Antithrombotic Group Research Articles

Impact of pre-admission antithrombotic therapy on disease severity and mortality in patients hospitalized for COVID-19.

Anticoagulant therapy is a cornerstone treatment for coronavirus disease 2019 (COVID-19) due to the high rates of thromboembolic complications associated with this disease. We hypothesized that chronic antithrombotic therapy could play a protective role in patients hospitalized for COVID-19. Retrospective, observational study of all patients admitted to our hospital for ≥ 24 h from March 1 to May 31, 2020 with SARS-CoV-2. The objective was to evaluate clinical outcomes and mortality in COVID-19 patients receiving chronic anticoagulation (AC) or antiplatelet therapy (AP) prior to hospital admission. A total of 1612 patients were evaluated. The mean (standard deviation; SD) age was 66.5 (17.1) years. Patients were divided into three groups according to the use of antithrombotic therapy prior to admission (AP, AC, or no-antithrombotic treatment). At admission, 9.6% of the patients were taking anticoagulants and 19.1% antiplatelet therapy. The overall mortality rate was 19.3%. On the multivariate analysis there were no significant differences in mortality between the antithrombotic groups (AC or AP) and the no-antithrombotic group (control group). Patients on AC had lower ICU admission rates than the control group (OR: 0.41, 95% CI, 0.18–0.93). Anticoagulation therapy prior to hospitalization for COVID-19 was associated with lower ICU admission rates. However, there were no significant differences in mortality between the patients receiving chronic antithrombotic therapy and patients not taking antithrombotic medications. These findings suggest that chronic anticoagulation therapy at the time of COVID-19 infection may reduce disease severity and thus the need for ICU admission.

Antithrombotic drugs have a minimal effect on intraoperative blood loss during emergency surgery for generalized peritonitis: a nationwide retrospective cohort study in Japan

BackgroundThe effect of antithrombotic drugs on intraoperative operative blood loss volume in patients undergoing emergency surgery for generalized peritonitis is not well defined. The purpose of this study was to investigate the effect of antithrombotic drugs on intraoperative blood loss in patients with generalized peritonitis using a nationwide surgical registry in Japan.MethodThis retrospective cohort study used a nationwide surgical registry data from 2011 to 2017 in Japan. Propensity score matching for the use of antithrombotic drugs was used for the adjustment of age, gender, comorbidities, frailty, preoperative state, types of surgery, surgical approach, laboratory data, and others. The main outcome was intraoperative blood loss: comparison of intraoperative blood loss, ratio of intraoperative blood loss after adjusted for confounding factors, and variable importance of all covariates.ResultsA total of 70,105 of the eligible 75,666 patients were included in this study, and 2947 patients were taking antithrombotic drugs. Propensity score matching yielded 2864 well-balanced pairs. The blood loss volume was slightly higher in the antithrombotic drug group (100 [10–349] vs 70 [10–299] ml). After adjustment for confounding factors, the use of antithrombotic drugs was related to a 1.30-fold increase in intraoperative blood loss compared to non-use of antithrombotic drugs (95% CI, 1.16–1.45). The variable importance revealed that the effect of the use of antithrombotic drugs was minimal compared with surgical approach or type of surgery.ConclusionThis study shows that while taking antithrombotic drugs is associated with a slight increase in intraoperative blood loss in patients undergoing emergency surgery for generalized peritonitis, the effect is likely of minimal clinical significance.

Preceding direct oral anticoagulant administration reduces the severity of stroke in patients with atrial fibrillation – K-PLUS registry

BackgroundStroke severity can be mitigated by preceding anticoagulant administration in acute ischemic stroke patients with atrial fibrillation (AF). We investigated if such mitigative effects are different between warfarin and direct oral anticoagulants (DOACs). Material and methodsWe collected data from a regional multicenter stroke registry. Ischemic stroke or transient ischemic attack patients with AF were included. Background characteristics, National Institutes of Health Stroke Scale (NIHSS) score on admission, lesion characteristics, and in-hospital death were analyzed according to preceding antithrombotic agents at onset. ResultsA total of 2173 patients had AF; 628 were prescribed warfarin, 272 DOACs, 429 antiplatelets alone, and 844 no antithrombotics. The NIHSS score on admission was lowest in the DOACs group compared to the other groups. In neuroimaging analysis, small ischemic lesions were observed more frequently in the DOACs group, while large ischemic lesions were less frequent in this group. When the no antithrombotics group was used as a reference, the adjusted odds ratio for moderate to severe stroke was 0.56 (95% confidence interval, 0.40–0.78) in the DOACs group, while it was 0.98 (0.77–1.24) in the warfarin group and 0.94 (0.72–1.22) in the antiplatelets group. In-hospital mortality was lowest in the DOACs group compared to the other groups. ConclusionPreceding DOAC administration might mitigate the severity of stroke in AF patients more strongly than other antithrombotics, possibly leading to a better outcome in patients with stroke.

