Stopping vs. Continuing Aspirin before Coronary Artery Surgery

Cardiac Surgical Bleeding, Transfusion, and Quality Metrics: Joint Consensus Statement by the Enhanced Recovery After Surgery Cardiac Society and Society for the Advancement of Patient Blood Management

BACKGROUND

Excessive perioperative bleeding is associated with major complications in cardiac surgery, resulting in increased morbidity, mortality, and cost.

METHODS

An international expert panel was convened to develop consensus statements on the control of bleeding and management of transfusion and to suggest key quality metrics for cardiac surgical bleeding. The panel reviewed relevant literature from the previous 10 years and used a modified RAND Delphi methodology to achieve consensus.

RESULTS

The panel developed 30 consensus statements in 8 categories, including prioritizing control of bleeding, prechest closure checklists, and the need for additional quality indicators beyond reexploration rate, such as time to reexploration. Consensus was also reached on the need for a universal definition of excessive bleeding, the use of antifibrinolytics, optimal cessation of antithrombotic agents, and preoperative risk scoring based on patient and procedural factors to identify those at greatest risk of excessive bleeding. Furthermore, an objective bleeding scale is needed based on the volume and rapidity of blood loss accompanied by viscoelastic management algorithms and standardized, patient-centered blood management strategies reflecting an interdisciplinary approach to quality improvement.

CONCLUSIONS

Prioritizing the timely control and management of bleeding is essential to improving patient outcomes in cardiac surgery. To this end, a cardiac surgical bleeding quality metric that is more comprehensive than reexploration rate alone is needed. Similarly, interdisciplinary quality initiatives that seek to implement enhanced quality indicators will likely lead to improved patient care and outcomes.

Perioperative aspirin and coronary artery bypass graft surgery: An updated meta-analysis of randomized controlled trials

BACKGROUND

The decision to continue aspirin before elective coronary artery bypass graft surgery remains contentious because of competing thrombotic and bleeding risks. We performed a contemporary systematic review and meta-analysis to compare outcomes between patients undergoing coronary artery bypass grafting who stopped and continued aspirin before surgery.

METHODS

PubMed, MEDLINE, and CENTRAL databases were searched from inception to 4 October 2023 for randomized controlled trials comparing patients undergoing coronary artery bypass grafting who continued preoperative aspirin with those who discontinued before surgery. Studies with cointervention arms and multivariable-adjusted or propensity matched observational studies were excluded. Summary odds ratios were calculated using a random effects model for dichotomous and continuous variables. Subgroup and sensitivity analyses were conducted in order to explore sources of heterogeneity.

RESULTS

Fifteen eligible randomized controlled trials were included with a total of 6,188 patients. Patients who continued aspirin demonstrated no significant difference in all-cause mortality (odds ratio, 1.37; confidence interval, 0.81-2.33), perioperative myocardial infarction (odds ratio, 0.81; confidence interval, 0.55-1.18), and postoperative blood loss (mean difference, 66.12 mL; confidence interval, -1.45 to 133.69). No significant difference was observed between low-dose and greater doses of aspirin. There was minimal heterogeneity amongst included studies (I2 = 0%, P = .97, I2 = 33%, P = .13, and I2= 76, P = .06, respectively). Studies were of low methodologic quality according to Cochrane Risk of Bias for Randomized Trials.

CONCLUSIONS

This largest to-date systematic review and meta-analysis found no significant difference for risk of all-cause mortality, perioperative myocardial infarction, and postoperative bleeding between patients continuing and stopping aspirin before coronary artery bypass grafting.

To be or not to be on: aspirin and coronary artery bypass graft surgery

Aspirin's role in secondary prevention for patients with known coronary artery disease (CAD) is well established, validated by numerous landmark trials over the past several decades. However, its perioperative use in coronary artery bypass graft (CABG) surgery remains contentious due to the delicate balance between the risks of thrombosis and bleeding. While continuation of aspirin in patients undergoing CABG following acute coronary syndrome is widely supported due to the high risk of re-infarction, the evidence is less definitive for elective CABG procedures. The literature indicates a significant benefit of aspirin in reducing cardiovascular events in CAD patients, yet its impact on perioperative outcomes in CABG surgery is less clear. Some studies suggest increased bleeding risks without substantial improvement in cardiac outcomes. Specific to elective CABG, evidence is mixed, with some data indicating no significant difference in thrombotic or bleeding complications whether aspirin is continued or withheld preoperatively. Advancements in pharmacological therapies and perioperative care have evolved significantly since the initial aspirin trials, raising questions about the contemporary relevance of earlier findings. Individualized patient assessments and the development of risk stratification tools are needed to optimize perioperative aspirin use in CABG surgery. Further research is essential to establish clearer guidelines and improve patient outcomes. The objective of this review is to critically evaluate the existing evidence into the optimal management of perioperative aspirin in elective CABG patients.

Pharmacotherapy for Coronary Artery Disease and Acute Coronary Syndrome in the Aging Population

PURPOSE OF REVIEW

To provide a comprehensive summary of relevant studies and evidence concerning the utilization of different pharmacotherapeutic and revascularization strategies in managing coronary artery disease and acute coronary syndrome specifically in the older adult population.

RECENT FINDINGS

Approximately 30% to 40% of hospitalized patients with acute coronary syndrome are older adults, among whom the majority of cardiovascular-related deaths occur. When compared to younger patients, these individuals generally experience inferior clinical outcomes. Most clinical trials assessing the efficacy and safety of various therapeutics have primarily enrolled patients under the age of 75, in addition to excluding those with geriatric complexities. In this review, we emphasize the need for a personalized and comprehensive approach to pharmacotherapy for coronary heart disease and acute coronary syndrome in older adults, considering concomitant geriatric syndromes and age-related factors to optimize treatment outcomes while minimizing potential risks and complications. In the realm of clinical practice, cardiovascular and geriatric risks are closely intertwined, with both being significant factors in determining treatments aimed at reducing negative outcomes and attaining health conditions most valued by older adults.

