Effect of preoperative aspirin use in off-pump coronary artery bypass operations

The π-Circuit Technique in Coronary Surgery: Analysis of 1359 Consecutive Cases

Coronary artery bypass surgery still has its unique role in the treatment of coronary artery disease. It faces, however, the continuous challenge of becoming even less invasive and more effective as cases become more complex. We here present the results of 1359 cases treated with the π-circuit technique which consists of an off-pump total myocardial revascularization using composite arterial grafts. The results demonstrate that it is a safe technique providing low mortality, stroke, renal failure, wound infection, and other complication rates. We suggest the application of this technique, as well as of other similar techniques regarding similar principles, especially in high-risk patients.

Aspirin for patients undergoing major lung resections: hazardous or harmless?†

OBJECTIVES

Acetylsalicylic acid (ASA, aspirin) is a medication widely used for primary and secondary prevention of cardiovascular diseases, which are the leading cause of morbidity and mortality worldwide. Whether aspirin should be continued or paused in the perioperative period remains controversial, especially in thoracic surgical settings.

METHODS

A single-centred retrospective study comprised 486 patients. Of these, 329 patients did not use aspirin (group ASA-0) and 157 did (group ASA-1) during the perioperative period after anatomical lung resection at our hospital from January 2013 to December 2016. Major outcome measures were the amount of blood loss during the operation and during the first 5 days postoperatively (per Mercuriali's formula), as well as the amount and proportion of the blood transfusion (packed red cells) received. The need for reoperation due to a postoperative haemothorax and/or bleeding was recorded. The groups were also compared according to their rates of morbidity and mortality. Inferential statistical methods with bootstrap analysis using 1000 samples and the Mersenne Twister, a random number generator, were used.

RESULTS

There were no significant differences between the 2 groups in intraoperative bleeding [ASA-0M = 418.69 ml, standard deviation (SD) ± 364.87; ASA-1M = 399.8 ml, SD ± 323.84; P = 0.58] or in total blood loss according to Mercuriali's formula (ASA-0M = 1111.62 ml, SD ± 816.69; ASA-1M = 1115.08 ml, SD ± 682.12; P = 0.95). A total of 104 patients received transfusions up to postoperative day 5: 71 patients in the ASA-0 group received 151 blood transfusions, whereas 33 patients in the ASA-1 group received 65 blood transfusions (P = 0.66). The indication for reoperation due to bleeding (ASA-1 = 3, ASA-0 = 4; P = 0.69) was similar between the groups. There was a trend towards higher rates of postoperative complications in the ASA-1 group (risk ratio (RR) = 1.28; P = 0.055); neither cardiovascular complications nor deaths were more frequent in either of the 2 groups (P = 0.73).

CONCLUSIONS

Patients taking aspirin therapy and undergoing anatomical lung resection seem not to be at any disadvantage regarding bleeding. However, a trend towards a higher rate of postoperative complications indicates a basically increased risk for operations due to comorbidities in these patients.

Use of preoperative aspirin in combined coronary and valve operations

BACKGROUND

The aim of this study was to determine the relationship between preoperative aspirin use and postoperative outcomes in patients undergoing combined coronary artery bypass grafting and valve operations.

METHODS

All combined coronary artery bypass grafting and valve procedures from 2008 to 2015 at our institution were identified. After exclusions, patients were stratified according to those that received preoperative aspirin and those who did not. Propensity score methodology was used to match the 2 groups using baseline and operative characteristics. Logistic regression models were then developed to assess differences in postoperative outcomes between groups.

RESULTS

Of the 563 patients identified, 534 met inclusion criteria: preoperative aspirin = 327 (61.2%), no preoperative aspirin = 207 (38.8%). After propensity matching, 194 patient pairs were analyzed, with no significant differences in preoperative characteristics. No significant differences were observed between the preoperative aspirin and no preoperative aspirin groups in rates of 30-day mortality (3.6% vs 4.1%, P = 1.00), major adverse cardiovascular events (23.2% vs 24.2%, P = .91), or 30-day readmission (12.4% vs 11.9%, P = 1.00), among others.

CONCLUSION

Preoperative aspirin use in patients undergoing combined coronary artery bypass grafting and valve operations was not associated with significant differences in major postoperative outcomes. Large-scale, randomized trials are needed to better establish the role of preoperative aspirin in this population.

