The Effect of Aspirin on Bleeding and Transfusion in Contemporary Cardiac Surgery

Preoperative continuation of aspirin before isolated heart valve surgery and postoperative bleeding and transfusion: a single-center retrospective study

BACKGROUND

The risks and benefits of preoperative aspirin continuation in patients undergoing isolated heart valve replacement surgery are unclear. We investigated the effect of aspirin continuation on the risk of bleeding and transfusion in these patients.

METHODS

In this single center, retrospective study, among 474 adult patients who underwent isolated heart valve surgery between April 2013 and June 2018, 269 continued aspirin within 5 days before surgery (aspirin group) and 205 patients did not take or stopped aspirin no later than 5 days before surgery (non-aspirin group). The chi-square test, the Mann-Whitney U-test, and the Student's T-test were used to compare data between the groups. Univariate and Multivariate logistic regressions were used to assess crude and adjusted relationships between outcome and exposure.

RESULTS

The primary outcome, red blood cell (RBC) transfusion, occurred in 59 patients (22%) of the aspirin group and in 24 patients (12%) of the non-aspirin group (p = 0.004). After adjustment for confounding factors, continuation of aspirin was no longer associated with RBC transfusion (aOR1.8;95%CI,0.98-3.2;p = 0.06). The amount of allogenic blood products, the incidence of surgical re-exploration for bleeding, the volume of re-transfused cell-saved blood, and the cumulative chest tube drainage during the first 24 postoperative hours were similar between groups.

CONCLUSION

Preoperative continuation of aspirin in patients undergoing isolated heart valve surgery is neither associated with a higher incidence of RBC transfusion, nor with larger perioperative blood loss, or more frequent surgical revision for bleeding.

TRIAL REGISTRATION

Clinicaltrials.gov (NCT05151796).

Perioperative Management of Antiplatelet Therapy: A Systematic Review and Meta-analysis

OBJECTIVE

To summarize the available evidence about the perioperative management of patients who are receiving long-term antiplatelet therapy and require elective surgery/procedures.

METHODS

This systematic review supports the development of the American College of Chest Physicians guideline on the perioperative management of antiplatelet therapy. A literature search of MEDLINE, EMBASE, Scopus and Cochrane databases was conducted from each database's inception to July 16, 2020. Meta-analyses were conducted when possible.

RESULTS

In patients receiving long-term antiplatelet therapy and undergoing elective noncardiac surgery, the available evidence did not show a significant difference in major bleeding between a shorter vs longer antiplatelet interruption, with low certainty of evidence (COE). Compared with patients who received placebo perioperatively, aspirin continuation was associated with increased risk of major bleeding (relative risk [RR], 1.31; 95% CI, 1.15-1.50; high COE) and lower risk of major thromboembolism (RR, 0.74; 95% CI, 0.58-0.94; moderate COE). During antiplatelet interruption, bridging with low-molecular-weight heparin was associated with increased risk of major bleeding compared with no bridging (RR, 1.86; 95% CI, 1.24-2.79; very low COE). Continuation of antiplatelets during minor dental and ophthalmologic procedures was not associated with a statistically significant difference in the risk of major bleeding (very low COE).

CONCLUSION

This systematic review summarizes the current evidence about the perioperative management of antiplatelet therapy and highlights the urgent need for further research, particularly with the increasing prevalence of patients taking 1 or more antiplatelet agents.

Big data analysis of the risk factors and rates of perioperative transfusion in immediate autologous breast reconstruction

Patients undergoing autologous breast reconstruction (ABR) are more likely to require perioperative transfusions due to the increased intraoperative bleeding. In addition to the mastectomy site, further incisions and muscle dissection are performed at the donor sites, including the back or abdomen, increasing the possibility of transfusion. The purpose of this study was to evaluate perioperative transfusion rates and risk factors according to the type of ABR through analysis of big data. Patients who underwent total mastectomy for breast cancer between 2014 and 2019 were identified. The patients were divided into mastectomy only and immediate ABR groups. The transfusion rate was 14-fold higher in the immediate ABR group (16.1%) compared to the mastectomy only group (1.2%). The transfusion rate was highest with the pedicled transverse rectus abdominis myocutaneous flap (24.2%). Performance of the operation in medical institutions located in the provinces and coronary artery disease (CAD) were significant risk factors for the need for transfusion. The perioperative transfusion risk among patients undergoing immediate ABR was related to the flap type, location of medical institution, and CAD. Based on the higher transfusion rate in this study (16.1%) compared to previous studies, the risk factors for the need for transfusion should be determined and evidence-based guidelines should be developed to reduce the transfusion rates.

