Reexploration for hemorrhage following coronary artery bypass grafting: incidence and risk factors. Northern New England Cardiovascular Disease Study Group

Clopidogrel and Bleeding after General Surgery Procedures

Although many studies in the cardiothoracic literature exist about the relationship between clopidogrel and postoperative bleeding, there is scarce data in the general surgery literature. We assessed whether there are increased bleeding complications, morbidity, mortality, and resource utilization in patients who are on clopidogrel (Plavix®) within 1 week before undergoing a general surgery procedure. Fifty consecutive patient charts were retrospectively reviewed after identifying patients who had pharmacy orders for clopidogrel and who underwent a general surgery procedure between 2003 and 2007. Patients who took clopidogrel within 6 days before surgery (group I, n = 28) were compared with patients who stopped clopidogrel for 7 days or more (group II, n = 22). A larger percentage of patients who took their last dose of clopidogrel within 1 week of surgery (21.4% vs 9.5%) had significant bleeding after surgery requiring blood transfusion. However, there were no significant differences between the groups in operative or postoperative blood transfusions ( P = 0.12, 0.53), decreases in hematocrit ( P = 0.21), hospital stay ( P = 0.09), intensive care unit stay ( P = 0.41), late complications ( P = 0.45), or mortality ( P = 0.42). Although our cohort is limited in size, these results suggest that in the case of a nonelective general surgery procedure where outcomes depend on timely surgery, clopidogrel taken within 6 days before surgery should not be a reason to delay surgery. However, careful attention must be paid to meticulous hemostasis, and platelets must be readily available for transfusion in the operating room.

Effect of clopidogrel on bleeding and transfusions after off-pump coronary artery bypass graft surgery: impact of discontinuation prior to surgery

OBJECTIVE

The use of antiplatelet drugs to treat acute myocardial infarction, unstable angina, acute coronary syndrome and secondary prevention following percutaneous coronary interventions is well accepted. However, it constitutes a serious risk of bleeding for patients undergoing coronary artery bypass grafting surgery (CABG). We evaluated the effect of aspirin and clopidogrel (CPDG), both irreversible platelet aggregation inhibitors, on operative bleeding and determined the optimal timing for their discontinuation before surgery.

METHOD

Between July 2001 and December 2004, we reviewed our experience with 453 patients undergoing off-pump CABG surgery (OPCAB) who received CPDG (n=101) or not (n=352) preoperatively, and compared the intraoperative and postoperative bleeding to determine risks factors associated with blood or platelet transfusions.

RESULTS

Clopidogrel in OPCAB surgery is associated with higher intraoperative (702.24 ml vs 554.13 ml, p=0.03) and postoperative bleeding (864.93 ml vs 603.75 ml, p=0.03). The mean operative blood loss is higher in patients still on CPDG at the time of surgery compared to patients off CPDG at least 72 h before surgery (802 ml vs 554.13 ml, p<0.0001). Blood loss in the later subgroup of patients is comparable to the control group without CPDG (p=NS). Clopidogrel is associated with more platelet transfusions (OR=11.79, [1.48; 93.86]).

CONCLUSION

Blood loss is higher in OPCAB patients receiving clopidogrel before surgery. However, discontinuation of clopidogrel three days (72 h) prior to the operation demonstrated a similar blood loss pattern compared to a control group. Clopidogrel is associated with more platelets, but not red blood cell transfusions following OPCAB surgery.

Coagulation and fibrinolytic protein kinetics in cardiopulmonary bypass

The development of Cardiopulmonary Bypass (CPB) catopulted the field of cardiothoracic surgery into a new dimension--one that changed the lives of individuals with congenital and acquired heart disease worldwide. Despite its contributions, CPB has clear limitations and creates unique challenges for clinicians and patients alike, stemming from profound hemostatic pertubations and accompanying risk for bleeding and possibly thrombotic complications.

Sonoclot analysis in elderly compared with younger patients undergoing coronary surgery

BACKGROUND

The Sonoclot analyzer is a point-of-care method for assessment of the clotting mechanism in whole blood. The results are available within 20 min. The aim of the present study was to investigate whether repeated Sonoclot analyses could identify peri-operative differences in hemostatic function between elderly and younger patients undergoing coronary artery bypass grafting (CABG). In addition, we investigated whether Sonoclot analyses could identify disturbances in hemostatic function leading to post-operative bleeding.

METHODS

Twenty-five elderly and 25 younger patients undergoing CABG were included. Blood samples for Sonoclot analyses were drawn pre-operatively, during surgery, and during the first 20 post-operative hours. The Sonoclot variables sonACT, clot rate, time-to-peak, amplitude of the peak, and R3 were analyzed, and the results were compared between the two groups. Post-operative blood loss volumes were recorded and correlated to the Sonoclot variables. The Sonoclot variables were also correlated to previously reported results on various hemostatic variables measured in the same patient population.

RESULTS

There was a significant difference in sonACT between the two groups (P=0.018). There were no differences between the groups in any of the other Sonoclot variables. There were no significant correlations between any of the Sonoclot variables and post-operative bleeding, or between the Sonoclot variables and other hemostatic variables.

CONCLUSIONS

The difference in sonACT between the two groups indicates a reduced hemostatic function in the elderly patients. However, repeated Sonoclot analyses were not able to identify more specific disturbances in hemostatic function, and did not predict increased post-operative bleeding.

Preoperative Fibrinogen Levels as a Predictor of Postoperative Bleeding after Open Heart Surgery

BACKGROUND

Open heart surgery still involving major bleeding continues to be a major challenge after cardiac surgery and is also a significant cause of morbidity and mortality. Most hemostatic factors are intercorrelated with postoperative bleeding, and fibrinogen seems the most fundamental hemostatic risk factor for open heart surgery.

METHODS

The study included 97 patients who underwent elective coronary artery surgery (78 men and 19 women; mean age, 60.9 +/- 10.3). Preoperative blood samples were obtained and preoprative quantitative determination of plasma fibrinogen levels were measured by the clotting method of Clauss using the fibrinogen kit. Patients were operated on by the same team and the same technique. The total amount of drainage blood from chest tubes was recorded after termination of operation.

RESULTS

There were statistical significance between the fibrinogen levels and the drainage (r = -0.897, P < .001). Chest drainage was a mean of 972 mL (range, 240-2445 mL) in the first 48 hours after sternotomy closure. Fibrinogen level and relation to age was statistically significant (P = .015). There was no statistical significance between fibrinogen levels and gender (male gender = 400.7 +/- 123.0 versus female gender = 395.6 +/- 148.1; P = .877) and between drainage and gender (male gender = 968.2 +/- 538.5 versus female gender = 990.0 +/- 554.7; P = .876). Two patients (2%) died early after the surgery. There were no significant differences between the postoperative bleeding and cardiopulmonary bypass time (P = .648) or cross-clamp time (P = .974).