Effect of preoperatively continued aspirin use on early and mid-term outcomes in off-pump coronary bypass surgery: a propensity score-matched study of 1418 patients

Background

To date, effect of preoperatively continued aspirin administration in off-pump coronary artery bypass grafting (CABG) is less known. We aimed to assess the effect of preoperatively continued aspirin use on early and mid-term outcomes in patients receiving off-pump CABG.

Methods

From October 2009 to September 2013 at the Fuwai Hospital, 709 preoperative aspirin users were matched with unique 709 nonaspirin users using propensity score matching to obtain risk-adjusted outcome comparisons between the two groups. Early outcomes were in-hospital death, stroke, intra- and post-operative blood loss, reoperation for bleeding and blood product transfusion. Major adverse cardiac events (death, myocardial infarction or repeat revascularization), angina recurrence and cardiogenic readmission were considered as mid-term endpoints.

Results

There were no significant differences among the groups in baseline characteristics after propensity score matching. The median intraoperative blood loss (600 ml versus 450 ml, P = 0.56), median postoperative blood loss (800 ml versus 790 ml, P = 0.60), blood transfusion requirements (25.1% versus 24.4%, P = 0.76) and composite outcome of in-hospital death, stroke and reoperation for bleeding (2.8% versus 1.6%, P = 0.10) were similar in aspirin and nonaspirin use group. At about 4 years follow-up, no significant difference was observed among the aspirin and nonaspirin use group in major adverse cardiac events free survival estimates (95.7% versus 91.5%, P = 0.23) and freedom from cardiogenic readmission (88.5% versus 85.3%, P = 0.77) whereas the angina recurrence free survival rates was 83.7% and 73.9% in the aspirin and nonaspirin use group respectively (P = 0.02), with odd ratio for preoperative aspirin estimated at 0.71 (95% confidence interval, 0.49-1.04, P = 0.08).

Conclusions

Preoperatively continued aspirin use was not associated with increased risk of intra- and post-operative blood loss, blood transfusion requirements and composite outcome of in-hospital death, stroke and reoperation for bleeding in off-pump CABG. Preoperative aspirin use tended to decrease the hazard of mid-term angina recurrence.

Safety and Efficacy Outcomes of Preoperative Aspirin in Patients Undergoing Coronary Artery Bypass Grafting

Background:

The administration of aspirin is traditionally discontinued prior to coronary artery bypass grafting (CABG), given a potential risk of excessive postoperative bleeding. Few studies have previously suggested the benefits of continuing aspirin until the time of surgery. The primary aim of this review is to evaluate the effects of preoperative aspirin therapy on several clinically important outcomes in patients undergoing CABG.

Methods:

A meta-analysis of eligible studies of patients undergoing CABG, reporting preoperative aspirin in comparison with no aspirin/placebo and our outcomes, was carried out. The safety outcomes included postoperative bleeding, packed red blood cell (PRBC) transfusion requirements, and reoperation for bleeding. The efficacy outcomes included perioperative myocardial infarction (MI), cerebrovascular accidents (CVAs), and mortality.

Results:

In 8 randomized controlled trials (RCTs; n = 1538), preoperative aspirin increased postoperative bleeding (difference in means = 132.30 mL; 95 % confidence interval [CI] 47.10-217.51; P = .002), PRBC transfusion requirements (difference in means = 0.67 units; 95% CI 0.10-1.24; P = .02), and reoperation for bleeding (odds ratio [OR] = 1.76; 95% CI 1.05-2.93; P = .03). In 19 observational studies (n = 19551), preoperative aspirin increased postoperative bleeding (difference in means = 132.74 mL; 95% CI 45.77-219.72; P = .003) and PRBC transfusion requirements (difference in means = 0.19 units; 95% CI 0.02-0.35; P = .02) but not reoperation for bleeding (OR = 1.13; 95% CI 0.91-1.42; P = .27). Subgroup analyses for RCTs demonstrated that aspirin given at doses ≤ 100 mg/d might not increase the postoperative bleeding, and the dose of 325 mg/d might not be a cutoff value that has clinical and statistical significance. No statistically significant differences in the rate of perioperative MI, CVAs, or mortality were seen between the 2 groups.