Stroke prevention strategies for cardiac surgery: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Stroke is a much-feared complication of cardiac surgery, but existing literature on preventive strategies is fragmented. Hence, a systematic review and meta-analysis of stroke prevention strategies for cardiac surgery was conducted.

METHODS

An electronic literature search was conducted to retrieve randomized controlled trials (RCTs) investigating perioperative interventions for cardiac surgery, with stroke as an outcome. Random-effects meta-analyses were conducted to generate risk ratios (RRs), 95% confidence intervals (95% CI), and forest plots. Descriptive analysis and synthesis of literature was conducted for interventions not amenable to meta-analysis, focusing on risks of stroke, myocardial infarction and study-defined major adverse cardiovascular events (MACE).

RESULTS

Fifty-six RCTs (61 894 patients) were retrieved. Many included trials were underpowered to detect differences in stroke risk. Among pharmacological therapies, only preoperative amiodarone was shown to reduce stroke risk in one trial. Concomitant left atrial appendage closure (LAAC) significantly reduced stroke risk (RR = 0.55, 95% CI = 0.36-0.84, P = 0.006) in patients with preoperative atrial fibrillation, and there was no difference in on-pump versus off-pump coronary artery bypass grafting (CABG) (RR = 0.94, 95% CI = 0.64-1.37, P = 0.735). Much controversy exists in literature on the timing of carotid endarterectomy relative to CABG in patients with severe carotid stenosis. The use of preoperative remote ischemic preconditioning was not found to reduce rates of stroke or MACE.

CONCLUSION

This review presents a comprehensive synthesis of existing interventions for stroke prevention in cardiac surgery, and identifies gaps in research which may benefit from future, large-scale RCTs. LAAC should be considered to reduce stroke incidence in patients with preoperative atrial fibrillation.

Perioperative Acute Kidney Injury: Implications, Approach, Prevention

Acute kidney injury remains a common and significant contributor to perioperative morbidity. Acute kidney injury worsens patient outcomes, and anesthesiologists should make significant efforts to prevent, assess, and treat perioperative renal injury. The authors discuss the impact of renal injury on patient outcomes and putative underlying mechanisms, evidence underlying treatments for acute kidney injury, and practices that may prevent the development of perioperative renal injury.

An international expert consensus statement focusing on pre and post hair transplantation care

AIM

To achieve international expert consensus and give recommendations on best practices in hair transplantation surgery, focusing on pre- and post-transplantation care.

METHODS

A modified Delphi method was used to reach consensus. An international scientific committee developed an 81-statement questionnaire. A panel of 38 experts in hair transplantation from 17 countries across 4 continents assessed the questionnaire.

RESULTS

Two consensus rounds were carried out, with 59 out of 81 statements (73%) reaching consensus. Expert recommendations emphasize the correct selection of candidates for hair transplantation and the need for patients to have received adequate medical treatment for alopecia before transplant. Comorbidities should be assessed and considered while planning surgery, and an individualized plan for perioperative care should be drawn up before transplant. Certain medications associated with increased risk of bleeding should be withdrawn before surgery. Specific recommendations for post-transplantation care are given. After transplantation, patients should gradually resume their normal haircare regimen. Close follow-up should be carried out during the first year after transplant.

CONCLUSIONS

This study presents numerous consensus-based recommendations on general aspects of hair transplantation, including candidate selection, medical therapy prior to transplantation, anesthesia, and resuming haircare after transplantation.

The impact of long-term aspirin use on the patients undergoing shoulder arthroplasty

BACKGROUND

Although aspirin is increasingly utilized to reduce the event of severe perioperative complications, the effect of long-term aspirin use (L-AU) on perioperative complications in patients undergoing shoulder arthroplasty (SA) has not been well studied. The goal of the present study is to identify the influence of L-AU on perioperative complications in individuals undergoing SA.

METHODS

We selected data from the National Inpatient Sample database between 2010 and 2019, to identify adult patients with SA. Patients were subsequently categorized into L-AU and whole non-L-AU cohorts according to the presence of aspirin use. The demographic and comorbidity characteristics were matched using propensity score matching (PSM). The Pearson chi-square test, Wilcoxon rank test and logistic regression were utilized to assess the association of L-AU with perioperative complications.

RESULTS

From 2010 to 2019, a total of 162,418 SA patients satisfied the inclusion criteria, with 22,659 (13.95%) using aspirin on a long-term basis. The vast majority of the patients with pre-existing L-AU were aged 65-74 years, female, White and had Medicare insurance. L-AU before surgery was linked to increased risks of perioperative complications, such as blood transfusion (adjusted odds ratio [aOR]: 1.339), genitourinary disease (aOR: 1.349), acute renal failure (aOR: 1.292), acute myocardial infarction (aOR: 1.494), higher total charge (L-AU vs. the whole non-L-AU vs. matched non-L-AU: $66,727.15 vs. $59,697.08 vs. $59,926.32), and prolonged hospitalization stay (LOS) (aOR: 0.837). However, L-AU was considered a protective factor of acute cerebrovascular disease (aOR: 0.722) and stroke (aOR: 0.725).

CONCLUSIONS

Our study is based on the largest open-access all-payer inpatient database, revealing a noteworthy finding of aspirin's protective and adverse impact on different postoperative complications in the US population, such as acute cardiovascular disease, and stroke, etc. Further studies assessing the optimum preoperative aspirin duration and dosage to meet the best benefit quantity for patients with planned joint arthroplasties are suggested.

Midterm outcomes of simultaneous carotid revascularization combined with coronary artery bypass grafting

BACKGROUND

Simultaneous carotid endarterectomy (CEA) combined with coronary artery bypass grafting (CABG) has been widely used in patients with coronary heart disease complicated with severe carotid stenosis to reduce the risk of stroke and death. Carotid artery stenting (CAS) has been proven to be an alternative to CEA in recent years. We investigated the early and mid-term outcomes of simultaneous CEA or CAS combined with CABG in these patients.

