 59 ± 10 years) were premedicated with morphine, 0.15 mg/kg, and scopolamine, 0.008 mg/kg. Anesthesia was induced with lorazepam, 50 μg/kg, followed by fentanyl, 50 μg/kg, oxygen and pancuronium, 0.15 mg/kg. Isoflurane was given for short periods before and after cardiopulmonary bypass to 57 patients when hypertension was uncontrolled by addition of fentanyl and/or nitroglycerin. Morphine was used as the sole sedative postoperatively. Patients were interviewed following discharge from the surgical intensive care unit to assess the incidence of operative awareness, and to assess amnesia for events occurring during four preoperative and two postoperative periods of the patients' hospital stay. During three preoperative periods (day of admission, evening before, and morning before operation), 1%, 3%, and 2% of patients had complete amnesia, and 19%, 41%, and 31% had partial amnesia of events. Fifty-five percent of patients exhibited complete, and 34% of patients exhibited partial amnesia to events occurring in the preinduction period. Two patients reported intra-operative awareness (noises, conversation) occurring at the end of the anesthetic. In the two postoperative periods (morning of the day after surgery and intensive care stay), 9% and 15% of patients had complete, and 35% and 47% of patients exhibited partial amnesia. Amnesia was statistically significantly greater in patients over 60 years of age in the preinduction period. Duration of cardiopulmonary bypass did not affect the incidence of amnesia.     

Preoperative aspirin therapy and reoperation for bleeding after coronary artery bypass surgery

We performed a case-control study to estimate the relative risk of reoperation for bleeding in coronary artery bypass graft patients who had taken aspirin within the 7 days preceding surgery. Comparison of 90 cases of reoperation with 180 matched control subjects gave an estimated odds ratio for reoperation of 1.82 (95% confidence interval, 1.23 to 3.32). Although their preoperative coagulation values were similar, cases used significantly more whole blood (cases, 9.5 +/- 5.2 units; control subjects, 3.0 +/- 2.0 units; median +/- interquartile range), packed red blood cells (cases, 2.1 +/- 4.0 units; control subjects, 0.9 +/- 2.0 units), and platelets (cases, 12.2 +/- 12.0 units; control subjects, 2.9 +/- 4.0 units) than control subjects. Cases had intensive care unit stays of 4.7 +/- 5.7 days (mean +/- SD) vs 2.1 +/- 1.9 days for control subjects and postoperative hospitalizations of 10.9 +/- 8.2 days vs 7.0 +/- 3.2 days for control subjects. We conclude that aspirin exposure within 7 days before coronary bypass surgery is associated with an increased rate of reoperation for bleeding and that reoperation is associated with large increases in transfusion requirements and intensive care unit and hospital stays.     

Porcine heparin increases postoperative bleeding in cardiopulmonary bypass patients

Summary One hundred thirteen patients undergoing cardiopulmonary bypass were randomly assigned to receive either bovine or porcine heparin. Heparin was infused at 4.5 mg/kg during bypass and administered at the lesser of 70 units/kg or 5000 units/dose at 12-hour intervals postoperatively. Platelet counts decreased to 45% of preoperative levels during the first 3 days postoperatively (porcine, 44±13%, n =50; bovine, 46±15%), but returned to preoperative levels by the seventh postoperative day. The average blood loss in the porcine heparin group significantly exceeded that of the bovine heparin group (porcine, 1350.7±727.8 ml; bovine, 1059.6±381.0 ml; p<.01). Consequently, the platelet transfusion requirement was greater in the porcine heparin group (porcine, 1.7±3.9 units; bovine, 0.5±1.7 units; p<.05); however, blood and blood component (with the exception of platelets) administration was not significantly different between the two groups. The four patients taking anticoagulants or antiinflammatory agents in the porcine group required a mean of 8.5 units of red blood cells (RBC) plus supplemental platelets. The seven such patients in the bovine group received a mean of 3.0 units of RBC and no platelets. Thus, the use of porcine heparin resulted in a generalized increase in postoperative bleeding with increased management problems in patients undergoing cardiopulmonary bypass.     

Effect of pretreatment with aspirin versus aspirin plus dipyridamole on frequency and type of acute complications of percutaneous transluminal coronary angioplasty

It is unknown whether the addition of dipyridamole to aspirin as pretreatment for patients undergoing percutaneous transluminal coronary angioplasty (PTCA) decreases acute complications. In this study 232 patients were prospectively randomized to receive either aspirin 325 mg orally 3 times daily (group 1, n = 115) or aspirin 325 mg orally 3 times daily plus dipyridamole 75 mg orally 3 times daily (group 2, n = 117) before elective PTCA. All clinical, angiographic and PTCA-related variables were similar between groups. Angiographic success rate was 93% in both groups. Clinical success was achieved in 107 patients (92%) in group 1 and in 101 patients (88%) in group 2 (difference not significant). Q-wave myocardial infarction occurred in 2 patients (1.7%) in group 1 and 5 patients (4.3%) in group 2 (difference not significant). Emergency coronary artery bypass grafting was required in 3 patients (2.6%) in group 1 and 7 patients (6.1%) in group 2 (difference not significant). There was 1 in-hospital death (in group 2). In this study, the addition of dipyridamole to aspirin as pretreatment of patients undergoing PTCA did not significantly reduce acute complications compared to aspirin alone.     

