Should dual antiplatelet therapy be used in patients following coronary artery bypass surgery? A meta-analysis of randomized controlled trials

Antiplatelet Resistance in Coronary Artery Bypass Grafting: A Systematic Review

Background

This systematic review examines the occurrence and implications of resistance to primary antiplatelet agents, aspirin and clopidogrel, often utilised in patients undergoing coronary artery bypass grafting (CABG), alongside the methodologies for assessment of such resistance.

Methods

An extensive literature search across various databases such as PubMed, MEDLINE via Ovid, Embase, and Cochrane CENTRAL until May 2024 was conducted to identify studies evaluating antiplatelet resistance in on-pump and off-pump CABG patients. Following quality assessment, only high-quality studies were incorporated into this review.

Results

This review included 19 studies with 3,915 patients, four of which were randomised controlled trials and 15 were observational studies. Aspirin resistance incidence ranged from 11.0% to 51.5%, while clopidogrel resistance was 22%. Antiplatelet resistance, assessed through a wide variety of methods, was associated with a 13 times increase in the risk of vein graft occlusion and increased rates of mortality, myocardial infarction, and target vessel revascularisation in the case of clopidogrel resistance. The effect of cardiopulmonary bypass on antiplatelet resistance remains ambiguous.

Conclusion

The academic literature lacks a standardised definition for antiplatelet resistance. Assessment methodologies greatly vary, leading to noninterchangeable outcomes. While aspirin resistance has a conflicting overall significant impact on adverse outcomes, clopidogrel resistance correlates with poorer clinical outcomes.

Safety outcomes of anti-platelet therapy post coronary artery bypass graft surgery: A systematic review and network meta-analysis of randomized control trials

BACKGROUND

Antiplatelet therapy is used to decrease the risk of graft failure post coronary artery bypass graft surgery. We aimed to compare dual antiplatelet therapy (DAPT) with monotherapy along with a comparison of Aspirin, Ticagrelor, Aspirin+Ticagrelor (A+T) and Aspirin+Clopidogrel (A+C) to determine the major and minor bleeding risk, risk of postoperative myocardial infarction (MI), stroke, and all-cause mortality (ACM).

METHODS

Randomized Controlled Trials comparing the four groups were included. Odds ratio (OR) and Absolute Risk (AR) were employed to assess the mean and standard deviation (SD) with 95% confidence intervals (CI). The Bayesian random-effects model was used for statistical analysis. Risk difference and Cochran Q tests were used to calculate rank probability (RP) and heterogeneity, respectively.

RESULTS

We included 10 trials, consisting of 21 arms and 3926 patients. For the risk of major and minor bleed, A + T and Ticagrelor showed the lowest mean value of 0.040 (0.043) and 0.067 (0.073), respectively, and the highest RP of being the safest group. While a direct comparison between DAPT and monotherapy resulted in an OR of 0.57 [0.34, 0.95] for the risk of minor bleed. A + T was found to have the highest RP and the lowest mean value in terms of ACM, MI, and stroke.

CONCLUSION

No significant difference was found between monotherapy or dual-antiplatelet therapy for the major bleeding risk safety outcome, however DAPT was found to have a significantly higher rate of minor bleeding complications post-CABG. DAPT should be considered as the antiplatelet modality of choice post-CABG.

Antiplatelet therapy around CABG: the latest evidence

PURPOSE OF REVIEW

The optimal antiplatelet strategy in patients after coronary artery bypass graft (CABG) surgery is unclear. We review the evidence on the efficacy and safety of DAPT after CABG and discuss potential novel antiplatelet strategies that reduce the risk of bleeding without loss of efficacy.

RECENT FINDINGS

Adding the potent P2Y12 inhibitor ticagrelor to aspirin for 1 year after CABG is associated with a reduction in the risk of vein graft failure, at the expense of an increased risk of clinically important bleeding. Ticagrelor monotherapy is not associated with better efficacy than aspirin alone, but is not associated with increased bleeding risk.

SUMMARY

Dual antiplatelet therapy (DAPT) is recommended after acute coronary syndrome events, but aspirin as single antiplatelet therapy remains the cornerstone of antithrombotic therapy in stable ischemic heart disease because of a lack of solid evidence on the benefit of DAPT on clinical outcomes. Shorter duration DAPT, based on the pathophysiology of vein graft failure, may be a promising strategy that requires testing in adequately powered randomized trials.

Dual or single antiplatelet therapy after coronary surgery for acute coronary syndrome (TACSI trial): Rationale and design of an investigator-initiated, prospective, multinational, registry-based randomized clinical trial

The TACSI trial (ClinicalTrials.gov Identifier: NCT03560310) tests the hypothesis that 1-year treatment with dual antiplatelet therapy with acetylsalicylic acid (ASA) and ticagrelor is superior to only ASA after isolated coronary artery bypass grafting (CABG) in patients with acute coronary syndrome. The TACSI trial is an investigator-initiated pragmatic, prospective, multinational, multicenter, open-label, registry-based randomized trial with 1:1 randomization to dual antiplatelet therapy with ASA and ticagrelor or ASA only, in patients undergoing first isolated CABG, with a planned enrollment of 2200 patients at Nordic cardiac surgery centers. The primary efficacy end point is a composite of time to all-cause death, myocardial infarction, stroke, or new coronary revascularization within 12 months after randomization. The primary safety end point is time to hospitalization due to major bleeding. Secondary efficacy end points include time to the individual components of the primary end point, cardiovascular death, and rehospitalization due to cardiovascular causes. High-quality health care registries are used to assess primary and secondary end points. The patients will be followed for 10 years. The TACSI trial will give important information useful for guiding the antiplatelet strategy in acute coronary syndrome patients treated with CABG.

Bleeding risk in patients prescribed dual antiplatelet therapy and triple therapy after coronary interventions: the ADAPTT retrospective population-based cohort studies

Background

Bleeding among populations undergoing percutaneous coronary intervention or coronary artery bypass grafting and among conservatively managed patients with acute coronary syndrome exposed to different dual antiplatelet therapy and triple therapy (i.e. dual antiplatelet therapy plus an anticoagulant) has not been previously quantified.

Objectives

The objectives were to estimate hazard ratios for bleeding for different antiplatelet and triple therapy regimens, estimate resources and the associated costs of treating bleeding events, and to extend existing economic models of the cost-effectiveness of dual antiplatelet therapy.

Design

The study was designed as three retrospective population-based cohort studies emulating target randomised controlled trials.

Setting

The study was set in primary and secondary care in England from 2010 to 2017.

Participants

Participants were patients aged ≥ 18 years undergoing coronary artery bypass grafting or emergency percutaneous coronary intervention (for acute coronary syndrome), or conservatively managed patients with acute coronary syndrome.

Data sources

Data were sourced from linked Clinical Practice Research Datalink and Hospital Episode Statistics.