Radiofrequency Ablation of Liver Tumors in Patients on Antithrombotic Therapy: A Case-Control Analysis of over 10,000 Treatments

PurposeTo evaluate the safety of radiofrequency ablation (RFA) for liver tumors in patients on antithrombotic therapy. Materials and MethodsA total of 10,653 consecutive RFA treatments in 3,485 patients with liver tumors were analyzed. The incidence of complications was analyzed on a treatment basis. The treatments for patients who had received antithrombotic medication up to 1 week prior to RFA comprised the antithrombotic therapy group (n = 806), and the others comprised the control group (n = 9,847). Antithrombotic agents were ceased prior to RFA (aspirin, ticlopidine, clopidogrel, and prasugrel ceased 7 days before RFA; cilostazol, 2 or 3 days before RFA; warfarin, 3 days before RFA; and direct oral anticoagulants, 1 day before RFA) and resumed as soon as possible after RFA. Logistic regression analysis was performed to assess whether the antithrombotic therapy increased the risk of hemorrhagic complications. ResultsHemorrhagic complications were diagnosed after 6 treatments (0.7%) in the antithrombotic group and 48 (0.5%) in the control group, and there was no significant difference between the groups (P = .30). In 3 treatments, hemorrhage was diagnosed on or after 8 days of RFA, all of which were in the antithrombotic group. Thrombotic complications were diagnosed after 2 treatments (0.2%) in the antithrombotic group and after 5 (0.1%) in the control group. In a multivariate analysis, receiving antithrombotic therapy was not an independent risk factor for hemorrhagic complications (adjusted odds ratio, 1.52; 95% confidence interval, 0.60–3.87; P = .38). ConclusionsRFA of liver tumors in patients on antithrombotic therapy is generally safe with appropriate cessation and resumption. Late-onset hemorrhage should be noted in the patients on antithrombotic therapy.

Outcomes of Endoscopic Ultrasound-Guided Biliary Drainage in Patients Undergoing Antithrombotic Therapy

Background/AimsThe Japan Gastroenterological Endoscopy Society (JGES) has published guidelines for gastroenterological endoscopy in patients undergoing antithrombotic treatment. These guidelines classify endoscopic ultrasound-guided biliary drainage (EUS-BD) as a high-risk procedure. Nevertheless, the bleeding risk of EUS-BD in patients undergoing antithrombotic therapy is uncertain. Therefore, this study aimed to assess the bleeding risk in patients undergoing antithrombotic therapy. MethodsThis single-center retrospective study included 220 consecutive patients who underwent EUS-BD between January 2013 and December 2018. We managed the withdrawal and continuation of antithrombotic agents according to the JGES guidelines. We compared the bleeding event rates among patients who received and those who did not receive antithrombotic agents. ResultsA total of 18 patients (8.1%) received antithrombotic agents and 202 patients (91.8%) did not. Three patients experienced bleeding events, with an overall bleeding event rate of 1.3% (3/220): one patient was in the antithrombotic group (5.5%) and two patients were in the non-antithrombotic group (0.9%) (p=0.10). All cases were moderate. The sole thromboembolic event (0.4%) was a cerebral infarction in a patient in the non-antithrombotic group. ConclusionsThe rate of EUS-BD-related bleeding events was low. Even in patients receiving antithrombotic therapy, the bleeding event rates were not significantly different from those in patients not receiving antithrombotic therapy.

Small diameter polycaprolactone vascular grafts are patent in sheep carotid bypass but require antithrombotic therapy.

