Expert position paper on the management of antiplatelet therapy in patients undergoing coronary artery bypass graft surgery

Antiplatelet therapy after coronary artery bypass surgery: five year follow-up of randomised DACAB trial

OBJECTIVE

To assess the effect of different antiplatelet strategies on clinical outcomes after coronary artery bypass grafting.

DESIGN

Five year follow-up of randomised Different Antiplatelet Therapy Strategy After Coronary Artery Bypass Grafting (DACAB) trial.

SETTING

Six tertiary hospitals in China; enrolment between July 2014 and November 2015; completion of five year follow-up from August 2019 to June 2021.

PARTICIPANTS

500 patients aged 18-80 years (including 91 (18.2%) women) who had elective coronary artery bypass grafting surgery and completed the DACAB trial.

INTERVENTIONS

Patients were randomised 1:1:1 to ticagrelor 90 mg twice daily plus aspirin 100 mg once daily (dual antiplatelet therapy; n=168), ticagrelor monotherapy 90 mg twice daily (n=166), or aspirin monotherapy 100 mg once daily (n=166) for one year after surgery. After the first year, antiplatelet therapy was prescribed according to standard of care by treating physicians.

MAIN OUTCOME MEASURES

The primary outcome was major adverse cardiovascular events (a composite of all cause death, myocardial infarction, stroke, and coronary revascularisation), analysed using the intention-to-treat principle. Time-to-event analysis was used to compare the risk between treatment groups. Multiple post hoc sensitivity analyses examined the robustness of the findings.

RESULTS

Follow-up at five years for major adverse cardiovascular events was completed for 477 (95.4%) of 500 patients; 148 patients had major adverse cardiovascular events, including 39 in the dual antiplatelet therapy group, 54 in the ticagrelor monotherapy group, and 55 in the aspirin monotherapy group. Risk of major adverse cardiovascular events at five years was significantly lower with dual antiplatelet therapy versus aspirin monotherapy (22.6% v 29.9%; hazard ratio 0.65, 95% confidence interval 0.43 to 0.99; P=0.04) and versus ticagrelor monotherapy (22.6% v 32.9%; 0.66, 0.44 to 1.00; P=0.05). Results were consistent in all sensitivity analyses.

CONCLUSIONS

Treatment with ticagrelor dual antiplatelet therapy for one year after surgery reduced the risk of major adverse cardiovascular events at five years after coronary artery bypass grafting compared with aspirin monotherapy or ticagrelor monotherapy.

TRIAL REGISTRATION

NCT03987373ClinicalTrials.gov NCT03987373.

Ticagrelor inverse agonist activity at the P2Y12 receptor is non-reversible versus its endogenous agonist adenosine 5´-diphosphate

BACKGROUND AND PURPOSE

Ticagrelor is labelled as a reversible, direct-acting platelet P2Y12 receptor (P2Y12 R) antagonist that is indicated clinically for the prevention of thrombotic events in patients with acute coronary syndrome (ACS). As with many antiplatelet drugs, ticagrelor therapy increases bleeding risk in patients, which may require platelet transfusion in emergency situations. The aim of this study was to further examine the reversibility of ticagrelor at the P2Y12 R.

EXPERIMENTAL APPROACH

Studies were performed in human platelets, with P2Y12 R-stimulated GTPase activity and platelet aggregation assessed. Cell-based bioluminescence resonance energy transfer (BRET) assays were undertaken to assess G protein-subunit activation downstream of P2Y12 R activation.

KEY RESULTS

Initial studies revealed that a range of P2Y12 R ligands, including ticagrelor, displayed inverse agonist activity at P2Y12 R. Only ticagrelor was resistant to washout and, in human platelet and cell-based assays, washing failed to reverse ticagrelor-dependent inhibition of ADP-stimulated P2Y12 R function. The P2Y12 R agonist 2MeSADP, which was also resistant to washout, was able to effectively compete with ticagrelor. In silico docking revealed that ticagrelor and 2MeSADP penetrated more deeply into the orthosteric binding pocket of the P2Y12 R than other P2Y12 R ligands.

CONCLUSION AND IMPLICATIONS

Ticagrelor binding to P2Y12 R is prolonged and more akin to that of an irreversible antagonist, especially versus the endogenous P2Y12 R agonist ADP. This study highlights the potential clinical need for novel ticagrelor reversal strategies in patients with spontaneous major bleeding, and for bleeding associated with urgent invasive procedures.