CONCLUSION

The results of this study suggested that low preoperative fibrinogen level appears to be a useful diagnostic marker to assess the activity of the coagulation system, and that its preoperative level may serve as a potential risk factor for postoperative bleeding after coronary artery bypass surgery.

Use of activated recombinant factor VII for severe coagulopathy post ventricular assist device or orthotopic heart transplant

BACKGROUND

Ventricular assist devices(VAD) implantation/removal is a complex surgical procedure with perioperative bleeding complications occurring in nearly half of the cases. Recombinant activated factor VII (rFVIIa) has been used off-label to control severe hemorrhage in surgery and trauma. We report here our experience with rFVIIa as a rescue therapy to achieve hemostasis in patients undergoing orthotopic heart transplant (OHT) and/or VAD implantation.

METHODS

A retrospective review was conducted from Jan 03 to Aug 05 for patients who received rFVIIa for the management of intractable bleeding unresponsive to standard hemostatic blood component therapy. Blood loss and the quantity of blood products, prior to, and for at least 12 hours after, administration of rFVIIa were recorded.

RESULTS

Mean patient age was 53, (38-64 yrs), mean dose of rFVIIa administered was 78.3 microg/kg (24-189 microg/kg) in 1-3 doses. All patients received the drug either intraoperatively or within 6 hours of arrival in ICU. Mean transfusion requirements and blood loss were significantly reduced after rFVIIa administration (PRBC's; 16.9 +/- 13.3 to 7.1 +/- 6.9 units, FFP; 13.1 +/- 8.2 to 4.1 +/- 4.9 units, platelets; 4.0 +/- 2.8 to 2.1 +/- 2.2 units, p < 0.04 for all). 5 patients expired including 3 with thromboembolic cause. One patient developed a lower extremity arterial thrombus, and another deep vein thrombosis.

CONCLUSION

In this review, there was a significant decrease in transfusion requirement and blood loss after rFVIIa administration. Although, 5/17 developed thromboembolic complications, these patients may have been at higher risk based on the multiple modality therapy used to manage intractable bleeding. Nevertheless, the exact role of rFVIIa with respect to development of thromboembolic complications cannot be clearly determined. Further investigation is needed to determine rFVIIa's safety and its effectiveness in improving postoperative morbidity and mortality.

Monitoring the rate of re-exploration for excessive bleeding after cardiac surgery in adults

BACKGROUND

The monitoring of adverse events in clinical care can be an important part of quality assurance. There is little evidence on the monitoring of re-exploration after cardiac surgery.

OBJECTIVE

To apply statistical monitoring techniques to the rate of re-exploration for excessive bleeding in adult patients undergoing cardiac surgery procedures using cardiopulmonary bypass at Geelong Hospital, Victoria, Australia, between 1997 and 2003.

METHODS

Shewhart charts, moving average plots and cumulative sum (CUSUM) charts were used to demonstrate changes in the rate of re-exploration over time.

RESULTS

A CUSUM chart was used retrospectively at a time of perceived deteriorating clinical outcomes in patients of the cardiac surgery service. At this time, an intervention aimed at reducing the re-exploration rate was performed, and subsequent CUSUM charts indicated an improvement in this rate. The CUSUM chart has become an important part of the quality feedback of clinical care outcomes within the Anaesthesia & Pain Management unit of Geelong Hospital.

CONCLUSION

Statistical monitoring techniques for quality assurance can identify important changes in clinical performance, and their adoption by clinicians is recommended.

The effect of preoperative clopidogrel on bleeding after coronary artery bypass surgery

INTRODUCTION

Clopidogrel treatment is associated with a reduction in thrombotic complications in coronary stent placement, improved outcome after acute coronary syndromes, and decreased mortality in patients with coronary artery disease. The purpose of this study was to analyze the effect of preoperative clopidogrel exposure on bleeding complications, blood transfusions requirements, and reoperations in patients undergoing coronary artery bypass grafting (CABG).

PATIENTS AND METHODS

This study included 320 patients from a single institution that underwent an isolated CABG who were discharged between July 2003 and June 2004. The cohort of 320 patients was classified into 3 groups. The control group consisted of 255 patients that did not receive clopidogrel or stopped clopidogrel 7 days before surgery but were treated with aspirin instead. Clopidogrel I consisted of 25 patients that were taking clopidogrel within 3 days of surgery, and Clopidogrel II consisted of 40 patients that were taking clopidogrel 4 to 7 days before surgery. Patients were compared based on preoperative data (age, gender, use of clopidogrel, preoperative hemoglobin, and ejection fraction), intraoperative data (cross-clamp time), postoperative data (chest tube output, rate of reoperation, units of transfused blood, length of stay in the intensive care unit, and length of intubation).

RESULT

There were no significant differences among the 3 groups concerning age, sex, ejection fraction, or preoperative hemoglobin. There were no differences in length of intensive care unit stay and length of intubation among the 3 groups of patients. Patients in the clopidogrel I group had more units of blood transfused than either the control or the Clopidogrel II group (p=0.027). There is also a trend toward more chest tube output in clopidogrel I group compared with the control group. Fifteen patients (4.6%) of the total group required reoperation secondary to bleeding: 2 (8.0%) in the Clopidogrel I group, 2 (5%) in the clopidogrel II group, and 11 (4.3%) in the control group (p=0.41).

CONCLUSION

This study demonstrated that clopidogrel within 3 days preoperatively increases the requirement for blood transfusion in patients undergoing CABG. Waiting more than 3 days after the last dose of clopidogrel decreases blood transfusion requirements. There is also a trend toward more postoperative bleeding for those patients that took clopidogrel within 3 days before their CABG. The reoperation rate of patients that took clopidogrel within 3 days of their procedure required almost twice as many reoperations as the patients that did not take clopidogrel.

Transfusion Algorithms and How They Apply to Blood Conservation: The High-risk Cardiac Surgical Patient

Considerable blood product support is administered to the cardiac surgery population. Due to the multifactorial etiology of bleeding in the cardiac bypass patient, blood products frequently and empirically are infused to correct bleeding, with varying success. Several studies have demonstrated the benefit of algorithm-guided transfusion in reducing blood loss, transfusion exposure, or rate of surgical re-exploration for bleeding. Some transfusion algorithms also incorporate laboratory-based decision points in their guidelines. Despite published success with standardized transfusion practices, generalized change in blood use has not been realized, and it is evident that current laboratory-guided hemostasis measures are inadequate to define and address the bleeding etiology in these patients.