METHODS

From January 2011 to January 2021, 88 patients who underwent simultaneous carotid revascularization combined with CABG under the same anesthesia in Beijing Anzhen Hospital were retrospectively analyzed, and this study included 25 patients who underwent CAS-CABG and 63 patients who underwent CEA-CABG. The main outcomes included all-cause death, stroke, myocardial infarction and combined adverse events. The main outcomes of the two groups were compared at 30 days after the operation and the mid-term follow-up. Univariate and multivariate Cox proportional hazards regression analyses were performed to determine the independent risk factors affecting mid-term mortality.

RESULTS

Within 30 days after the operation, there was no significant difference in combined adverse events between the two groups (P = 0.88). During the median follow-up period of 6.69 years (IQR, 5.82-7.57 years), 9 patients (14.30%) in the combined CEA-CABG group died, while 1 patient (4.00%) in the combined CAS-CABG group died. There were no significant differences in mid-term death (P = 0.20), stroke (P = 0.78), myocardial infarction (P = 0.88), or combined adverse events (P = 0.62) between the two groups. Univariate and multivariate Cox proportional hazards regression showed that NYHA grade IV (HR 5.01, 95% CI 1.16-21.64, P = 0.03) and previous myocardial infarction (HR 5.43, 95% CI 1.01-29.29, p = 0.04) were independent risk factors for mid-term mortality. We also found that combined CEA-CABG surgery may be associated with a higher risk of death (HR, 13.15; 95% CI 1.10-157.69, p = 0.04).

CONCLUSIONS

Combined CAS-CABG is a safe and effective treatment for patients with coronary heart disease complicated with severe carotid stenosis. NYHA grade IV and previous MI were independent risk factors for mid-term mortality.

Perioperative management of P2Y12 inhibitors in patients undergoing cardiac surgery within 1 year of PCI

AIMS

To evaluate the impact of perioperative P2Y12 receptor inhibitor therapy among patients undergoing cardiac surgery within 1 year of percutaneous coronary intervention (PCI).

METHODS AND RESULTS

Patients undergoing cardiac surgery in the year post-PCI at three tertiary care centres between 2011 and 2018 were stratified into those who had received at least one dose of P2Y12 inhibitor prior to surgery (within 5 days for clopidogrel or prasugrel, or within 3 days for ticagrelor) and those who had not. The outcomes of interest were major adverse cardiac and cerebrovascular events (MACCEs) and bleeding. Among 20 279 PCI patients, 359 (1.8%) underwent cardiac surgery in the ensuing year, 76.3% of whom received coronary artery bypass grafts. Overall, 33 (9.2%) MACCEs and 85 (23.7%) bleeding events occurred within 30 days post-cardiac surgery. Perioperative P2Y12 inhibition (N = 133, 37%) was not associated with the risk of MACCEs or bleeding, despite numerically lower rates of myocardial infarction or stent thrombosis (0.0% vs. 2.6%; P = 0.089). Patients who continued the P2Y12 inhibitor until the day of surgery (N = 60, 17%) had significantly higher bleeding risk [adjusted odds ratio 2.93, 95% confidence interval 1.53-5.59)]. Predictors of MACCEs included a time interval from PCI to cardiac surgery of ≤30 days and reduced ejection fraction, whereas urgent/emergent surgery predicted bleeding. Chronic kidney disease and myocardial infarction as indication for PCI predicted both MACCEs and bleeding.

CONCLUSION

Among patients undergoing cardiac surgery in the year after PCI, the perioperative risk of ischaemic and bleeding events might be influenced by P2Y12 inhibitor therapy in addition to other risk parameters, including the timing and urgency of the procedure.

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.

Impact of aspirin on bleeding and blood product usage in off-pump and on-pump coronary artery bypass graft surgery

Major bleeding is linked to poorer outcomes following cardiac surgery. Current guidelines recommend continuation of aspirin prior to coronary artery by-pass graft (CABG) but the effect of continuing aspirin in patients with prior indication for aspirin, in particular during off-pump CABG (OPCABG), has not been systematically assessed. In this study, we analysed the effect of continuing aspirin prior to OPCABG and on-pump CABG with respect to bleeding and blood product usage. We compared propensity-matched cohorts of patients who continued aspirin until the day of OPCABG or CABG to controls (no antiplatelet) and to patients discontinuing aspirin 5-7 days prior. Length of hospital stay, 30-day mortality and thromboembolism rates were similar for both OPCABG and CABG. During OPCABG, aspirin-continued patients received more intraoperative red cell units compared to controls without difference in bleeding. Aspirin-continued patients received more blood products perioperatively and bled more than aspirin-discontinued patients undergoing OPCABG. The only difference during CABG was a small increase in the volume of cells salvaged among aspirin-continued patients compared to controls. Current guidelines on the continuation of aspirin prior to CABG and OPCABG are safe. Continuation of aspirin prior to OPCABG may result in more bleeding and blood product usage.

Antiplatelet agents for chronic kidney disease

BACKGROUND

Antiplatelet agents are widely used to prevent cardiovascular events. The risks and benefits of antiplatelet agents may be different in people with chronic kidney disease (CKD) for whom occlusive atherosclerotic events are less prevalent, and bleeding hazards might be increased. This is an update of a review first published in 2013.

OBJECTIVES

To evaluate the benefits and harms of antiplatelet agents in people with any form of CKD, including those with CKD not receiving renal replacement therapy, patients receiving any form of dialysis, and kidney transplant recipients.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 13 July 2021 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We selected randomised controlled trials of any antiplatelet agents versus placebo or no treatment, or direct head-to-head antiplatelet agent studies in people with CKD. Studies were included if they enrolled participants with CKD, or included people in broader at-risk populations in which data for subgroups with CKD could be disaggregated.