Interventions

Coronary artery bypass grafting and conservatively managed acute coronary syndrome: aspirin (reference) compared with aspirin and clopidogrel. Percutaneous coronary intervention: aspirin and clopidogrel (reference) compared with aspirin and prasugrel (ST elevation myocardial infarction only) or aspirin and ticagrelor.

Main outcome measures

Primary outcome: any bleeding events up to 12 months after the index event. Secondary outcomes: major or minor bleeding, all-cause and cardiovascular mortality, mortality from bleeding, myocardial infarction, stroke, additional coronary intervention and major adverse cardiovascular events.

Results

The incidence of any bleeding was 5% among coronary artery bypass graft patients, 10% among conservatively managed acute coronary syndrome patients and 9% among emergency percutaneous coronary intervention patients, compared with 18% among patients prescribed triple therapy. Among coronary artery bypass grafting and conservatively managed acute coronary syndrome patients, dual antiplatelet therapy, compared with aspirin, increased the hazards of any bleeding (coronary artery bypass grafting: hazard ratio 1.43, 95% confidence interval 1.21 to 1.69; conservatively-managed acute coronary syndrome: hazard ratio 1.72, 95% confidence interval 1.15 to 2.57) and major adverse cardiovascular events (coronary artery bypass grafting: hazard ratio 2.06, 95% confidence interval 1.23 to 3.46; conservatively-managed acute coronary syndrome: hazard ratio 1.57, 95% confidence interval 1.38 to 1.78). Among emergency percutaneous coronary intervention patients, dual antiplatelet therapy with ticagrelor, compared with dual antiplatelet therapy with clopidogrel, increased the hazard of any bleeding (hazard ratio 1.47, 95% confidence interval 1.19 to 1.82), but did not reduce the incidence of major adverse cardiovascular events (hazard ratio 1.06, 95% confidence interval 0.89 to 1.27). Among ST elevation myocardial infarction percutaneous coronary intervention patients, dual antiplatelet therapy with prasugrel, compared with dual antiplatelet therapy with clopidogrel, increased the hazard of any bleeding (hazard ratio 1.48, 95% confidence interval 1.02 to 2.12), but did not reduce the incidence of major adverse cardiovascular events (hazard ratio 1.10, 95% confidence interval 0.80 to 1.51). Health-care costs in the first year did not differ between dual antiplatelet therapy with clopidogrel and aspirin monotherapy among either coronary artery bypass grafting patients (mean difference £94, 95% confidence interval -£155 to £763) or conservatively managed acute coronary syndrome patients (mean difference £610, 95% confidence interval -£626 to £1516), but among emergency percutaneous coronary intervention patients were higher for those receiving dual antiplatelet therapy with ticagrelor than for those receiving dual antiplatelet therapy with clopidogrel, although for only patients on concurrent proton pump inhibitors (mean difference £1145, 95% confidence interval £269 to £2195).

Conclusions

This study suggests that more potent dual antiplatelet therapy may increase the risk of bleeding without reducing the incidence of major adverse cardiovascular events. These results should be carefully considered by clinicians and decision-makers alongside randomised controlled trial evidence when making recommendations about dual antiplatelet therapy.

Limitations

The estimates for bleeding and major adverse cardiovascular events may be biased from unmeasured confounding and the exclusion of an eligible subgroup of patients who could not be assigned an intervention. Because of these limitations, a formal cost-effectiveness analysis could not be conducted.

Future work

Future work should explore the feasibility of using other UK data sets of routinely collected data, less susceptible to bias, to estimate the benefit and harm of antiplatelet interventions.

Trial registration

This trial is registered as ISRCTN76607611.

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 27, No. 8. See the NIHR Journals Library website for further project information.

Role of Antiplatelet Therapy in Patients with Severe Coronary Artery Disease Undergoing Coronary Artery Endarterectomy within Coronary Artery Bypass Surgery

Background—Coronary endarterectomy (CEA) has been introduced to allow revascularization in end-stage coronary artery disease (CAD). After CEA, the injured remnants of the vessel’s media could result in fast neo intimal tissue ingrowth, which require an anti-proliferation agent (antiplatelet therapy (APT). We aimed to review outcomes of patients undergoing CEA within bypass surgery who received either single-APT (SAPT) or dual-APT (DAPT). Methods—We retrospectively evaluated 353 consecutive patients undergoing CEA within isolated coronary artery bypass grafting (CABG) in the period 01/2000–07/2019. After surgery, patients received either SAPT (n = 153), or DAPT (n = 200) for six months then lifelong SAPT. Endpoints included early, late survival, and freedom from major-adverse-cardiac and cerebrovascular events (MACCE), which were defined as incidence of stroke, myocardial infarction, need for coronary intervention (PCI or CABG) or death for any cause. Results—Patients’ mean age was 67 ± 9.3 years; they were predominantly male 88.1%. Both DAPT- and SAPT-groups had the same extent of CAD (mean SYNTAX-Score-II: 34.1 ± 11.6 vs. 34.4 ± 17.2, p = 0.91). Postoperatively, no difference between DAPT- and SAPT-groups was reported in the incidence of low-cardiac-output syndrome (5% vs. 9.8%, p = 0.16), revision for bleeding (5% vs. 6.5% p = 0.64), 30-day mortality (4.5% vs. 5.2%, p = 0.8) or MACCE (7.5% vs. 11.8%, p = 0.19). Imaging follow-up reported significantly higher CEA and total grafts patency (90% vs. 81.5% and 95% vs. 81%, p = 0.017) in DAPT patients. Late outcomes within 97.4 ± 67.4 months show lower incidence of overall mortality (19 vs. 51%, p < 0.001) and MACCE (24.5 vs. 58.2%, p < 0.001) in the DAPT patients when compared with SAPT patients. Conclusions—Coronary endarterectomy allows revascularization in end-stage CAD when the myocardium is still viable. The use of dual APT after CEA for at least six months seems to improve mid-to-long-term patency rates and survival, and reduced the incidence of major adverse cardiac and cerebrovascular events.

Predictors of Long-Term Outcomes after Surgical Myocardial Revascularization

High mortality from cardiovascular diseases (CVD) requires improved approaches to the treatment of this socially significant pathology. Wide implementation of surgical myocardial revascularization makes it possible to improve significantly both life quality and expectancy in patients with coronary heart disease. The aim of this work was to analyze the literature on the impact of preoperative, operative and postoperative factors on the long-term prognosis after coronary artery bypass grafting (CABG). The review refers to both recent and earlier informative works. The target groups for this article are therapists, cardiologists, rehabilitologists, who work with patients in the short and long term after CABG. Data of Russian and foreign literature show that the long-term prognosis after CABG is largely determined by preoperative factors, in particular – age, set of cardiovascular risk factors (RF) and comorbidity, specifically – severity of coronary and systemic atherosclerosis, incident cardiovascular complications, structural and functional state of the heart. In the aggregate these factors reflect the cumulative effect and further potential of actual cardiovascular RFs, affect longterm risk of adverse events, and determine the therapeutic targets of secondary prevention. Priority of arterial conduits and completeness of revascularization are the main operative factors that determine the course of the long-term period after CABG. Among the postoperative factors, the efficiency of secondary CVD prevention is of paramount importance, in particular – achievement of target RF levels, compensation of cardiac and extracardiac pathology, adherence to the long-term medical therapy, known to improve outcomes based on specific comorbidity. Efficiency of secondary CVD prevention largely depends on patient's health attitudes, the key influence on which beyond attending physician can be provided by participation in rehabilitation programs, teaching patients the meaning and essentials of lifestyle modification and cardiovascular RFs’ control.