Management of antiplatelet therapy for minimization of bleeding risk before cardiac surgery

Antiplatelet therapy is commonly administered for primary and secondary prevention of stroke, recurrent angina, myocardial infarction, and death in patients with cardiovascular disorders. It also is associated with an increased risk of bleeding. We describe the management of antiplatelet therapy in patients undergoing coronary artery bypass graft surgery. In addition, we provide basic information about the mechanisms of action by which the most common antiplatelet agents inhibit platelet function. This information is integrated with results from pharmacologic studies and clinical trials. Determining the net effect in patients undergoing coronary artery bypass graft surgery requires knowledge about the pharmacokinetics, pharmacodynamics, and clinical efficacy of each drug, and an estimation of the absolute thrombotic versus hemorrhagic risk for each patient.

Impact of platelet testing on presurgical screening and implications for cardiac and noncardiac surgical procedures

Bleeding is a common complication of cardiac surgery, accounting for a significant portion of the total transfusions performed in the United States. This may be due in part to surgical factors and to the fibrinolysis and platelet activation induced by cardiopulmonary bypass. The increasing frequency with which antiplatelet medications are used to prevent thrombosis in cardiac surgical patients with cardiovascular disease also elevates the risk for postoperative bleeding. The resulting coagulopathy and need for transfusions may increase morbidity and mortality risk in cardiac surgical patients, depending on the specific antiplatelet agent used, as well as on patient factors. Empiric platelet transfusion, the frequency of which varies greatly among institutions, does not reliably prevent these complications and may even increase the risk for adverse outcomes. Platelet function testing, particularly with newer testing systems, may be a valuable tool for making decisions about stopping antiplatelet drug administration, surgical timing with respect to bleeding risk, and platelet transfusion in cardiac surgical patients.

Balancing the benefit and risk of oral antiplatelet agents in coronary artery bypass surgery

Concern about possible hemorrhagic complications arising from use of oral antiplatelet agents in immediate proximity to coronary artery bypass graft (CABG) surgery leads many clinicians to avoid or discontinue these agents preoperatively. Recent evidence suggests that aspirin and clopidogrel can be used with relative safety in the preoperative period; dual antiplatelet therapy in the 5 days immediately preceding CABG surgery results in a moderate and variable increase in the risk of procedural bleeding. This modest hemorrhagic risk may be acceptable, given the clinical benefits of sustained antiplatelet therapy in preventing graft occlusion and ischemic complications pre- and post-CABG. Because the bleeding risk with aspirin is dose dependent, use of a low dose is preferred post-CABG.

The impact of administration of tranexamic acid in reducing the use of red blood cells and other blood products in cardiac surgery

Background

To study the effect of administration of tranexamic acid on the use of blood and blood products, return to theatre for post-operative bleeding and the length of intensive care stay after primary cardiac surgery, data for 4191 patients, of all priorities, who underwent primary cardiac operation during the period between 30/10/00 and 21/09/04 were analysed.

Methods

Retrospective analysis of data collected prospectively during the study period. The main outcome measures were whether or not patients were transfused with red blood cells, fresh frozen plasma or any blood product, the proportion of patients returned to theatre for investigation for post-operative bleeding and length of stay in the intensive care unit. We performed univariate analysis to identify the factors influencing the outcome measures and multivariate analysis to identify the effect of administration of tranexamic acid on the outcome measures.

Results

Administration of tranexamic acid was an independent factor affecting the transfusion of red blood cells, fresh frozen plasma or any blood product. It was also an independent factor influencing the rate of return to theatre for exploration of bleeding. The odds of receiving a transfusion or returning to theatre for bleeding were significantly lower in patients receiving tranexamic acid. The administration of tranexamic acid also significantly decreased blood loss. We did not find any association between the administration of tranexamic acid and the length of intensive care stay.

Conclusion

Based on the analysis of 4191 patients who underwent a primary cardiac operation, administration of tranexamic acid decreased the number of patients exposed to a transfusion or returned to theatre for bleeding in our institute.

Determinants of complications with recombinant factor VIIa for refractory blood loss in cardiac surgery

PURPOSE

Recombinant factor VIIa (rFVIIa) is being used for refractory, excessive blood loss (EBL) after cardiac surgery, but its safety for this indication is not known.

METHODS

The unadjusted and risk-adjusted adverse event (AE) rates were compared between 114 consecutive cardiac surgical patients who received rFVIIa for refractory EBL and 541 concurrent patients who developed EBL but did not receive rFVIIa. Similarly, timing of rFVIIa therapy was assessed by dichotomizing rFVIIa patients based on median number of red blood cell (RBC) units received before therapy. The measured AE was a composite of death, stroke, renal failure, myocardial infarction, and major vein thrombosis. For risk adjustment, logistic regression models for this outcome were constructed using known predictors of AEs.

RESULTS

The median RBC units transfused before rFVIIa therapy was eight. The AE rates in the untreated, early (< or = 8 U), and late (> 8 U) treated patients were 24% (129/541), 30% (20/66), and 60% (29/48). The risk-adjustment model included total RBC units, pump time, weaning difficulty, gender, weight, and age. The unadjusted and adjusted AE odds ratios (OR) in the treated vs untreated groups were 2.41 [confidence interval (CI) 1.58-3.67; P < 0.0001] and 1.04 (CI 0.60-1.81; P = 0.9). In the rFVIIa group, the adjusted AE OR was lower in the early treated group (OR 0.41; CI 0.18-0.92; P = 0.03).

CONCLUSION

In cardiac surgical patients with refractory hemorrhage, rFVIIa therapy is not associated with increased risk of AEs, and early treatment may be associated with better outcomes.

Prediction of massive blood transfusion in cardiac surgery

PURPOSE

In cardiac surgery with cardiopulmonary bypass (CPB), excessive blood loss requiring the transfusion of multiple red blood cell (RBC) units is a common complication that is associated with significant morbidity and mortality. The objective of this study was to develop a prediction rule for massive blood transfusion (MBT) that could be used to optimize the management of, and research on, at-risk patients.

METHODS

Data were collected prospectively over the period from 2000 to 2005, on patients who underwent surgery with CPB at one hospital. Patients who received > or = five units of RBC within one day of surgery were classified as MBT. Logistic regression was used to appropriately select and weigh perioperative variables in the prediction rule, which was developed on the initial 60% of the sample and validated on the remaining 40%.