DATA COLLECTION AND ANALYSIS

Four authors independently extracted data from primary study reports and any available supplementary information for study population, interventions, outcomes, and risks of bias. Risk ratios (RR) and 95% confidence intervals (CI) were calculated from numbers of events and numbers of participants at risk which were extracted from each included study. The reported RRs were extracted where crude event rates were not provided. Data were pooled using the random-effects model. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We included 113 studies, enrolling 51,959 participants; 90 studies (40,597 CKD participants) compared an antiplatelet agent with placebo or no treatment, and 29 studies (11,805 CKD participants) directly compared one antiplatelet agent with another. Fifty-six new studies were added to this 2021 update. Seven studies originally excluded from the 2013 review were included, although they had a follow-up lower than two months. Random sequence generation and allocation concealment were at low risk of bias in 16 and 22 studies, respectively. Sixty-four studies reported low-risk methods for blinding of participants and investigators; outcome assessment was blinded in 41 studies. Forty-one studies were at low risk of attrition bias, 50 studies were at low risk of selective reporting bias, and 57 studies were at low risk of other potential sources of bias. Compared to placebo or no treatment, antiplatelet agents probably reduces myocardial infarction (18 studies, 15,289 participants: RR 0.88, 95% CI 0.79 to 0.99, I² = 0%; moderate certainty). Antiplatelet agents has uncertain effects on fatal or nonfatal stroke (12 studies, 10.382 participants: RR 1.01, 95% CI 0.64 to 1.59, I² = 37%; very low certainty) and may have little or no effect on death from any cause (35 studies, 18,241 participants: RR 0.94, 95 % CI 0.84 to 1.06, I² = 14%; low certainty). Antiplatelet therapy probably increases major bleeding in people with CKD and those treated with haemodialysis (HD) (29 studies, 16,194 participants: RR 1.35, 95% CI 1.10 to 1.65, I² = 12%; moderate certainty). In addition, antiplatelet therapy may increase minor bleeding in people with CKD and those treated with HD (21 studies, 13,218 participants: RR 1.55, 95% CI 1.27 to 1.90, I² = 58%; low certainty). Antiplatelet treatment may reduce early dialysis vascular access thrombosis (8 studies, 1525 participants) RR 0.52, 95% CI 0.38 to 0.70; low certainty). Antiplatelet agents may reduce doubling of serum creatinine in CKD (3 studies, 217 participants: RR 0.39, 95% CI 0.17 to 0.86, I² = 8%; low certainty). The treatment effects of antiplatelet agents on stroke, cardiovascular death, kidney failure, kidney transplant graft loss, transplant rejection, creatinine clearance, proteinuria, dialysis access failure, loss of primary unassisted patency, failure to attain suitability for dialysis, need of intervention and cardiovascular hospitalisation were uncertain. Limited data were available for direct head-to-head comparisons of antiplatelet drugs, including prasugrel, ticagrelor, different doses of clopidogrel, abciximab, defibrotide, sarpogrelate and beraprost.

AUTHORS' CONCLUSIONS

Antiplatelet agents probably reduced myocardial infarction and increased major bleeding, but do not appear to reduce all-cause and cardiovascular death among people with CKD and those treated with dialysis. The treatment effects of antiplatelet agents compared with each other are uncertain.

Perioperative Guidelines on Antiplatelet and Anticoagulant Agents: 2022 Update

Purpose of Review

Multiple guidelines and recommendations have been written to address the perioperative management of antiplatelet and anticoagulant drugs. In this review, we evaluated the recent guidelines in non-cardiac, cardiac, and regional anesthesia. Furthermore, we focused on unresolved problems and novel approaches for optimized perioperative management.

Recent Findings

Vitamin K antagonists should be stopped 3 to 5 days before surgery. Preoperative laboratory testing is recommended. Bridging therapy does not decrease the perioperative thromboembolic risk and might increase perioperative bleeding risk. In patients on direct-acting oral anticoagulants (DOAC), a discontinuation interval of 24 and 48 h in those scheduled for surgery with low and high bleeding risk, respectively, has been shown to be saved. Several guidelines for regional anesthesia recommend a conservative interruption interval of 72 h for DOACs before neuraxial anesthesia. Finally, aspirin is commonly continued in the perioperative period, whereas potent P2Y12 receptor inhibitors should be stopped, drug-specifically, 3 to 7 days before surgery.

Summary

Many guidelines have been published from various societies. Their applicability is limited in emergent or urgent surgery, where novel approaches might be helpful. However, their evidence is commonly based on small series, case reports, or expert opinions.

2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The guideline for coronary artery revascularization replaces the 2011 coronary artery bypass graft surgery and the 2011 and 2015 percutaneous coronary intervention guidelines, providing a patient-centric approach to guide clinicians in the treatment of patients with significant coronary artery disease undergoing coronary revascularization as well as the supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from May 2019 to September 2019, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, CINHL Complete, and other relevant databases. Additional relevant studies, published through May 2021, were also considered.

STRUCTURE

Coronary artery disease remains a leading cause of morbidity and mortality globally. Coronary revascularization is an important therapeutic option when managing patients with coronary artery disease. The 2021 coronary artery revascularization guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with coronary artery disease who are being considered for coronary revascularization, with the intent to improve quality of care and align with patients' interests.

Perioperative management of antithrombotic therapy: a case-based narrative review

The periprocedural management of patients who are receiving vitamin K antagonists, direct oral anticoagulants and antiplatelet therapy is a common and challenging clinical scenario as the decision to interrupt or continue these medications is anchored on patient and procedure-related risks for bleeding and thrombosis. Adding to the complexity of clinical management is the fact that anticoagulants have varied pharmacokinetic and pharmacodynamic properties and indications for clinical use. In many minimal-bleed-risk procedures, anticoagulants can be safely continued, without interruption, whereas in cases where anticoagulants cannot be safely continued, the timing of interruption and resumption, as well as the need for heparin bridging requires consideration. Perioperative antithrombotic management scenarios occur most often in patients with atrial fibrillation, mechanical heart valves, coronary stents, and cerebrovascular disease as such patients are likely to be prescribed anticoagulant and/or antiplatelet therapy. The objective of this case-based narrative review is to provide a practical evidence-based approach to the perioperative management of patients on anticoagulation and antiplatelet therapy. Four clinical scenarios will be provided: (1) managing patients in whom anticoagulants can be continued; (2) perioperative management of direct oral anticoagulants; (3) management of patients on dual antiplatelet therapy; and (4) anticoagulant management for emergency or urgent surgery.