De-escalation or abbreviation of dual antiplatelet therapy in acute coronary syndromes and percutaneous coronary intervention: a Consensus Statement from an international expert panel on coronary thrombosis

Conventional dual antiplatelet therapy (DAPT) for patients with acute coronary syndromes undergoing percutaneous coronary intervention comprises aspirin with a potent P2Y purinoceptor 12 (P2Y12) inhibitor (prasugrel or ticagrelor) for 12 months. Although this approach reduces ischaemic risk, patients are exposed to a substantial risk of bleeding. Strategies to reduce bleeding include de-escalation of DAPT intensity (downgrading from potent P2Y12 inhibitor at conventional doses to either clopidogrel or reduced-dose prasugrel) or abbreviation of DAPT duration. Either strategy requires assessment of the ischaemic and bleeding risks of each individual. De-escalation of DAPT intensity can reduce bleeding without increasing ischaemic events and can be guided by platelet function testing or genotyping. Abbreviation of DAPT duration after 1-6 months, followed by monotherapy with aspirin or a P2Y12 inhibitor, reduces bleeding without an increase in ischaemic events in patients at high bleeding risk, particularly those without high ischaemic risk. However, these two strategies have not yet been compared in a head-to-head clinical trial. In this Consensus Statement, we summarize the evidence base for these treatment approaches, provide guidance on the assessment of ischaemic and bleeding risks, and provide consensus statements from an international panel of experts to help clinicians to optimize these DAPT approaches for individual patients to improve outcomes.

Perioperative Management of Patients Receiving Antithrombotic Therapy in Schemes and Algorithms

Currently, antithrombotic therapy is the basis of the pathogenetic treatment of many cardiovascular diseases, such as coronary heart disease, stroke, peripheral vascular disease, as well as mechanical heart valves, heart rhythm disturbances, venous thromboembolism. At the same time, chronic use of antiplatelet and/or anticoagulant drugs is a complicating factor in invasive and surgical procedures, as it increases the risk of bleeding. In this regard, a fundamentally important and complex question arises: how to minimize the risk of periprocedural bleeding without exposing the patient to an increased risk of ischemic and thromboembolic complications? Perioperative management of patients who take antithrombotic drugs for a long time is a complex problem that depends on many factors - the risk of surgery, anesthesia, cardiovascular risks, and the urgency of surgery. Each clinical situation should be assessed individually, collegially, with the participation of surgeons, anesthesiologists, and therapists. The introduction of a checklist into clinical practice for each planned surgical patient will allow us to calculate the individual risk of bleeding and thromboembolic complications, and provide an optimal preventive strategy for perioperative management of the patient. The algorithms and schemes presented in the article for the perioperative management of patients with non-cardiac interventions are aimed at standardizing the management of patients before non-cardiac surgical interventions, which will reduce hemorrhagic risks in the presence of the necessary antithrombotic therapy.

Antithrombotic drug removal from whole blood using Haemoadsorption with a porous polymer bead sorbent

AIM

To evaluate the ability of the DrugSorb™-AntiThrombotic Removal (ATR) haemoadsorption device utilizing porous polymer bead sorbent technology to remove three commonly used antithrombotic drugs from whole blood.

METHODS AND RESULTS

We evaluated the removal of apixaban, rivaroxaban, and ticagrelor by the DrugSorb-ATR haemoadsorption device in a benchtop clinical scale model using bovine whole blood. Blood spiked at clinically relevant concentrations of an antithrombotic agent was continuously circulated through a 300-mL DrugSorb-ATR haemoadsorption device at a flow rate of 300 mL/min. Drug concentration was monitored over 6 h to evaluate drug removal. Results were compared with a control circuit without the haemoadsorption device. Removal rates at 30, 60, 120, and 360 minutes were: apixaban: 81.5%, 96.3%, 99.3% >99.8%; rivaroxaban: 80.7%, 95.1%, 98.9%, >99.5%; ticagrelor: 62.5%; 75%, 86.6%, >95% (all P <0.0001 vs. control). Blood pH and haematological parameters were not significantly affected by the DrugSorb-ATR haemoadsorption device when compared with the control circuit.

CONCLUSION

DrugSorb-ATR efficiently removes apixaban, rivaroxaban, and ticagrelor in a clinical-scale benchtop recirculation circuit with the bulk of removal occurring in the first 60 minutes. The clinical implications of these findings are currently investigated in patients undergoing on-pump cardiothoracic surgery in two US pivotal trials (ClinicalTrials.gov Identifiers: NCT04976530 and NCT05093504).