RESULTS

Of the 10,667 patients included, 925 (8.7%) had MBT. The clinical prediction rule included 12 variables (listed in order of predictive value: CPB duration, preoperative hemoglobin concentration, body surface area, nadir CPB hematocrit, previous sternotomy, preoperative shock, preoperative platelet count, urgency of surgery, age, surgeon, deep hypothermic circulatory arrest, and type of procedure) and was highly discriminative (c-index = 0.88). In the validation set, those classified as low-, moderate-, and high-risk by a simple risk score derived from the prediction rule had a 5%, 27%, and 58% chance of MBT, respectively.

CONCLUSION

A clinical prediction rule was developed that accurately identified patients at low-risk or high-risk for MBT. Studies are needed to determine the external generalizability and clinical utility of the prediction rule.

Small-Dose Recombinant Activated Factor VII (NovoSeven??) in Cardiac Surgery

Recombinant activated factor VII (rFVIIa) has been used at different doses in cardiac surgery patients. We tested the efficacy of small-dose rFVIIa in patients with intractable bleeding after cardiac surgery. The study group comprised 15 cardiac surgery patients with intractable bleeding treated with small-dose (1.2 mg) rFVIIa as a slow IV bolus at the end of complete step-by step transfusion protocol. Fifteen matched patients undergoing the same transfusion protocol in the pre-rFVIIa era represented the control group. Blood loss at the end of the transfusion protocol was a primary outcome. Median, 25th-75th 24-h blood loss percentiles were 1685 (1590-1770) mL versus 3170 (2700-3850) mL in study group and controls, respectively (P = 0.0004). Transfused red blood cells, fresh-frozen plasma, and platelets in the study group and controls were as follows: 7 (4-8) U versus 18 (12-21) U (P = 0.001); 7.5 (6-11) U versus 11 (9-15) U (P = 0.003); 0 (0-4) U versus 9 (6-13) U (P = 0.001). In addition, significant improvements of prothrombin time (P = 0.015), international normalized ratio (P = 0.006), activated partial prothrombin time (P = 0.01), and platelet count (P = 0.003) were detected in the study group versus controls. Finally, patients receiving rFVIIa showed a reduced intensive care unit length of stay (chi2 = 15.9, P = 0.0001) and had infrequent surgical re-exploration (chi2 = 16.2,P < 0.0001). Small-dose rFVIIa showed satisfactory results in cardiac patients with intractable bleeding. Further randomized studies are necessary to confirm our findings.

Effect of Clopidogrel Premedication in Off-Pump Cardiac Surgery

Background— Premedication with clopidogrel has reduced thrombotic complications after percutaneous coronary revascularization procedures. However, because of the enhanced and irreversible platelet inhibition by clopidogrel, patients requiring surgical revascularization have a higher risk of bleeding complications and transfusion requirements. A principal benefit of surgical coronary revascularization without cardiopulmonary bypass is its lower hemorrhagic sequelae. The purpose of this study was to evaluate the effect of preoperative clopidogrel administration in the incidence of hemostatic reexploration, blood product transfusion rates, morbidity, and mortality in patients undergoing off-pump coronary artery bypass graft surgery using a large patient sample and a risk-adjusted approach.

Methods and Results— Two hundred eighty-one patients (17.9%) did and 1291 (82.1%) did not receive clopidogrel before their surgery, for a total of 1572 patients undergoing isolated off-pump coronary artery bypass graft surgery between January 2000 and June 2002. Risk-adjusted logistic regression analyses and a matched pair analyses by propensity scores were used to assess the association between clopidogrel administration and reoperation as a result of bleeding, intraoperative and postoperative blood transfusions received, and the need for multiple transfusions. Hemorrhage-related preoperative risk factors identified in the literature and those found significant in a univariate model were used. The clopidogrel group had a higher likelihood of hemostatic reoperations (odds ratio [OR], 5.1; 95% confidence interval [CI], 2.47 to 10.47; P <0.01) and an increased need in overall packed red blood cell (OR, 2.6; 95% CI, 1.94 to 3.60; P <0.01), multiple unit (OR, 1.6; 95% CI, 1.07 to 2.48; P =0.02), and platelet (OR, 2.5; 95% CI, 1.77 to 3.66; P <0.01) transfusions. Surgical outcomes and operative mortality (1.4% versus 1.4%; P =1.00) were not statistically different.

Conclusions— Clopidogrel administration in the cardiology suite increases the risk for hemostatic reoperation and the requirements for blood product transfusions during and after off-pump coronary artery bypass graft surgery.

Increased Fibrinolysis and Platelet Activation in Elderly Patients Undergoing Coronary Bypass Surgery

Reexploration for hemorrhage after cardiac surgery is associated with increased morbidity and mortality. Elderly cardiac surgical patients have an increased risk of excessive bleeding and reexploration. In the present study we investigated the perioperative hemostatic function in elderly patients compared with younger patients undergoing coronary artery bypass grafting. Twenty-five elderly (75 yr and older) and 25 younger (younger than 60 yr) patients were included in the study. Blood samples for the analysis of platelet counts, international normalized ratio, activated partial thromboplastin time, fibrinogen, d-dimer, antithrombin, prothrombin fragment 1 + 2, thrombin-antithrombin complex, plasmin inhibitor, neutrophil-activating peptide 2, and platelet-monocyte complexes were drawn preoperatively, 30 min, and 3 h postoperatively and approximately 20 h postoperatively. Elderly patients had an increased activation of the hemostatic system. In particular, elderly patients showed a more pronounced increase in fibrinolysis and platelet activation postoperatively compared with younger patients.

Recombinant Activated Factor VII: Treating Postoperative Hemorrhage in Cardiac Surgery

BACKGROUND

The purpose of this study is to review the effect of recombinant activated factor VII (rFVIIa) as rescue therapy in continuing severe postoperative hemorrhage, despite conventional measures in a series of cardiac patients at our institution.

METHODS

A series of all patients who received rFVIIa as rescue therapy for uncontrollable postoperative hemorrhage after cardiac surgery over a 2-year period was analyzed. We assessed and compared the use of blood products, coagulation indicators (international normalized ratio [INR], activated partial thromboplastin [APTT], and fibrinogen), and platelet levels immediately before and after the rFVIIa was given.