Emergency cardiac surgery in patients on oral anticoagulants and antiplatelet medications

BACKGROUND

Emergency surgery, blood transfusion, and reoperation for bleeding have been associated with increased operative morbidity and mortality. The recent increased use of direct oral anticoagulants and antiplatelet medications has made the above more challenging. In addition, cardiopulmonary bypass (CPB), with its associated hemodilution, fibrinolysis, and platelet consumption, may exacerbate the pre-existing coagulopathy and increase the risk of bleeding.

AIM

The aim of this study was to examine available literature with regard to treating patients who are on the above medications and require emergency cardiac surgery.

RESULTS

Management decisions are typically made on a case-by-case basis. Surgery is delayed when possible, and less invasive percutaneous options should be considered if feasible. Attention is paid to exercising meticulous techniques, avoiding excessive hypothermia, and treating coexisting issues such as sepsis. Ensuring a dry operative field upon entry by correcting the coagulopathy with reversal agents is offset by the concern of potentially hindering efforts to anticoagulate the patient (heparin resistance) in preparation for CPB, in addition to possibly increasing the risk of thromboembolism.

CONCLUSION

Proper knowledge of anticoagulants, their reversal agents, and the usefulness of laboratory testing are all essential. Platelet transfusion remains the mainstay for antiplatelet medications. Four-factor prothrombin complex concentrate is considered in patients on oral anticoagulants if CPB needs to be instituted quickly. Specific reversal agents such as idarucizumab and andexanet alfa can be considered if significant tissue dissection is anticipated, such as redo sternotomy, but are costly and may lead to heparin resistance and anticoagulant rebound.

Saphenous Vein Graft Failure: From Pathophysiology to Prevention and Treatment Strategies

Saphenous vein grafts (SVGs) remain the most frequently used conduits in coronary artery bypass graft surgery (CABG). Despite advances in surgical techniques and pharmacotherapy, SVG failure rates remain high, often leading to repeat coronary revascularization. The no-touch SVG harvesting technique (minimal graft manipulation with preservation of vasa vasorum and nerves) reduces the risk of SVG failure, whereas the effect of the off-pump technique on SVG patency remains unclear. Use of buffered storage solutions, intraoperative graft flow measurement, careful selection of the target vessels, and physiological assessment of the native coronary circulation before CABG may also reduce the incidence of SVG failure. Perioperative aspirin and high-intensity statin administration are the cornerstones of secondary prevention after CABG. Dual antiplatelet therapy is recommended for off-pump CABG and in patients with a recent acute coronary syndrome. Intermediate (30%-60%) SVG stenoses often progress rapidly. Stenting of intermediate SVG stenoses failed to improve outcomes; hence, treatment focuses on strict control of coronary artery disease risk factors. Redo CABG is associated with higher perioperative mortality compared with percutaneous coronary intervention (PCI); hence, the latter is preferred for most patients requiring repeat revascularization after CABG. SVG PCI is limited by high rates of no-reflow and a high incidence of restenosis during follow-up. Drug-eluting and bare metal stents provide similar long-term outcomes in SVG PCI. Embolic protection devices reduce no-reflow and should be used when feasible. PCI of the corresponding native coronary artery is associated with better short- and long-term outcomes and is preferred over SVG PCI, if technically feasible.

Tranexamic acid rapidly inhibits fibrinolysis, yet transiently enhances plasmin generation in vivo

Tranexamic acid (TXA) is a lysine analogue that inhibits plasmin generation and has been used for decades as an antifibrinolytic agent to reduce bleeding. Recent reports have indicated that TXA can paradoxically promote plasmin generation. Blood was obtained from 41 cardiac surgical patients randomly assigned to TXA or placebo before start of surgery (preOP), at the end of surgery (EOS), then again on postoperative day 1 (POD-1) as well as POD-3. Plasma levels of tissue-type plasminogen activator (t-PA), urokinase (u-PA), the plasmin-antiplasmin (PAP) complex, as well as t-PA and u-PA-induced clot lysis assays were then determined. Clot lysis and PAP complex levels were also assessed in healthy volunteers before and at various time points after taking 1 g TXA orally. Surgery induced an increase in circulating t-PA, yet not u-PA at EOS. t-PA levels were unaffected by TXA; however, u-PA levels were significantly reduced in patients on POD-3. t-PA and u-PA-induced clot lysis were both inhibited in plasma from TXA-treated patients. In contrast, PAP complex formation, representing plasmin generation, was unexpectedly enhanced in the plasma of patients administered TXA at the EOS time point. In healthy volunteers, oral TXA effectively blocked fibrinolysis within 30 min and blockade was sustained for 8 h. However, TXA also increased PAP levels in volunteers 4 h after administration. Our findings demonstrate that TXA can actually augment PAP complex formation, consistent with an increase in plasmin generation in vivo despite the fact that it blocks fibrinolysis within 30 min. This may have unanticipated consequences in vivo.

The safety of continued low dose aspirin therapy during Complete Supine Percutaneous Nephrolithotomy (csPCNL)

OBJECTIVE

Using anticoagulants and antiplatelet drugs in patients with cardiovascular and medical comorbidities is prevalent. Because of hyper vascular nature of kidney, physicians tend to stop using aspirin before percutaneous nephrolithotomy (PCNL). We have shown the effects of remaining on low dose aspirin in complete supine PCNL (csPCNL).

MATERIAL AND METHODS

The records of 643 patients who underwent csPCNL between 2012 and 2018 were analyzed. Surgical outcomes and complications of patients who were on aspirin therapy and continued it daily (group A) were compared with those not taking aspirin (group B).

RESULTS

Of the 643 csPCNLs, 40 (6%) were performed in patients of group A and the rest of 603 (94%) cases were in group B. The differences between the mean age of groups were statistically significant (60.08±9.45, group A and 48.66±12.32, group B) (P<0.001). Thirty-nine (97.5%) of patients in group A and 548 (90.9%) of group B were stone free by the end of the study which was not statistically significant (P=0.118). The mean operative time between groups A and B (43.20±21.37 and 44.83±16.83, respectively) was not considered significant (P=0.561). There was also no significant difference between 2 groups in any types of complications. Multivariate analysis showed that, perioperative aspirin use was not a significant predictor of transfusion, Hb drop, operative time and other complications.