Effect of Preoperative Continuation of Aspirin on Postoperative Bleeding After Off-Pump Coronary Artery Bypass Graft: A Prospective Cohort Study

Background

Despite ample evidence of continuing preoperative aspirin to improve coronary artery bypass surgery outcomes, practice for the routine continuation of preoperative aspirin is inconsistent due to concern for increased postoperative bleeding. The purpose of this study was to investigate preoperative aspirin use and its effect on postoperative bleeding after off-pump coronary artery bypass grafting (OPCABG).

Methodology

This cohort study involved patients (n = 74) who underwent OPCABG at a single center between August 2017 and January 2018. After considering the inclusion and exclusion criteria, the patients were divided into two groups: one (n = 37) received tablet aspirin 75 mg till the day of the surgery, and for the other group (n = 37) aspirin was stopped five days before the surgery. Postoperative bleeding was recorded in both groups. After considering preoperative, intraoperative, and postoperative variables, statistical analysis was performed.

Results

There was no significant difference between the two groups concerning peroperative and postoperative variables. In addition, no significant difference was observed between the two groups in chest tube drainage at one, two, three, twenty-four, forty-eight, and seventy-two hours (p = 0.845, 0.126, 0.568, 0.478, 0.342, and 0.717, respectively). No significant difference was seen in the transfusion requirement of blood and fresh frozen plasma (FFP).

Conclusions

Continuation of preoperative aspirin till the day of the surgery is neither associated with an increase in chest tube drainage, reoperation for bleeding complications nor transfusion of blood and FFP.

Pleiotropic Effects of Acetylsalicylic Acid after Coronary Artery Bypass Grafting-Beyond Platelet Inhibition

Acetylsalicylic acid (ASA) is one of the most frequently used medications worldwide. Yet, the main indications for ASA are the atherosclerosis-based cardiovascular diseases, including coronary artery disease (CAD). Despite the increasing number of percutaneous procedures to treat CAD, coronary artery bypass grafting (CABG) remains the treatment of choice in patients with multivessel CAD and intermediate or high anatomical lesion complexity. Taking into account that CABG is a potent activator of inflammation, ASA is an important part in the postoperative therapy, not only due to ASA antiplatelet action, but also as an anti-inflammatory agent. Additional benefits of ASA after CABG include anticancerogenic, hypotensive, antiproliferative, anti-osteoporotic, and neuroprotective effects, which are especially important in patients after CABG, prone to hypertension, graft occlusion, atherosclerosis progression, and cognitive impairment. Here, we discuss the pleiotropic effects of ASA after CABG and provide insights into the mechanisms underlying the benefits of treatment with ASA, beyond platelet inhibition. Since some of ASA pleiotropic effects seem to increase the risk of bleeding, it could be considered a starting point to investigate whether the increase of the intensity of the treatment with ASA after CABG is beneficial for the CABG group of patients.

Impact of Thrombocytopenia on Postoperative Bleeding Incidence in Patients Receiving Aspirin Following Coronary Artery Bypass Grafting

BACKGROUND

Early postoperative aspirin following coronary artery bypass graft (CABG) surgery has been shown to maintain bypass graft patency, reduce mortality, and prevent adverse cardiovascular events. Despite this known benefit, aspirin may be delayed due to thrombocytopenia and perceived higher bleeding risk. The purpose of this study was to assess the impact of postoperative platelet count on bleeding in patients receiving aspirin after CABG.

METHODS

A retrospective analysis included all patients who underwent CABG surgery at our institution from April 2014 to June 2018 and received aspirin within 24 hours. The primary outcome was International Society on Thrombosis and Hemostasis (ISTH) major bleeding within 7 days (or up to discharge) following CABG surgery compared between patients with and without postoperative thrombocytopenia.

RESULTS

This study included 280 patients. Major bleeding occurred in 24.6% of the population, with no difference when stratified by the presence or absence of postoperative thrombocytopenia (27.3% versus 23.8%, p = 0.571). There was no significant difference in hemoglobin fall (13.6% versus 14%, p = 0.948), transfusion requirement (6.1% versus 4.2%, p = 0.531), or critical site bleeding (12.1% versus 7.9%, p = 0.298).

CONCLUSION

In this single-center analysis of patients who received aspirin within 24 hours of CABG, postoperative thrombocytopenia was not associated with an increase in bleeding.

Perioperative aspirin and long-term survival in patients undergoing coronary artery bypass graft

This study aimed to examine association between perioperative uses of aspirin and long-term survival in patients undergoing CABG. A retrospective cohort study was performed in 9,584 consecutive patients receiving cardiac surgery from three tertiary hospitals. Of all the patients, 4,132 patients undergoing CABG met inclusion criteria and were divided into four groups: with or without preoperative or postoperative aspirin respectively. 30-day postoperative and long-term mortality were compared with the use of propensity scores and inverse probability weighting adjustment to reduce the treatment-selection bias. The patients taking preoperative aspirin presented significantly more with comorbidities. However, the results of this study showed that preoperative aspirin (vs. no preoperative aspirin) was associated with significantly reduced the risk of 30-day mortality in the patients undergoing CABG. Further, the results of long-term mortality showed that the patients taking preoperative aspirin and postoperative aspirin (vs. not taking) were associated with significantly reduced the risk of 4-year mortality (14.8% vs. 18.1%, RR: 0.82, 95% CI: 0.75–0.89, P = 0.005; 10.7% vs. 16.2%, RR: 0.66, 95% CI: 0.50–0.82, P = 0.003). In conclusion, this cohort study showed that perioperative (before and after surgery) use of aspirin was associated with significant reduction in 30-day mortality without significant bleeding complications, also improved long-term survival in patients undergoing CABG.