Background: Polycaprolactone (PCL) scaffolds exhibit high biocompatibility and are attractive as vascular conduits. Materials & methods: PCL tubes were cultivated in bioreactor with human adipose regenerative cellsto assess ex vivo cytocompatibility, whereas in vivo PCL tube patency was evaluated in sheep carotid bypass with and without antithrombotic treatment. Results:Ex vivo results revealed increasing adipose regenerative cells on PCL using dynamic bioreactor culturing. In vivo data showed that 67% (2/3) of grafts in the antithrombotic group were patent at day 28, while 100% (3/3) of control grafts were occluded already during the first week due to thrombosis. Histology showed that patent PCL grafts were recellularized by host cells. Conclusion: PCL tubes may work as small diameter vascular scaffolds under antithrombotic treatment.

Antithrombotic therapy has no beneficial effect in conservative treatment of spontaneous isolated superior mesenteric arterial dissection.

PurposeInitial conservative treatment with selective endovascular or surgical intervention has shown successful outcomes in the treatment of spontaneous isolated superior mesenteric artery dissection (SISMAD). However, the benefits of antithrombotic therapy as a part of conservative treatment have not been clarified. This study aimed to investigate the clinical course of SISMAD patients and determine differences in clinical outcomes between the antithrombotic and no-antithrombotic groups.MethodsWe retrospectively reviewed 79 cases of SISMAD that were treated conservatively from January 2004 to December 2019 at Chonnam National University Hospital. Clinical outcomes, including the length of hospital stay, pain resolution time, image remodeling, and maximal remodeling time, were compared between the antithrombotic and no-antithrombotic groups.ResultsThere were 30 patients in the no-antithrombotic group and 49 patients in the antithrombotic group. There was no significant difference in clinical characteristics between the 2 groups, except for dyslipidemia (P = 0.011). The follow-up period (32.6 months vs. 14.6 months, P = 0.009) and imaging follow-up period (31.6 months vs. 13.9 months, P = 0.011) were longer in the antithrombotic group than in the no-antithrombotic group. The length of hospital stay (5.1 days vs. 7.7 days, P = 0.002) was significantly shorter in the no-antithrombotic group than in the antithrombotic group because patients in the antithrombotic group required longer hospitalization for warfarin titration.ConclusionIn patients with SISMAD, conservative treatment without antithrombotic therapy may have clinical benefits such as decreased length of hospital stay compared with conservative treatment with antithrombotic therapy.

Abstract 13675: Impact of Antithrombotic Therapy on Clinical Outcomes in Patients With Type B Acute Aortic Syndrome

Introduction: In type B acute aortic syndrome (B-AAS), degree of false lumen thrombosis is known to affect clinical outcome. Antithrombotic therapy might have impact on prognosis through affecting false lumen thrombosis.We aimed to assess the impact of antithrombotic therapy on clinical outcomes in patients with B-AAS. Methods: A total of 429 patients with acute B-AAS admitted to our hospital and discharged alive were retrospectively analyzed. The primary outcome was aorta-related adverse events, defined as a composite of aorta-related death, aortic rupture, surgical or endovascular aortic repair and progressive aortic dilation. Results: Of the 429 patients, 72 patients (17 %) were discharged with antithrombotic therapy and 357 (83 %) without antithrombotic therapy. 254 patients (59 %) presented with intramural hematoma with complete thrombosis of false lumen, and 175 (41 %) presented with classic aortic dissection. Reasons for prescription were coronary artery disease (n=25), cerebral ischemia (n=17) and others (n=30). In the antithrombotic group, patients were significantly older than no-antithrombotic group (73 ± 13 vs 67 ± 13 years, P= 0.001) and had more comorbidities such as dyslipidemia (40 % vs 26 %, P= 0.011), diabetes mellitus (22 % vs 11 %, P= 0.007) and coronary artery disease (36 % vs 5 %, P< 0.001). During a mean follow-up of 4.8 ± 5.2 years, 37 patients (51 %) in the antithrombotic group and 98 patients (27 %) in the no-antithrombotic group had a primary outcome event. Event-free survival rate among antithrombotic versus no-antithrombotic group was 36 % vs 73 % at 5 years (P< 0.001). Multivariate Cox regression analysis adjusted for age, sex, comorbidity and medication revealed that antithrombotic therapy was a significant risk factor for aorta-related adverse events (hazard ratio 2.08, 95% confidence interval 1.247-3.463; P= 0.005). Conclusion: In B-AAS, antithrombotic therapy was associated with an increased risk of aorta-related events. For patients with indispensable need of antithrombotic therapy, careful follow-up should be provided.

