Avoidance of Bleeding During Surgery in Patients Receiving Anticoagulant and/or Antiplatelet Therapy

Preoperative and intraoperative tirofiban during endovascular thrombectomy in large vessel occlusion stroke due to large artery atherosclerosis

BACKGROUND AND PURPOSE

The aim of this study is to investigate the efficacy and safety of preoperative versus intraoperative tirofiban in patients with large vessel occlusion (LVO) due to large artery atherosclerosis (LAA).

METHODS

This is a retrospective multicenter cohort study based on the RESCUE-RE (Registration Study for Critical Care of Acute Ischemic Stroke After Recanalization) trial enrolling patients with anterior circulation LVO classified as LAA within 24 h of onset. Patients were divided into three groups: preoperative tirofiban (PT), intraoperative tirofiban (IT), and no tirofiban (NT). Propensity score matching (PSM) was used to balance baseline characteristics. The efficacy outcomes included 90-day functional independence (modified Rankin Scale score = 0-2) and early partial recanalization (EPR; defined as a modified Thrombolysis in Cerebral Infarction score = 1-2a). The safety outcomes included symptomatic intracranial hemorrhage (sICH).

RESULTS

A total of 104 matched triplets were obtained through PSM. Compared with NT, PT increased 90-day functional independence (60.8% vs. 42.3%, p = 0.008) and EPR (42.7% vs. 18.3%, p < 0.001) rate, with a tendency to increase the asymptomatic intracranial hemorrhage (aICH) proportion (28.8% vs. 18.3%, p = 0.072). Compared with IT, PT had a higher 90-day functional independence (60.8% vs. 45.2%, p = 0.025) and EPR (42.7% vs. 20.2%, p = 0.001) rate, with no significant difference in sICH (14.4% vs. 7.7%, p = 0.122) and aICH (28.8% vs. 21.2%, p = 0.200). Compared with NT, IT had a lower 90-day mortality rate (9.6% vs. 24.0%, p = 0.005).

CONCLUSIONS

Tirofiban shows good adjuvant therapy potential in acute ischemic stroke-LVO due to LAA patients. PT is associated with higher rates of EPR and better therapeutic efficacy. In addition, EPR may be a potential way to improve prognosis.

Glycoprotein IIb/IIIa inhibitors in the treatment of thromboembolic events related to endovascular treatment of cerebral aneurysms-systematic review and meta-analysis

BACKGROUND AND AIMS

Thromboembolism complication is considered the most common complication associated with the treatment of endovascular. This systematic review and meta-analysis aimed to assess the studies investigating the effect of glycoprotein IIb/IIIa inhibitor agents on thromboembolic complications during endovascular aneurysm coiling.

MATERIALS AND METHODS

This systematic review investigated the outcome of the use of three glycoprotein IIb/IIIa inhibitor agents (ie abciximab, tirofiban, and eptifibatide) on the thromboembolic complications during endovascular aneurysm coiling. The electronic databases of PubMed, Web of Science, Scopus, and Medline were searched up to 25 June 2021, using the keywords "Abciximab," "Tirofiban," and "Eptifibatide" incombination with "Thromboembolism Complication," "Aneurysms," and "Endovascular Aneurysm Coiling."

RESULTS

A total of 21 articles were found to be eligible and included in this review. The rates of complete and partial recanalization were estimated to be 56% and 92% in patients who underwent abciximab and tirofiban therapy, respectively. Rupture aneurysms were found in the majority of patients. In general, the mortality rate of the patients treated for thromboembolic complications during endovascular treatment of cerebral aneurysms with glycoprotein IIb/IIIa inhibitors was found to be 4.8% (CI 95%:0.027-0.067; p < .005). The average remission rate in studies investigating thromboembolism was 91% (CI 95%:0.88-0.95, I2 : 65.65/p < .001).

CONCLUSION

Based on the obtained results, a higher mean rate of complete recanalization by eptifibatide was found in studies in which abciximab or tirofiban were used, compared to other mentioned agents. Moreover, the amount of hemorrhage was reported to be less after using tirofiban rather than abciximab.

Bleeding After Dental Extraction in Patients Undergoing Percutaneous Coronary Intervention During Uninterrupted Single and Dual Antiplatelet Therapy

Purpose

This study aimed to assess bleeding risk after exodontia in patients with recent percutaneous coronary intervention during uninterrupted single or dual antiplatelet therapy.

Study design

A total of 100 patients who had a history of percutaneous stent insertion during the past year candidate for extraction of teeth were included in the study. Fifty patients took aspirin 100mg (monotherapy group), and 50 patients took a combination of aspirin 100mg and clopidogrel 75mg (dual therapy group). After exodontia, the bleeding status was categorized as "complete hemostasis," "persistent bleeding," and "delayed bleeding." Personal data, underlying diseases, number of teeth and roots extracted, and type of procedure required for exodontia were statistically analyzed.

Results

No significant difference was observed in the status of bleeding between the two groups regarding sex, age, underlying diseases, number of teeth and roots extracted, and type of procedure (p > 0.05). 39/50 (78%) of monotherapy patients and 32/50 (64%) of dual therapy patients achieved complete hemostasis. Persistent bleeding was noted in 11/50 (22%) of monotherapy participants, and 14/50 (28%) of dual therapy patients. Only 4/50 (8%) of dual therapy patients experienced delayed bleeding. However, these differences were not significant (p = 0.08). All persistent and delayed bleeding was easily controlled via local measures.

Conclusion

Simple or complicated extraction of multiple teeth can be performed safely during the first year after percutaneous coronary intervention without interruption of antiplatelet therapy.

The safety and efficacy of intra-arterial low-dose tirofiban administration during endovascular therapy in patients with large ischemic core volume

This study aimed to evaluate the safety and efficacy of intra-arterial (IA) administration of low- dose tirofiban during endovascular therapy in patients with large ischemic core volumes on initial brain CT. Patients were divided into two groups based on the use of IA tirofiban. We identified 87 patients (16 and 71 patients in the tirofiban and no-tirofiban groups, respectively) with acute ischemic stroke due to intracranial artery occlusion who underwent endovascular therapy with a low Alberta Stroke Program Early CT scores (2-5). Multivariate logistic regression analysis revealed no association between IA tirofiban administration and serious postprocedural hemorrhagic complications (adjusted odds ratio (aOR), 0.720; 95% confidence interval (CI) 0.099-5.219; p = 0.960), any radiologic hemorrhage (aOR 0.076; 95% CI 0.003-2.323; p = 0.139), or 3-month mortality (aOR, 0.087; 95% CI 0.005-1.501; p = 0.093). However, IA tirofiban was associated with a lower 90-day mRS score (aOR, 0.197; 95% CI 0.015-1.306; p = 0.017) and change of NIHSS compared with baseline (aOR, 0.698; 95% CI 0.531-0.917; p = 0.010). IA tirofiban administration during endovascular therapy in patients with large ischemic core volumes may be effective and safe.

The Efficacy and Safety of Tirofiban Use in Endovascular Thrombectomy for Intravenous Thrombolysis Applicable Patients with Large Vessel Occlusion Stroke-a Post Hoc Analysis from the Direct-MT Trial

PURPOSE

The purpose of the study was to evaluate the efficacy and safety of tirofiban use in endovascular thrombectomy for intravenous thrombolysis applicable patients of large vessel occlusion stroke with data from Direct-MT trial.