Conclusions:

Preoperative aspirin therapy is associated with increased postoperative bleeding, PRBC transfusion requirements, and reoperation for bleeding in patients undergoing CABG. Doses lower than 100 mg/d may minimize the risk of bleeding. Additional RCTs are needed to assess the effects of preoperative aspirin on the safety and efficacy outcomes in patients undergoing CABG.

Should more patients continue aspirin therapy perioperatively?: clinical impact of aspirin withdrawal syndrome

OBJECTIVE

To provide an evidence-based focused review of aspirin use in the perioperative period along with an in-depth discussion of the considerations and risks associated with its preoperative withdrawal.

BACKGROUND

For patients with established cardiovascular disease, taking aspirin is considered a critical therapy. The cessation of aspirin can cause a platelet rebound phenomenon and prothrombotic state leading to major adverse cardiovascular events. Despite the risks of aspirin withdrawal, which are exacerbated during the perioperative period, standard practice has been to stop aspirin before elective surgery for fear of excessive bleeding. Mounting evidence suggests that this practice should be abandoned.

METHODS

We performed a PubMed and Medline literature search using the keywords aspirin, withdrawal, and perioperative. We manually reviewed relevant citations for inclusion.

RESULTS/CONCLUSIONS

Clinicians should employ a patient-specific strategy for perioperative aspirin management that weighs the risks of stopping aspirin with those associated with its continuation. Most patients, especially those taking aspirin for secondary cardiovascular prevention, should have their aspirin continued throughout the perioperative period. When aspirin is held preoperatively, the aspirin withdrawal syndrome may significantly increase the risk of a major thromboembolic complication. For many operative procedures, the risk of perioperative bleeding while continuing aspirin is minimal, as compared with the concomitant thromboembolic risks associated with aspirin withdrawal. Those cases where aspirin should be stopped include patients undergoing intracranial, middle ear, posterior eye, intramedullary spine, and possibly transurethral prostatectomy surgery.

Preoperative aspirin resistance does not increase myocardial injury during off-pump coronary artery bypass surgery

We performed a prospective cohort trial on 220 patients undergoing elective off-pump coronary artery bypass surgery and taking aspirin to evaluate the effect of aspirin resistance on myocardial injury. The patients were divided into aspirin responders and aspirin non-responders by the value of the aspirin reaction units obtained preoperatively using the VerifyNow™ Aspirin Assay. The serum levels of troponin I were measured before surgery and 1, 6, 24, 48 and 72 hr after surgery. In-hospital major adverse cardiac and cerebrovascular events, graft occlusion, the postoperative blood loss and reexploration for bleeding were recorded. Of the 220 patients, 181 aspirin responders (82.3%) and 39 aspirin non-responders (17.7%) were defined. There were no significant differences in troponin I levels (ng/mL) between aspirin responders and aspirin non-responders: preoperative (0.04 ± 0.08 vs 0.03 ± 0.06; P = 0.56), postoperative 1 hr (0.72 ± 0.87 vs 0.86 ± 1.10; P = 0.54), 6 hr (2.92 ± 8.76 vs 1.50 ± 2.40; P = 0.94), 24 hr (4.16 ± 13.44 vs 1.25 ± 1.95; P = 0.52), 48 hr (2.15 ± 7.06 vs 0.65 ± 0.95; P = 0.64) and 72 hr (1.20 ± 4.63 vs 0.38 ± 0.56; P = 0.47). Moreover, no significant differences were observed with regard to in-hospital outcomes. In conclusion, preoperative aspirin resistance does not increase myocardial injury in patients undergoing off-pump coronary artery bypass surgery. Postoperative dual antiplatelet therapy might have protected aspirin resistant patients.

Perioperative management of antiplatelet-drugs in cardiac surgery

The management of coronary patients scheduled for a coronary artery bypass grafting (CABG), who are receiving one or more antiplatelet drugs, is plenty of controversies. It has been shown that withdrawal of antiplatelet drugs is associated with an increased risk of a thrombotic event, but surgery under an altered platelet function also means an increased risk of bleeding in the perioperative period. Because of the conflict recommendations, this review article tries to evaluate the outcome of different perioperative antiplatelet protocols in patients with coronary artery disease undergoing CABG.