Safety of Inguinal Hernia Repair in the Elderly with Perioperative Continuation of Antithrombotic Therapy

Introduction: This study aimed to evaluate the safety of an inguinal hernia repair (IHR) under local anesthesia (LA) in the elderly with a perioperative continuation of antithrombotic therapy (AT). Methods: A total of 120 patients undergoing elective primary IHR between August 2018 and August 2019 at the West China Hospital of China were prospectively studied, among which 60 patients also had coexisting cardiovascular diseases and had a continuation of AT perioperatively (antithrombotic group); the other 60 patients were not on any prior AT (control group). The primary endpoints were intra- and postoperative hemorrhagic complications, the required interventions for complications based on the Clavien-Dindo classification, and postoperative thromboembolic complications. The secondary endpoints were nonhemorrhagic complications, intraoperative duration, and postoperative length of stay (LOS). Results: None of the patients in both groups had significant intraoperative bleeding >10 mL, and there were no significant differences between the 2 groups in terms of the postoperative hemorrhagic complications: bruising (2 vs. 0%, p = 1.000), serosanguinous soakage (7 vs. 3%, p = 0.679), and no hematoma was observed. Interventions required for encountered complications based on the Clavien-Dindo classification grade I (7 vs. 5%, p = 1.000) were assessed. There were no episodes of postoperative thromboembolic complications within 60 days in both groups. There were also no significant differences between the 2 groups in terms of nonhemorrhagic complications, intraoperative duration, and postoperative LOS (p > 0.05 in all). Conclusions: The perioperative continuation of AT did not increase the risk of intra- and postoperative hemorrhagic complications following IHR in the elderly. Thus, IHR under LA seems to be safe and feasible in this setting.

Antithrombotic Strategies in Patients with Atrial Fibrillation Following Percutaneous Coronary Intervention: A Systemic Review and Network Meta-Analysis of Randomized Controlled Trials.

Up to 10% of patients with atrial fibrillation (AF) undergo percutaneous coronary intervention (PCI). A systematic review and network meta-analysis were conducted by searching PubMed, Embase, and the Cochrane database of systematic reviews for randomized control trials that studied the safety and efficacy of different antithrombotic strategies in these patients. Six studies, including 12,158 patients were included. Compared to that in the triple antithrombotic therapy group (vitamin K antagonist (VKA) plus P2Y12 inhibitor and aspirin), thrombolysis in myocardial infarction (TIMI) major bleeding was significantly reduced in the dual antithrombotic therapy (non-vitamin K oral anticoagulants (NOACs) plus P2Y12 inhibitor) group by 47% (Odds ratio (OR), 0.53; 95% credible interval [CrI], 0.35–0.78; I2 = 0%). Besides, NOAC plus a P2Y12 inhibitor was associated with less intracranial hemorrhage compared to VKA plus single antiplatelet therapy (OR: 0.20, 95% CrI: 0.05–0.77). There was no significant difference in the trial-defined major adverse cardiac events or the individual outcomes of all-cause mortality, cardiovascular death, myocardial infarction, stroke or stent thrombosis among all antithrombotic strategies. In conclusion, antithrombotic strategy of NOACs plus P2Y12 inhibitor is safer than, and as effective as, the strategies including aspirin when used in AF patients undergoing PCI.

Treatment of Acute Nonvariceal Upper Gastrointestinal Bleeding in Chinese Patients on Antithrombotic Therapy