MATERIALS AND METHODS

Direct-MT was the first randomized controlled trial to prove the non-inferiority of thrombectomy alone to bridging therapy (intravenous thrombolysis before thrombectomy) for large vessel occlusion stroke. Patients who underwent endovascular procedure were included and divided into thrombectomy-alone group and bridging therapy group. The effect of tirofiban use on 90 days MRS distribution, MRS 0-2 and mortality, successful reperfusion, the ASPECTS and outcome lesion volume of index stroke, re-occlusion of the treated vessel, futile recanalization and safety outcomes were further evaluated in both groups after adjustment for relevant confounding factors. The interaction between tirofiban and rt-PA was also assessed.

RESULTS

Of 639 patients included in this analysis, 180 patients underwent thrombectomy with tirofiban use (28.2%). Patients with tirofiban use had lower percentage of bridging therapy (41.1% vs 54.3%, P = 0.003), higher proportion of large artery atherosclerosis (P < 0.001) and more emergent stenting (30.56% vs 6.97%, P < 0.001). After adjustment for confounding factors, the 90-day modified Rankin Scale distribution, successful final recanalization rate, outcome lesion volume of index stroke on CT and intracranial hemorrhage risk showed no difference after tirofiban use in thrombectomy-alone group and in bridging therapy group. No interaction effect between tirofiban and rt-PA was detected.

CONCLUSION

Based on data from Direct-MT trial, tirofiban is a safe medication for intravenous thrombolysis applicable patients with large vessel occlusion stroke undergoing thrombectomy.

LEVEL OF EVIDENCE

Level 3, cohort study of randomized trial.

Editor's Choice -- European Society for Vascular Surgery (ESVS) 2024 Clinical Practice Guidelines on the Management of Abdominal Aorto-Iliac Artery Aneurysms

OBJECTIVE

The European Society for Vascular Surgery (ESVS) has developed clinical practice guidelines for the care of patients with aneurysms of the abdominal aorta and iliac arteries in succession to the 2011 and 2019 versions, with the aim of assisting physicians and patients in selecting the best management strategy.

METHODS

The guideline is based on scientific evidence completed with expert opinion on the matter. By summarising and evaluating the best available evidence, recommendations for the evaluation and treatment of patients have been formulated. The recommendations are graded according to a modified European Society of Cardiology grading system, where the strength (class) of each recommendation is graded from I to III and the letters A to C mark the level of evidence.

RESULTS

A total of 160 recommendations have been issued on the following topics: Service standards, including surgical volume and training; Epidemiology, diagnosis, and screening; Management of patients with small abdominal aortic aneurysm (AAA), including surveillance, cardiovascular risk reduction, and indication for repair; Elective AAA repair, including operative risk assessment, open and endovascular repair, and early complications; Ruptured and symptomatic AAA, including peri-operative management, such as permissive hypotension and use of aortic occlusion balloon, open and endovascular repair, and early complications, such as abdominal compartment syndrome and colonic ischaemia; Long term outcome and follow up after AAA repair, including graft infection, endoleaks and follow up routines; Management of complex AAA, including open and endovascular repair; Management of iliac artery aneurysm, including indication for repair and open and endovascular repair; and Miscellaneous aortic problems, including mycotic, inflammatory, and saccular aortic aneurysm. In addition, Shared decision making is being addressed, with supporting information for patients, and Unresolved issues are discussed.

CONCLUSION

The ESVS Clinical Practice Guidelines provide the most comprehensive, up to date, and unbiased advice to clinicians and patients on the management of abdominal aorto-iliac artery aneurysms.

Patient blood management in major digestive surgery: Recommendations from the Italian multisociety (ACOI, SIAARTI, SIdEM, and SIMTI) modified Delphi consensus conference

Patient blood management (PBM) is defined as the timely application of evidence-based medical and surgical concepts designed to maintain a surgical patient’s hemoglobin concentration, optimize hemostasis, and minimize blood loss in an effort to improve the outcomes. PBM is able to reduce mortality up to 68%, reoperation up to 43%, readmission up to 43%, composite morbidity up to 41%, infection rate up to 80%, average length of stay by 16%–33%, transfusion from 10% to 95%, and costs from 10% to 84% after major surgery. It should be noticed, however, that the process of PBM implementation is still in its infancy, and that its potential to improve perioperative outcomes could be strictly linked to the degree of adherence/compliance to the whole program, with decoupling and noncompliance being significant factors for failure. Therefore, the steering committees of four major Italian scientific societies, representing general surgeons, anesthesiologists and transfusion medicine specialists (Associazione Chirurghi Ospedalieri Italiani; Società Italiana di Anestesia, Analgesia, Rianimazione e Terapia Intensiva; Società Italiana di Emaferesi e Manipolazione Cellulare; Società Italiana di Medicina Trasfusionale e Immunoematologia), organized a joint modified Delphi consensus conference on PBM in the field of major digestive surgery (upper and lower gastrointestinal tract, and hepato-biliopancreatic resections), whose results and recommendations are herein presented.

Perioperative Management of Anticoagulant and Antiplatelet Therapy

Anticoagulant and Antiplatelet Drug ManagementManagement of patients on an anticoagulant or antiplatelet drug who require surgery or an invasive procedure is a common clinical problem. Douketis and Spyropoulos provide an evidence-based but practical approach to managing anticoagulants and antiplatelet drugs in the perioperative setting.

Perioperative Management of Antithrombotic Therapy: An American College of Chest Physicians Clinical Practice Guideline

BACKGROUND

The American College of Chest Physicians Clinical Practice Guideline on the Perioperative Management of Antithrombotic Therapy addresses 43 Patients-Interventions-Comparators-Outcomes (PICO) questions related to the perioperative management of patients who are receiving long-term oral anticoagulant or antiplatelet therapy and require an elective surgery/procedure. This guideline is separated into four broad categories, encompassing the management of patients who are receiving: (1) a vitamin K antagonist (VKA), mainly warfarin; (2) if receiving a VKA, the use of perioperative heparin bridging, typically with a low-molecular-weight heparin; (3) a direct oral anticoagulant (DOAC); and (4) an antiplatelet drug.

METHODS

Strong or conditional practice recommendations are generated based on high, moderate, low, and very low certainty of evidence using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology for clinical practice guidelines.

RESULTS

A multidisciplinary panel generated 44 guideline recommendations for the perioperative management of VKAs, heparin bridging, DOACs, and antiplatelet drugs, of which two are strong recommendations: (1) against the use of heparin bridging in patients with atrial fibrillation; and (2) continuation of VKA therapy in patients having a pacemaker or internal cardiac defibrillator implantation. There are separate recommendations on the perioperative management of patients who are undergoing minor procedures, comprising dental, dermatologic, ophthalmologic, pacemaker/internal cardiac defibrillator implantation, and GI (endoscopic) procedures.

CONCLUSIONS

Substantial new evidence has emerged since the 2012 iteration of these guidelines, especially to inform best practices for the perioperative management of patients who are receiving a VKA and may require heparin bridging, for the perioperative management of patients who are receiving a DOAC, and for patients who are receiving one or more antiplatelet drugs. Despite this new knowledge, uncertainty remains as to best practices for the majority of perioperative management questions.