Postoperative Revision Surgery for Bleeding in a Tertiary Heart Center

We analyzed cases of re-exploration for bleeding after 19,680 open heart operations performed between January 1995 and January 2009 to determine the risk factors for mortality and morbidity. Half of the 282 patients reexplored had nonsurgical causes of bleeding. The patients were grouped according to the timing of reoperation, early reexploration being on the day of the operation. Mortality, total morbidity, and the need for transfusion of any blood product were compared between the early and late reexploration groups. Most patients (77.7%) were reexplored early. Overall mortality was 8.5% (24 patients). Mortality, total morbidity, renal, gastrointestinal, neurologic and infectious complications, and low cardiac output differed significantly between the 2 groups. Significant predictors of mortality were old age, female sex, left ventricular dysfunction, noncoronary operations, and delayed reoperation. Predictors of morbidity were old age, preoperative dialysis, tobacco use, chronic lung disease, and delayed reoperation. No factors were found to be associated with the need for transfusion.

A critical appraisal of propensity-score matching in the medical literature between 1996 and 2003

Propensity-score methods are increasingly being used to reduce the impact of treatment-selection bias in the estimation of treatment effects using observational data. Commonly used propensity-score methods include covariate adjustment using the propensity score, stratification on the propensity score, and propensity-score matching. Empirical and theoretical research has demonstrated that matching on the propensity score eliminates a greater proportion of baseline differences between treated and untreated subjects than does stratification on the propensity score. However, the analysis of propensity-score-matched samples requires statistical methods appropriate for matched-pairs data. We critically evaluated 47 articles that were published between 1996 and 2003 in the medical literature and that employed propensity-score matching. We found that only two of the articles reported the balance of baseline characteristics between treated and untreated subjects in the matched sample and used correct statistical methods to assess the degree of imbalance. Thirteen (28 per cent) of the articles explicitly used statistical methods appropriate for the analysis of matched data when estimating the treatment effect and its statistical significance. Common errors included using the log-rank test to compare Kaplan-Meier survival curves in the matched sample, using Cox regression, logistic regression, chi-squared tests, t-tests, and Wilcoxon rank sum tests in the matched sample, thereby failing to account for the matched nature of the data. We provide guidelines for the analysis and reporting of studies that employ propensity-score matching.

Aspirin and Tranexamic Acid for Coronary Artery Surgery (ATACAS) Trial: rationale and design

BACKGROUND

Despite some concern that recent aspirin ingestion increases blood loss after coronary artery surgery, there is some evidence that this may reduce thrombotic complications. In contrast, antifibrinolytic drugs can reduce blood loss in this setting, but there is concern that they may increase thrombotic complications. Published guidelines are limited by a lack of large randomized trials addressing the risks and benefits of each of these commonly used therapies in cardiac surgery. The ATACAS Trial is a study comparing aspirin, tranexamic acid, or both, with placebo in patients undergoing on-pump or off-pump coronary artery surgery.

METHODS

We discuss the rationale for conducting ATACAS, a 4600-patient, multicenter randomized trial in at-risk coronary artery surgery, and the features of the ATACAS study design (objectives, end points, target population, allocation, treatments, patient follow-up, and analysis).

CONCLUSIONS

The ATACAS Trial will be the largest study yet conducted to ascertain the benefits and risks of aspirin and antifibrinolytic therapy in coronary artery surgery. Results of the trial will guide the routine clinical care of patients in this setting.

Perioperative use of cardiac medical therapy among patients undergoing coronary artery bypass graft surgery: a systematic review

BACKGROUND

The use of perioperative cardiac medical therapy among patients undergoing coronary artery bypass graft surgery (CABG) has not been closely examined.

OBJECTIVES

The objective of this study was to systematically review the medical literature examining the effects of perioperative cardiac medical therapy on clinical outcomes among patients undergoing CABG.

METHODS

Using the Medline database and online clinical trial databases, we reviewed all randomized controlled trials (RCTs) and observational studies examining the effect of perioperative angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, antilipid agents (including statins), aspirin, beta-blockers, and calcium-channel blockers on clinical outcomes.