Preoperative aspirin use and acute kidney injury after cardiac surgery: A propensity-score matched observational study

BACKGROUND

The association between preoperative aspirin use and postoperative acute kidney injury (AKI) in cardiovascular surgery is unclear. We sought to evaluate the effect of preoperative aspirin use on postoperative AKI in cardiac surgery.

METHODS

A total of 770 patients who underwent cardiovascular surgery under cardiopulmonary bypass were reviewed. Perioperative clinical parameters including preoperative aspirin administration were retrieved. We matched 108 patients who took preoperative aspirin continuously with patients who stopped aspirin more than 7 days or did not take aspirin for the month before surgery. The parameters used in the matching included variables related to surgery type, patient's demographics, underlying medical conditions and preoperative medications.

RESULTS

In the first seven postoperative days, 399 patients (51.8%) developed AKI, as defined by the Kidney Disease Improving Global Outcomes (KDIGO) criteria and 128 patients (16.6%) required hemodialysis. Most patients took aspirin 100 mg once daily (n = 195, 96.5%) and the remaining 75 mg once daily. Multivariable analysis showed that preoperative maintenance of aspirin was independently associated with decreased incidence of postoperative AKI (odds ratio [OR] 0.46, 95% confidence interval [CI] 0.21-0.98, P = 0.048; after propensity score matching: OR 0.39, 95% CI 0.22-0.67, P = 0.001). Preoperative maintenance of aspirin was associated with less incidence of AKI defined by KDIGO both in the entire and matched cohort (n = 44 [40.7%] vs. 69 [63.9%] in aspirin and non-aspirin group, respectively in matched sample, relative risk [RR] 0.64, 95% CI 0.49, 0.83, P = 0.001). Preoperative aspirin was associated with decreased postoperative hospital stay after matching (12 [9-18] days vs. 16 [10-25] in aspirin and non-aspirin group, respectively, P = 0.038). Intraoperative estimated or calculated blood loss using hematocrit difference and estimated total blood volume showed no difference according to aspirin administration in both entire and matched cohort.

CONCLUSIONS

Preoperative low dose aspirin administration without discontinuation was protective against postoperative AKI defined by KDIGO criteria independently in both entire and matched cohort. Preoperative aspirin was also associated with decreased hemodialysis requirements and decreased postoperative hospital stay without increasing bleeding. However, differences in AKI and hospital stay were not associated with in-hospital mortality.

Impact of aspirin use on morbidity and mortality in massively transfused cardiac surgery patients: a propensity score matched cohort study

PURPOSE

Aspirin may prevent organ dysfunction in critically ill patients and mitigate transfusion associated acute lung injury. We hypothesized that aspirin use might be associated with decreased morbidity and mortality in massively transfused cardiac surgery patients.

METHODS

A single center retrospective cohort study was performed using data from an 8.5-year period (2006-2014). Massive transfusion was defined as receiving at least 2400 ml (8 units) of red blood cell units intraoperatively. A propensity score model was created to account for the likelihood of receiving aspirin and matched pairs were identified using global optimal matching. The primary endpoint, in-hospital mortality, was compared between aspirin users and non-users. Secondary outcomes including: ICU hours, mechanical lung ventilation hours, prolonged mechanical lung ventilation (>24 h), pneumonia, stroke, acute renal failure, atrial fibrillation, deep sternal wound infection, and multiple organ dysfunction syndrome were also compared.

RESULTS

Of 7492 cardiac surgery patients, 452 (6 %) were massively transfused and mortality was 30.6 %. There were 346 patients included in the matched cohort. No significant association was found between preoperative aspirin use and in-hospital mortality; absolute risk reduction with aspirin = 7.5 % (95 % CI -2.0 to 16.9 %, p = 0.12). Preoperative aspirin use was associated with fewer total mechanical lung ventilation hours (p = 0.02) and less prolonged mechanical lung ventilation; absolute risk reduction = 11.0 % (95 % CI 1.1-20.5 %, p = 0.02).

CONCLUSIONS

Preoperative aspirin use is not associated with decreased in-hospital mortality in massively transfused cardiac surgery patients, but may be associated with less mechanical lung ventilation time.