Preoperative platelet aggregation predicts perioperative blood loss and rethoracotomy for bleeding in patients receiving dual antiplatelet treatment prior to coronary surgery

Platelet inhibitor withdrawal and outcomes after coronary artery surgery: an individual patient data meta-analysis

OBJECTIVES

To evaluate the association between guideline-conforming as compared to shorter than recommended withdrawal period of P2Y12 receptor inhibitors prior to isolated on-pump coronary artery bypass grafting (CABG) and the incidence of severe bleeding and ischaemic events. Randomized controlled trials are lacking in this field.

METHODS

We searched PUBMED, Embase and other suitable databases for studies including patients on P2Y12 receptor inhibitors undergoing isolated CABG and reporting bleeding and postoperative ischaemic events from 2013 to March 2024. The primary outcome was incidence of Bleeding Academic Research Consortium type 4 (BARC-4) bleeding defined as any of the following: perioperative intracranial bleeding, reoperation for bleeding, transfusion of ≥5 units of red blood cells, chest tube output of ≥2 l. The secondary outcome was postoperative ischaemic events according to the Academic Research Consortium 2 Consensus Document. Patient-level data provided by each observational trial were synthesized into a single dataset and analysed using a 2-stage IPD-MA.

RESULTS

Individual data of 4837 patients from 7 observational studies were synthesized. BARC-4 bleeding, 30-day mortality and postoperative ischaemic events occurred in 20%, 2.6% and 5.2% of patients. After adjusting for EuroSCORE II and cardiopulmonary bypass time, guideline-conforming withdrawal was associated with decreased BARC-4 bleeding risk in patients on clopidogrel [adjusted odds ratio (OR) 0.48; 95% confidence intervals (CI) 0.28-0.81; P = 0.006] and a trend towards decreased risk in patients on ticagrelor (adjusted OR 0.48; 95% CI 0.22-1.05; P = 0.067). Guideline-conforming withdrawal was not significantly associated with 30-day mortality risk (clopidogrel: adjusted OR 0.70; 95% CI 0.30-1.61; ticagrelor: adjusted OR 0.89; 95% CI 0.37-2.18) but with decreased risk of postoperative ischaemic events in patients on clopidogrel (clopidogrel: adjusted OR 0.50; 95% CI 0.30-0.82; ticagrelor: adjusted OR 0.78; 95% CI 0.45-1.37). BARC-4 bleeding was associated with 30-day mortality risk (adjusted OR 4.76; 95% CI 2.67-8.47; P < 0.001).

CONCLUSIONS

Guideline-conforming preoperative withdrawal of ticagrelor and clopidogrel was associated with a 50% reduced BARC-4 bleeding risk when corrected for EuroSCORE II and cardiopulmonary bypass time but was not associated with increased risk of 30-day mortality or postoperative ischaemic events.

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.

Fibrin clot susceptibility to lysis is impaired after on-pump coronary artery by-pass grafting with tranexamic acid: clinical implications

Coronary artery bypass grafting (CABG) done on-pump may cause a significant blood loss. Low fibrinogen is associated with perioperative bleeding. The influence of cardiopulmonary bypass on fibrin clot properties is poorly investigated. We studied 55 patients with isolated coronary artery disease on aspirin undergoing on-pump CABG with tranexamic acid. Fibrinogen levels, fibrinolytic capacity expressed as clot lysis time (CLT), thrombin generation potential and platelet count were assessed before and after the surgery (prior to admission to the intensive care unit). A postoperative drop in haemoglobin (-30% from baseline), haematocrit (-31% from baseline) and platelet count (-42% from baseline) was observed (all, P < 0.0001). Postoperative fibrinogen level was lower by 57%, compared with preoperative value (1.5 [1.3-1.8] vs. 3.5 [2.8-3.9] g/l, P < 0.0001). Postoperative CLT was longer by 48 min, compared with preoperative (182 [170-218] vs. 134 [122-165] min, P < 0.0001). Thrombin generation was impaired postoperatively: both lag time and time to peak thrombin were prolonged by 44 and 45%, respectively, whereas endogenous thrombin potential and peak thrombin generation decreased by 45 and 78%, respectively (all P < 0.0001). Median postoperative drainage at 12 h was 400 [290-570] ml. Predictors of blood loss at 12 h identified in multivariable linear regression model adjusted for sex and preoperative fibrinogen level were: BMI (b = -23.4, P = 0.048) and postoperative CLT (b = -2.4, P = 0.042). Despite decreased fibrinogen levels after on-pump CABG with tranexamic acid, fibrin clot susceptibility to lysis is impaired, as reflected by prolonged CLT. Postoperative CLT is associated with mediastinal drainage at 12 h.