RESULTS

Our review identified 27 studies (6 RCTs, 21 observational studies), involving >700,000 patients, that examined the impact of perioperative medical therapy on clinical outcomes after CABG. Although studies provide conflicting results, the literature suggests that perioperative aspirin use may decrease inhospital mortality and myocardial infarction, whereas perioperative angiotensin-converting enzyme inhibitor use does not appear to be beneficial. Perioperative statin use reduces all-cause mortality at 30 days and cardiac death at 60 days and 1 year post-CABG but does not appear to reduce myocardial infarction or congestive heart failure rates. Multiple studies have demonstrated that pre- and postoperative beta-blockers are associated with a decrease in atrial fibrillation. In addition, beta-blockers may reduce inhospital and 30-day mortality, although these results are not consistent across all studies. Calcium-channel blockers do not appear to improve inhospital or 30-day mortality. No studies examined the perioperative use of angiotensin II receptor blockers or nonstatin antilipid agents among CABG patients.

CONCLUSIONS

The perioperative use of cardiac medical therapy among CABG patients remains understudied. Given their proven benefits among patients with cardiovascular disease and their potential to improve outcomes among CABG patients, further studies, particularly large RCTs, are needed.

Does the Use of Preoperative Aspirin Increase the Risk of Bleeding in Patients Undergoing Coronary Artery Bypass Grafting Surgery? Systematic Review and Meta-Analysis

BACKGROUND

The traditional recommendation has been to stop Aspirin seven to 10 days prior to coronary artery bypass surgery to reduce the potential risk of bleeding. A few reports have shown that Aspirin did not increase the risk of bleeding and may be beneficial to be continued until the time of surgery. The objective of this review was to evaluate the effect of preoperative Aspirin on bleeding in patients undergoing elective bypass surgery.

METHODS

A meta-analysis of 10 randomized and nonrandomized studies reporting comparisons between Aspirin and control was undertaken. The primary outcome was the total amount of postoperative chest tube drainage. Secondary outcomes were the number of units of packed red blood cell transfusion, platelet transfusion, fresh frozen plasma transfusion, and number of patients reexplored for bleeding.

RESULTS

Ten studies, involving 1748 patients, met the inclusion criteria for this review of whom 913 were in the Aspirin group and 835 were in the control group. Pooling the results of all studies showed a significant increase in blood loss and transfusion of red blood cells and fresh frozen plasma in the Aspirin group (p < 0.05). There was no significant difference between the two groups in the rate of platelet transfusion, or the incidence of reexploration (p > 0.05). Included studies were heterogeneous and of low methodological quality.

CONCLUSION

Aspirin is associated with increased chest tube drainage and may be associated with a greater requirement for blood products. High-quality prospective studies are warranted to reassess the effect of Aspirin on important postoperative outcomes.

Discontinuation of perioperative antiplatelet and anticoagulant therapy in stroke patients

Growing evidence suggests that perioperative withdrawal of ASA for secondary stroke prevention increases thromboembolic risk without the associated benefit of decreased bleeding complications. ASA maintenance is acceptable in many procedures, including invasive ones. Many procedures, in particular ophthalmologic, dermatologic, and dental surgeries, also are safe while continuing oral AC. Warfarin has been continued successfully even in some surgeries that have high bleeding risk. When the risk is too high, temporary bridging therapy with LWMH is safe in many populations. Although the exact thromboembolic risks associated with temporary cessation of AP and AC are unknown and likely low, morbidity and mortality associated with thromboembolism are high. Further studies investigating the risks and benefits of maintaining AP and AC during procedures, particularly invasive ones, are needed. Meanwhile, it is critical that physicians understand the risks and benefits of perioperative AP and AC and the variety of procedures in which these agents can be safely continued.

Early administration of clopidogrel is safe after off-pump coronary artery bypass surgery

BACKGROUND

Patients who undergo off-pump coronary artery bypass graft surgery (OPCAB) may be hypercoagulable with an increased risk of graft thrombosis due to the lack of platelet dysfunction that accompanies "on-pump" surgery. Clopidogrel may be indicated in these patients to prevent recurrent ischemic events. The purpose of this observational study was to determine the safety of early clopidogrel administration after OPCAB.

METHODS

Thirty-day follow-up of 364 consecutive OPCAB patients (January to June, 2002) was determined from a computerized database. One hundred ninety-three patients received clopidogrel 4 hours postoperatively if chest tube output was less than 100 cc/h for 4 hours, then daily for 4 weeks. Aspirin was administered preoperatively and postoperatively to all patients. Telephone follow-up was made 6 to 12 months after OPCAB.