RESULTS

Twelve patients received rFVIIa. Eight patients (75%) had thoracic aortic surgery. Bleeding stopped in all cases. Prior to the administration of rFVIIa, mean blood product usage was the following: fresh frozen plasma (FFP) 18.7 units (range, 10-40); packed cells 7.7U (range, 0-18); cryoprecipitate 19.5U (range, 8-32); and platelets 22.5U (range, 10-40). The mean coagulation results immediately prior to rFVIIa were the following: INR 2.0 (range, 1.3-8.5); APTT 60 seconds (range, 30-220); fibrinogen 3.2 gm/L (range, 1.6-6.4), and platelet count was 174,000 (range, 78,000-257,000). After rFVIIa administration the mean blood product usage was the following: FFP 0U (range, 0-2); red cells 0U (range, 0-1); cryoprecipitate 0 (range, 0); and platelets 0 (range, 0); p less than 0.0005. The mean INR was 0.9 (range, 0.7-1.5), p less than 0.001; mean APTT was 42 seconds (range, 30-87), mean fibrinogen was 3.1 (range, 1.7-4.5), and the mean platelet count was 170,000 (range, 93,000-289,000); p values not significant. There were no thrombotic complications, no cardiac ischemic events, and no deaths.

CONCLUSIONS

Our results support the use of rFVIIa as rescue therapy in severe, uncontrollable, nonsurgical, postoperative hemorrhage after cardiac surgery as efficacious and safe.

Adverse 30-Day Outcomes After Cardiac Surgery: Predictive Role of Intraoperative Myocardial Acidosis

BACKGROUND

Regional myocardial acidosis in patients undergoing cardiac surgery has been shown to be reflective of regional myocardial ischemia. This study elucidates the relationship between intraoperative regional myocardial acidosis and 30-day postoperative outcomes after cardiac surgery.

METHODS

Intramyocardial tissue pH in the anterior and posterior left ventricular walls was measured in 397 adult patients undergoing valve replacement or coronary revascularization surgery between 1987 and 2001. Dedicated nurses and research assistants prospectively collected preoperative, intraoperative, and outcomes data. Regional myocardial acidosis was defined in terms of pH thresholds identified by recursive partitioning. Adverse 30-day outcome, defined as death or any one of six complications, was the dependent variable in a multivariate logistic regression analysis. A morbidity score was developed on the basis of the sensitivity of each of the six complications in predicting death, and was the dependent variable in a multivariate linear regression analysis.

RESULTS

During the period of aortic clamping, a mean intramyocardial tissue pH less than 6.85 was identified to be significant by recursive partitioning, and was encountered in either the anterior or posterior left ventricular wall in 85.4% of patients. After adjusting for preoperative and intraoperative variables, this pH threshold was found to be significantly associated with increased adverse outcomes within 30 days after surgery (p = 0.045). It was also significantly associated with increase in the morbidity score (p = 0.05).

CONCLUSIONS

Regional myocardial acidosis of a magnitude frequently encountered during aortic clamping is an independent determinant of adverse 30-day outcomes after cardiac surgery. Its reversal by pH-guided myocardial management has the potential of improving postoperative patient outcomes.

Recombinant activated factor VII for refractory bleeding after cardiac surgery—A retrospective analysis of safety and efficacy

OBJECTIVE

Analysis of safety and efficacy of recombinant activated factor VII (rFVIIa) used as the last resort for refractory bleeding after cardiac surgery.

DESIGN

Retrospective cohort analysis and matched pairs analysis with historic controls were performed. In the rFVIIa group, which also received conventional hemostatic therapy, data were collected for a median of 14 hrs from admission to the intensive care unit (ICU) to the administration of rFVIIa and for the following 24 hrs. In the control group, which received only conventional hemostatic therapy, data were collected for 14 and then for 24 hrs after admission to the ICU.

SETTING

University hospital.

PATIENTS

Twenty-four patients matched with historic controls.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

No thromboembolic complications were observed in the rFVIIa group. Blood loss and transfusion requirements were significantly reduced in the period after the administration of rFVIIa. However, in the 24-hr period after rFVIIa administration, blood loss (p = .140) and transfusion of packed red blood cells (p = .442) and fresh frozen plasma (p = .063) were not different between the rFVIIa and control groups. Platelet concentrates (p = .004) were transfused less in the control group. Mortality and 6-month survival rates were not different between the groups.

CONCLUSIONS

When used as a last resort, rFVIIa was safe but not incrementally efficacious over conventional hemostatic therapy.

Aprotinin Reduces Bleeding and Blood Product Use in Patients Treated With Clopidogrel Before Coronary Artery Bypass Grafting

BACKGROUND

An increased proportion of patients undergoing urgent coronary artery bypass graft surgery (CABG) is being treated with clopidogrel, an irreversible platelet inhibitor. Clopidogrel in combination with aspirin is known to augment bleeding, transfusion requirements, and reoperation rates after CABG. Aprotinin, a protease inhibitor, is approved for use in cardiac surgery to reduce bleeding. The aim of this study was to investigate whether or not intraoperative use of aprotinin decreases bleeding and number of transfusions after CABG in patients treated with clopidogrel less than 5 days before surgery.

METHODS

We retrospectively reviewed the medical records of all consecutive patients, with preoperative clopidogrel exposure less than 5 days before surgery, who underwent urgent CABG at our institution during 1 year (n = 33). Eighteen patients received a full-dose aprotinin regime intraoperatively whereas 15 patients not receiving aprotinin served as a control group.

RESULTS

The two groups were comparable with respect to baseline characteristics and operative data. Mean postoperative bleeding was 710 mL (95% confidence interval [CI]: 560 to 860) in the aprotinin group versus 1,210 mL (95% CI: 860 to 1550) in the control group (p = 0.004). The aprotinin group received fewer transfusions of packed red blood cells (0.9 U, 95% CI: 0.1 to 1.7, versus 2.7 U, 95% CI: 1.4 to 4.1; p = 0.01), platelets (0.1 U, 95% CI: 0 to 0.3, versus 0.6 U, 0.2 to 0.9; p = 0.02), and fewer blood product units (1.1 U, 95% CI: 0.1 to 2.0, versus 3.7 U, 95% CI: 2.1 to 5.4; p = 0.002). There were 3 reoperations for bleeding, all in the control group (p = 0.05).

CONCLUSIONS

Aprotinin reduces bleeding, transfusion requirements of packed red blood cells, platelets, and total blood units in patients on clopidogrel undergoing urgent CABG.

Clopidogrel and Bleeding After Coronary Artery Bypass Graft Surgery

BACKGROUND

There is evidence that clopidogrel (with or without aspirin) confers superior outcomes in patients with coronary artery disease. The purpose of this study is to review the effect of preoperative clopidogrel administration on clinical outcome, bleeding complications and resource utilization after coronary artery bypass graft surgery.

METHODS

Patient data were prospectively collected from 919 patients who had isolated coronary surgery during the period 2000 to 2003. Outcome comparisons were studied, firstly between patients who received preoperative clopidogrel with those who did not, and secondly between patients on clopidogrel only, aspirin only, both or neither medications.

