Stopping Aspirin Within 1 Month After Stenting for Ticagrelor Monotherapy in Acute Coronary Syndrome: The T-PASS Randomized Noninferiority Trial.

BACKGROUND: Stopping aspirin within 1 month after implantation of a drug-eluting stent for ticagrelor monotherapy has not been exclusively evaluated for patients with acute coronary syndrome. The aim of this study was to investigate whether ticagrelor monotherapy after <1 month of dual antiplatelet therapy (DAPT) is noninferior to 12 months of ticagrelor-based DAPT for adverse cardiovascular and bleeding events in patients with acute coronary syndrome. METHODS: In this randomized, open-label, noninferiority trial, 2850 patients with acute coronary syndrome who underwent drug-eluting stent implantation at 24 centers in South Korea were randomly assigned (1:1) to receive either ticagrelor monotherapy (90 mg twice daily) after <1 month of DAPT (n=1426) or 12 months of ticagrelor-based DAPT (n=1424) between April 24, 2019, and May 31, 2022. The primary end point was the net clinical benefit as a composite of all-cause death, myocardial infarction, definite or probable stent thrombosis, stroke, and major bleeding at 1 year after the index procedure in the intention-to-treat population. Key secondary end points were the individual components of the primary end point. RESULTS: Among 2850 patients who were randomized (mean age, 61 years; 40% ST-segment-elevation myocardial infarction), 2823 (99.0%) completed the trial. Aspirin was discontinued at a median of 16 days (interquartile range, 12-25 days) in the group receiving ticagrelor monotherapy after <1 month of DAPT. The primary end point occurred in 40 patients (2.8%) in the group receiving ticagrelor monotherapy after <1-month DAPT, and in 73 patients (5.2%) in the ticagrelor-based 12-month DAPT group (hazard ratio, 0.54 [95% CI, 0.37-0.80]; P<0.001 for noninferiority; P=0.002 for superiority). This finding was consistent in the per-protocol population as a sensitivity analysis. The occurrence of major bleeding was significantly lower in the ticagrelor monotherapy after <1-month DAPT group compared with the 12-month DAPT group (1.2% versus 3.4%; hazard ratio, 0.35 [95% CI, 0.20-0.61]; P<0.001). CONCLUSIONS: This study provides evidence that stopping aspirin within 1 month for ticagrelor monotherapy is both noninferior and superior to 12-month DAPT for the 1-year composite outcome of death, myocardial infarction, stent thrombosis, stroke, and major bleeding, primarily because of a significant reduction in major bleeding, among patients with acute coronary syndrome receiving drug-eluting stent implantation. Low event rates, which may suggest enrollment of relatively non-high-risk patients, should be considered in interpreting the trial. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03797651.

Safety of cold snare resection techniques for removal of small colon polyps in patients with clopidogrel and aspirin: A Korean Association for the Study of Intestinal Diseases prospective, multicenter study.

BACKGROUND: /Aims: Polypectomy is a procedure associated with a high risk of bleeding. Guidelines recommend uninterrupted aspirin use during polypectomy, whereas cessation of clopidogrel 5-7 days before polypectomy is recommended. The cold snare resection technique, with or without submucosal injection, is considered safer than conventional polypectomy using electrocoagulation for post-polypectomy bleeding. In this study, we aimed to compare the bleeding complications associated with cold snare resection between clopidogrel and aspirin users. METHODS: This multicenter, prospective cohort study was conducted in five academic hospitals in Korea and included clopidogrel and aspirin users who underwent polypectomy. Antiplatelet agents were used without interruption, with ≤ 3 days of interruption defined as continuous use. The primary endpoint was delayed bleeding, which was defined as bleeding occurring several hours after polypectomy, whereas immediate bleeding was defined as bleeding requiring hemostasis 2 min after polypectomy. Risk factors for immediate bleeding were investigated for each polyp. RESULTS: Among the 263 patients (clopidogrel, n = 129; aspirin, n = 134), 509 underwent polypectomies. The rate of delayed bleeding per patient in the clopidogrel and aspirin groups was 0.8% and 0.7%, respectively, meeting noninferiority (rate difference 0.03% [95% confidence interval: -2.07% to 2.13%]). Hemostasis was achieved in 100 patients who underwent polypectomy (19.8%). Immediate bleeding risk factors included female sex, end-stage renal disease, submucosal injection before resection, and polyp size ≥ 5 mm. CONCLUSIONS: This multicenter prospective study demonstrated the safety of cold snare resection in patients treated with uninterrupted clopidogrel and aspirin (NCT04328987).