Balancing the Risks of Recurrent Ischaemic and Bleeding Events in a Stable Post ACS Population

OBJECTIVE

To better guide decisions regarding antithrombotic treatment in individual patients surviving 6 months following an acute coronary syndrome (ACS) by balancing between subsequent recurrent ischaemic and bleeding risk.

METHODS

Patients surviving 6 months following an ACS were followed in an Australian registry. Ischaemic (composite of cardiovascular death, myocardial infarction or stroke) and bleeding (≥BARC 2) events were collected. A dual binary outcome modelling strategy was used arriving at a common set of variables from which bleeding and ischaemic risk could be independently determined in individual patients. Patients in whom bleeding rates exceeded composite ischaemic event rates during the follow-up period were identified.

RESULTS

The cohort comprised 5,905 patients in whom 215 experienced an ischaemic event and 49 a bleeding event. The single set of variables included in both ischaemic and bleeding models (C-statistics 0.71 and 0.72 respectively) included modified TIGRIS¹ ischaemic score, mode of revascularisation, history of heart failure, anaemia, multivessel disease, readmission within 6 months of index ACS and age >75. In the majority, ischaemic events were more frequent than bleeding events. In higher risk patients post coronary artery bypass grafting (CABG), bleeding events were more frequent than recurrent ischaemic events.

CONCLUSION

The risk of recurrent ischaemic events exceeds bleeding in most patients followed 6 to 24 months following an ACS. Post CABG patients with comorbidities have a higher risk of bleeding over this period during which time attention should be directed towards modifiable bleeding risk factors including requirement for dual antiplatelet therapy.

Dual antiplatelet therapy before coronary artery bypass grafting in patients with myocardial infarction: a prospective cohort study

BACKGROUND

Dual antiplatelet therapy (DAPT) in patients with MI who are candidates for early coronary artery bypass grafting (CABG) can affect intraoperative and postoperative outcomes. Therefore, the aim of this study was to evaluate the effect of DAPT up to the day before CABG on the outcomes during and after surgery in patients with MI.

METHODS

In this prospective cohort study, 224 CABG candidate patients with and without MI were divided into two groups: (A) patients without MI who were treated with aspirin 80 mg/day before surgery (noMI-aspirin group; n = 124) and (B) patients with MI who were treated with aspirin 80 mg/day before surgery and clopidogrel (Plavix brand) at a dose of 75 mg/day (MI-DAPT group; n = 120). Dual or mono-antiplatelet therapy continued until the day before surgery. Patients were followed to assess in-hospital and 6-months outcomes.

RESULTS

The in-hospital mortality in MI-DAPT group was similar with noMI-aspirin group (OR 4.2; 95% CI 0.9-20.5; p = 0.071). The prevalence of CVA (p = 0.098), duration of hospital stay (p = 0.109), postoperative ejection fraction level (p = 0.693), diastolic dysfunction grade (p = 0.651) and postoperative PAP level (p = 0.0364) did not show difference between two groups. No mild or severe bleeding was observed in the patients. Six-month follow up showed that number of readmissions (p = 0.801), number of cases requiring angiography (p = 0.100), cases requiring re-PCI (p = 0.156), need for re-CABG (p > 0.999) and CVA (p > 0.999) did not differ between the two groups. During the 6-month follow-up, out-hospital mortality did not differ significantly between the two groups (p = 0.446).

CONCLUSIONS

A 6-month follow-up showed that DAPT with aspirin and clopidogrel before CABG in patients with MI has no effect on postoperative outcomes more than mono-APT with aspirin. Therefore, DAPT is recommended in the preoperative period for these patients.

Atrial fibrillation following coronary artery bypass graft: Where do we stand?

Atrial fibrillation (AF) is the most common atrial arrhythmia following coronary artery bypass graft (CABG). Its prevalence is 15-45% and is associated with poor long-term prognosis. Risk factors can be patient-related, intraoperative, and/or postoperative. Therapeutic and preventive strategies have been developed to curtail AF burden. Cardioversion is recommended for unstable or symptomatic patients and rate control if asymptomatic. Anticoagulation is challenging with risk of thromboembolism and bleeding. However, patients should be anticoagulated after cardioversion or if AF persists >48 h and risk factors of stroke exist. A minimum of 4 weeks is recommended but longer duration should be considered in patients at high risk of stroke irrespective of recurrence of AF.

Dual antiplatelet therapy is under-prescribed in patients with surgically treated acute myocardial infarction

OBJECTIVES

Despite guideline recommendations, previous reports, coming mainly from outside Europe, showed low rates of prescriptions for dual antiplatelet therapy (DAPT) in patients with acute myocardial infarction (AMI) undergoing surgical revascularization. The present study assesses this issue in the era of potent P2Y12 inhibitors in Switzerland.

METHODS

All patients with a diagnosis of AMI included in the Acute Myocardial Infarction in Switzerland Plus Registry from January 2014 to December 2019 were screened; 9050 patients undergoing either percutaneous (8727, 96.5%) or surgical (323, 3.5%) revascularization were included in the analysis.

RESULTS

Surgically treated patients were significantly less likely to receive DAPT at discharge (56.3% vs 96.7%; P < 0.001). Even when discharged with a prescription for DAPT, those patients were significantly less likely to receive a regimen containing a new P2Y12 inhibitor (67/182 [36.8%] vs 6945/8440 [83.2%]; P < 0.001). At multivariate analysis, surgical revascularization was independently associated with a lower likelihood of receiving a prescription for DAPT at discharge (odds ratio 0.03, 95% confidence interval 0.02-0.06).

CONCLUSIONS

DAPT prescriptions for patients with AMI undergoing surgical revascularization are not in line with current guideline recommendations. Efforts are necessary to clarify the role of DAPT for secondary prevention in these patients and increase the confidence of treating physicians in guideline recommendations.

CLINICAL TRIAL REGISTRATION

Acute Myocardial Infarction in Switzerland Plus Registry; registration number at ClinicalTrials.gov: NCT01305785.

The relationship between dual antiplatelet treatment (DAPT) score and saphenous venous grafts patency after coronary artery bypass grafting surgery

BACKGROUND

Coronary artery bypass grafting (CABG) remains the gold standard treatment for mutivessel and left main coronary artery disease (CAD). Saphenous vein graft (SVG) patency is still a problem in CAD patients after CABG surgery. The Dual Antiplatelet Treatment (DAPT) score is a clinical prediction tool that predicts ischaemic and bleeding risk in CAD patients. The aim of this study is to investigate the relationship between DAPT score and SVG patency in CABG patients.