Objective To assess the treatment of acute nonvariceal upper gastrointestinal bleeding (ANVUGIB) in Chinese patients on antithrombotic therapy. Methods The clinical data of patients with ANVUGIB who underwent upper gastrointestinal endoscopy 24 h after bleeding at Beijing Anzhen Hospital, Capital Medical University, from 2016 to 2018, were analyzed retrospectively. The patients were divided into antithrombotic therapy and control groups and into high-risk (Forrest Ia, Ib, IIa, and IIb) and low-risk (Forrest IIc and III) bleeding groups according to the results of endoscopy. Results In all, 230 patients were enrolled, with 99 cases in the antithrombotic group (antiplatelet therapy 80 patients, anticoagulant therapy 19 patients) and 131 cases in the control group (without antithrombotic therapy). A total of 78 and 21 and 84 and 47 patients were at high- and low- risk for bleeding (P = 0.019) in the antithrombotic and control groups, respectively; 12.1% and 4.6% had esophageal bleeding (P = 0.047), and 8 and 2 patients received interventional therapy (P = 0.021). Overall, 21 patients with hemodynamic instability were treated via endoscopy with anesthesia under tracheal intubation and ventilator support: 20 patients in the antithrombotic group (13 patients within 1 month after coronary intervention, 5 patients within 1 month of cardiac-valve replacement, and 2 patients within 4 years of cardiac-valve replacement) and 1 patient with third-degree atrioventricular block in the control group. Ten patients received interventional therapy: eight and two in the two groups, respectively. Multidisciplinary consultation was conducted to regulate the use of antithrombotic drugs. Conclusion Compared to the controls, patients in the antithrombotic group had a significantly higher incidence of critical and active bleeding. Patients with hemodynamic instability should be examined and treated via upper gastrointestinal endoscopy under anesthesia with tracheal intubation and ventilator support.

Multicenter Study of the Hemorrhage Risk after Endoscopic Mucosal Resection Associated with Direct Oral Anticoagulants.

Backgrounds and Aims Recently, direct oral anticoagulants (DOACs) have become widely used for preventing thromboembolism. However, postoperative hemorrhage (POH) is a major complication associated with endoscopic mucosal resection (EMR) for colorectal lesions. In this multicenter study, we analyzed the incidence of POH after EMR associated with DOACs and explored the associated risk factors. Materials and Methods This study was a multicenter retrospective cohort study conducted at 8 Japanese institutions. A total of 2062 cases that underwent EMR for colorectal lesions at these 8 institutions from October 2016 to September 2017 were analyzed. The cases were divided into 4 groups: the DOAC group (63 cases), warfarin group (34 cases), antiplatelet group (185 cases), and no antithrombotics group (1780 cases). In all lesions of the DOAC and warfarin groups, endoscopic clipping was performed after EMR. The rate of POH in the DOAC group, patients' clinical characteristics, the risk factors of POH, and the rate of thromboembolism due to stopping DOACs were compared with other groups. Results The rates of POH were 7.9%∗ (5/63), 2.9% (1/34), 3.2% (6/185), and 0.6%∗∗ (11/1780) in the DOAC, warfarin, antiplatelet, and no antithrombotics groups, respectively (∗ vs. ∗∗, p < 0.001). Regarding risk factors, the tumor size with POH (mm) was significantly bigger than that without POH (16.2 ± 8.3 vs. 7.2 ± 4.9, p < 0.001). There were no significant differences in the rates of POH based on the type of DOAC. In addition, no thromboembolisms occurred due to stopping of DOAC treatment. Conclusions Patients receiving DOACs had significantly higher rates of POH after EMR than those without antithrombotics.

Antithrombotic drugs do not increase intraoperative blood loss in emergency gastrointestinal surgery: a single-institution propensity score analysis

BackgroundThe use of antithrombotic drugs is increasing with the aging population. Prior to elective procedures, antithrombotic drugs are often discontinued. For emergency procedures in patients taking antithrombotic drugs, their effect cannot be attenuated which may lead to an increased risk of hemorrhagic events. However, there are few studies showing increased intraoperative blood loss in patients taking antithrombotic drugs who undergo emergency gastrointestinal surgery. The aim of this study is to determine whether the use of antithrombotic agents increases intraoperative blood loss in emergency gastrointestinal surgery.MethodsA retrospective review of patients who underwent emergency abdominal surgery between January 2013 and December 2017 was conducted. The primary outcome measure was intraoperative blood loss. Patients were divided into the antithrombotic drug group and a control group, and a propensity score was developed using multivariate logistic regression. We use 1:1 propensity score matching analysis to compare outcomes between the two groups.ResultsOf 1555 patients included in this study, 1184 patients, including 170 patients taking antithrombotic drugs, were eligible for propensity score matching analysis. A 1:1 matching yielded 117 well-balanced pairs. There was no statistically significant difference in intraoperative blood loss (antithrombotic drug group vs control group, median (interquartile): 60 (225–10) vs 100 (243–10) ml, p = 0.43).ConclusionsThis study suggests that antithrombotic drugs do not increase intraoperative blood loss in patients undergoing emergency gastrointestinal surgery. Emergency gastrointestinal surgery for patients currently taking antithrombotic drugs can be performed safely, and the use of antithrombotic drugs is not a reason to delay surgical intervention.