Antithrombotic Therapy for Aortic Aneurysms: A Systematic Review and Meta-Analysis

OBJECTIVES

The role of antithrombotic therapy in the management of aortic and peripheral aneurysms is unclear. This systematic review and meta-analysis aimed to assess the impact of antithrombotics on clinical outcomes for aortic and peripheral aneurysms.

METHODS

Medline, Embase, and CENTRAL databases were searched. Randomised controlled trials and observational studies investigating the effect of antithrombotic therapy on clinical outcomes for patients with any aortic or peripheral artery aneurysm were included.

RESULTS

Fifty-nine studies (28 with antiplatelet agents, 12 anticoagulants, two intra-operative heparin, and 16 any antithrombotic agent) involving 122 102 patients were included. Abdominal aortic aneurysm (AAA) growth rate was not significantly associated with the use of antiplatelet therapy (SMD -0.36 mm/year; 95% CI -0.75 - 0.02; p = .060; GRADE certainty: very low). Antithrombotics were associated with increased 30 day mortality for patients with AAAs undergoing intervention (OR 2.30; 95% CI 1.51 - 3.51; p < .001; GRADE certainty: low). Following intervention, antiplatelet therapy was associated with reduced long term all cause mortality (HR 0.84; 95% CI 0.76 - 0.92; p < .001; GRADE certainty: moderate), whilst anticoagulants were associated with increased all cause mortality (HR 1.64; 95% CI 1.14 - 2.37; p = .008; GRADE certainty: very low), endoleak within three years (OR 1.99; 95% CI 1.10 - 3.60; p = .020; I² = 60%; GRADE certainty: very low), and an increased re-intervention rate at one year (OR 3.25; 95% CI 1.82 - 5.82; p < .001; I² = 35%; GRADE certainty: moderate). Five studies examined antithrombotic therapy for popliteal aneurysms. Meta-analysis was not possible due to heterogeneity.

CONCLUSIONS

There was a lack of high quality data examining antithrombotic therapy for patients with aneurysms. Antiplatelet therapy was associated with a reduction in post-intervention all cause mortality for AAA, whilst anticoagulants were associated with an increased risk of all cause mortality, endoleak, and re-intervention. Large, well designed trials are still required to determine the therapeutic benefits of antithrombotic agents in this setting.

Platelet function changes in patients undergoing endovascular aortic aneurysm repair: Review of the literature

Patients with abdominal aortic aneurysm (AAA) have a higher risk of cardiovascular (CV) events, which seems to be associated with disturbed platelet (PLT) function. Endovascular aneurysm repair (EVAR) is an emerging, less-invasive treatment alternative to surgical AAA repair. Both platelet function abnormalities in patients with AAA and the effect of EVAR on platelet function are poorly understood. In this review, we aim to fill the gap regarding the effect of EVAR on PLT function in AAA patients by discussing PLT function disturbances in patients with AAA, PLT function changes after EVAR, evidence from clinical studies regarding PLT function before and after EVAR, and antiplatelet or and antithrombotic treatment in patients undergoing EVAR. The goal of our review is to summarize the contemporary knowledge and initiate further studies to better understand PLT function changes in patients undergoing EVAR, optimize the pharmacotherapy before and after EVAR and further improve outcomes in this group of patients.

The Safety of Intra-arterial Tirofiban during Endovascular Therapy after Intravenous Thrombolysis

BACKGROUND AND PURPOSE

The safety and efficacy of tirofiban during endovascular therapy in patients undergoing intravenous thrombolysis with recombinant IV tPA remain unclear. This study aimed to investigate the safety and efficacy of intra-arterial tirofiban use during endovascular therapy in patients treated with IV tPA.

MATERIALS AND METHODS

Using a multicenter registry, we enrolled patients with acute ischemic stroke who underwent endovascular therapy. Safety outcomes included postprocedural parenchymal hematoma type 2 and/or thick subarachnoid hemorrhage, intraventricular hemorrhage, and 3-month mortality. Efficacy outcomes included the successful reperfusion rate, postprocedural reocclusion, and good outcomes at 3 months (mRS scores of 0-2). The tirofiban effect on the outcomes was evaluated using a multivariable analysis while adjusting for potential confounders.

RESULTS

Among enrolled patients, we identified 314 patients with stroke (279 and 35 patients in the no tirofiban and tirofiban groups, respectively) due to an intracranial artery occlusion who underwent endovascular therapy with intravenous thrombolysis. A multivariable analysis revealed no association of intra-arterial tirofiban with postprocedural parenchymal hematoma type and/or thick subarachnoid hemorrhage (adjusted OR, 1.07; 95% CI, 0.20-4.10; P = .918), intraventricular hemorrhage (adjusted OR, 0.43; 95% CI, 0.02-2.85; P = .467), and 3-month mortality (adjusted OR, 0.38; 95% CI, 0.04-1.87; P = .299). Intra-arterial tirofiban was not associated with good outcome (adjusted OR, 2.22; 95% CI, 0.89 -6.12; P = .099).

CONCLUSIONS

Using intra-arterial tirofiban during endovascular therapy after IV tPA could be safe.

Outcome of Major Hemorrhage at a Major Cardiothoracic Center in Patients with Activated Major Hemorrhage Protocol versus Nonactivated Protocol

This study aimed to determine the impact of major hemorrhage (MH) protocol (MHP) activation on blood administration and patient outcome at a UK major cardiothoracic center. MH was defined in patients (> 16 years) as those who received > 5 units of red blood cells (RBCs) in < 4 hours, or > 10 units in 24 hours. Data were collected retrospectively from patient electronic records and hospital transfusion databases recording issue of blood products from January 2016 to December 2018. Of 134 patients with MH, 24 had activated MHP and 110 did not have activated MHP. Groups were similar for age, sex, baseline hemoglobin, platelet count, coagulation screen, and renal function with no difference in the baseline clinical characteristics. The total number of red cell units (median and [IQR]) transfused was no different in the patients with activated (7.5 [5-11.75]) versus nonactivated (9 [6-12]) MHP (p = 0.35). Patients in the nonactivated MHP group received significantly higher number of platelet units (median: 3 vs. 2, p = 0.014), plasma (median: 4.5 vs. 1.5, p = 0.0007), and cryoprecipitate (median: 2 vs. 1, p = 0.008). However, activation of MHP was associated with higher mortality at 24 hours compared with patients with nonactivation of MHP (33.3 vs. 10.9%, p = 0.005) and 30 days (58.3 vs. 30.9%, p = 0.01). The total RBC and platelet (but not fresh frozen plasma [FFP]) units received were higher in deceased patients than in survivors. Increased mortality was associated with a higher RBC:FFP ratio. Only 26% of patients received tranexamic acid and these patients had higher mortality at 30 days but not at 24 hours. Deceased patients at 30 days had higher levels of fibrinogen than those who survived (median: 2.4 vs. 1.8, p = 0.01). Patients with activated MHP had significantly higher mortality at both 24 hours and 30 days despite lack of difference in the baseline characteristics of the patients with activated MHP versus nonactivated MHP groups. The increased mortality associated with a higher RBC:FFP ratio suggests dilutional coagulopathy may contribute to mortality, but higher fibrinogen at baseline was not protective.