CONCLUSIONS

Remaining on aspirin does not increase the risk of bleeding, transfusionand other complications. Consequently, continuing aspirin prioperatively in csPCNL appears safe. There is no fear for continuing aspirin in csPCNL.

LEVEL OF EVIDENCE

3.

Perioperative Clinical Trials in AKI

To characterize current evidence and current foci of perioperative clinical trials, we systematically reviewed Medline and identified perioperative trials involving 100 or more adult patients undergoing surgery and reporting renal end points that were published in high-impact journals since 2004. We categorized the 101 trials identified based on the nature of the intervention and summarized major trial findings from the five categories most applicable to perioperative management of patients. Trials that targeted ischemia suggested that increasing perioperative renal oxygen delivery with inotropes or blood transfusion does not reliably mitigate acute kidney injury (AKI), although goal-directed therapy with hemodynamic monitors appeared beneficial in some trials. Trials that have targeted inflammation or oxidative stress, including studies of nonsteroidal anti-inflammatory drugs, steroids, N-acetylcysteine, and sodium bicarbonate, have not shown renal benefits, and high-dose perioperative statin treatment increased AKI in some patient groups in two large trials. Balanced crystalloid intravenous fluids appear safer than saline, and crystalloids appear safer than colloids. Liberal compared with restrictive fluid administration reduced AKI in a recent large trial in open abdominal surgery. Remote ischemic preconditioning, although effective in several smaller trials, failed to reduce AKI in two larger trials. The translation of promising preclinical therapies to patients undergoing surgery remains poor, and most interventions that reduced perioperative AKI compared novel surgical management techniques or existing processes of care rather than novel pharmacologic interventions.

Short-term and long-term outcomes of revascularization interventions for patients with severely reduced left ventricular ejection fraction: a meta-analysis

AIMS

This meta-analysis aimed to determine whether coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI) should be preferred in patients with severely reduced left ventricular (LV) ejection fraction.

METHODS AND RESULTS

We searched the PubMed, EMBASE, and Cochrane Library databases from the conception of the databases till 1 May 2020 for studies on patients with severely reduced LV ejection fraction undergoing CABG and PCI. The primary clinical endpoints were 30 day and long-term mortalities. The secondary endpoints were 30 day and long-term incidences of myocardial infarction (MI) and stroke, long-term cardiovascular mortality, and repeat revascularization. Eighteen studies involving 11 686 patients were analysed. Compared with PCI, CABG had lower long-term mortality [hazard ratio (HR): 0.70, 95% confidence interval (CI): 0.61-0.80, P < 0.01], cardiovascular mortality (HR: 0.60, 95% CI: 0.43-0.85, P < 0.01), MI (HR: 0.51, 95% CI: 0.36-0.72, P < 0.01), and repeat revascularization (HR: 0.32, 95% CI: 0.23-0.47, P < 0.01) risk. Significant differences were not observed for long-term stroke (HR: 1.18, 95% CI: 0.74-1.87, P = 0.49), 30 day mortality (HR: 1.18, 95% CI: 0.89-1.56, P = 0.25), and MI (HR: 0.42, 95% CI: 0.16-1.11, P = 0.08) risk. CABG was associated with a higher risk of stroke within 30 days (HR: 2.88, 95% CI: 1.07-7.77, P = 0.04). In a subgroup analysis of propensity score-matched studies, CABG was associated with a higher long-term risk of stroke (HR: 1.61, 95% CI: 1.20-2.16, P < 0.01).

CONCLUSIONS

Among patients with severely reduced LV ejection fraction, CABG resulted in a lower mortality rate and an increased risk of stroke.

Platelet Function Testing in Patients on Antiplatelet Therapy before Cardiac Surgery

Based on variable pharmacodynamic responsiveness and platelet reactivity recovery after discontinuation of P2Y12 receptor inhibitors, preoperative platelet function testing may individualize discontinuation and be a part of transfusion algorithm triggering targeted postpump hemostatic management.

Point-of-Care Platelet Function Monitoring: Implications for Patients With Platelet Inhibitors in Cardiac Surgery

Although most physicians are comfortable managing the limited anticoagulant effect of aspirin, the recent administration of potent P2Y₁₂ receptor inhibitors in patients undergoing cardiac surgery remains a dilemma. Guidelines recommend discontinuation of potent P2Y₁₂ inhibitors 5- to- 7 days before surgery to reduce the risk of postoperative hemorrhage. Such a strategy might not be feasible before urgent surgery, due to ongoing myocardial ischemia or in patients at high risk for thromboembolic events. Recently, different point-of-care devices to assess functional platelet quality have become available for clinical use. The aim of this narrative review was to evaluate the implications and potential benefits of platelet function monitoring in guiding perioperative management and therapeutic options in patients treated with antiplatelets, including aspirin or P2Y₁₂ receptor inhibitors, undergoing cardiac surgery. No objective superiority of one point-of-care device over another was found in a large meta-analysis. Their accuracy and reliability are generally limited in the perioperative period. In particular, preoperative platelet function testing has been used to assess platelet contribution to bleeding after cardiac surgery. However, predictive values for postoperative hemorrhage and transfusion requirements are low, and there is a significant variability between and within these tests. Further, platelet function monitoring has been used to optimize the preoperative waiting period after cessation of dual antiplatelet therapy before urgent cardiac surgery. Furthermore, studies assessing their value in therapeutic decisions in bleeding patients after cardiac surgery are scarce. A general and liberal use of perioperative platelet function testing is not yet recommended.