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.

Dual Antiplatelet Therapy with Clopidogrel and Aspirin Versus Aspirin Monotherapy in Patients Undergoing Coronary Artery Bypass Graft Surgery

Background The optimal antiplatelet therapy after coronary artery bypass grafting remains unclear. We evaluated the association of dual antiplatelet therapy (DAPT) with clopidogrel plus aspirin and clinical outcomes among patients undergoing coronary artery bypass grafting. Methods and Results A total of 18 069 consecutive patients who underwent primary isolated coronary artery bypass grafting between 2013 and 2017 were identified from a contemporary registry, and 10 854 (60.1%) received DAPT with clopidogrel plus aspirin as determined by claimed prescriptions after surgery. Cox regression models with inverse probability of treatment weighting were used to examine the associations between DAPT and outcomes. Patients who received DAPT, compared with those who received aspirin monotherapy, had a lower incidence of a composite of all-cause death, myocardial infarction, stroke, or repeat revascularization at 6 months (2.9% versus 4.2%; inverse probability of treatment weighting-adjusted hazard ratio [HR], 0.65; 95% CI, 0.55-0.77; P<0.001) as well as death (HR, 0.61; 95% CI, 0.41-0.90), myocardial infarction (HR, 0.55; 95% CI, 0.40-0.74), and stroke (HR, 0.58; 95% CI, 0.46-0.74). The incidence of major bleeding did not differ significantly between the 2 groups (HR, 1.11; 95% CI, 0.69-1.78). Similar results were noted across multiple subgroups as well as when using different analytic methods. Conclusions Among patients undergoing coronary artery bypass grafting, DAPT with clopidogrel plus aspirin as secondary prevention was associated with reduced risk of major adverse cardiovascular and cerebrovascular events within 6 months as compared with aspirin monotherapy, and there was no significant increase in major bleeding.

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.

Managing the coagulopathy associated with cardiopulmonary bypass

Cardiopulmonary bypass (CPB) has allowed for significant surgical advancements, but accompanying risks can be significant and must be expertly managed. One of the foremost risks is coagulopathic bleeding. Increasing levels of bleeding in cardiac surgical patients at the time of separation from CPB are associated with poor outcomes and mortality. CPB-associated coagulopathy is typically multifactorial and rarely due to inadequate reversal of systemic heparin alone. The components of the bypass circuit induce systemic inflammation and multiple disturbances of the coagulation and fibrinolytic systems. Anticipating coagulopathy is the first step in managing it, and specific patient and procedural risk factors have been identified as predictors of excessive bleeding. Medication management pre-procedure is critical, as patients undergoing cardiac surgery are commonly on anticoagulants or antiplatelet agents. Important adjuncts to avoid transfusion include antifibrinolytics, and perfusion practices such as red cell salvage, sequestration, and retrograde autologous priming of the bypass circuit have varying degrees of evidence supporting their use. Understanding the patient's coagulation status helps target product replacement and avoid larger volume transfusion. There is increasing recognition of the role of point-of-care viscoelastic and functional platelet testing. Common pitfalls in the management of post-CPB coagulopathy include overdosing protamine for heparin reversal, imperfect laboratory measures of thrombin generation that result in normal or near-normal laboratory results in the presence of continued bleeding, and delayed recognition of surgical bleeding. While challenging, the effective management of CPB-associated coagulopathy can significantly improve patient outcomes.

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.

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.

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.

Ticagrelor Removal by CytoSorb® in Patients Requiring Emergent or Urgent Cardiac Surgery: A UK-Based Cost-Utility Analysis

BACKGROUND

Acute coronary syndrome patients receiving dual antiplatelet therapy who need emergent or urgent cardiac surgery are at high risk of major bleeding, which can impair postoperative outcomes. CytoSorb^®, a blood purification technology based on adsorbent polymer, has been demonstrated to remove ticagrelor from blood during on-pump cardiac surgery.

OBJECTIVE

The aim of this study was to evaluate the cost utility of intraoperative removal of ticagrelor using CytoSorb versus usual care among patients requiring emergent or urgent cardiac surgery in the UK.

METHODS

A de novo decision analytic model, based on current treatment pathways, was developed to estimate the short- and long-term costs and outcomes. Results from randomised clinical trials and national standard sources such as National Health Service (NHS) reference costs were used to inform the model. Costs were estimated from the NHS and Personal Social Services perspective. Deterministic and probabilistic sensitivity analyses (PSAs) explored the uncertainty surrounding the input parameters.