Preparation and characterization of biodegradable and hemocompatible copolymers

In this study, we developed biodegradable polyesters with hemocompatibility and anti-thrombotic functions. First, we synthesized 3-benzyloxymethyl-6-methyl-1,4-dioxane-2,5-dione (LA-Bz). The ring opening polymerization of ε-caprolactone (CL), l-lactide (LA), and LA-Bz monomers provided poly(ε-caprolactone-ran-l-lactide-ran-3-benzyloxymethyl lactide) (PCLA-Bz) copolymers. Poly(ε-caprolactone-ran-l-lactide) (PCLA) was prepared as a control biodegradable copolymer. Subsequent deprotective benzyl reactions of PCLA-Bz and additional reactions with glutaric anhydride yielded PCLA copolymers with COOH pendant groups (PCLA-COOH). Afterward, methoxypolyethylene glycol (PCLA-MPEG) or heparin (PCLA-heparin) as an anti-thrombotic group was introduced in the pendant position of PCLA. The in vitro degradation and mechanical properties of PCLA, PCLA-COOH, PCLA-MPEG, and PCLA-heparin were examined over 8 weeks. In the hemocompatibility testing, PCLA-COOH, PCLA-MPEG, and PCLA-heparin exhibited hemocompatibility with little adherence of platelets. In addition, PCLA-heparin exhibited significantly reduced platelet adhesion and enhanced blood stability and thrombin inactivation. These results show that the introduction of anti-thrombotic groups in the pendant position of PCLA represents a useful approach to prepare biodegradable and hemocompatible copolymers.

Novel Approach of Antithrombotic Potency Amongst Patients Admitted to Hospital with Bleeding Using HEMORR2HAGES Score: A Retrospective Cohort Study.

The purpose of this study was to evaluate whether a relationship exists between baseline HEMORR2HAGES score and antithrombotic potency amongst patients presenting with bleeding complication. We hypothesized that the more antithrombotic regimen potency, the less HEMORR2HAGES score you have. This is a retrospective observational study of patients admitted with a diagnosis of active bleeding between November 1, 2013 and August 31, 2015. The antithrombotic groups included patients on the following regimens: single antiplatelet therapy (SAP), single oral anticoagulant therapy (SOAC), dual antiplatelet therapy (DAPT), dual combination (SOAC+SAP), and triple antithrombotic therapy. The primary outcome was to review the mean HEMORR2HAGES score among the various groups. There were a total of 180 patients in the study. No significant difference was noted among the five groups in the HEMORR2HAGES score (P = .36). The highest HEMORR2HAGES score was in the SAP group (3.23 ± 1.1). The lowest HEMORR2HAGES score was in the DAPT group (2.59 ± 1.2). In the Sub Group analysis, we compared single versus dual versus triple therapy, and we found the lowest HEMORR2HAGES score in the triple therapy group (2.70 ± 1.6); (P = .29). Among patients admitted with active bleeding, the HEMORR2HAGES score did not differentiate antithrombotic potency amongst groups with various regimens. This study highlights the necessity to evaluate antithrombotic therapy according to benefits and harms.

Postoperative bleeding complications after endoscopic inguinal hernia repair in patients receiving anticoagulation agents, antiplatelet agents, or both.