Topical Skin Application of Small-Molecule Antiplatelet Agent against Pressure Injury in Rat Models.

Due to prolonged forced positioning, the incidence of intraoperative pressure injuries is high. This study aimed to explore the impact of small-molecule antiplatelet drugs on pressure injuries by locally applying them before an injury occurs. In the first part of this study, water-soluble tracers with different molecular weights were applied to normal and early-stage pressure-injured skin. Through digital cameras, spectrophotometers, and histological observations, the penetration of tracers into the epidermis was clarified. In the second part of this study, a water-soluble antiplatelet drug called Trapidil (molecular weight = 205 Da) was applied to the left side of the back of a rat before, during, and after compression, and the contralateral side served as a non-intervention control group. The differences in pressure injuries between the two groups were observed through a digital camera, an ultraviolet camera, and temperature measurement, and skin circulation and perfusion were assessed via an intravenous injection of Evans Blue. The first part of this study found that water-soluble tracers did not easily penetrate normal skin but could more easily penetrate pressure-damaged skin. The smaller the molecular weight of the tracer, the easier it penetrated the skin. Therefore, in the next step of research, water-soluble drugs with smaller molecular weights should be selected. The second part of this study found that, compared with the control group, the occurrence rates and areas of ulcers were lower, the gray value was higher, and the skin temperature was lower in the Trapidil group (p < 0.05). After the intravenous Evans Blue injection, skin circulation and perfusion in the Trapidil group were found to be better. In conclusion, this study found that the topical skin application of a small-molecule antiplatelet agent may have significant effects against pressure injuries by improving post-decompression ischemia, providing new insights into the prevention and treatment of intraoperative pressure injuries.

Effects of aspirin on cardiovascular outcomes in patients with chronic kidney disease.

Patients with chronic kidney disease (CKD) carry a high cardiovascular (CV) risk. Since whether this risk is reduced by aspirin is unclear, we examined if the effect of aspirin on cardiovascular outcomes varied by baseline kidney function in a primary cardiovascular disease prevention trial. The International Polycap Study-3 (TIPS-3) trial had randomized people without previous cardiovascular disease to aspirin (75 mg daily) or placebo. We now examined aspirin versus placebo on cardiovascular events in participants grouped by estimated glomerular filtration rate (eGFR), using a threshold of 60 ml/min/1.73 m2, and by using tertiles of eGFR. The primary outcome was a composite of non-fatal myocardial infarction, non-fatal stroke or cardiovascular death. A total of 5712 participants were randomized with a mean follow-up of 4.6 years. Of these, 983 (17.2%) had an eGFR under 60 ml/min/1.73 m2 (mean eGFR 49 ml/min/1.73 m2) and 4,729 over 60 ml/min/1.73 m2 (mean 84 ml/min/1.73 m2). In participants with an eGFR under 60 ml/min/1.73 m2 there were 26 primary outcomes in 502 participants on aspirin and 39/481 on placebo (hazard ratio 0.57; 95% confidence interval 0.34-0.94). In participants with an eGFR over 60 ml/min/1.73 m2 there were 90 primary outcomes in 2357 participants on aspirin and 95/2372 on placebo (0.95; 0.71-1.27). With tertiles of eGFR under 70, 70-90, and over 90 ml/min/1.73 m2, risk reductions with aspirin for the primary outcome were larger at lower eGFR levels (0.62; 0.43-0.91) for the lowest tertile, (0.96; 0.62-1.49) for the middle, and (1.30; 0.77-2.18) for the highest tertile. Thus, our findings support aspirin may reduce cardiovascular events in people with moderate to advanced stage CKD.

Ideal Timing of Discontinuation of Antiplatelet Agents Before Gastric Endoscopic Submucosal Dissection for Reducing Delayed Bleeding.