RESULTS

In emergent cardiac surgery, intraoperative removal of ticagrelor using CytoSorb was less costly (£12,933 vs. £16,874) and more effective (0.06201vs. 0.06091 quality-adjusted life-years) than cardiac surgery without physiologic clearance of ticagrelor over a 30-day time horizon. For urgent cardiac surgery, the use of CytoSorb was less costly than any of the three comparators-delaying surgery for natural washout without adjunctive therapy, adjunctive therapy with short-acting antiplatelet agents, or adjunctive therapy with low-molecular-weight heparin. Results from the PSAs showed that CytoSorb has a high probability of being cost saving (99% in emergent cardiac surgery and 53-77% in urgent cardiac surgery, depending on the comparators). Cost savings derive from fewer transfusions of blood products and re-thoracotomies, and shorter stay in the hospital/intensive care unit.

CONCLUSIONS

The implementation of CytoSorb as an intraoperative intervention for patients receiving ticagrelor undergoing emergent or urgent cardiac surgery is a cost-saving strategy, yielding improvement in perioperative and postoperative outcomes and decreased health resource use.

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.

In-hospital and mid-term outcomes in patients reoperated on due to bleeding following coronary artery surgery (from the KROK Registry)

OBJECTIVES

Surgical re-exploration due to postoperative bleeding that follows coronary artery surgery is associated with significant morbidity and mortality. The aim of this study was to assess a relationship between re-exploration, major postoperative complications, in-hospital mortality and mid-term outcomes in patients following coronary surgery, on the basis of nationwide registry data.

METHODS

We identified all consecutive patients enrolled in Polish National Registry of Cardiac Surgical Procedures (KROK Registry) who underwent isolated coronary surgery between January 2012 and December 2014. Preoperative data, major postoperative complications, hospital mortality and mid-term all-cause mortality were, respectively, analysed. Comparisons were performed in all patients, low-risk patients (EuroSCORE II < 2%, males, aged 60-70 years) and propensity-matched patients. The starting point for follow-up was the date of hospital discharge.

RESULTS

Among 41 353 analysed patients, 1406 (3.4%) underwent re-exploration. Reoperated patients had more comorbidities, more frequent major postoperative complications, higher in-hospital mortality (13.2% vs 1.8%, P < 0.001) and higher mid-term mortality in survivors (P < 0.001). In the low-risk population, 3.0% of patients underwent re-exploration. Reoperated low-risk patients and propensity-matched patients also had more frequent major postoperative complications and higher in-hospital mortality, but mid-term mortality in survivors was similar. In a multivariable analysis, re-exploration was an independent predictor of death and all major postoperative complications.

CONCLUSIONS

Surgical re-exploration due to postoperative bleeding following coronary artery surgery carries a high risk of perioperative mortality and is linked to major postoperative complications. Among patients who survive to hospital discharge, mid-term mortality is associated primarily with preoperative comorbidities.

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.

Impact of Timing on the Functional Recovery Achieved With Platelet Supplementation After Treatment With Ticagrelor

BACKGROUND

American College of Cardiology/American Heart Association guidelines advise waiting 5 to 7 days before operating on P2Y₁₂ inhibitor-treated acute coronary syndrome patients, to allow dissipation of its antiplatelet effects. Platelet transfusion is often used to restore hemostasis during operations, but its effectiveness and optimal timing are unclear. We investigated the degree of functional gains obtained from platelet supplementation after loading and maintenance of dual antiplatelet therapy with ticagrelor and the influence of timing on this strategy.

METHODS AND RESULTS

After baseline platelet testing (Multiplate Analyzer and VerifyNow), cardiovascular disease patients (n=20; 56.9±7.9 years; 65% men; 75% diabetic) received dual antiplatelet therapy as a single loading dose (ticagrelor 180 mg plus aspirin 325 mg) and as daily/maintenance treatment for 5 to 7 days (maintenance therapy: ticagrelor 90 mg BID plus aspirin 81 mg QD). At 4, 6, 24, and 48 hours from (last) dosing, patients' blood samples were supplemented with concentrated platelets from healthy donors in vitro, raising platelet counts by 0% (unsupplemented control), 25%, 50%, and 75%, and the function retested. Reactivity in supplemented samples was compared with respective 0% sample and with the pretreatment baseline. Results under loading dose and maintenance therapy regimens were nearly identical. Platelet reactivity was higher (P<0.05) in nearly all supplemented samples versus respective controls. Aggregations with supplementation were 59% to 79% of baseline at 24 hours and equal to baseline at 48 hours.