The Utility of Diffusion-Weighted MRI Lesions to Compare the Effects of Different Heparinization Schemes in Intracranial Aneurysms Treated by Endovascular Intervention

Objective: Heparinization is applied to prevent ischemic complications in the endovascular treatment of intracranial aneurysms, but there is no unified heparinization scheme. Diffusion-weighted imaging (DWI) can be used to evaluate ischemia after endovascular therapy for intracranial aneurysms. The goal of this study is to apply DWI to evaluate the effects of different heparinization schemes on intracranial aneurysms treated with endovascular therapy.

Methods: We retrospectively reviewed 141 patients with 149 aneurysms treated with endovascular interventions from July 2019 to April 2020 at our center, including 96 aneurysms treated with local heparinization and 53 aneurysms treated with systemic heparinization. We collected the basic information of the patients, including age, sex, comorbidities, and aneurysm characteristics, and associated treatment data. New ischemic lesions detected by DWI were categorized belonging to four types. Multivariate logistic regression was used to compare the effects of different heparinization schemes on intracranial aneurysms treated with endovascular therapy.

Results: There were no significant differences in age, sex, hypertension, diabetes, and aneurysm size or location between the two groups. The incidence and distribution types of DWI abnormalities in the local heparinization groups and systemic heparinization groups were not significantly different (P > 0.05). There was a correlation between the laser engraving stent and postoperative DWI abnormalities (P < 0.003). Multivariate logistic regression analysis showed that the laser engraving stent was significantly correlated with postoperative DWI abnormalities (odds ratio, 4.71; 95% CI: 1.51–14.58; P = 0.007).

Conclusion: Compared with systemic heparinization, local heparinization does not increase the incidence of DWI abnormalities after endovascular treatment, and its application in this group of patients is safe and effective.

The safety and efficacy of low-dosage tirofiban for stent-assisted coiling of ruptured intracranial aneurysms

Stent-assisted coiling (SAC) of acutely ruptured aneurysms with antiplatelet therapy has been controversial. Tirofiban has been used for the treatment of thromboembolism of ruptured aneurysms with a stent. However, there are few comparative studies of a reasonable dosage for the prophylactic use of tirofiban. This study evaluated the safety and efficacy of reducing the dosage of tirofiban for the ruptured aneurysms with SAC. Patients with ruptured intracranial aneurysms in our institution from January 2014 to June 2018 were retrospectively reviewed. Three hundred and nine patients were treated using SAC within 72 h of onset. Patients were divided into either a standard group (211 patients, 10 μg/kg intravenous bolus within 3 min, maintained with 0.15 μg/kg/min) or a half-dose group (98 patients, 5 μg/kg intravenous bolus within 3 min, maintained with 0.075 μg/kg/min) according to the dose of tirofiban received intraoperatively. Medical records including clinical and radiological details were reviewed. No significant differences in demographic information or aneurysm characteristics existed between the two groups. Thromboembolic complications were found in 15 patients (4.9%), including 11 patients (5.2%) in the standard group and four patients (4.1%) in the half-dose group, without significant difference (P = 0.782). Intracranial hemorrhage was found in 13 patients (4.2%), and all occurred in the standard group, which was significantly different (6.2% vs 0%, P = 0.011). Of these 13 patients, four were left disabled and five died. Except for three patients who had intraoperative aneurysm rupture, the incidence of postoperative early rebleeding (10 patients) was significantly different between the two groups (4.7% vs 0%, P = 0.034). The rate of initial complete occlusion in the half-dose group was significantly higher than that in the standard group (55.1% vs 39.8%). The rate of a good outcome (modified Rankin Scale 0-2) was not significantly different between the standard group and half-dose group (78.7% vs 87.8%, P > 0.05). Intravenous tirofiban for SAC of acutely ruptured intracranial aneurysms is feasible and safe. The half-dose tirofiban treatment was associated with a decrease in the prevalence of intracranial hemorrhage but no increase in thromboembolic events compared with those in standard-dose tirofiban treatment.

Continuation of aspirin therapy before pars plana vitrectomy: Safe or not?

PURPOSE

To assess the safety of pars plana vitrectomy (PPV) in patients undergoing systemic treatment with aspirin.

METHODS

This prospective study enrolled consecutive patients undergoing PPV under percutaneous retrobulbar anesthesia between February 2016 and July 2018. Sixty-seven eyes from 67 patients on regular aspirin therapy were randomized into two groups: the continuation group (33 eyes), with aspirin continued during the perioperative period; and the discontinuation group (34 eyes), with aspirin discontinued for 3 to 7 days before surgery. Forty-three eyes from 43 patients who had no antiplatelet/anticoagulant therapy were used as a control group.

RESULTS

There was no significant difference in the incidence of hemorrhagic complications or the need for additional operations due to hemorrhagic complications among the three groups (p = 0.740 and p = 0.324, respectively). None of the patients in these three groups suffered from thromboembolic events during the follow-up period. Except for one case (3.0%) of lid ecchymosis in the continuation group, no eye experienced bleeding complications associated with the retrobulbar local anesthesia. In the continuation group, three eyes (9.1%) demonstrated postoperative hyphema that resolved spontaneously. In the discontinuation group, two eyes (5.9%) suffered from postoperative vitreous hemorrhage, of which one eye required secondary surgery and the other cleared spontaneously. One eye (2.9%) in the discontinuation group demonstrated postoperative hyphema that absorbed spontaneously. Three eyes (7.0%) in the control group experienced hyphema that absorbed spontaneously.

CONCLUSION

The outcomes of our study indicate that PPV under retrobulbar anesthesia can be safely performed without discontinuing systemic aspirin therapy.

Increased risk of Ventriculostomy-Associated hemorrhage in patients treated with antiplatelet agents for stent-assisted coiling of ruptured intracranial aneurysms

PURPOSE

The aim of this study is to evaluate the impact of antiplatelet agents for stent-assisted coiling, including intravenous (IV) tirofiban as an antiplatelet premedication, on rates of external ventricular drain (EVD)-related hemorrhage in acutely ruptured intracranial aneurysms. The impact of IV tirofiban in particular was also evaluated.

METHODS

Rates of radiographically identified hemorrhage associated with EVD placement were compared between patients who received an antiplatelet agent for stent-assisted coil embolization (SACE), and patients who did not receive an antiplatelet agent between June 2013 and June 2019.

RESULTS

78 patients treated for a ruptured aneurysm which required an EVD were included. A total of 46 patients who underwent stent-assisted coiling and received IV tirofiban and oral asipirin and clopidogrel (DAPT) were included in the antiplatelet group, while 32 who underwent single coiling and received no antiplatelet therapy were included in the control group. Overall, EVD-related hemorrhage occurred in 13 patients (16.67%): 11 (23.91%) in the antiplatelet group and 2 (6.25%) in the control group (p = 0.040). Of 37 patients who underwent computed tomography after SACE, but before the use of DAPT, 8 (21.62%) exhibited EVD-related hemorrhage after IV tirofiban therapy (p = 0.070 vs. control group). EVD-related hemorrhage was not significantly different between patients with EVD placement after coil embolization versus before coil embolization (p = 0.124). In the subgroup analysis for the antiplatelet group, we did not observed increased EVD-related hemorrhage in patients receiving EVD placement after administration of antiplatelet agents (8/27 [29.63%]) versus before administration of antiplatelet agents (3/19 [15.79%]).