In patients receiving chronic anticoagulation agents, antiplatelet agents, or both, perioperative antithrombotic therapy for inguinal hernia repair requires an understanding of potential side-effects-specifically, the postoperative bleeding risks. In the present study, we evaluated postoperative bleeding complications after transabdominal preperitoneal patch plasty (TAPP) in patients undergoing antithrombotic therapy. We retrospectively reviewed 413 patients who had undergone TAPP between February 2013 and June 2017. Individuals in the antithrombotic group received one of three regimens of perioperative antithrombotic therapy. The clinical indications for chronic anticoagulation agents (ie bridging therapy with unfractionated heparin), antiplatelet agents (ie continuation of aspirin), or both were followed. The antithrombotic group was compared to the control group in terms of surgical outcomes. We primarily focused on the incidence of postoperative bleeding complications. A total of 83 patients received antithrombotic therapy. We observed significant differences between the groups in terms of mean age, ASA physical status, and length of postoperative stay. In contrast, postoperative complications were not significantly different between the antithrombotic and control groups (4.8% vs 5.5%, P = 0.818). In addition, a significantly greater postoperative bleeding rate was not observed in the antithrombotic group than in the control group (1.2% vs 0.6%, P = 0.566). Likewise, other complications were similar in both groups. Antithrombotic therapy is not a risk factor for postoperative bleeding complications in patients who have undergone TAPP, suggesting its safety and efficacy in this patient population. Indeed, this group has the same incidence rates of morbidity and postoperative bleeding complications as patients who have not undergone antithrombotic therapy.

Abstract TP226: Impact of Non-Vitamin K Antagonist Oral Anticoagulant Withdrawal on Stroke Outcomes

Introduction: Discontinuation of antithrombotics can be associated with an increased risk of cardiovascular events and poor outcomes. Abrupt warfarin withdrawal may also induce a rebound or a paradoxical prothrombotic state, subsequently leading to an increased incident risk of stroke for up to 3 months. Hypothesis: Considering the potent anticoagulant effect of non-vitamin K oral anticoagulants (NOACs) on the suppression of thrombogenesis, NOAC withdrawal may be associated with profound hypercoagulable state, leading to severe stroke and poor outcomes in patients with non-valvular atrial fibrillation (NVAF) related stroke. The aim of this study was to compare the initial stroke severity and functional outcome associated with NOAC withdrawal to those associated with other prior medication statuses including warfarin withdrawal in patients with NVAF. Methods: A total of 719 patients with ischemic stroke or transient ischemic attack and NVAF who were admitted at five regional hospitals between January 2013 and December 2016 were included. Prior medication status was categorized into seven groups such as no antithrombotics, antiplatelet-only, warfarin with a subtherapeutic intensity, warfarin with a therapeutic intensity, NOAC, warfarin withdrawal, and NOAC withdrawal. We compared initial National Institute of Health Stroke Scale (NIHSS) scores between groups. Results: The mean age was 73.9 ±10.2 years, and 397 (55.2%) patients were men. Median CHA 2 DS 2 -VASc score was 4 (interquartile range [IQR] 3-5). Among 719 patients, the NOAC withdrawal group had the highest median NIHSS scores at stroke onset (16, interquartile range, IQR [4-20]), followed by the warfarin withdrawal group (11, IQR [3-17]), the no antithrombotic group (5, IQR [2-16]), and the warfarin with subtherapeutic intensity group (5, IQR [2-13]). Multivariable analysis demonstrated that NOAC withdrawal was independently associated with higher NIHSS scores at stroke onset (B 4.645, 95% CI 0.384-8.906, P=0.033). Conclusions: Stroke occurred after discontinuing oral anticoagulants, particularly NOAC, was independently associated with severe stroke severity.

Safety of Cold Snare Polypectomy in Patients Receiving Treatment with Antithrombotic Agents.

With the aging of the population and rising incidence of thromboembolic events, the clinical use of antithrombotic agents is also increasing. There are few reports yet on the management of antithrombotic agent use in patients undergoing cold snare polypectomy (CSP). The aim of this study was to evaluate whether continued administration of antithrombotic agents in patients undergoing CSP would be associated with an increased rate of delayed post-polypectomy bleeding (DPPB). A total of 1177 colorectal polyps in 501 patients were resected at Omori Red Cross Hospital between October 2017 and March 2018. The polyps were divided into two groups depending on whether the patients received antithrombotic agent treatment or not: the antithrombotic group (911 polyps) and the no-antithrombotic group (266 polyps). Among the 1177 polyp resections, there was no case of DPPB, including in the antithrombotic group. Immediate bleeding occurred in a total of 63 (5.4%) cases. Polyp location in the rectum (OR (95% CI) 2.64 (1.223-5.679); p = 0.013), polyp size ≥ 6mm (OR (95% CI) 4.64 (2.719-7.933); p < 0.001), polypoid growth pattern (OR (95% CI) 2.78 (1.607-4.793); p < 0.001), and antithrombotic agent use (OR (95% CI) 2.98 (1.715-5.183); p < 0.001) were identified as significant risk factors of immediate bleeding. Continued use of antithrombotic agents does not increase the risk of DPPB, even in those receiving multiple antithrombotic agents. Thus, it is safe to perform CSP even in multiple agent users. Prospective, randomized studies are necessary to confirm our results.