CONCLUSIONS

Platelet reactivity of ticagrelor-treated patients can be restored using concentrated platelets after a loading dose/maintenance therapy in a time-dependent manner under in vitro testing. Although statistically significant improvements are evident 6 hours after (last) dosing, ≥24 hours maybe needed for clinically meaningful restoration in platelet function.

CLINICAL TRIAL REGISTRATION

URL: https://clinicaltrials.gov. Unique identifier: NCT02201394.

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.

Platelet function testing in acute cardiac care – is there a role for prediction or prevention of stent thrombosis and bleeding?

The role of platelet function testing in acute coronary syndrome patients undergoing percutaneous coronary intervention remains controversial despite the fact that high platelet reactivity is an independent predictor of stent thrombosis and emerging evidence suggests also a link between low platelet reactivity and bleeding. In this expert opinion paper, the Study Group on Biomarkers in Cardiology of the Acute Cardiovascular Care Association and the Working Group on Thrombosis of the European Society of Cardiology aim to provide an overview of current evidence in this area and recommendations for practicing clinicians.

Antiplatelet Agents for the Treatment and Prevention of Coronary Atherothrombosis

Antiplatelet drugs provide first-line antithrombotic therapy for the management of acute ischemic syndromes (both coronary and cerebrovascular) and for the prevention of their recurrence. Their role in the primary prevention of atherothrombosis remains controversial because of the uncertain balance of the potential benefits and risks when combined with other preventive strategies. The aim of this consensus document is to review the evidence for the efficacy and safety of antiplatelet drugs, and to provide practicing cardiologists with an updated instrument to guide their choice of the most appropriate antiplatelet strategy for the individual patient presenting with different clinical manifestations of coronary atherothrombosis, in light of comorbidities and/or interventional procedures.

Platelet aggregation in response to ADP is highly variable in normal donors and patients on anti-platelet medication

BACKGROUND

P2Y12 inhibitors are indicated in patients following percutaneous coronary intervention. Several studies have demonstrated that high on treatment platelet reactivity is correlated with outcomes yet prospective studies of guided therapy have failed to show benefit. There is a paucity of studies on the platelet aggregation response to ADP before P2Y12 therapy is started. The aim of this study was to characterize platelet responses to 20 μM ADP by light transmission aggregometry (LTA) in a homogenous population.

METHODS

Platelet aggregation was assessed in 201 patients on dual antiplatelet therapy, 98 patients on aspirin alone and 47 normal, healthy volunteers free from anti-platelet medication.

RESULTS

Consensus guidelines suggest that a platelet aggregation response in response to the agonist ADP of <57% is an adequate therapeutic response to P2Y12 inhibition. Seven healthy donors and 38 patients taking aspirin only had aggregation responses below 57%.

CONCLUSIONS

The results of our study demonstrate that 15% of normal donors and 38% of patients taking aspirin only would be classified as having a therapeutic response to P2Y12 inhibition using current guidelines.

Platelet function testing in cardiac surgery

Bleeding in cardiac surgery is known to cause increased morbidity and mortality. The rise in the use of anti-platelet medication has led to an increase in the number of patients presenting for cardiac surgery with platelet dysfunction, who are at a heightened risk of bleeding. However, the extent of platelet inhibition is well known to differ among individuals. In the past few years, a number of point-of-care platelet function testing devices, which may be able to assess platelet reactivity, have entered the market. This review will examine the devices most commonly studied and the evidence surrounding their use in cardiac surgery and their effect on blood loss.

Efficacy of ex vivo autologous and in vivo platelet transfusion in the reversal of P2Y12 inhibition by clopidogrel, prasugrel, and ticagrelor: the APTITUDE study

BACKGROUND

Allogenic platelet transfusions (PT) are administered to treat excessive bleeding in patients on P2Y12 receptor inhibitors (RI). We assessed the effect of ex vivo and in vivo PT on platelet activation and aggregation in patients on dual antiplatelet therapy.