RESULTS

Twenty-four patients (2.6%) were on clopidogrel only, 598 (65.1%) were on aspirin only, 61 (6.6%) were on both, and 236 (25.7%) were on neither. Clopidogrel (n = 85) versus no clopidogrel (n = 834): there were no significant differences in the off-pump patients. In the on-pump patients, the clopidogrel group had significantly increased bleeding (p = 0.02), blood transfused (p = 0.01), intensive care (p = 0.03), and hospital stays (p = 0.03). There were no significant differences in surgical reexploration, perioperative myocardial infarction, intraoperative balloon pump use, inotropic support or 30-day mortality. Clopidogrel versus aspirin versus both versus neither: patients on both clopidogrel and aspirin had significantly more postoperative bleeding than patients on aspirin alone or on neither medication.

CONCLUSIONS

The preoperative use of clopidogrel in patients undergoing coronary artery bypass graft surgery showed limited clinical benefits; however, its use significantly increased the risk of bleeding, blood transfusion, and resource utilization.

Major Clinical Outcomes in Adults Undergoing Thoracic Aortic Surgery Requiring Deep Hypothermic Circulatory Arrest: Quantification of Organ-Based Perioperative Outcome and Detection of Opportunities for Perioperative Intervention

OBJECTIVE

The purpose of this study was to describe clinical outcome after adult thoracic aortic surgery requiring standardized deep hypothermic circulatory arrest (DHCA), to determine mortality and length of stay, neurologic outcome, cardiorespiratory outcome, and hemostatic and renal outcome after DHCA.

DESIGN

Retrospective and observational.

SETTING

Cardiothoracic operating rooms and intensive care unit (ICU).

PARTICIPANTS

All adults requiring thoracic aortic repair with DHCA.

INTERVENTIONS

None. The study was observational.

MAIN RESULTS

The cohort size was 110. All patients received an antifibrinolytic. The mortality rate was 8.2%. The mean length of stay was 6.8 days (ICU) and 14.0 days (hospital). The incidence of stroke was 8.1% and postoperative delirium was 10.9%. The rate of postoperative atrial fibrillation was 43.6%; 19.1% required postoperative mechanical ventilation longer than 72 hours. Chest tube drainage was 931 mL for the first 24 hours. Postoperative dialysis was required in 1.8% of patients. Renal dysfunction occurred in 40% to 50% of patients, depending on the definition.

CONCLUSIONS

The protocol for DHCA at the authors' institution is associated with superior or equivalent perioperative outcomes to those reported in the literature. This study identified the need for further quantification of the clinical outcomes after DHCA in order to prioritize outcome-based hypothesis-driven prospective intervention in DHCA.

Bleeding in Cardiac Surgery: Its Prevention and Treatment—an Evidence-Based Review

Expected and unexpected bleeding occur frequently in patients undergoing cardiac surgery. Bleeding after cardiac surgery can be broadly divided into two groups: surgical (unrecognized bleeding vessel, anastomosis, or other suture line) or nonsurgical bleeding (caused by coagulopathy). Factors influencing both surgical and nonsurgical bleeding can be further broken down into those occurring preoperatively and those that occur intraoperatively and postoperatively. A thorough understanding of these factors is necessary to reduce bleeding. This is a desirable clinical goal, because excessive bleeding is associated with adverse outcomes.

Clinical Outcomes in Cardiac Surgery: Conventional Surgery versus Bloodless Surgery

Bleeding during and after cardiac operations and the effects of cardiopulmonary bypass hemodilution commonly result in blood transfusions. Excessive microvascular bleeding can result in re-exploration and prolonged hospitalization. Nearly 20% of all blood transfusions in the United States are associated with cardiac surgery. The risks associated with the use of allogeneic blood product transfusion include mistransfusion, immunologic complications, and transmission of infectious diseases. The large demand for blood products places significant pressure on the national blood supply, resulting in frequent shortages. The variability in transfusion practice of cardiac surgery patients suggests that sound blood management and a conservative approach to this population can result in reduced transfusions without increasing morbidity or mortality and avoiding complications associated with allogeneic blood transfusion.

Use of Recombinant Activated Factor VII for Bleeding Following Operations Requiring Cardiopulmonary Bypass

Postoperative bleeding is a common complication following cardiothoracic surgical procedures requiring cardiopulmonary bypass (CPB). Serious bleeding complications requiring the administration of blood products, hemostatic drugs, and even repeat surgery are associated with considerable morbidity, mortality, and resource consumption. Therapy with recombinant activated factor VII (rFVIIa) may be an effective treatment strategy for patients with refractory bleeding. We report the successful use of rFVIIa for the treatment of intractable postoperative bleeding following aortic aneurysm repair in two patients with Marfan syndrome. In both patients, surgical reexploration was avoided, and the patients' clinical status was stabilized after the administration of rFVIIa. In one patient, hemostasis was rapidly achieved within minutes, whereas hemostasis occurred gradually over several hours in the second patient. Including our personal experience with the two cases, the use of rFVIIa has been reported in 20 patients who required CPB for cardiothoracic surgical procedures. Hemostasis was achieved in all patients. In 14 patients (70%), rapid hemostasis was achieved following a single dose of rFVIIa (mean dose, 57 microg/kg). In the remaining six patients, gradual hemostasis was achieved after a mean of 3.4 doses (mean cumulative dose, 225 microg/kg). Two patients (10%) were believed to have experienced thromboembolic complications after the administration of rFVIIa (one was fatal), and, in another patient, intracoronary thrombosis was suspected but was not confirmed. In patients experiencing postoperative bleeding complications that are refractory to treatment with blood products, hemostatic agents, and/or repeat surgery, the use of rFVIIa may be considered.

Coagulation Disorders and Blood Product Use in Patients Undergoing Thoracoabdominal Aortic Aneurysm Repair

Repair of thoracoabdominal aortic aneurysms (TAAA) is associated with major blood loss, often exceeding the patient's intravascular volume, and complex intraoperative and postoperative coagulopathies necessitating large-volume transfusion of blood products. Abnormalities sufficient to cause thrombocytopenia or clinically important prolongation of clotting parameters are rarely present before surgery in elective aneurysms but are more common with ruptured aneurysms. The finding of intraoperative and postoperative deficiencies of clotting factors, along with thrombin generation and activation of the thrombolytic system, is reflective of massive blood losses, visceral ischemia, and massive transfusions. An aggressive strategy of transfusion of blood products is critical to the prevention of clinically significant coagulopathy during surgery. Adjuncts to reduce blood losses and blood product use include low-dose aprotinin or epsilon -aminocaproic acid, intraoperative blood salvaging, and acute normovolemic hemodilution. In TAAA repair, an average blood loss of 5000 to 6000 mL and average transfusion of allogeneic blood products of 50 to 60 U are to be anticipated.