Platelet Function Testing in Patients on Antiplatelet Therapy before Cardiac Surgery

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

Perioperative management of antithrombotic treatment

End-stage liver disease is characterized by multiple and complex alterations of hemostasis that are associated with an increased risk of both bleeding and thrombosis. Liver transplantation further challenges the feeble hemostatic balance of patients with decompensated cirrhosis, and the management of antithrombotic treatment during and after transplant surgery, which is particularly difficult. Bleeding was traditionally considered the major concern during and early after surgery, but it is increasingly recognized that transplant recipients may also develop thrombotic complications. Pathophysiology of hemostatic complications during and after transplantation is multifactorial and includes pre-, intra-, and postoperative risk factors. Risk stratification is important, as it helps the identification of high-risk recipients in whom antithrombotic prophylaxis should be considered. In recipients who develop thrombosis during or after surgery, prompt treatment is indicated to prevent graft failure, retransplantation, and death.

Absence of perioperative excessive bleeding in on-pump coronary artery bypass grafting cases performed by residents

OBJECTIVES

On-pump coronary artery bypass grafting (CABG) is associated with elevated bleeding risk. Our aim was to evaluate the role of surgical experience in postoperative blood loss.

METHODS

A propensity score-matched analysis was employed to compare on-pump CABG patients operated on by residents and specialists. End points included drainage volume and bleeding severity, as assessed by the Universal Definition of Perioperative Bleeding in cardiac surgery and E-CABG scale.

RESULTS

A total of 212 matched pairs (c-statistics 0.693) were selected from patients operated on by residents (n = 294) and specialists (n = 4394) between October 2012 and May 2018. Patients did not differ in bleeding risk. There were no statistically significant differences in postoperative 6-, 12- and 24-h drainages between subjects operated on by residents and specialists, and there was no between-group difference in rethoracotomy or transfusion rate. There were no differences in Universal Definition of Perioperative Bleeding or E-CABG grades. In June 2018, after a median follow-up of 2.8 years (range 0.1-5.7 years), the overall survival was 94%, with no differences between the patients operated on by residents (95%) and specialists (92%) (P = 0.27).

CONCLUSIONS

Patients undergoing on-pump CABG, when operated on by a resident, are not exposed to an elevated bleeding risk, as compared with patients operated on by experienced surgeons.

Ministernotomy or sternotomy in isolated aortic valve replacement? Early results

Introduction

Aortic valve replacement (AVR) is the gold standard in treating symptomatic aortic valve defects. To improve the healing process and limit the trauma, the minimally invasive approach was introduced.

Aim

To compare the peri- and post-operative results of aortic valve replacement performed via conventional full sternotomy (con-AVR) and of AVR performed via partial upper sternotomy (mini-AVR).

Material and methods

The total study population was divided into 2 demographically homogeneous groups: mini-AVR (n = 74) and con-AVR (n = 76). There were no statistically significant differences in preoperative echocardiography.

Results

Aortic cross-clamp time and cardiopulmonary bypass time were significantly longer in the mini-AVR group. Shorter mechanical ventilation time, hospital stay and lower postoperative drainage were observed in the mini-AVR group (p < 0.05). Biological prostheses were more frequently implanted in the mini-AVR group (p < 0.05). Patients from the mini-AVR group reported less postoperative pain. No significant differences were found in the diameter of the implanted aortic prosthesis, the amount of inotropic agents and painkillers, postoperative left ventricular ejection fraction (LVEF), medium and maximum transvalvular gradient or the number of transfused blood units. There were no differences in the frequency of postoperative complications such as mortality, stroke, atrial fibrillation, renal failure, wound infection, sternal instability, or the need for rethoracotomy.