The effect of preoperative aspirin administration on postoperative level of von Willebrand factor in off-pump coronary artery bypass surgery

The effect of preoperative administration of aspirin on endothelial function in the patients undergoing off-pump coronary artery bypass (OPCAB) surgery is still unclear. Fifty consecutive patients undergoing OPCAB between May 2006 and May 2007 were equally divided into two groups — one without preoperative aspirin (group A; the first 25 patients) and the other with preoperative aspirin (group B; the next 25 patients). We investigated the degree of postoperative endothelial dysfunction by measuring the von Willebrand factor activity, which is a possible indicator of endothelial damage. The level of von Willebrand factor was not different between groups before surgery (group A 166% ± 53% vs group B 181% ± 62%; P = 0.39). Immediately after surgery it was significantly higher than before surgery in group A (231% ± 79%; rate of increase 1.24 ± 0.58), but not in group B (183% ± 77%; rate of increase 1.03 ± 0.55) (P < 0.02). The level was still significantly higher in group A than in group B on postoperative day 1 (group A 294 ± 66 vs 254 ± 51; P = 0.03), but there was no difference between groups on postoperative day 6. Although the frequency of blood transfusion was higher in group B, there was no difference in the amount of intraoperative bleeding between the groups. Preoperative use of aspirin before OPCAB could suppress the postoperative increase in von Willebrand factor, a possible indicator of endothelial damage, only in the early postoperative phase.     

Role of preoperative atorvastatin administration in protection against postoperative atrial fibrillation following conventional coronary artery bypass grafting

Atrial fibrillation (AF) is one of the most common postoperative arrhythmias in patients who undergo coronary artery bypass grafting (CABG). The aim of this study was to evaluate the effect of preoperative atorvastatin on postoperative atrial fibrillation following coronary artery bypass grafting with cardiopulmonary bypass (CCABG). One hundred consecutive patients undergoing elective CCABG, without history of AF or previous statin treatment, were enrolled and randomly assigned to a statin group (atorvastatin 20 mg/d, n = 49) or a control group (placebo, n = 51) starting 7 days preoperatively. The primary endpoint was the occurrence of postoperative AF. C-reactive protein (CRP) levels were assessed in all selected patients before surgery and every 24 hours postoperatively until discharge from hospital. Atorvastatin significantly reduced the incidence of postoperative AF and postoperative peak CRP level versus placebo (18% versus 41%, P = 0.017; 129.3 ± 24.3 mg/L versus 149.3 ± 32.5 mg/L, P < 0.0001). Kaplan-Meier curves confirmed a significantly better postoperative atrial fibrillation-free survival in the statin group (χ(2) = 7.466, P = 0.006). Logistic regression analysis showed preoperative atorvastatin treatment was an independent factor associated with a significant reduction in postoperative AF (OR = 0.235, P = 0.007), whereas high postoperative CRP levels were associated with increased risk (OR = 2.421, P = 0.015). Preoperative atorvastatin administration may inhibit inflammatory reactions to prevent atrial fibrillation following coronary artery bypass grafting with cardiopulmonary bypass.     

Minor infection encouraged by steroid administration during cardiac surgery

The aim of this study was to investigate whether steroid administration would increase the risk of postoperative infection. Sixty adults who underwent elective cardiac surgery under cardiopulmonary bypass were prospectively randomized into two groups. Thirty-one patients received hydrocortisone (50 mg x kg(-1)) before and after cardiopulmonary bypass, the other 29 served as controls. Various hemodynamic and pulmonary measurements were obtained perioperatively, and the white blood cell counts and levels of C-reactive protein were checked up to the 14(th) postoperative day. Steroid administration did not have any favorable effects during the perioperative period. Re-administration of antibiotics was needed in 7 patients (22.6%) after the 7(th) postoperative day in the steroid group, and in 3 (10.3%) in the control group. The peak white cell counts and C-reactive protein levels after the 7(th) postoperative day were significantly higher in the steroid group. Steroid administration offered no clinical benefit to patients undergoing cardiac surgery with cardiopulmonary bypass, and it may encourage minor infections in the late postoperative period.