METHOD

This retrospective study enrolled a total of 398 patients (68 female; mean age 65.8 ± 9.1 years) with a history of CABG surgery. The study population was divided into two subgroups according to SVG patency. The DAPT score was calculated for each patients and compared between the two groups.

RESULTS

Coronary angiography revealed SVG disease in 212 patients and SVG patency in 186 patients. The rates of diabetes mellitus and hypertension, red cell distribution width values, DAPT Score, time interval after CABG and number of SVGs were significantly higher while LVEF was significantly lower in patients with SVG disease. The presence of diabetes mellitus, high DAPT score, long time interval after CABG and high number of SVGs were found to be independent predictors of SVG patency. DAPT score above 2.5 predicted SVG disease with a sensitivity of 77.1% and a specificity of 87.1% (AUC: 0.873; 95%CI: 0.823-0.924; p < 0.001).

CONCLUSION

The DAPT score may provide useful information for SVG patency in CABG patients. Patients with high DAPT score should be followed up closely for SGV occlusion. DAPT score may be useful prior to CABG in determining the duration of dual anti-platelet therapy and in encouraging the use of arterial grafts with better patency.

Comparison of Midterm Outcomes Associated With Aspirin and Ticagrelor vs Aspirin Monotherapy After Coronary Artery Bypass Grafting for Acute Coronary Syndrome

IMPORTANCE

Guidelines recommend dual antiplatelet therapy after coronary artery bypass grafting (CABG) for patients with acute coronary syndrome (ACS). However, the evidence for these recommendations is weak.

OBJECTIVE

To compare midterm outcomes after CABG in patients with ACS treated postoperatively with acetylsalicylic acid (ASA) and ticagrelor or with ASA monotherapy.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used merged data from several national registries of Swedish patients who were diagnosed with ACS and subsequently underwent CABG. All included patients underwent isolated CABG in Sweden between 2012 and 2017 with an ACS diagnosis less than 6 weeks before the procedure, survived 14 days after discharge from hospital, and were treated postoperatively with ASA plus ticagrelor or ASA monotherapy. A multivariable Cox regression model was used for the main analysis, and propensity score-matched models were performed as sensitivity analysis. Data were analyzed between May and September 2020.

EXPOSURES

Postoperative antiplatelet treatment, defined as filled prescriptions, with either ASA and ticagrelor or ASA only.

MAIN OUTCOMES AND MEASURES

Major adverse cardiovascular events (MACE), defined as all-cause mortality, myocardial infarction, and stroke, and major bleeding, at 12 months and at the end of follow-up.

RESULTS

A total of 6558 patients (5281 [80.5%] men; mean [SD] age at surgery, 67.6 [9.3] years) were included; 1813 (27.6%) were treated with ASA plus ticagrelor and 4745 (72.4%) were treated with ASA monotherapy. Crude MACE rate was 3.0 per 100 person years (95% CI, 2.5-3.6 per 100 person years) in the ASA plus ticagrelor group and 3.8 per 100 person years (95% CI, 3.5-4.1 per 100 person years) in the ASA group. After adjustment, there was no significant difference in MACE risk between ASA plus ticagrelor vs ASA only, neither during the first 12 months (adjusted hazard ratio [aHR], 0.84; 95% CI, 0.58-1.21; P = .34) or during total follow-up (aHR, 0.89; 95% CI, 0.71-1.11; P = .29). The use of ASA plus ticagrelor was associated with a significantly increased risk for major bleeding during the first 12 months (aHR, 1.90; 95% CI, 1.16-3.13; P = .011). Sensitivity analyses confirmed the results.

CONCLUSIONS AND RELEVANCE

In patients with ACS who survived 2 weeks after CABG, no significant difference in the risk of death or ischemic events could be demonstrated between ASA plus ticagrelor and patients treated with ASA only, while the risk for major bleeding was higher in patients treated with ASA plus ticagrelor. Sufficiently powered prospective randomized trials comparing different antiplatelet therapy strategies after CABG are warranted.

Guidelines for enhanced recovery after cardiac surgery. Consensus document of Spanish Societies of Anesthesia (SEDAR), Cardiovascular Surgery (SECCE) and Perfusionists (AEP)

The ERAS guidelines are intended to identify, disseminate and promote the implementation of the best, scientific evidence-based actions to decrease variability in clinical practice. The implementation of these practices in the global clinical process will promote better outcomes and the shortening of hospital and critical care unit stays, thereby resulting in a reduction in costs and in greater efficiency. After completing a systematic review at each of the points of the perioperative process in cardiac surgery, recommendations have been developed based on the best scientific evidence currently available with the consensus of the scientific societies involved.

Angiographic Patency of Coronary Artery Bypass Conduits: A Network Meta-Analysis of Randomized Trials

Background Several randomized trials have compared the patency of coronary artery bypass conduits. All of the published studies, however, have performed pairwise comparisons and a comprehensive evaluation of the patency rates of all conduits has yet to be published. We set out to investigate the angiographic patency rates of all conduits used in coronary bypass surgery by performing a network meta-analysis of the current available randomized evidence. Methods and Results A systematic literature search was conducted for randomized controlled trials comparing the angiographic patency rate of the conventionally harvested saphenous vein, the no-touch saphenous vein, the radial artery (RA), the right internal thoracic artery, or the gastroepiploic artery. The primary outcome was graft occlusion. A total of 4160 studies were retrieved of which 14 were included with 3651 grafts analyzed. The weighted mean angiographic follow-up was 5.1 years. Compared with the conventionally harvested saphenous vein, both the RA (incidence rate ratio [IRR] 0.54; 95% CI, 0.35-0.82) and the no-touch saphenous vein (IRR 0.55; 95% CI, 0.39-0.78) were associated with lower graft occlusion. The RA ranked as the best conduit (rank score for RA 0.87 versus 0.85 for no-touch saphenous vein, 0.23 for right internal thoracic artery, 0.29 for gastroepiploic artery, and 0.25 for the conventionally harvested saphenous vein). Conclusions Compared with the conventionally harvested saphenous vein, only the RA and no-touch saphenous vein grafts are associated with significantly lower graft occlusion rates. The RA ranks as the best conduit. Registration URL: https://www.crd.york.ac.uk/prospero; Unique identifier: CRD42020164492.

Secondary Prevention Medications Post Coronary Artery Bypass Grafting Surgery-A Literature Review

Secondary prevention after coronary artery bypass graft (CABG) surgery is imperative in slowing the progression of atherosclerosis in both native and grafted vessels. Aspirin and statins remain the key medications for all patients without significant contraindications. The evidence for dual antiplatelet therapy with clopidogrel is less convincing, but there is hope for newer antiplatelet agents, such as ticagrelor. Meanwhile, β-blockers and angiotensin converting enzyme inhibitors might only offer benefits to specific sub-groups. Post-CABG patients appear to have different medication needs to the general cardiovascular patient and respond differently. In this review, we cover the drug regimens proposed by recent guidelines and the evidence behind their use. Assessing the evidence behind these recommendations, we find that there is an unmet need in some areas for robust population-specific evidence. We hope that future research will address this gap.