RESULTS

None of the patients who received clopidogrel in the early postoperative period required reoperation for mediastinal hemorrhage. Mean chest tube drainage at 24 hours was 1,024 +/- 563 mL in patients who received clopidogrel and 942 +/- 501 mL in patients who did not receive clopidogrel. The total number of blood units transfused and the number of patients receiving blood transfusions were similar between groups. In-hospital mortality was 1.6% in patients who received clopidogrel and 3.5% in patients who did not receive clopidogrel. No group differences in mortality or adverse cardiac events were observed at 6 months. Gastrointestinal bleeding occurred in 2.2% clopidogrel patients versus 0.7% of patients who did not receive clopidogrel.

CONCLUSIONS

When administered according to our postoperative protocol, OPCAB patients can safely receive clopidogrel in the early postoperative period without increased risk for mediastinal hemorrhage.

A review of the application of propensity score methods yielded increasing use, advantages in specific settings, but not substantially different estimates compared with conventional multivariable methods

OBJECTIVE

Propensity score (PS) analyses attempt to control for confounding in nonexperimental studies by adjusting for the likelihood that a given patient is exposed. Such analyses have been proposed to address confounding by indication, but there is little empirical evidence that they achieve better control than conventional multivariate outcome modeling.

STUDY DESIGN AND METHODS

Using PubMed and Science Citation Index, we assessed the use of propensity scores over time and critically evaluated studies published through 2003.

RESULTS

Use of propensity scores increased from a total of 8 reports before 1998 to 71 in 2003. Most of the 177 published studies abstracted assessed medications (N=60) or surgical interventions (N=51), mainly in cardiology and cardiac surgery (N=90). Whether PS methods or conventional outcome models were used to control for confounding had little effect on results in those studies in which such comparison was possible. Only 9 of 69 studies (13%) had an effect estimate that differed by more than 20% from that obtained with a conventional outcome model in all PS analyses presented.

CONCLUSIONS

Publication of results based on propensity score methods has increased dramatically, but there is little evidence that these methods yield substantially different estimates compared with conventional multivariable methods.

Pocket Hematoma After Pacemaker or Implantable Cardioverter Defibrillator Surgery

STUDY OBJECTIVES

Pocket hematoma is a common complication after pacemaker or implantable cardioverter defibrillator (ICD) implantation. Thus, we investigated the influence of patient comorbidity, implantation strategy, operator experience, antiplatelet therapy, and anticoagulation therapy on hematoma rate.

DESIGN

Between 1990 and 2002, a total of 3,164 devices (pectoral pacemakers, 2,792; ICDs, 372) were implanted at our institution. Predictors of hematoma occurrence were determined prospectively and were analyzed by multivariate regression analysis. Operator experience was graded by individual implantation number, as follows: low, < 50; medium, 50 to 100; and high, > 100.

RESULTS

The incidence of pocket hematoma was 4.9%, leading to prolonged hospitalization in 2.0% of all patients. Reoperation for pocket hematoma was required in 1.0% of patients. High-dose heparinization (hazard ratio [HR], 4.2), combined acetylsalicylic acid (ASA)/thienopyridine treatment after coronary stenting (HR, 5.2), and low operator experience (HR, 1.6) were independently predictive of hematoma development. Therapy with ASA alone did not increase the hematoma rate compared to patients who did receive antiplatelet or anticoagulation therapy (3.1% vs 2.5%, respectively; difference not significant). In patients with nonvalvular atrial fibrillation, postoperative high-dose heparinization substantially increased the hematoma rate (10.7% vs 2.9%, respectively; p < 0.001) without reducing the rate of arterial embolism within the first month after implantation (0.18% vs 0.21%, respectively; difference not significant). The infection rate (0.28% within 3 months after implantation) was not influenced by the presence of the pocket hematoma.

CONCLUSIONS

The use of high-dose heparinization and combined ASA/thienopyridine treatment are highly predictive for the occurrence of intraoperative bleeding and pocket hematoma in patients who have undergone pacemaker and ICD surgery. We propose recommendations for the management of antiplatelet and anticoagulation therapy in patients undergoing these interventions.

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.