Outcomes of EUS-FNA in patients receiving antithrombotic therapy.

Background and study aims To investigate bleeding risk and thromboembolic risk in patients receiving antithrombotic therapy who underwent endoscopic ultrasound-guided fine-needls aspiration (EUS-FNA). Patients and methods A single-center retrospective study of 908 consecutive patients undergoing EUS-FNA for pancreatic and non-pancreatic lesions patients between March 2013 and March 2017 was performed. Antithrombotic management was classified into three groups: continuous, discontinuation, and heparin replacement. Results A total of 114 patients (12.6 %) were on antithrombotic drugs and 794 (84.6 %) were not. There were six cases of significant bleeding (0.7 %) four in the antithrombotic group (0.4 %) and two (0.2 %) in the non-antithrombotic group, (odds ratio, 9.59; 95 % confidence interval, 2.12 – 43.1; P = 0.006). Of the four cases in the antithrombotic group, two were on continuous treatment, one was on discontinuation treatment and one was on heparin replacement. All cases of non-significant bleeding occurred in the non-antithrombotic group (3 peri-tumoral hematomas, 1 submucosal hematoma, and 1 intraluminal bleed). The sole thromboembolic event (0.9 %) was a cerebral infarction in the antithrombotic group in a patient on thienopyridine who switched to aspirin before the procedure. Conclusions There was a slight increase in risk of bleeding in patients receiving antithrombotic therapy especially postoperative bleeding; however, there were no cases of severe bleeding was seen and only one case of cerebral infarction which occurred in a high-risk thromboembolic patients. We concluded that EUS-FNA in a safe procedure for patients on antithrombotics, even when antithrombotic therapy is not discontinued during EUS-FNA.

Laparoscopic total extraperitoneal inguinal hernia repair is safe and feasible in patients with continuation of antithrombotics.

Aims:We aimed to evaluate the safety and feasibility of laparoscopic total extraperitoneal (TEP) inguinal hernia repair in patients with the continuation of their antithrombotic agents.Settings and Design:This was prospective cohort study.Materials and Methods:A total of 115 patients who underwent TEP inguinal hernia repair between January 2015 and September 2016 were included in the analysis. Seventeen patients continued their antithrombotics (antithrombotic group); the other 98 had not been on antithrombotics (control group).Statistical Analysis Used:The analysis was performed by using Mann–Whitney U-test, Chi-square or Fisher's exact test.Results:The antithrombotic group had a greater mean age (65.9 ± 8.0 vs. 57.7 ± 13.6, P = 0.002) and higher prevalence of hypertension (64.7% vs. 33.7%, P = 0.015), cardiovascular diseases (64.7% vs. 7.1%, P < 0.001), atrial fibrillation (23.5% vs. 0, P < 0.001), ischaemic heart disease (35.3% vs. 0, P < 0.001) and the American Society of Anaesthesiologists ≥2 (94.1% vs. 81.6%, P = 0.005). The operation time for the antithrombotic group was longer than that of the control group (92.06 ± 32.81 min vs. 72.33 ± 20.99 min, P = 0.015). None experienced conversion to open surgery in either group. There was no difference in the post-operative complications (29.4% vs. 28.6%) and sero-haematoma formation (23.5% vs. 11.1%). The analgesic requirement, hospital stays (23.72 ± 7.74 vs. 22.35 ± 10.33 h) and the time for return to normal daily activity (3.56 ± 1.74 vs. 3.63 ± 1.90) were not statistically different between the two groups. None in either group experienced major cardiovascular events within 30 days.Conclusions:Laparoscopic TEP inguinal hernia repair can be safely performed in patients with the continuation of their antithrombotic agents in experienced hands.