Conclusions

Ministernotomy for AVR is a safe method and does not increase morbidity and mortality. It significantly reduces post-operative blood loss and shortens hospital stay. Ministernotomy can be successfully used as an alternative method to sternotomy.

The role of platelet hyperreactivity in venous thromboembolism after total knee arthroplasty in elderly population without pharmacologic prophylaxis: A single-center study

INTRODUCTION

While it is suggested that platelet hyperreactivity plays a role in the arterial thrombi, its link with venous thromboembolism (VTE) is not well defined. Aggregometry using low concentrations of agonists is proposed as a reliable method to detect hyperreactivity. The aim of this study was to examine whether platelet hyperreactivity affects the development of VTE after total knee arthroplasty (TKA).

METHODS

Total 150 elderly patients without VTE history were enrolled. Mechanical prophylaxis was used for VTE after TKA. We performed platelet aggregation using Chrono-log (Chrono-log Corporation, USA) in the presence of low concentrations of ADP (1.0 μmol/L) and epinephrine (0.4, 1.0 μmol/L), and measured maximal aggregation (%).

RESULTS

At 0.4 μmol/L epinephrine, 69.3%, 15.3%, and 15.3% displayed low (<40%), moderate (40-60%), and high (>60%) levels of aggregation, respectively. The proportion of high level of aggregation was 36.7%, 30.7% at 1.0 μmol/L of epinephrine and ADP, respectively. The incidence of VTE was higher in the moderate/high aggregation group (10/46, 21.7%) than in the low aggregation group (1/104, 1.0%) at 0.4 μmol/L epinephrine (P < 0.0001). In predicting postoperative VTE, sensitivity and specificity of ≥40% aggregation at 0.4 μmol/L epinephrine were 90.9% and 74.1%. Higher mean platelet volume and lower volume of blood loss were seen in the high aggregation group than in the low aggregation group.

CONCLUSION

Aggregation response to 0.4 μmol/L epinephrine is an optimal assay to classify platelet activity. Platelet hyperreactivity may increase the risk of postoperative VTE in an elderly population, and can be an indication of pharmacologic prophylaxis.

Organ transplantation and drug eluting stents: Perioperative challenges

Patients listed for organ transplant frequently have severe coronary artery disease (CAD), which may be treated with drug eluting stents (DES). Everolimus and zotarolimus eluting stents are commonly used. Newer generation biolimus and novolimus eluting biodegradable stents are becoming increasingly popular. Patients undergoing transplant surgery soon after the placement of DES are at increased risk of stent thrombosis (ST) in the perioperative period. Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor such as clopidogrel, prasugrel and ticagrelor is instated post stenting to decrease the incident of ST. Cangrelor has recently been approved by Food and Drug Administration and can be used as a bridging antiplatelet drug. The risk of ischemia vs bleeding must be considered when discontinuing or continuing DAPT for surgery. Though living donor transplant surgery is an elective procedure and can be optimally timed, cadaveric organ availability is unpredictable, therefore, discontinuation of antiplatelet medication cannot be optimally timed. The type of stent and timing of transplant surgery can be of utmost importance. Many platelet function point of care tests such as Light Transmittance Aggregrometry, Thromboelastography Platelet Mapping, VerifyNow, Multiple Electrode Aggregrometry are used to assess bleeding risk and guide perioperative platelet transfusion. Response to allogenic platelet transfusion to control severe intraoperative bleeding may differ with the antiplatelet drug. In stent thrombosis is an emergency where management with either a drug eluting balloon or a DES has shown superior outcomes. Post-transplant complications often involved stenosis of an important vessel that may need revascularization. DES are now used for endovascular interventions for transplant orthotropic heart CAD, hepatic artery stenosis post liver transplantation, transplant renal artery stenosis following kidney transplantation, etc. Several antiproliferative drugs used in the DES are inhibitors of mammalian target of rapamycin. Thus they are used for post-transplant immunosuppression to prevent acute rejection in recipients with heart, liver, lung and kidney transplantation. This article describes in detail the various perioperative challenges encountered in organ transplantation surgery and patients with drug eluting stents.