Bleeding complications after dual antiplatelet therapy with ticagrelor versus dual antiplatelet therapy with clopidogrel-a propensity-matched comparative study of two antiplatelet regimes in off-pump coronary artery bypass grafting

Purpose

Ticagrelor combined with aspirin had shown better saphenous vein graft patency than aspirin with clopidogrel after off-pump coronary artery bypass grafting. However, the safety of this drug in regard to bleeding complications remains unknown. The aim of our study was to assess the bleeding complications of dual antiplatelet therapy with aspirin and ticagrelor compared with aspirin and clopidogrel within the first 3 months after off-pump surgery.

Methods

Three hundred eighty-two consecutive patients who were prescribed aspirin with ticagrelor (ticagrelor group) were compared with 660 patients who received aspirin and clopidogrel (clopidogrel group). After propensity matching, 144 patients in each group were compared for bleeding events and major adverse cardiac and cerebral events. Major bleeding was defined as composite outcome of re-exploration for bleeding, any fatal bleeding, intracranial bleeding, and any bleeding requiring hospitalization.

Results

Patients in the ticagrelor group had more incidence of re-exploration for bleeding (p = 0.042), pericardial effusion requiring drainage (p = 0.007), readmissions (p < 0.01), gastrointestinal bleeding (p = 0.01), and major bleeding (5.8% vs. 2.1%, p < 0.01, OR 2.8 (1.43-5.58)). After propensity analysis, gastrointestinal bleed (p = 0.024), major bleeding (7.6% vs.1.4%, p < 0.001, OR 5.8 (1.28-26.97)), length of ICU stay (p = 0.039), and readmissions (p = 0.003, OR 11.83 (1.51-92.86)) were more in the ticagrelor group. Major adverse cardiac and cerebral events were similar between the groups.

Conclusion

Dual antiplatelet therapy with aspirin and ticagrelor increased gastrointestinal bleeding events, major bleeding events, and readmission rates compared with aspirin and clopidogrel after off-pump coronary artery bypass grafting.

Antithrombotic regimens in patients after coronary artery bypass grafting and coronary endarterectomy

Background: Coronary artery bypass grafting (CABG) remains the gold standard in the treatment of complex chronic forms of coronary heart disease (CHD). Coronary endarterectomy (CEAE) is a useful adjunctive technique to CABG in patients with diffuse coronary artery disease. In order to maintain the patency of the coronary arteries and graft conduits, various antithrombotic protocols have been introduced over the years, combining various antiplatelet and anticoagulant drugs, but still there is no consensus.

Aim: The aim of the study is to compare results between two antithrombotic regimens after CEAE. The first one is a combination of acenocoumarol combined with acetylsalicylic acid (ASA), the second regimen is a dual antiplatelet therapy (DAPT) of clopidogrel combined with ASA.

Material and methods: We retrospectively reviewed 56 consecutive patients (60 ± 8.2 years) undergoing isolated CABG in association with CEAE between January 2018 and December 2019. In the postoperative period, patients were divided into two groups according to the antithrombotic regimens described above. Twenty-four were in the ASA and acenocoumarol group (AA) and 32 were in the ASA and clopidogrel group (AC). Patients were followed up to 30 days after the operation and we access the mortality rate, new ECG changes, levels of myocardial fraction of creatinine phosphokinase (CPK-MB), left ventricular systolic function, pericardial or pleural effusions requiring drainage or revision for bleeding.

Results: Operative mortality was 3,6 %. No differences in the antithrombotic efficacy of the two regimens. A significantly higher level of hemorrhagic complications was observed in the ASA + acenocoumarol treatment group.

Conclusion: Dual antiplatelet therapy (DAPT) after CABG and coronary endarterectomy is an effective pharmacological regimen in regard to 30-day postoperative outcomes and is considerably safety in terms of bleeding complications.

Development of a risk score for early saphenous vein graft failure: An individual patient data meta-analysis

OBJECTIVES

Early saphenous vein graft (SVG) occlusion is typically attributed to technical factors. We aimed at exploring clinical, anatomical, and operative factors associated with the risk of early SVG occlusion (within 12 months postsurgery).

METHODS

Published literature in MEDLINE was searched for studies reporting the incidence of early SVG occlusion. Individual patient data (IPD) on early SVG occlusion were used from the SAFINOUS-CABG Consortium. A derivation (n = 1492 patients) and validation (n = 372 patients) cohort were used for model training (with 10-fold cross-validation) and external validation respectively.

RESULTS

In aggregate data meta-analysis (48 studies, 41,530 SVGs) the pooled estimate for early SVG occlusion was 11%. The developed IPD model for early SVG occlusion, which included clinical, anatomical, and operative characteristics (age, sex, dyslipidemia, diabetes mellitus, smoking, serum creatinine, endoscopic vein harvesting, use of complex grafts, grafted target vessel, and number of SVGs), had good performance in the derivation (c-index = 0.744; 95% confidence interval [CI], 0.701-0.774) and validation cohort (c-index = 0.734; 95% CI, 0.659-0.809). Based on this model. we constructed a simplified 12-variable risk score system (SAFINOUS score) with good performance for early SVG occlusion (c-index = 0.700, 95% CI, 0.684-0.716).

CONCLUSIONS

From a large international IPD collaboration, we developed a novel risk score to assess the individualized risk for early SVG occlusion. The SAFINOUS risk score could be used to identify patients that are more likely to benefit from aggressive treatment strategies.

Effects of Liraglutide on Cardiovascular Outcomes in Patients With Type 2 Diabetes Mellitus With or Without History of Myocardial Infarction or Stroke

BACKGROUND

The glucagon-like peptide-1 analog liraglutide reduced cardiovascular events and mortality in patients with type 2 diabetes mellitus in the LEADER trial (Liraglutide and Cardiovascular Outcomes in Type 2 Diabetes). In a post hoc analysis, we evaluated the efficacy of liraglutide in those with and without a history of myocardial infarction (MI) and/or stroke.

METHODS

LEADER was a randomized trial of liraglutide (1.8 mg or maximum tolerated dose) versus placebo in 9340 patients with type 2 diabetes mellitus and high cardiovascular risk, with a median follow-up of 3.8 years. The primary outcome was a composite of cardiovascular death, nonfatal MI, or nonfatal stroke (major adverse cardiovascular events). Risk groups in this post hoc analysis were defined by history of MI/stroke, established atherosclerotic cardiovascular disease without MI/stroke, or cardiovascular risk factors alone.