Antifibrinolytic agents in cardiac surgery: Current controversies

Antifibrinolytic agents play a prominent role in adult cardiac surgery. This article is a review of the modern published experience of antifibrinolytic agent use in adult cardiac surgery. The use of tranexamic acid, epsilon-aminocaproic acid, and aprotinin is examined during primary cardiac surgery, deep hypothermic circulatory arrest, reoperative cardiac surgery, and off-pump coronary artery bypass surgery. In addition, the issues of vein graft patency and hypersensitivity reaction in the presence of antifibrinolytic agents are examined.

Clopidogrel administration prior to coronary artery bypass grafting surgery: the cardiologist's panacea or the surgeon's headache?

AIMS

Thrombotic complications after percutaneous coronary intervention procedures have decreased in past years mainly due to the use of clopidogrel antiplatelet therapy. However, the risk of bleeding due to enhanced and irreversible platelet inhibition in patients who will require surgical coronary revascularization instead has not been adequately addressed in the literature. The purpose of this study was to evaluate the effect of pre-operative clopidrogel exposure in haemorrhage-related re-exploration rates, peri-operative transfusion requirements, morbidity, and mortality in patients undergoing coronary artery bypass grafting (CABG) surgery.

METHODS AND RESULTS

A study population of 2359 patients undergoing isolated CABG between January 2000 and June 2002 was reviewed. Of these, 415 (17.6%) received clopidogrel prior to CABG surgery, and 1944 (82.4%) did not. A risk-adjusted logistic regression analysis was used to assess the association between clopidogrel pre-medication (vs. no) and haemostatic re-operation, intraoperative and post-operative blood transfusion rates, and multiple transfusions received. Haemorrhage-related pre-operative risk factors identified from the literature and those found significant in a univariate model were used. Furthermore, a sub-cohort, matched-pair by propensity scores analysis, was also conducted. The clopidogrel group had a higher likelihood of haemostatic re-operation [OR = 4.9, (95% CI, 2.63-8.97), P < 0.01], an increase in total packed red blood cell transfusions [OR = 2.2, (95% CI, 1.70-2.84), P < 0.01], multiple unit blood transfusions [OR = 1.9, (95% CI, 1.33-2.75), P < 0.01] and platelet transfusions [OR = 2.6, (95% CI, 1.95-3.56), P < 0.01]. Surgical outcomes and operative mortality [OR = 1.5, (95% CI, 0.36-6.51), P = 0.56] were not significantly different.

CONCLUSION

Pre-operative clopidogrel exposure increases the risk of haemostatic re-operation and the requirements for blood and blood product transfusion during, and after, CABG surgery.

Preoperative use of enoxaparin increases the risk of postoperative bleeding and re-exploration in cardiac surgery patients

OBJECTIVE

The purpose of this study was to investigate if the preoperative use of new platelet inhibitors and low-molecular-weight heparins may contribute to bleeding after cardiac surgery.

DESIGN

Retrospective data review.

SETTING

University teaching hospital.

PARTICIPANTS

One hundred eleven patients divided in 5 groups.

INTERVENTIONS

Patients were grouped according to preoperative antithrombotic regimen: group 1, control, no agents (n=55); group 2, clopidogrel (n=9); group 3, enoxaparin (n=17); group 4, any GP IIb/IIIa inhibitor (n=14); and group 5, any drug combination (n=15). Data included cumulative mediastinal chest tube drainage, allogeneic blood transfusions, total blood donor exposures, and re-exploration.

MEASUREMENTS AND MAIN RESULTS

Use of any drug (groups 2-5) resulted in greater total blood transfusions and donor exposure (p=0.0003) than control, especially red cells (p=0.002) and platelets (p=0.006). A greater percentage of patients on enoxaparin required mediastinal re-exploration for nonsurgical bleeding versus control (3/17 v 0/55, p=0.001). The use of enoxaparin was associated with significantly higher chest tube output after the first 24 hours postoperatively (p=0.048).

CONCLUSION

Newer antithrombotic agents were associated with greater transfusion rates and total donor exposures. Enoxaparin use was associated with greater overall blood loss and with higher incidence of mediastinal re-exploration. The relative risk-benefit ratio of reduced periprocedure morbidity versus increased bleeding complications has yet to be determined.

Activated recombinant factor VII in cardiac surgery

PURPOSE OF REVIEW

Severe bleeding after cardiac surgery is a potential problem that poses major risks and challenges. Severe bleeding after cardiac surgery still occurs despite many pharmacological approaches to decrease bleeding and reduce transfusion requirements. Activated recombinant factor VII may be a therapy that is potentially useful in the management of refractory bleeding after cardiac surgery and in other postoperative bleeding states.

RECENT FINDINGS

Several small, uncontrolled case series have suggested that activated recombinant factor VII may be useful in the management of some patients with intractable bleeding after cardiopulmonary bypass in both pediatric and adult populations. Blood loss or transfusion requirements have been reported to be substantially reduced in some patients who receive activated recombinant factor VII perioperatively. However, these reports have not established the optimal dosing or ideal timing of the administration of activated recombinant factor VII, or determined the frequency of serious adverse events related to its use.

SUMMARY

Current reports summarized in this review suggest that activated recombinant factor VII may be a promising agent in the management of uncontrolled bleeding after cardiopulmonary bypass, but additional randomized, placebo-controlled trials are needed to support this use.

Recombinant activated factor VII (rFVIIa) as salvage treatment for intractable hemorrhage

BACKGROUND: Recently, there has been an increased use of recombinant activated factor VII (rFVIIa) to promote hemostasis in various hemorrhagic conditions. The objective of this study was to determine the outcome of patients treated with rFVIIa who had intractable bleeding associated with cardiac surgery (CSP) or as a result of other causes (OBP). METHODS: The medical records of 40 consecutive patients treated with rFVIIa were retrospectively reviewed for blood product use before and after treatment. In all patients, rFVIIa was given only after all other measures to stop bleeding had failed. The number of transfused units of red cells (R), platelets (P), fresh frozen plasma (F), and cryoprecipitate (C) were determined both before and after administration of rFVIIa, and the results compared. Mortality at 4 hours and 30 days was assessed. Patients dying within 4 hours of rFVIIa administration were not evaluable for response. Patient characteristics were also assessed as risk factors for mortality. RESULTS: Twelve of 24 CSP survived for more than 4 hours. These 12 patients required an average of 17 units (U) of R, 18 U of P, 18 U of F and 15 U of C pre-treatment compared to an average of 6 U, 10 U, 9 U and 4 U of R, P, F and C respectively, post-treatment. These differences were statistically significant. For the OBP, 11 of 16 survived more than four hours. These 11 patients required an average of 10 U of R, 11 U of P, 14 U of F and 10 U of C pretreatment compared to an average of 1 U, 2 U, 2 U and 0 U of R, P, F, and C respectively, post-treatment. With the exception of C, there was a statistically significant decrease in blood product use following treatment with rFVIIa. Of the survivors in each group, 6 of 12 CSP and 2 of 11 OBP died between 3 and 30 days post-treatment from causes other than bleeding. Mortality at 30 days for CSP and OBP survivors was 50% and 18% respectively, whereas overall 30 day mortality was 75% for CSP and 44% for OBP. CONCLUSIONS: rFVIIa is effective in decreasing blood product use and promoting hemostasis in patients with intractable bleeding associated with cardiac surgery and a variety of other causes.