METHODS AND RESULTS

In the Antagonize P2Y12 Treatment Inhibitors by Transfusion of Platelets in an Urgent or Delayed Timing After Acute Coronary Syndrome or Percutaneous Coronary Intervention Presentation-Acute Coronary Syndrome (APTITUDE-ACS) study, patients presenting with acute coronary syndrome or for elective percutaneous coronary intervention, receiving loading doses of clopidogrel (600 mg, n=13 or 900 mg, n=12), prasugrel 60 mg (n=10), or ticagrelor 180 mg (n=10) were included. PT was performed ex vivo by mixing platelet-rich plasma from blood sampling performed at baseline in increasing proportions with platelet-rich plasma sampled 4 hours after loading dose. The percentage restoration of residual platelet aggregation achieved with 80% proportion PT (residual platelet aggregation 80% PT mix/residual platelet aggregation baseline×100) significantly decreased with increasing potency of P2Y12 RI (83.9±11%, 73±14%, 66.3±15%, 40.9±19% for clopidogrel 600 mg, clopidogrel 900 mg, prasugrel, and ticagrelor, respectively; P for trend <0.0001). In the APTITUDE-Coronary Artery Bypass Graft (APTITUDE-CABG) study, vasodilator-stimulated phosphoprotein-platelet reactivity index, a specific marker of the P2Y12 RI drug-effect, was assessed before and after in vivo PT administered for excessive bleeding in patients undergoing cardiac surgery while on a maintenance dose of aspirin and clopidogrel (n=45), prasugrel (n=6), or ticagrelor (n=3). When compared with baseline, there was a significant relative increase of 23.1% in platelet activation after PT transfusion (42.2±23.6% versus 56.6±18.2%; P=0.0008).

CONCLUSIONS

PT restores platelet reactivity in patients with acute coronary syndrome/percutaneous coronary intervention and in patients undergoing cardiac surgery on P2Y12 RI while bleeding with a less effect with increasing potency of P2Y12 inhibition.

CLINICAL TRIAL REGISTRATION

URL: http://www.recherche-biomedicale.sante.gouv.fr/pro/comites/coordonnees.htm and http://www.cnil.fr/. Unique identifiers: No. 301111 and No. 1547216v0.

Dual Antiplatelet Therapy (DAPT) versus No Antiplatelet Therapy and Incidence of Major Bleeding in Patients on Venoarterial Extracorporeal Membrane Oxygenation

Aims

Bleeding is a frequent complication in patients on venoarterial extracorporeal membrane oxygenation (VA-ECMO). An indication for dual antiplatelet therapy due to coronary stent implantation is present in a considerable number of these patients. The objective of this retrospective study was to evaluate if dual antiplatelet therapy (DAPT) significantly increases the high intrinsic bleeding risk in patients on VA-ECMO.

Methods and Results

A total of 93 patients were treated with VA-ECMO between October 2010 and October 2013. Average time on VA-ECMO was 58.9 ± 1.7 hours. Dual antiplatelet therapy was given to 51.6% of all patients. Any bleeding was recorded in 60.2% of all patients. There was no difference in bleeding incidence in patients on DAPT when compared to those without any antiplatelet therapy including any bleeding (66.7% vs. 57.1%, p = 0.35), BARC3 bleeding (43.8% vs. 33.3%, p = 0.31) or pulmonary bleeding (16.7% vs. 19.0%, p = 0.77). This holds true after adjustment for confounders. Rate of transfusion of red blood cells were similar in patients with or without DAPT (35.4% vs. 28.6%, p = 0.488).

Conclusions

Bleeding on VA-ECMO is frequent. This registry recorded no statistical difference in bleeding in patients on dual antiplatelet therapy when compared to no antiplatelet therapy. When indicated, DAPT should not be withheld from VA ECMO patients.

Point-of-care haemostasis and coagulation monitoring in cardiac surgery at IRCCS Policlinico San Donato

A rational management of perioperative and postoperative bleeding in modern cardiac surgery requires a thorough application of point-of-care (POC) monitoring in order to prevent and readily treat alterations of the haemostatic process. Preoperative platelet dysfunction, residual heparin after extracorporeal circulation, coagulation factors, and/or fibrinogen deficiency could be ruled out and specifically addressed with an appropriate treatment. Our approach includes preoperative platelet function testing of patients administered with thienopyridines or ticagrelor within 7-10 days before planned surgery and platelet function testing-based surgery timing. In the case of postoperative bleeding, residual heparin is tested and additional protamine is eventually administered. Simultaneously, an overall activity of coagulation factors (except fibrinogen) is assessed and, if significantly reduced, correction with prothrombotic complex concentrate is considered. If fibrinogen deficiency is suspected, a specific test is run, and in the case of severe reduction, the deficiency is compensated by fibrinogen concentrate or appropriate volume of fresh-frozen plasma. If both coagulation factors and fibrinogen activity are reduced, fibrinogen is usually considered for correction as first line, followed by prothrombin complex concentrate in the case of further bleeding. It is our clinical practice not to test nor to treat patients until postoperative bleeding appears clinically relevant. At IRCCS Policlinico San Donato, we firmly believe in the importance of the POC-based strategy for haemostatic treatment and constantly update our knowledge through research projects targeted in answering clinically relevant questions.