Tranexamic acid modulates the immune response and reduces postsurgical infection rates

Tranexamic acid (TXA) is an antifibrinolytic agent that blocks plasmin formation. Because plasmin is known to promote inflammatory and immunosuppressive responses, we explored the possibility that plasmin-mediated immunosuppression in patients undergoing cardiac surgery can be directly reversed by TXA and decrease postoperative infection rates. The modulatory effect of TXA on inflammatory cytokine levels and on innate immune cell activation were evaluated with multiplex enzyme-linked immunosorbent assay and flow cytometry, respectively. Postoperative infection rates were determined in patients undergoing cardiac surgery and randomized to TXA (ACTRN12605000557639; http://www.anzca.edu.au). We demonstrate that TXA-mediated plasmin blockade modulates the immune system and reduces surgery-induced immunosuppression in patients following cardiac surgery. TXA enhanced the expression of immune-activating markers while reducing the expression of immunosuppressive markers on multiple myeloid and lymphoid cell populations in peripheral blood. TXA administration significantly reduced postoperative infection rates, despite the fact that patients were being administered prophylactic antibiotics. This effect was independent of the effect of TXA at reducing blood loss. TXA was also shown to exert an immune-modulatory effect in healthy volunteers, further supporting the fibrin-independent effect of TXA on immune function and indicating that baseline plasmin levels contribute to the regulation of the immune system in the absence of any comorbidity or surgical trauma. Finally, the capacity of TXA to reduce infection rates, modulate the innate immune cell profile, and generate an antifibrinolytic effect overall was markedly reduced in patients with diabetes, demonstrating for the first time that the diabetic condition renders patients partially refractory to TXA.

DNA methylation patterns from peripheral blood separate coronary artery disease patients with and without heart failure

Aims

Natriuretic peptides are useful for diagnosis and prognostication of heart failure of any cause. Now, research aims to discover novel biomarkers that will more specifically define the heart failure phenotype. DNA methylation plays a critical role in the development of cardiovascular disease with the potential to predict fundamental pathogenic processes. There is a lack of data relating DNA methylation in heart failure that specifically focuses on patients with severe multi‐vessel coronary artery disease. To begin to address this, we conducted a pilot study uniquely exploring the utility of powerful whole‐genome methyl‐binding domain‐capture sequencing in a cohort of cardiac surgery patients, matched for the severity of their coronary artery disease, aiming to identify candidate peripheral blood DNA methylation markers of ischaemic cardiomyopathy and heart failure.

Methods and results

We recruited a cohort of 20 male patients presenting for coronary artery bypass graft surgery with phenotypic extremes of heart failure but who otherwise share a similar coronary ischaemic burden, age, sex, and ethnicity. Methylation profiling in patient blood samples was performed using methyl‐binding domain‐capture sequencing. Differentially methylated regions were validated using targeted bisulfite sequencing. Gene set enrichment analysis was performed to identify differences in methylation at or near gene promoters in certain known Reactome pathways. We detected 567 188 methylation peaks of which our general linear model identified 68 significantly differentially methylated regions in heart failure with a false discovery rate <0.05. Of these regions, 48 occurred within gene bodies and 25 were located near enhancer elements, some within coding genes and some in non‐coding genes. Gene set enrichment analyses identified 103 significantly enriched gene sets (false discovery rate <0.05) in heart failure. Validation analysis of regions with the strongest differential methylation data was performed for two genes: HDAC9 and the uncharacterized miRNA gene MIR3675. Genes of particular interest as novel candidate markers of the heart failure phenotype with reduced methylation were HDAC9, JARID2, and GREM1 and with increased methylation PDSS2.

Conclusions

We demonstrate the utility of methyl‐binding domain‐capture sequencing to evaluate peripheral blood DNA methylation markers in a cohort of cardiac surgical patients with severe multi‐vessel coronary artery disease and phenotypic extremes of heart failure. The differential methylation status of specific coding genes identified are candidates for larger longitudinal studies. We have further demonstrated the value and feasibility of examining DNA methylation during the perioperative period to highlight biological pathways and processes contributing to complex phenotypes.

Expert consensus on the diagnosis and treatment of thrombocytopenia in adult critical care patients in China

Thrombocytopenia is a common complication of critical care patients. The rates of bleeding events and mortality are also significantly increased in critical care patients with thrombocytopenia. Therefore, the Critical Care Medicine Committee of Chinese People's Liberation Army (PLA) worked with Chinese Society of Laboratory Medicine, Chinese Medical Association to develop this consensus to provide guidance for clinical practice. The consensus includes five sections and 27 items: the definition of thrombocytopenia, etiology and pathophysiology, diagnosis and differential diagnosis, treatment and prevention.

Effect of topical tranexamic acid in total hip arthroplasty patients who receive continuous aspirin for prevention of cardiovascular or cerebrovascular events: A prospective randomized study

BACKGROUND

Due to differences in pharmacological mechanism of action, the effect of tranexamic acid (TA) on aspirin-related bleeding remains unknown. We therefore conducted a prospective randomized study to elucidate: (1) the effect of topical TA administration on blood loss and transfusion rate in total hip arthroplasty (THA) patients receiving continuous aspirin for prevention of cardiovascular or cerebrovascular events; (2) 90-day complications of topical TA administration; (3) possible variables contributing to blood transfusion.

HYPOTHESIS

Topical TA administration reduces blood loss and transfusion rate in THA patients receiving continuous aspirin.

PATIENTS AND METHODS

A total of 102 consecutive THA patients taking continuous aspirin were enrolled and randomized into two groups. In the topical TA (TTA) group (n=55), topical TA was administered at three points during THA; in the control group (n=47), the patients received saline solution as placebo. Based on drop in hemoglobin concentration, total estimated blood loss was calculated as the main assessment criterion. Secondary assessment criteria included transfusion rate and 90-day complications. Finally, a multivariate regression model was used to assess possible predictive factors for blood transfusion.

RESULTS

(1) Significantly lower total blood loss was observed in the TTA group than in the control group (897±177ml vs. 1153±345ml, p<0.001). Furthermore, lower transfusion rate was observed in the TTA group than in the control group (10.9% vs. 34.0%, p=0.005). (2) No significant difference was observed between the two groups regarding 90-day complications. (3) We identified higher preoperative hemoglobin level (OR=0.675, p=0.002) and topical TA administration (OR=0.002, p=0.012) as negative predictive factors for blood transfusion.