RESULTS

Of the 9340 patients, 3692 (39.5%) had a history of MI/stroke, 3083 (33.0%) had established atherosclerotic cardiovascular disease without MI/stroke, and 2565 (27.5%) had risk factors alone. Major adverse cardiovascular events occurred in 18.8% of patients with a history of MI/stroke (incidence rate, 5.0 per 100 patient-years), 11.6% of patients with established atherosclerotic cardiovascular disease without MI/stroke (incidence rate, 3.0 per 100 patient-years), and 9.8% of patients with cardiovascular risk factors alone (incidence rate, 2.6 per 100 patient-years). Liraglutide reduced major adverse cardiovascular events in patients with a history of MI/stroke (322 of 1865 [17.3%] versus 372 of 1827 patients [20.4%]; hazard ratio, 0.85; 95% CI, 0.73-0.99) and in those with established atherosclerotic cardiovascular disease without MI/stroke (158 of 1538 [10.3%] versus 199 of 1545 patients [12.9%]; hazard ratio, 0.76; 95% CI, 0.62-0.94) compared with placebo. In patients with risk factors alone, the hazard ratio for liraglutide versus placebo was 1.08 (95% CI, 0.84-1.38, P_interaction=0.11). Similar results were seen for secondary outcomes across risk groups.

CONCLUSIONS

In this post hoc analysis of patients with type 2 diabetes mellitus and high cardiovascular risk, liraglutide reduced cardiovascular outcomes both in patients with a history of MI/stroke and in those with established atherosclerotic cardiovascular disease without MI/stroke. The cardiovascular effect appeared neutral in patients with cardiovascular risk factors alone.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov . Unique identifier: NCT01179048.

Consensus Report on Patient Blood Management in Cardiac Surgery by Turkish Society of Cardiovascular Surgery (TSCVS), Turkish Society of Cardiology (TSC), and Society of Cardio-Vascular-Thoracic Anaesthesia and Intensive Care (SCTAIC)

Anemia, transfusion and bleeding independently increase the risk of complications and mortality in cardiac surgery. The main goals of patient blood management are to treat anemia, prevent bleeding, and optimize the use of blood products during the perioperative period. The benefit of this program has been confirmed in many studies and its utilization is strongly recommended by professional organizations. This consensus report has been prepared by the authors who are the task members appointed by the Turkish Society of Cardiovascular Surgery, Turkish Society of Cardiology (TSC), and Society of Cardio-Vascular-Thoracic Anaesthesia and Intensive Care to raise the awareness of patient blood management. This report aims to summarize recommendations for all perioperative blood- conserving strategies in cardiac surgery.

Antiplatelet therapy and coronary artery bypass grafting: Protocol for a systematic review and network meta-analysis

INTRODUCTION

Saphenous vein graft (SVG) is the most common conduit used for coronary artery bypass grafting (CABG) surgery. Unfortunately, SVG are associated with poor long-term patency rates; a significant predictor of re-operation rates and survival. As such, medical therapy to prevent SVG narrowing or occlusion is of paramount importance. Aspirin (ASA) monotherapy is the standard of care after CABG, to improve long-term major adverse cardiovascular events (MACE) and graft patency. Benefits of dual antiplatelet therapy (DAPT) have not been well established in all CABG patients. We present a protocol for a network meta-analysis (NMA) comparing the effects of various antiplatelet therapy regimens on SVG patency, mortality, and bleeding among adult patients following CABG.

METHODS

We will search CENTRAL, MEDLINE, EMBASE, CINAHL ACPJC, and grey literature sources (AHA, ACC, ESC, and CCC conference proceedings, ISRCTN Register, and WHO ICTRP) for randomized controlled trials (RCTs) which fit our criteria. RCTs that evaluate different antiplatelet regimens at least 3-months after CABG and have any of SVG patency, mortality, MACE, and major bleeding as outcomes will be selected. We will perform title and abstract screening, full-text screening, and data extraction independently and in duplicate. Two independent reviewers will also assess risk of bias (ROB) for each study, as well as evaluate quality of evidence using the GRADE framework. We will use R to perform the NMA and use low-dose ASA as reference within our network. We will report results as odds ratios with confidence intervals for direct comparisons, and credible intervals for indirect or mixed comparisons. We will use the surface under the cumulative ranking curve (SUCRA) to estimate the ranking of interventions.

DISCUSSION

Given the limited direct comparison of various antiplatelet regimens, a network approach is ideal to clarify the optimum antiplatelet therapy after CABG. We hope that our NMA will be the largest quantitative synthesis evaluating antiplatelet regimens among patients requiring CABG. It should inform clinicians and guideline developers in selecting the most effective and safest antiplatelet regimen.Systematic Review registration: International Prospective Register for Systematic Reviews (PROSPERO)-CRD42019127695.

Randomized trial of ticagrelor vs. aspirin in patients after coronary artery bypass grafting: the TiCAB trial

Aims

The antiplatelet treatment strategy providing optimal balance between thrombotic and bleeding risks in patients undergoing coronary artery bypass grafting (CABG) is unclear. We prospectively compared the efficacy of ticagrelor and aspirin after CABG.

Methods and results

We randomly assigned in double-blind fashion patients scheduled for CABG to either ticagrelor 90 mg twice daily or 100 mg aspirin (1:1) once daily. The primary outcome was the composite of cardiovascular death, myocardial infarction (MI), repeat revascularization, and stroke 12 months after CABG. The main safety endpoint was based on the Bleeding Academic Research Consortium classification, defined as BARC ≥4 for periprocedural and hospital stay-related bleedings and BARC ≥3 for post-discharge bleedings. The study was prematurely halted after recruitment of 1859 out of 3850 planned patients. Twelve months after CABG, the primary endpoint occurred in 86 out of 931 patients (9.7%) in the ticagrelor group and in 73 out of 928 patients (8.2%) in the aspirin group [hazard ratio 1.19; 95% confidence interval (CI) 0.87–1.62; P = 0.28]. All-cause mortality (ticagrelor 2.5% vs. aspirin 2.6%, hazard ratio 0.96, CI 0.53–1.72; P = 0.89), cardiovascular death (ticagrelor 1.2% vs. aspirin 1.4%, hazard ratio 0.85, CI 0.38–1.89; P = 0.68), MI (ticagrelor 2.1% vs. aspirin 3.4%, hazard ratio 0.63, CI 0.36–1.12, P = 0.12), and stroke (ticagrelor 3.1% vs. 2.6%, hazard ratio 1.21, CI 0.70–2.08; P = 0.49), showed no significant difference between the ticagrelor and aspirin group. The main safety endpoint was also not significantly different (ticagrelor 3.7% vs. aspirin 3.2%, hazard ratio 1.17, CI 0.71–1.92; P = 0.53).

Conclusion

In this prematurely terminated and thus underpowered randomized trial of ticagrelor vs. aspirin in patients after CABG no significant differences in major cardiovascular events or major bleeding could be demonstrated.

ClinicalTrials.gov Identifier

NCT01755520.

Dual antiplatelet therapy versus aspirin monotherapy in diabetics with stable ischemic heart disease undergoing coronary artery bypass grafting

Background

Dual antiplatelet therapy (DAPT) in patients presenting with acute coronary syndrome (ACS) undergoing CABG is recommended to prevent recurrent ischemic events. The benefit of DAPT post-CABG in patients with stable ischemic heart disease (SIHD) is unknown. The aim of this study was to evaluate the utilization rate of DAPT and associated outcomes in patients with SIHD undergoing CABG via a secondary analysis of Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial data.