Does Clopidogrel Increase Blood Loss Following Coronary Artery Bypass Surgery?

BACKGROUND

Clopidogrel (Plavix) is a potent inhibitor of platelet aggregation used concomitantly with percutaneous coronary interventions and in patients with acute coronary syndromes. Its favorable effects on preventing thrombus formation may have deleterious effects on hemostasis in patients undergoing coronary surgery.

METHODS

Data were collected prospectively on 312 consecutive urgent or emergent coronary artery bypass patients from July 1999 through April 2001 at a tertiary care center. Patients were stratified into three groups: clopidogrel within 4 days of operation (n = 41), clopidogrel continued until 5 to 8 days before operation (n = 39), and clopidogrel discontinued more than 8 days before operation or were never taking clopidogrel (n = 232).

RESULTS

Preoperative and intraoperative characteristics were similar among all groups. Mediastinal and pericardial chest tube losses in the first 24 hours were 1,044 +/- 750 mL in the clopidogrel within 4 days group, 528 +/- 250 mL in the clopidogrel 5 to 8 days group, and 573 +/- 329 mL in the clopidogrel more than 8 days group (p < 0.01). The mean total blood product transfusions were 12.2 +/- 15.4 U, 1.2 +/- 2.0 U, and 2.6 +/- 5.7 U, respectively (p < 0.001). Reoperation for bleeding was noted in 14.6%, 2.6%, and 1.7%, respectively (p = 0.002). The median hospital lengths of stay for the three groups were 9 days, 7 days, and 7 days, respectively (p = 0.018). There were no statistically significant differences in mortality rate, myocardial infarction, stroke, mediastinitis, or postoperative renal failure among the groups. Multivariable analysis revealed that clopidogrel within 0 to 4 days of operation was an independent predictor of transfusion requirements (OR 4.22, 95% confidence interval [CI] 2.07, 9.34, p = 0.001), intensive care unit (ICU) length of stay (OR 3.14, 95% CI 1.40, 7.04, p = 0.006), and total hospital length of stay (coefficient 7.65, se 2.41, p = 0.002).

CONCLUSIONS

Clopidogrel within 4 days of coronary bypass surgery is associated with increased blood losses and reoperation for bleeding and, according to multivariable models, is an independent risk factor for increased transfusion requirements and prolonged ICU and hospital length of stay.

The independent association of massive blood loss with mortality in cardiac surgery

BACKGROUND

Although the association between massive perioperative blood loss (MBL) and adverse outcomes is well recognized, it is unclear whether MBL is an independent risk factor or, instead, simply a marker for other adverse events or severity of illness. The objective of this cohort study was to quantify the independent association of MBL in cardiac surgery with all-cause in-hospital mortality.

STUDY DESIGN AND METHODS

Data were prospectively collected on consecutive patients who underwent cardiac surgery with cardiopulmonary bypass at a quaternary-care academic center from 1999 to 2003. The number of red blood cell (RBC) units transfused within 1 day of surgery was used as a surrogate measure of perioperative blood loss. Receiver-operating characteristic curve analyses were employed to identify the most appropriate cutoff for defining MBL. The independent association of MBL with mortality was determined with multivariable logistic regression analyses. Bootstrapping and sensitivity analyses were used to confirm the validity of the results.

RESULTS

MBL was defined as receiving at least 5 units of RBCs within 1 day of surgery. Of 9215 patients analyzed, 1.8 percent (n = 169) died and 9.7 percent (n = 890) had MBL. After adjusting for multiple potential confounders (including perioperative adverse events), MBL was associated with an 8.1-fold (95% confidence interval, 3.9-17.0) increase in the odds of death. This risk estimate was stable across different modeling conditions as well as in bootstrap sampling.

CONCLUSION

MBL after cardiac surgery has a strong, independent association with in-hospital mortality.

Reexploration for bleeding after coronary artery bypass surgery: risk factors, outcomes, and the effect of time delay

BACKGROUND

We aimed to identify risk factors for reexploration for bleeding after surgical revascularization in our practice. We also looked at the impact of resternotomy and the effect of time delay on mortality and other in-hospital outcomes.

METHODS

In all, 2,898 consecutive patients undergoing coronary artery bypass grafting between April 1999 and March 2002 were retrospectively analyzed from our cardiac surgery registry. Multivariate logistic regression analysis was used to identify risk factors for reexploration for bleeding. To assess the effect of preoperative aspirin and heparin, reexploration patients were propensity matched with unique patients not requiring reexploration. We carried out a casenote review to ascertain the timing and causes for bleeding in patients undergoing resternotomy.

RESULTS

Eighty-nine patients (3.1%) underwent reexploration for bleeding. Multivariate analysis revealed smaller body mass index (p = 0.003), nonelective surgery (p = 0.022), 5 or more distal anastomoses (p = 0.035), and increased age (p = 0.041) to have increased risks. Propensity-matched analysis showed that preoperative use of aspirin (p = 0.004) and heparin (p = 0.001) were associated with increased risk in the on-pump coronary surgery group only. Patients requiring resternotomy had a significantly greater need for inotropic agents (p < 0.001), and longer intensive care unit stay (p < 0.001) and postoperative stay (p < 0.001) than their propensity-matched controls. However, there was no significant difference in the mortality rate. Adverse outcomes were significantly higher when patients waited more than 12 hours after return to the intensive care unit for resternotomy.

CONCLUSIONS

Risk factors for reexploration for bleeding after coronary artery bypass grafting include older age, smaller body mass index, nonelective cases, and 5 or more distal anastomoses. Preoperative aspirin and heparin were risk factors for the on-pump coronary artery surgery group. Patients needing reexploration are at higher risk of complications if the time to reexploration is prolonged. Policies that promote early return to the operating theater for reexploration should be encouraged.