The European Hematology Association Roadmap for European Hematology Research: a consensus document

The European Hematology Association (EHA) Roadmap for European Hematology Research highlights major achievements in diagnosis and treatment of blood disorders and identifies the greatest unmet clinical and scientific needs in those areas to enable better funded, more focused European hematology research. Initiated by the EHA, around 300 experts contributed to the consensus document, which will help European policy makers, research funders, research organizations, researchers, and patient groups make better informed decisions on hematology research. It also aims to raise public awareness of the burden of blood disorders on European society, which purely in economic terms is estimated at €23 billion per year, a level of cost that is not matched in current European hematology research funding. In recent decades, hematology research has improved our fundamental understanding of the biology of blood disorders, and has improved diagnostics and treatments, sometimes in revolutionary ways. This progress highlights the potential of focused basic research programs such as this EHA Roadmap.The EHA Roadmap identifies nine 'sections' in hematology: normal hematopoiesis, malignant lymphoid and myeloid diseases, anemias and related diseases, platelet disorders, blood coagulation and hemostatic disorders, transfusion medicine, infections in hematology, and hematopoietic stem cell transplantation. These sections span 60 smaller groups of diseases or disorders.The EHA Roadmap identifies priorities and needs across the field of hematology, including those to develop targeted therapies based on genomic profiling and chemical biology, to eradicate minimal residual malignant disease, and to develop cellular immunotherapies, combination treatments, gene therapies, hematopoietic stem cell treatments, and treatments that are better tolerated by elderly patients.

Impact of prasugrel pretreatment and timing of coronary artery bypass grafting on clinical outcomes of patients with non-ST-segment elevation myocardial infarction: From the A Comparison of Prasugrel at PCI or Time of Diagnosis of Non-ST-Elevation Myocardial Infarction (ACCOAST) study

OBJECTIVES

We evaluated impact of timing of coronary artery bypass grafting (CABG) and prasugrel pretreatment in patients with non-ST-segment elevation myocardial infarction undergoing CABG in the ACCOAST study.

METHODS

Of 4033 enrolled patients, 314 (7.8%) underwent isolated CABG through 30 days. Primary efficacy end point for this analysis was any cardiovascular death, myocardial infarction, stroke, urgent revascularization, or glycoprotein IIb/IIIa inhibitor bailout through 30 days.

RESULTS

More CABG versus percutaneous coronary intervention or medically managed patients were men, diabetic, or had peripheral arterial disease. Per randomization, 157 of 314 patients received a 30-mg prasugrel loading dose before CABG, and 157 of 314 received placebo. Patients were stratified by tertile of time from randomization to CABG: <2.98 days (n = 104), ≥2.98 and <6.95 days (n = 106), and ≥6.95 days (n = 104). Primary end point occurred in 12.5%, 4.7%, and 4.8%, respectively (<2.98 days vs other tertiles, hazard ratio [HR] = 2.80; P = .011). Similarly, the rate of all TIMI major bleeding was highest in the lowest tertile (26.0% vs 10.4% and 4.8%; P < .001), but no difference in all-cause death was observed through 30 days (3.9% vs 1.9% and 1.9%; P = .30). Time from randomization to CABG (HR = 0.84 for each day delay), left main disease (HR = 1.76), region of enrollment (Non-Eastern Europe vs Eastern Europe; HR = 3.83), but not prasugrel pretreatment and baseline troponin ≥3× upper limit of normal, were independent predictors of combined 30-day end point of all-cause death/myocardial infarction/stroke/TIMI major bleeding.

CONCLUSIONS

In ACCOAST, early (<2.98 days) surgical revascularization carried increased risk of bleeding and ischemic complications without affecting all-cause mortality through 30 days. Baseline troponin and prasugrel pretreatment did not impact ischemic clinical outcomes.