CONCLUSION

Patients with ruptured aneurysm who receive an antiplatelet agent for stent-assisted coiling are at a higher risk for EVD-related hemorrhage. The order of EVD placement and EVT, as well as the order of EVD placement and antiplatelet initiation do not appear to be significantly different regarding the outcome of EVD-related hemorrhage.HighlightsPatients with ruptured aneurysm who receive an antiplatelet agent for stent-assisted coiling are at a higher risk for EVD-related hemorrhage.There was a trend towards higher EVD related haemorrhage when tirofiban was used but it did not reach statisitical significance.The order of EVD-whether before vs after endovascular treatment, or before vs after antiplatelet therapy did not influence the EVD-related hemorrhage rates.

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

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

Clinical Evaluation of the Tolerability, Pharmacokinetics, and Inhibition of Platelet Aggregation of Eptifibatide in Healthy Chinese Subjects

The present study aimed to evaluate the pharmacokinetic properties and antiplatelet aggregation activity of eptifibatide in healthy Chinese subjects. Eptifibatide (180 μg/kg) was administrated by 2 bolus injections 10 minutes apart, followed by a 2.0 μg/kg/min infusion for 24 hours. The eptifibatide pharmacokinetic and antiplatelet aggregation activities were evaluated using nonlinear mixed-effects modeling and noncompartmental analysis. Safety assessments included adverse events, hematology, and biochemistry tests. Twelve Chinese healthy subjects were enrolled and completed the study. Steady-state concentrations were achieved at 0.5 to 24 hours after dosing. The median time to maximum concentration was 13 minutes, and the mean terminal elimination half-life was 148.19 minutes. The effective inhibition of platelet aggregation (<20% platelet aggregation) occurred by 3 minutes after starting dosing to 4 hours after termination of the infusion. Eptifibatide concentrations were fitted with a 3-compartment model, and the typical value of clearance was 0.11 L/min, with no significant covariates found. Three mild adverse events were detected in the study. Eptifibatide displays high sensitivity and excellent tolerability in healthy Chinese subjects. The dosage of eptifibatide recommended on the label for whites can effectively inhibit platelet aggregation.

Preventive Effects of Different Drugs on Asymptomatic Lower Extremities Deep Venous Thrombosis After Artificial Joint Replacement: A Mixed Treatment Comparison

This network meta-analysis aims to compare the preventive effects of 8 drugs (edoxaban, dabigatran, apixaban, rivaroxaban, warfarin, bemiparin, ximelagatran, and enoxaparin) on asymptomatic deep venous thrombosis (DVT) of lower extremities after artificial joint replacement. PubMed, Cochrane Library, and Embase were searched from their inception through October 2015 for randomized controlled trials comparing 8 drugs for the prevention of asymptomatic DVT of lower extremities after artificial joint replacement. Network meta-analysis combined the direct and indirect evidence to evaluate odd ratios (ORs) and surface under the cumulative ranking curves values. A total of 15 randomized controlled trials satisfying the inclusion criteria were enrolled. Edoxaban, apixaban, and rivaroxaban had poorer preventive effects on asymptomatic DVT of lower extremities after undergoing artificial joint replacement when compared with warfarin [OR = 0.16, 95% confidence interval (CI), 0.04-0.60; OR = 0.22, 95% CI, 0.07-0.64; OR = 0.16, 95% CI, 0.05-0.49, respectively]. When compared with enoxaparin, the preventive effects of edoxaban and rivaroxaban were poorer (OR = 0.37, 95% CI, 0.15-0.85; OR = 0.37, 95% CI, 0.21-0.59, respectively). The preventive effects of edoxaban and rivaroxaban were poorer than dabigatran (OR = 0.38, 95% CI, 0.14-0.99; OR = 0.38, 95% CI, 0.18-0.73, respectively). The surface under the cumulative ranking curves values showed that warfarin had better preventive effects on asymptomatic DVT of lower extremities after undergoing artificial joint replacement. Among the 8 drugs (edoxaban, dabigatran, apixaban, rivaroxaban, warfarin, bemiparin, ximelagatran, and enoxaparin), warfarin had better preventive effects on asymptomatic DVT of lower extremities after undergoing artificial joint replacement.

Safety and efficacy of the Derivo Embolization Device for the treatment of ruptured intracranial aneurysms

Background

The Derivo Embolization Device (DED) is a novel flow diverter with advanced X-ray visibility, potentially lower thrombogenicity, and an improved delivery system.

Objective

To evaluate the safety and efficacy of the DED for emergency treatment of ruptured intracranial aneurysms.

Methods

Between February 2016 and March 2018, 10 patients (median age 54.5 years, seven women) with 11 aneurysms were treated with the DED at three neurovascular centers. Procedural details, complications, morbidity, and aneurysm occlusion (O’Kelly-Marotta scale, OKM) were retrospectively reviewed.

Results

Among 11 aneurysms treated, there were nine anterior circulation and two posterior circulation aneurysms. Aneurysm morphology was saccular in four cases, dissecting in three, blister-like in three, and fusiform in one. In each case, a single DED was implanted and deployment was technically successful without exception. Adjunctive coiling was performed in two aneurysms. We observed one in-stent thrombosis, presumably due to low response to clopidogrel 4 days after the procedure, which remained with a mild hemiparesis after aspiration thrombectomy. No further thromboembolic or hemorrhagic events occurred. Favorable outcome (modified Rankin scale score ≤2) at last follow-up was achieved in all patients. Among 10 aneurysms available for angiographic follow-up, complete aneurysm occlusion (OKM D) was obtained in nine cases (90.0%).

Conclusions

In this pilot study, endovascular treatment of ruptured intracranial aneurysms with the DED was feasible and not associated with any incidence of rebleeding. Larger series with longer follow-up are warranted to reach a definite conclusion about this device.

Aspirin therapy discontinuation and intraoperative blood loss in spinal surgery: a systematic review

The purpose of this study was to determine the effect of aspirin therapy discontinuation on intraoperative blood loss in spinal surgery. We searched Medline and Google Scholar 1946 to January 2017 inclusive for case-control studies, cohort studies, and controlled trials reporting intraoperative blood loss during spinal surgery in patients on pre-operative aspirin. Other outcome measures reported in the eligible studies were collected as secondary outcomes. Two reviewers independently screened and extracted data from each study. Five retrospective cohort and two case-control studies were eligible for inclusion. Of the 1173 patients identified, 587 patients were never on aspirin (Ax), 416 patients had aspirin discontinued before surgery (Ad), ranging from 3 to 10 days, and 170 patients had aspirin continued until surgery (Ac). Six out of seven studies reported no statistically significant difference in intraoperative blood loss irrespective of aspirin discontinuation. Meta-analysis was not possible due to high risk of bias. Of the secondary outcome measures, operative time and postoperative complications were most commonly reported. One of six studies evaluating operative time reported a significantly longer operative time in the Ad group compared with the Ac group. The overall risk of postoperative haematoma in Ax, Ad, and Ac groups is 0.2% (n/N = 1/587), 0.2% (n/N = 1/416), and 1.2% (n/N = 2/170), respectively. No study reported a statistically significant difference in postoperative complications. There is no strong evidence demonstrating a difference in intraoperative blood loss, operation time, and postoperative complications, irrespective of aspirin discontinuation. This is, however, based on a limited number of studies and higher-quality research is required to answer this question with a higher degree of confidence.