DISCUSSION

Topical application of TA was safe and beneficial in THA patients receiving continuous aspirin for prevention of cardiovascular or cerebrovascular events, to reduce blood loss and transfusion rate, without increasing the risk of 90-day complications.

Society of Cardiovascular Anesthesiologists Clinical Practice Improvement Advisory for Management of Perioperative Bleeding and Hemostasis in Cardiac Surgery Patients

Bleeding after cardiac surgery is a common and serious complication leading to transfusion of multiple blood products and resulting in increased morbidity and mortality. Despite the publication of numerous guidelines and consensus statements for patient blood management in cardiac surgery, research has revealed that adherence to these guidelines is poor, and as a result, a significant variability in patient transfusion practices among practitioners still remains. In addition, although utilization of point-of-care (POC) coagulation monitors and the use of novel therapeutic strategies for perioperative hemostasis, such as the use of coagulation factor concentrates, have increased significantly over the last decade, they are still not widely available in every institution. Therefore, despite continuous efforts, blood transfusion in cardiac surgery has only modestly declined over the last decade, remaining at ≥50% in high-risk patients. Given these limitations, and in response to new regulatory and legislature requirements, the Society of Cardiovascular Anesthesiologists (SCA) has formed the Blood Conservation in Cardiac Surgery Working Group to organize, summarize, and disseminate the available best-practice knowledge in patient blood management in cardiac surgery. The current publication includes the summary statements and algorithms designed by the working group, after collection and review of the existing guidelines, consensus statements, and recommendations for patient blood management practices in cardiac surgery patients. The overall goal is creating a dynamic resource of easily accessible educational material that will help to increase and improve compliance with the existing evidence-based best practices of patient blood management by cardiac surgery care teams.

Patient Blood Management in Pediatric Cardiac Surgery: A Review

Efforts to reduce blood product transfusions and adopt blood conservation strategies for infants and children undergoing cardiac surgical procedures are ongoing. Children typically receive red blood cell and coagulant blood products perioperatively for many reasons, including developmental alterations of their hemostatic system, and hemodilution and hypothermia with cardiopulmonary bypass that incites inflammation and coagulopathy and requires systemic anticoagulation. The complexity of their surgical procedures, complex cardiopulmonary interactions, and risk for inadequate oxygen delivery and postoperative bleeding further contribute to blood product utilization in this vulnerable population. Despite these challenges, safe conservative blood management practices spanning the pre-, intra-, and postoperative periods are being developed and are associated with reduced blood product transfusions. This review summarizes the available evidence regarding anemia management and blood transfusion practices in the perioperative care of these critically ill children. The evidence suggests that adoption of a comprehensive blood management approach decreases blood transfusions, but the impact on clinical outcomes is less well studied and represents an area that deserves further investigation.

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.

The Effects of Preoperative Aspirin on Coronary Artery Bypass Surgery: a Systematic Meta-Analysis

Background and Objectives

Aspirin plays an important role in the maintenance of graft patency and the prevention of thrombotic event after coronary artery bypass graft surgery (CABG). However, the use of preoperative aspirin is still under debate due to the risk of bleeding.

Methods

From PubMed, EMBASE, and Cochrane Central Register of Controlled Trials, data were extracted by 2 independent reviewers. Meta-analysis using random effect model was performed.

Results

We performed a systemic meta-analysis of 17 studies (12 randomized controlled studies and 5 non-randomized registries) which compared clinical outcomes of 9,101 patients who underwent CABG with or without preoperative aspirin administration. Preoperative aspirin increased chest tube drainage (weighted mean difference 177.4 mL, 95% confidence interval [CI], 41.3–313.4; p=0.011). However, the risk of re-operation for bleeding was not different between the preoperative aspirin group and the control group (3.2% vs. 2.4%; odds ratio [OR], 1.23; 95% CI, 0.94–1.60; p=0.102). There was no difference in the rates of all-cause mortality (1.6% vs. 1.5%; OR, 0.98; 95% CI, 0.64–1.49; p=0.920) and myocardial infarction (MI) (8.7% vs. 10.4%; OR, 0.83; 95% CI, 0.66–1.04; p=0.102) between patients with and without preoperative aspirin administration.

Conclusions

Although aspirin increased the amount of chest tube drainage, it was not associated with increased risk of re-operation for bleeding. In addition, the risks of early postoperative all-cause mortality and MI were not reduced by using preoperative aspirin.

Analysis and reporting of adverse events in randomised controlled trials: a review

OBJECTIVE

To ascertain contemporary approaches to the collection, reporting and analysis of adverse events (AEs) in randomised controlled trials (RCTs) with a primary efficacy outcome.

DESIGN

A review of clinical trials of drug interventions from four high impact medical journals.

DATA SOURCES

Electronic contents table of the BMJ, the Journal of the American Medical Association (JAMA), the Lancet and the New England Journal of Medicine (NEJM) were searched for reports of original RCTs published between September 2015 and September 2016.

METHODS

A prepiloted checklist was used and single data extraction was performed by three reviewers with independent check of a randomly sampled subset to verify quality. We extracted data on collection methods, assessment of severity and causality, reporting criteria, analysis methods and presentation of AE data.

RESULTS

We identified 184 eligible reports (BMJ n=3; JAMA n=38, Lancet n=62 and NEJM n=81). Sixty-two per cent reported some form of spontaneous AE collection but only 29% included details of specific prompts used to ascertain AE data. Numbers that withdrew from the trial were well reported (80%), however only 35% of these reported whether withdrawals were due to AEs. Results presented and analysis performed was predominantly on 'patients with at least one event' with 84% of studies ignoring repeated events. Despite a lack of power to undertake formal hypothesis testing, 47% performed such tests for binary outcomes.

CONCLUSIONS

This review highlighted that the collection, reporting and analysis of AE data in clinical trials is inconsistent and RCTs as a source of safety data are underused. Areas to improve include reducing information loss when analysing at patient level and inappropriate practice of underpowered multiple hypothesis testing. Implementation of standard reporting practices could enable a more accurate synthesis of safety data and development of guidance for statistical methodology to assess causality of AEs could facilitate better statistical practice.

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.