Surgical Revascularization versus Percutaneous Coronary Intervention and Optimal Medical Therapy in Diabetic Patients with Multi-Vessel Coronary Artery Disease

Coronary artery disease (CAD) is the leading cause of death in patients with diabetes mellitus (DM). Patients with DM and CAD undergoing revascularization with either a surgical or a percutaneous approach are at higher risk of adverse outcomes and mortality compared with non-DM patients. It is within this background that the optimal choice of revascularization is of critical importance in this high-risk population. The large FREEDOM trial randomized 1900 patients with DM and multivessel CAD to either revascularization with coronary artery by-pass graft (CABG) surgery or percutaneous coronary intervention (PCI). Compared with PCI, CABG significantly reduced the rates of death and myocardial infarction but was associated with a higher risk of stroke. In a real-world setting the decision-making process for the optimal revascularization strategy in these patients is challenging as many clinical factors may influence the decision to either pursue a surgical or a percutaneous revascularization. However, the current consensus is that CABG should be the preferred revascularization strategy in diabetic patients with extensive multivessel CAD.

Practical experience with ticagrelor: an Australian and New Zealand perspective

OBJECTIVE

Ticagrelor is recommended in local and international guidelines as first-line therapy in combination with aspirin in patients presenting with acute coronary syndromes (ACS). The purpose of this article is to provide practical guidance regarding the use of ticagrelor in this setting.

METHODS AND RESULTS

Ticagrelor, a direct-acting, reversible P2Y12 receptor antagonist, has a faster onset, and a more potent and predictable antiplatelet effect compared with clopidogrel. The authors recommend considering the use of ticagrelor in moderate-to-high risk ACS patients treated with an invasive approach and those managed non-invasively who have elevated troponin levels. Consistent with outcomes observed in the PLATO trial overall, ticagrelor was superior to clopidogrel treatment in patients with chronic kidney disease, a history of stroke or transient ischemic attack, the elderly, and patients requiring surgical revascularization.

CONCLUSIONS

When switching from clopidogrel to ticagrelor, patients established on clopidogrel therapy can be switched directly without loading; patients not loaded with clopidogrel and not taking maintenance dose clopidogrel for at least 5 days should first be loaded with ticagrelor. Guidelines recommend discontinuing ticagrelor 5 days before surgery if antiplatelet effects are not desired and recommencing therapy as soon as safe following surgery. Ticagrelor should be avoided in individuals with a history of intracranial hemorrhage, moderate-to-severe hepatic impairment, high bleeding risk, within 24 hours of thrombolytic therapy, and in those treated with oral anticoagulants. Local, real-world experience suggests low bleeding rates with ticagrelor therapy. Dyspnoea is a common symptom in patients with ACS and is also a side-effect of ticagrelor therapy. Discontinuation of ticagrelor due to dyspnoea has been uncommon in clinical trials. However, local registry data suggest higher discontinuation rates (2-9%) related to dyspnoea in the real-world setting, indicating that clinicians may need to consider other potential causes of dyspnoea before discontinuing ticagrelor.

Dual Antiplatelet Therapy After Coronary Artery Bypass Grafting in the Setting of Acute Coronary Syndrome

After acute coronary syndrome (ACS), dual antiplatelet therapy (DAPT) is the standard of care for both invasive management with percutaneous intervention and noninvasive (medical) management. Conversely, studies using dual antiplatelet in the population of patients presenting with ACS who undergo coronary artery bypass grafting (CABG) are conflicting. The appropriate antiplatelet regimen after CABG remains an area of controversy. Plaque stability, prevention of graft closure, and secondary thrombosis form the basis for using a second antiplatelet drug, whereas the additional risk of bleeding and lack of conclusive evidence should also be considered. After an extensive literature search, 12 clinical trials with efficacy outcomes were identified. Most of the studies are retrospective, nonrandomized single-center trials. A few large patient populations have been examined using database information. To date, there is only 1 prospective, multicenter, randomized trial published. Recommendations from national guidelines differ, proposing single antiplatelet therapy with aspirin or DAPT with the combination of aspirin and clopidogrel. The purpose of this report is to review the available clinical trial data and provide guidance to practitioners when caring for this patient population. In conclusion, there is no clear consensus regarding the use of DAPT in patients after CABG. If not contraindicated, it is reasonable to use DAPT, starting in the postoperative period, in patients presenting with ACS. Large, multicenter, randomized clinical trials are needed to definitively investigate the role of DAPT in patients with ACS after CABG.