Perioperative management of patient with intracoronary stent presenting for noncardiac surgery

As the number of percutaneous coronary interventions increase annually, patients with intracoronary stents (ICS) who present for noncardiac surgery (NCS) are also on the rise. ICS is associated with stent thrombosis (STH) and requires mandatory antiplatelet therapy to prevent major adverse cardiac events. The risks of bleeding and ischemia remain significant and the management of these patients, especially in the initial year of ICS is challenging. The American College of Cardiologists guidelines on the management of patients with ICS recommend dual antiplatelet therapy (DAT) for minimal 14 days after balloon angioplasty, 30 days for bare metal stents, and 365 days for drug-eluting stents. Postponement of elective surgery is advocated during this period, but guidelines concerning emergency NCS are ambiguous. The risk of STH and surgical bleeding needs to be assessed carefully and many factors which are implicated in STH, apart from the type of stent and the duration of DAT, need to be considered when decision to discontinue DAT is made. DAT management should be a multidisciplinary exercise and bridging therapy with shorter acting intravenous antiplatelet drugs should be contemplated whenever possible. Well conducted clinical trials are needed to establish guidelines as regards to the appropriate tests for platelet function monitoring in patients undergoing NCS while on DAT.

Chronic Antiplatelet Use Associated With Increased Blood Loss in Lumbar Spinal Surgery Despite Adherence to Protocols

There are conflicting reports regarding postoperative bleeding risks associated with discontinuation of antiplatelet therapy at least 7 days preoperatively. Most of the studies in the spine literature are based on surveys or anecdotal evidence. The majority of surgeons discontinue therapy 7 days preoperatively, but this varies widely from 5 to 21 days. The purpose of this retrospective study was to assess whether chronic antiplatelet use is associated with increased intraoperative blood loss, need for transfusion, and perioperative complications. Of 454 patients who underwent elective lumbar spinal surgery, 85 were on antiplatelet therapy and 369 were not. All patients stopped antiplatelet therapy at least 7 days preoperatively with approval from their cardiologist or primary care provider. Multiple regression analysis was performed and corrected for age, sex, antiplatelet therapy, number of levels decompressed/fused/instrumented, preoperative hematocrit, and postoperative hematocrit. Results showed that preoperative antiplatelet therapy, despite at least 7 days of discontinuation, is a statistically significant predictor (P=.04) of increased intraoperative blood loss. Blood transfusion was not associated with antiplatelet use but was associated with the number of levels fused, age, and low preoperative hematocrit (all P<.01). There were no recorded complications in either group. The authors conclude that antiplatelet therapy is associated with an increased risk of intraoperative blood loss in spine patients despite discontinuation at least 7 days preoperatively, but the clinical significance of this is unclear given the lack of association with blood transfusions and perioperative complications. [Orthopedics. 2016; 39(4):e695-e700.].

Dental extraction without stopping single or dual antiplatelet therapy: results of a retrospective cohort study

The aim of this study was to investigate the incidence of bleeding after dental extraction without stopping antiplatelet therapy. Postoperative bleeding was assessed in a total of 1271 patients who were divided into two groups: a study group comprising 183 patients on antiplatelet therapy (aspirin 125 patients/185 occasions; clopidogrel 42 patients/65 occasions; dual therapy 16 patients/24 occasions) who underwent 548 dental extractions on 274 occasions, and a control group comprising 1088 patients who were not receiving any antiplatelet or anticoagulant therapy and underwent 2487 dental extractions on 1472 occasions. The incidence of postoperative bleeding was higher in the study group (5/274, 1.8%) than in the control group (10/1472, 0.7%), and also in the dual antiplatelet subgroup (1/24, 4.2%) than in the single antiplatelet subgroups (clopidogrel: 2/65, 3.1%; aspirin: 2/185, 1.1%); however, these differences were not significant. Postoperative bleeding was managed successfully by repacking with Gelfoam impregnated with tranexamic acid powder in 12 patients and by resuturing in three of the control patients undergoing extraction of impacted teeth with flap elevation. These findings indicate that there is no need to interrupt antiplatelet drugs before dental extraction.

Aspirin in the perioperative period: a review of the recent literature

PURPOSE OF REVIEW

The indications for aspirin (ASA) for both primary and secondary prevention of thrombotic events continue to evolve. We review some of these indications and the recent literature regarding the perioperative administration of ASA.

RECENT FINDINGS

ASA for primary prevention of cardiac ischemia, stroke, cancer, and death remains controversial. When used for primary prevention, ASA may be safely discontinued perioperatively. Patients with coronary or carotid artery stents should continue to receive ASA perioperatively. For patients with ischemic heart disease currently receiving ASA for secondary prevention of cardiac ischemia and stroke undergoing general surgery, orthopedic surgery, ophthalmological surgery, cardiovascular surgery, major vascular surgery, or a urological procedure, continuation of ASA is probably well tolerated, but further study is required. There is no indication to initiate ASA perioperatively in patients with stable ischemic heart disease as the risks outweigh the benefits. Until further data become available, decisions regarding the perioperative continuation of ASA should be made on a case-by-case risk-benefit analysis.

SUMMARY

The continuation or discontinuation of ASA perioperatively remains a complicated issue. Further, well designed trials are needed for additional clarification.

Safety and efficacy of a new prophylactic tirofiban protocol without oral intraoperative antiplatelet therapy for endovascular treatment of ruptured intracranial aneurysms

BACKGROUND

Coil embolization of intracranial aneurysms is being increasingly used; however, thromboembolic events have become a major periprocedural complication.

OBJECTIVE

To determine the safety and efficacy of prophylactic tirofiban in patients with ruptured intracranial aneurysms.

METHODS

Tirofiban was administered as an intravenous bolus (8.0 μg/kg over 3 min) followed by a maintenance infusion (0.10 μg/kg/min) before stent deployment or after completion of single coiling. Dual oral antiplatelet therapy (loading doses) was overlapped with half the tirofiban dose 2 h before cessation of the tirofiban infusion. Cases of intracranial hemorrhage or thromboembolism were recorded.

RESULTS

Tirofiban was prophylactically used in 221 patients, including 175 (79.19%) who underwent stent-assisted coiling and 46 (20.81%) who underwent single coiling, all in the setting of aneurysmal subarachnoid hemorrhage. Six (2.71%) cases of intracranial hemorrhage occurred, including four (1.81%) tirofiban-related cases and two (0.90%) antiplatelet therapy-related cases. There were two (0.90%) cases of fatal hemorrhage, one related to tirofiban and the other related to dual antiplatelet therapy. Thromboembolic events occurred in seven (3.17%) patients (6 stent-assisted embolization, 1 single coiling), of which one (0.45%) event occurred during stenting and six (2.72%) occurred during intravenous tirofiban maintenance. No thromboembolic events related to dual antiplatelet therapy were found.

CONCLUSIONS

Tirofiban bolus over 3 min followed by maintenance infusion appears to be a safe and efficient prophylactic protocol for the endovascular treatment of ruptured intracranial aneurysms and may be an alternative to intraoperative oral antiplatelet therapy, especially in the case of stent-assisted embolization.