Methods

In a post-hoc, nonrandomized analysis from the BARI 2D trial, we compared patients receiving DAPT and aspirin monotherapy within 90 days post-randomization. The primary outcome was the risk adjusted 5-year composite of all-cause mortality, nonfatal myocardial infarction (MI), or stroke. We analyzed patients assigned to prompt CABG treatment arm including both the insulin therapy assignments.

Results

Of 378 patients, within 90 days post-randomization, 59 (16%) patients received DAPT and 319 (84%) patients received aspirin alone. Cox proportional hazard analysis demonstrated that there was no significant difference in the 5-year composite event of death, MI, and stroke between DAPT and monotherapy cohorts [13 (22.0%) vs. 61 (19.1%); adjusted hazard ratio (HR): 1.06; 95% confidence interval (CI): 0.56 to 2.00; P=0.86]. There also was no significant difference at 1 year in the composite event [6 (10.2%) vs. 30 (9.4%); HR: 1.13; 95% CI: 0.46 to 2.79; P=0.79].

Conclusions

The use of DAPT in patients with diabetes post-CABG in this cohort was low. Compared with aspirin monotherapy, no associated differences were observed in cardiovascular outcomes. Larger prospective studies are needed to further elucidate this observation.

Increased platelet reactivity and platelet-leukocyte aggregation after elective coronary bypass surgery

Inflammatory mechanisms are activated, and thrombotic complications occur during the initial months after coronary artery bypass grafting (CABG). Therefore, changes over time of platelet activation and platelet-leukocyte interactions after CABG are of interest. Whole-blood flow cytometry was performed before, and 4-6 days, one month, and three months after elective CABG in 54 men with stable coronary artery disease treated with acetylsalicylic acid (ASA). Single platelets and platelet-leukocyte aggregates (PLAs) among monocytes (P-Mon), neutrophils (P-Neu), and lymphocytes (P-Lym) were studied without and with stimulation by submaximal concentrations of ADP, thrombin, and the thromboxane analog U46619. White blood cell counts were increased during the initial postoperative course, and platelet counts were increased after one month. Platelet P-selectin expression was significantly enhanced at one month when stimulated by thrombin and U46619 and at three months with ADP and thrombin. All PLAs subtypes were increased at one month without stimulation in vitro. P-Mon and P-Neu stimulated by ADP, thrombin, or U46619 were significantly increased one month after the operation but decreased compared to baseline at three months. Agonist stimulated P-Lyms were increased at one month and remained increased at three months after ADP stimulation. There was significant platelet activation and formation of PLAs unstimulated and after agonist stimulation by ADP, thrombin, and a thromboxane analog after CABG in patients with stable coronary artery disease irrespective of ASA treatment. Changes observed up to three months after CABG support further studies of the clinical implications of protracted increases in platelet activation and platelet-leukocyte interactions.

Network meta-analysis of antiplatelet therapy following coronary artery bypass grafting (CABG): none versus one versus two antiplatelet agents

Background

Numerous agents have been trialed following coronary artery bypass grafting (CABG) to maintain long-term graft patency. While clear evidence exists for the use of aspirin in maintaining graft patency, the role of dual-antiplatelet therapy in CABG patients is not as well established. This network meta-analysis aimed to compare the short-term post-CABG graft patency outcomes for patients with none, one or two antiplatelet agents.

Methods

Electronic databases were queried for randomized controlled trials comparing CABG graft patency rates at three months and beyond using various antiplatelet agents or placebo. Drug and graft patency data were compared using a mixed treatment comparison under a Bayesian hierarchical framework. A random-effects consistency model was applied. Direct and indirect comparisons were made between drugs and used to determine the relative efficacy for graft patency.

Results

The literature search identified 16 papers fulfilling the inclusion criteria, including a total of 3,133 patients with an average of 2.43 [95% confidence interval (CI): 2.20-2.66] grafts per patient. Graft types were incompletely reported, however, saphenous vein grafts (SVGs) were predominantly used [where specifically reported: 4,490 SVG, 1,226 internal mammary artery (IMA) grafts]. In all, five different agents and placebo in various regimens were compared by results of angiographic follow-up conducted at a mean of 10.4 months (95% CI: 9.28-11.5 months). Compared to placebo, aspirin alone [odds ratio (OR) 1.9; 95% credible interval (CrI): 1.3-2.8], aspirin + dipyridamole (OR 1.9; 95% CrI: 1.3-2.6), aspirin + clopidogrel (OR 2.9; 95% CrI: 1.5-5.7) and aspirin + ticagrelor (OR 3.8; 95% CrI: 1.2-13.0) significantly improved graft patency. When compared to aspirin monotherapy, aspirin + clopidogrel (OR 1.6; 95% CrI: 0.86-2.7) and aspirin + ticagrelor (OR 2.0; 95% CrI: 0.69-6.3) had OR that suggested a trend favoring patency compared to aspirin monotherapy, however, these results did not reach significance. Sub-group analysis of SVG graft patency was unable to reach significance (only eight studies with six treatment comparisons were evaluated). Secondary endpoints of death, bleeding, myocardial infarction and cerebrovascular accident were incompletely reported and were pooled but not compared between drug treatment arms.

Conclusions

Aspirin monotherapy and dual antiplatelet therapy (DAPT) provided significant all-graft patency benefit compared to placebo at three months and beyond. A trend existed for DAPT to improve graft patency compared to aspirin, although this did not reach statistical significance. Further randomized controlled studies comparing aspirin monotherapy to DAPT are required to determine the utility of DAPT in CABG patients for maintaining graft patency.

Genome-Wide Association Study Links Receptor Tyrosine Kinase Inhibitor Sprouty 2 to Thrombocytopenia after Coronary Artery Bypass Surgery

INTRODUCTION

 Thrombocytopenia after cardiac surgery independently predicts stroke, acute kidney injury and death. To understand the underlying risks and mechanisms, we analysed genetic variations associated with thrombocytopenia in patients undergoing coronary artery bypass grafting (CABG) surgery.

MATERIALS AND METHODS

 Study subjects underwent isolated on-pump CABG surgery at Duke University Medical Center. Post-operative thrombocytopenia was defined as platelet count < 100 × 10⁹/L. Using a logistic regression model adjusted for clinical risk factors, we performed a genome-wide association study in a discovery cohort (n = 860) and validated significant findings in a replication cohort (n = 296). Protein expression was assessed in isolated platelets by immunoblot.