A New Protocol for Anticoagulation With Tirofiban During Flow Diversion

BACKGROUND:

Flow diversion is increasingly used to treat intracranial aneurysms. In previous reports, patients were pretreated with aspirin and clopidogrel before the intervention for the prevention of thromboembolic complications.

OBJECTIVE:

To assess the safety and efficacy of a new protocol for anticoagulation using tirofiban during flow diversion.

METHODS:

All patients received a 0.10–μg.kg−1.min−1 maintenance infusion of tirofiban intraoperatively without a loading dose. All patients were loaded with aspirin (325 mg) and clopidogrel (600 mg) just before the procedure or intraoperatively. No patient was pretreated with aspirin or clopidogrel. Thromboembolic and hemorrhagic complications were recorded.

RESULTS:

A total of 46 patients were treated with this protocol. Six patients (13%) had sustained a subarachnoid hemorrhage and were treated with the Pipeline Embolization Device within 24 hours of aneurysm rupture. The mean number of devices was 1.2 ± 0.66; adjunctive coiling was performed in 3 patients (6.5%). There were 2 complications (4.3%), 1 thromboembolic (2.2%) and 1 hemorrhagic (2.2%; monocular vision loss from occlusion of the central retinal artery in 1 patient and a parenchymal hemorrhage managed conservatively in another patient). No patient developed thrombocytopenia or retroperitoneal, gastrointestinal, or genitourinary bleeding. Of 46 patients, 44 (95.7%) had a modified Rankin Scale score of 0 to 2 at their follow-up visit.

CONCLUSION:

A protocol of anticoagulation with tirofiban during flow diversion has an excellent safety profile. This protocol provides a reasonable alternative to pretreatment with aspirin and clopidogrel and is useful in patients with ruptured aneurysms or when the use of a stent is unexpected.

Hematologic issues in the geriatric surgical patient

Geriatric patients are at higher risk for hemorrhagic complications after surgery and traumatic injuries. The geriatric population is more likely to take anticoagulant or antiplatelet medications. Chronic disease, autoimmune disease, and nutritional deficiencies can lead to coagulation factor and platelet disorders. One must be familiar with the current anticoagulant and antiplatelet medications, their mechanism of action, and reversal agents to properly care for this group of patients. The new oral anticoagulants do not have Food and Drug Administration (FDA) approved reversal agents, but known procoagulant agents with other FDA indications may be effective.

Management of anticoagulation agents in trauma patients

A lack of consensus on anticoagulant reversal during acute trauma is compounded by an aging population and the expanding spectrum of new anticoagulation agents. Developments in laboratory assays and transfusion medicine, including thromboelastography, recombinant factors, and factor concentrates, have revolutionized care for anticoagulated trauma patients. Accordingly, clinicians must be fully aware of drug mechanisms, assays to determine drug activity, and appropriate reversal strategies for patients on anticoagulants. Drugs include vitamin K antagonists, direct thrombin inhibitors, direct factor Xa inhibitors, low molecular weight heparin, and antiplatelet agents. This article discusses the appropriate assessment and management of trauma patients receiving these agents.

Bleeding diatheses and preoperative screening

Bleeding disorders pose a significant perioperative risk. Surgeons and surgical consultants should have a working knowledge of the cell-based coagulation model. Careful screening for bleeding diatheses begins with a careful history and physical examination. It is paramount to ascertain what medications and nonprescribed supplements and herbal preparations a patient is taking, as these medications can have significant effects on perioperative bleeding tendencies. Finally, screening laboratory-based coagulation assays are available. These must be used judiciously with regard to a patient's history and the clinical circumstances surrounding the surgical stressor.

Safety and efficacy of tirofiban in stent-assisted coil embolization of intracranial aneurysms

BACKGROUND

Thromboembolic complications are a major concern in stent-assisted coiling of intracranial aneurysms that may be prevented with adequate antiplatelet therapy.

OBJECTIVE

To assess the safety and efficacy of tirofiban in stent-assisted coiling.

METHODS

Two protocols were used. In the initial protocol, tirofiban was administered intravenously as a 0.4 μg/kg per min bolus for 30 minutes followed by 0.10 μg·kg min maintenance infusion. The revised protocol consisted of a 0.10 μg·kg min maintenance infusion alone.

RESULTS

Sixty-seven patients received tirofiban, 16 under the initial protocol and 51 under the revised protocol. Thirty (44.8%) patients had sustained a subarachnoid hemorrhage (SAH). Tirofiban infusion was initiated after thromboembolic events in 9 (13.4%) patients and prophylactically in 58 (86.6%). Four (6.0%) intracranial hemorrhages were noted. Three (18.8%) intracranial hemorrhages occurred with the initial protocol in patients treated electively and were fatal in 2 (66.7%) cases. The only complication (1.9%) under the revised protocol was a subclinical worsening of the computed tomographic appearance of an SAH. There was no tirofiban-related morbidity or deaths with the revised protocol. Of 9 patients that received tirofiban as a rescue treatment, 7 (77.8%) had complete and 2 (22.2%) had partial arterial recanalization. No thromboembolic events occurred in patients receiving prophylactic tirofiban.

CONCLUSION

A bolus followed by a maintenance dose of tirofiban appears to have a high risk of cerebral hemorrhage. A maintenance infusion without an initial bolus, however, has an exceedingly low risk of hemorrhage and appears to be very safe and effective, even in the setting of SAH.

Antiplatelet drugs: mechanisms and risks of bleeding following cardiac operations

Preoperative antiplatelet drug use is common in patients undergoing coronary artery bypass grafting (CABG). The impact of these drugs on bleeding and blood transfusion varies. We hypothesize that review of available evidence regarding drug-related bleeding risk, underlying mechanisms of platelet dysfunction, and variations in patient response to antiplatelet drugs will aid surgeons as they assess preoperative risk and attempt to limit perioperative bleeding. The purpose of this review is to (1) examine the role that antiplatelet drugs play in excessive postoperative blood transfusion, (2) identify possible mechanisms to explain patient response to antiplatelet drugs, and (3) formulate a strategy to limit excessive blood product usage in these patients. We reviewed available published evidence regarding bleeding risk in patients taking preoperative antiplatelet drugs. In addition, we summarized our previous research into mechanisms of antiplatelet drug-related platelet dysfunction. Aspirin users have a slight but significant increase in blood product usage after CABG (0.5 U of nonautologous blood per treated patient). Platelet adenosine diphosphate (ADP) receptor inhibitors are more potent antiplatelet drugs than aspirin but have a half-life similar to aspirin, around 5 to 10 days. The American Heart Association/American College of Cardiology and the Society of Thoracic Surgeons guidelines recommend discontinuation, if possible, of ADP inhibitors 5 to 7 days before operation because of excessive bleeding risk, whereas aspirin should be continued during the entire perioperative period in most patients. Individual variability in response to aspirin and other antiplatelet drugs is common with both hyper- and hyporesponsiveness seen in 5 to 25% of patients. Use of preoperative antiplatelet drugs is a risk factor for increased perioperative bleeding and blood transfusion. Point-of-care tests can identify patients at high risk for perioperative bleeding and blood transfusion, although these tests have limitations. Available evidence suggests that multiple blood conservation techniques benefit high-risk patients taking antiplatelet drugs before operation. Guidelines for patients who take aspirin and/or thienopyridines before cardiac procedures include some or all of the following: (1) preoperative identification of high-risk patients using point-of-care testing; (2) withdrawal of aspirin or other antiplatelet drugs for a few days and delay of operation in patients at high risk for bleeding if clinical circumstances permit; (3) selective perioperative use of evidence-based blood conservation interventions (e.g., short-course erythropoietin, off-pump procedures, and use of intraoperative blood conservation techniques), especially in high-risk patients; and (4) platelet transfusions if clinical bleeding occurs.