RESULTS

 A total of 63 single-nucleotide polymorphisms met a priori discovery thresholds for replication, but only 1 (rs9574547) in the intergenic region upstream of sprouty 2 (SPRY2) met nominal significance in the replication cohort. The minor allele of rs9574547 was associated with a lower risk for thrombocytopenia (discovery cohort, odds ratio, 0.45, 95% confidence interval, 0.30-0.67, p = 9.76 × 10^-5) with the overall association confirmed by meta-analysis (meta-p = 7.88 × 10^-6). Immunoblotting demonstrated expression of SPRY2 and its dynamic regulation during platelet activation. Treatment with a functional SPRY2 peptide blunted platelet extracellular signal-regulated kinase (ERK) phosphorylation after agonist stimulation.

CONCLUSION

 We identified the association of a genetic polymorphism in the intergenic region of SPRY2 with a decreased incidence of thrombocytopenia after CABG surgery. Because SPRY2-an endogenous receptor tyrosine kinase inhibitor-is present in platelets and modulates essential signalling pathways, these findings support a role for SPRY2 as a novel modulator of platelet responses after cardiac surgery.

Effect of thrombelastography on timing of coronary artery bypass grafting

The guiding value of thrombelastography (TEG) on the selection of surgical timing for patients scheduled for coronary artery bypass grafting (CABG) was investigated. A total of 90 subjects with acute coronary syndrome (ACS) treated between February 2014 and December 2016 in Henan Provincial People's Hospital were recruited. The patients received dual antiplatelet therapy (DAPT) and were scheduled for CABG. Subjects were randomly allocated into two groups, TEG group (n=45) and non-TEG group (n=45). Patients in the TEG group withheld medications at 24 h prior to surgery and received TEG examination. Based on maximum amplitude of adenosine diphosphate (MA_ADP), subjects were further grouped into three sub-groups with MA_ADP <35 mm, 35–50 mm, and >50 mm, and accordingly received CABG within 1 day, 3–5 days and 5 days later, respectively. Subjects in the control group (non-TEG group) received CABG 5–7 days after medication withdrawal. Chest drainage volume within 24 h after surgery and red blood cell transfusion during perioperative period were compared. Other recorded parameters were incubation period, intensive care unit length of stay, hospital stay, incidence of 30-day adverse events and readmission rate. The average waiting time before CABG for patients of TEG group was shorter compared with the commonly recommended time. The red blood cell transfusions during perioperative period of subjects in TEG group and non-TEG group were significantly different (P=0.23). The median hospital stay of subjects in TEG group was shorter than that of non-TEG group (P=0.037). The bleeding amount of patients in TEG group was 220.16±80.56 ml, which was significantly lower than that of non-TEG group (435.29±90.16). The difference was statistically significant (P=0.032). The results suggested that TEG assay-based evaluation of platelet function for patients scheduled for CABG reasonably guides surgeons with appropriate surgical timing and reduces the amount of time patients wait to be treated.

Impact of dual antiplatelet therapy after coronary artery bypass surgery on 1-year outcomes in the Arterial Revascularization Trial

OBJECTIVES

There is still little evidence to boldport routine dual antiplatelet therapy (DAPT) with P2Y12 antagonists following coronary artery bypass grafting (CABG). The Arterial Revascularization Trial (ART) was designed to compare 10-year survival after bilateral versus single internal thoracic artery grafting. We aimed to get insights into the effect of DAPT (with clopidogrel) following CABG on 1-year outcomes by performing a post hoc ART analysis.

METHODS

Among patients enrolled in the ART (n = 3102), 609 (21%) and 2308 (79%) were discharged on DAPT or aspirin alone, respectively. The primary end-point was the incidence of major adverse cerebrovascular and cardiac events (MACCE) at 1 year including cardiac death, myocardial infarction, cerebrovascular accident and reintervention; safety end-point was bleeding requiring hospitalization. Propensity score (PS) matching was used to create comparable groups.

RESULTS

Among 609 PS-matched pairs, MACCE occurred in 34 (5.6%) and 34 (5.6%) in the DAPT and aspirin alone groups, respectively, with no significant difference between the 2 groups [hazard ratio (HR) 0.97, 95% confidence interval (CI) 0.59-1.59; P = 0.90]. Only 188 (31%) subjects completed 1 year of DAPT, and in this subgroup, MACCE rate was 5.8% (HR 1.11, 95% CI 0.53-2.30; P = 0.78). In the overall sample, bleeding rate was higher in DAPT group (2.3% vs 1.1%; P = 0.02), although this difference was no longer significant after matching (2.3% vs 1.8%; P = 0.54).

CONCLUSIONS

Based on these findings, when compared with aspirin alone, DAPT with clopidogrel prescribed at discharge was not associated with a significant reduction of adverse cardiac and cerebrovascular events at 1 year following CABG.

Systematic review and meta-analysis in cardiac surgery: a primer

PURPOSE OF REVIEW

The purpose of this article is to review the strengths and weaknesses of systematic reviews and meta-analyses to inform our current understanding of cardiac surgery.

RECENT FINDINGS

A systematic review and meta-analysis of a focused topic can provide a quantitative estimate for the effect of a treatment intervention or exposure. In cardiac surgery, observational studies and small, single-center prospective trials provide most of the clinical outcomes that form the evidence base for patient management and guideline recommendations. As such, meta-analyses can be particularly valuable in synthesizing the literature for a particular focused surgical question. Since the year 2000, there are over 800 meta-analysis-related publications in our field. There are some limitations to this technique, including clinical, methodological and statistical heterogeneity, among other challenges. Despite these caveats, results of meta-analyses have been useful in forming treatment recommendations or in providing guidance in the design of future clinical trials.

SUMMARY

There is a growing number of meta-analyses in the field of cardiac surgery. Knowledge translation via meta-analyses will continue to guide and inform cardiac surgical practice and our practice guidelines.

Meta-Analysis of Aspirin Versus Dual Antiplatelet Therapy Following Coronary Artery Bypass Grafting

Although aspirin monotherapy is considered the standard of care after coronary artery bypass grafting (CABG), more recent evidence has suggested a benefit with dual antiplatelet therapy (DAPT) after CABG. We performed a meta-analysis of observational studies and randomized controlled trials comparing outcomes of aspirin monotherapy with DAPT in patients after CABG. Subgroup analyses were conducted according to surgical technique (i.e., on vs off pump) and clinical presentation (acute coronary syndrome vs no acute coronary syndrome). Random effects overall risk ratios (RR) were calculated using the DerSimonian and Laird model. Eight randomized control trials and 9 observational studies with a total of 11,135 patients were included. At a mean follow-up of 23 months, major adverse cardiac events (10.3% vs 12.1%, RR 0.84, confidence interval [CI] 0.71 to 0.99), all-cause mortality (5.7% vs 7.0%, RR 0.67, CI 0.48 to 0.94), and graft occlusion (11.3% vs 14.2%, RR 0.79, CI 0.63 to 0.98) were less with DAPT than with aspirin monotherapy. There was no difference in myocardial infarction, stroke, or major bleeding between the 2 groups. In conclusion, DAPT appears to be associated with a reduction in graft occlusion, major adverse cardiac events, and all-cause mortality, without significantly increasing major bleeding compared with aspirin monotherapy in patients undergoing CABG.