Perioperative antiplatelet management in patients with coronary artery stenting

Coronary artery disease is the primary cause of mortality in men and women in the United States. Transcatheter coronary intervention is the mainstay of treatment for patients with acute coronary artery disease presentations and patients with stable disease. Although percutaneous intervention initially only included balloon angioplasty, it now typically involves the placement of intracoronary stents. To overcome the limitations of bare-metal stents, namely in-stent restenosis, stents have been developed that remove pharmaceuticals that reduce neointimal hyperplasia and in-stent restenosis. However, these pharmaceutical agents also delay stent endothelialization, posing a prolonged risk of in situ thrombosis. Placement of an intracoronary stent (eg, bare-metal or drug-eluting stent) requires dual antiplatelet therapy to prevent the potentially life-threatening complication of stent thrombosis. The optimal duration of dual antiplatelet therapy following stent placement is unknown. This article discusses the factors to be considered when deciding when dual antiplatelet therapy can be safely discontinued. Unfortunately, in the hospital setting, this decision to interrupt dual antiplatelet therapy frequently must be made shortly after stent placement because of unanticipated surgical procedures or other unforeseen complications. The decision of when dual antiplatelet therapy can be safely interrupted needs to be individualized for each patient and involves factoring in the type of stent; the location and complexity of the lesion stented; post-stent lesion characteristics; the amount of time since stent placement; and the antiplatelet regimen currently in use, along with its implication for bleeding during the proposed procedure. Having a protocol in place, such as the protocol described in this article, can help guide this decision-making process and avoid confusion and potential error.

Perioperative management of antithrombotic therapy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

This guideline addresses the management of patients who are receiving anticoagulant or antiplatelet therapy and require an elective surgery or procedure.

METHODS

The methods herein follow those discussed in the Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines. Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines article of this supplement.

RESULTS

In patients requiring vitamin K antagonist (VKA) interruption before surgery, we recommend stopping VKAs 5 days before surgery instead of a shorter time before surgery (Grade 1B). In patients with a mechanical heart valve, atrial fibrillation, or VTE at high risk for thromboembolism, we suggest bridging anticoagulation instead of no bridging during VKA interruption (Grade 2C); in patients at low risk, we suggest no bridging instead of bridging (Grade 2C). In patients who require a dental procedure, we suggest continuing VKAs with an oral prohemostatic agent or stopping VKAs 2 to 3 days before the procedure instead of alternative strategies (Grade 2C). In moderate- to high-risk patients who are receiving acetylsalicylic acid (ASA) and require noncardiac surgery, we suggest continuing ASA around the time of surgery instead of stopping ASA 7 to 10 days before surgery (Grade 2C). In patients with a coronary stent who require surgery, we recommend deferring surgery > 6 weeks after bare-metal stent placement and > 6 months after drug-eluting stent placement instead of undertaking surgery within these time periods (Grade 1C); in patients requiring surgery within 6 weeks of bare-metal stent placement or within 6 months of drug-eluting stent placement, we suggest continuing antiplatelet therapy perioperatively instead of stopping therapy 7 to 10 days before surgery (Grade 2C).

CONCLUSIONS

Perioperative antithrombotic management is based on risk assessment for thromboembolism and bleeding, and recommended approaches aim to simplify patient management and minimize adverse clinical outcomes.

Intraarterial tirofiban thrombolysis for thromboembolisms during coil embolization for ruptured intracranial aneurysms

OBJECTIVE

Thromboembolus can occur during endovascular coil embolization. The aim of our study was to show our experience of intraarterial (IA) tirofiban infusion for thromboembolism during coil embolization for ruptured intracranial aneurysms.

METHODS

This retrospective analysis was conducted in 64 patients with ruptured aneurysms who had emergent endovascular coil embolization from May 2007 to April 2011 at a single institute. Thromboembolic events were found in ten patients (15.6%). Anticoagulation treatment with intravenous heparin was started after the first coil deployment in ruptured aneurysmal sac. When a thrombus or embolus was found during the procedure, we tried to resolve them without delay with an initial dosage of 0.3 mg of tirofiban up to 1.2 mg.

RESULTS

Three patients of four with total occlusion had recanalizations of thrombolysis in myocardial infarction (TIMI) grade III and five of six with partial occlusion had TIMI grade III recanalizations. Eight patients showed good recovery, with modified Rankin Scale (mRS) score of 0 and one showed poor outcome (mRS 3 and 6). There was no hemorrhagic or hematologic complication.

CONCLUSION

IA tirofiban can be feasible when thromboembolic clots are found during coil embolization in order to get prompt recanalization, even in patients with subarachnoid hemorrhage.

Short-acting P2Y12 blockade to reduce platelet dysfunction and coagulopathy during experimental extracorporeal circulation and hypothermia

BACKGROUND

Extracorporeal circulation (ECC) and hypothermia are routinely used in cardiac surgery to maintain stable circulatory parameters and to increase the ischaemic tolerance of the patient. However, ECC and hypothermia cause platelet activation and dysfunction possibly followed by a devastating coagulopathy. Stimulation of the adenosinediphosphate (ADP) receptor P(2)Y(12) plays a pivotal role in platelet activation. This experimental study tested P(2)Y(12) receptor blockade as an approach to protect platelets during ECC.

METHODS

Human blood was treated with the short-acting P(2)Y(12) blocker cangrelor (1 µM, t(1/2)<5 min) or the P(2)Y(12) inhibitor 2-MeSAMP (100 µM) and circulated in an ex vivo ECC model at normothermia (37°C) and hypothermia (28°C). Before and after circulation, markers of platelet activation and of coagulation (thrombin-antithrombin complex generation) were analysed. During hypothermic ECC in pigs, the effect of reversible P(2)Y(12) blockade on platelet function was evaluated by cangrelor infusion (0.075 µg kg(-1) min(-1)).

RESULTS

During ex vivo hypothermic ECC, P(2)Y(12) blockade inhibited platelet granule release (P<0.01), platelet-granulocyte binding (P<0.05), and platelet loss (P<0.001), whereas no effects on platelet-ECC binding, platelet CD42bα expression, glycoprotein IIb/IIIa activation, or thrombin-antithrombin complex generation were observed. During hypothermic ECC in pigs, cangrelor inhibited platelet-fibrinogen binding (P<0.05) and ADP-induced platelet aggregation (P<0.001). Platelet function was rapidly restored after termination of cangrelor infusion.

CONCLUSIONS

P(2)Y(12) blockade by cangrelor prevents platelet activation during ECC and hypothermia. Owing to its short half-life, platelet inhibition can be well controlled, thus potentially reducing bleeding complications. This novel pharmacological strategy has the potential to reduce complications associated with ECC and hypothermia.