BACKGROUND AND AIMS: This study aimed to evaluate whether the use of antiplatelet agents increases the risk of bleeding after gastric endoscopic submucosal dissection (ESD) and to determine the appropriate time to discontinue antiplatelet agents to minimize complications. METHODS: This retrospective observational study utilized a collected dataset of patients who underwent ESD for gastric adenoma and cancer between January 2010 and December 2020. Patients were classified into three groups according to antiplatelet agent use and discontinuation status. We investigated the risk of post-ESD bleeding with different interruption times and antiplatelet agent types. RESULTS: Of 1879 patients, 1389 were non-users, 190 were in the continuous group, and 203 were in the interrupted group. The rates of overall and delayed bleeding were significantly higher in patients who continued or were interrupted within three days before ESD than in the non-users and interrupted group (6.3% vs. 1.2%, p < 0.001, 6.3% vs. 2.5%, p = 0.01, respectively). Significant differences in delayed bleeding between the continuous and interrupted groups decreased with longer cessation periods. In multivariate analysis, continuous antiplatelet agents were still the strongest risk factor for bleeding (OR 2.81, 95% CI 1.14-6.90). Lower third location and longer procedure times were also independent risk factors for post-ESD bleeding (OR 2.75; 95% CI 1.08-6.97; OR 1.02; 95% CI 1.01-1.02). CONCLUSION: Continuous antiplatelet agent use increases the risk of delayed bleeding after gastric ESD. Therefore, the optimal timing of interruption, rather than the type of antiplatelet agent, should be considered to avoid an additional risk of bleeding and thromboembolism.

Antiplatelet effect of ginkgo diterpene lactone meglumine injection in acute ischemic stroke: A randomized, double-blind, placebo-controlled clinical trial.

This study was designed to evaluate antiplatelet effect and therapeutic effect of ginkgo diterpene lactone meglumine injection (GDLI) in acute ischemic stroke (AIS) patients. In this randomized, double-blind, placebo-controlled trial, we randomly assigned 70 inpatients within 48 hr after the onset of AIS to combination therapy with GDLI and aspirin (GDLI at a dose of 25 mg/d for 14 days plus aspirin at a dose of 100 mg/d for 90 days) or to placebo plus aspirin in a ratio of 1:1. Platelet function, the National Institute of Health Stroke Scale (NIHSS), and the modified Rankin Scale (mRS) were evaluated. A good outcome was defined as NIHSS scores decrease ≥5 or mRS scores decrease ≥2. Results showed that arachidonic acid induced maximum platelet aggregation rate (AA-MAR) and mean platelet volume (MPV) of the GDLI-aspirin group were much lower than that of the aspirin group (p = 0.013 and p = 0.034, respectively) after the 14-day therapy. The combination of GDLI and aspirin was superior to aspirin alone, and had significant impact on the good outcome at day 90 (ORadj 7.21 [95%CI, 1.03-50.68], p = 0.047). In summary, GDLI has antiplatelet effect and can improve the prognosis of AIS patients.

Antiplatelet Action of Chloramine Derivatives of Adenosine Phosphates and Their Chemical Activity in Relation to Sulfur-Containing Compounds.

We studied the properties of N6-chloroadenosine phosphates (ATP, ADP, and AMP chloramines) as compounds with potentially increased antiplatelet efficacy determined by their binding to the plasma membrane of platelets. Chloramine derivatives of ATP, ADP, and AMP do not differ in their optical absorption characteristics: their absorption spectra are in the range of 220-340 nm with a maximum at 264 nm. Chloramines of adenosine phosphates are characterized by high reactivity with respect to thiol compounds. In particular, the rate constants of the reaction of N6-chloroadenosine-5'-diphosphate with N-acetylcysteine, reduced glutathione, dithiothreitol, and cysteine reach 59,000, 250,000, 340,000, and 1,250,000 M-1×sec-1, respectively, and only 1.10±0.02 M-1×sec-1 with methionine. It has been found that N6-chloradenosine-5'-triphosphate is a strong inhibitor of platelet functions: it effectively suppresses ADP-induced cell aggregation (IC50 in the whole blood is 5 µM) and inhibits aggregation of preactivated platelets and induces dissociation of their aggregates.

[Recent research on platelet-leukocyte aggregates and their role in the pathogenesis of Kawasaki disease]. / 血小板-ç™½ç»†èƒžèšé›†ä½“åŠå ¶åœ¨å·å´Žç— å‘ç— ä¸­çš„ç ”ç©¶è¿›å±•.

Activated platelets may interact with various types of leukocytes such as monocytes, neutrophils, dendritic cells, and lymphocytes, trigger intercellular signal transduction, and thus lead to thrombosis and synthesis of massive inflammatory mediators. Elevated levels of circulating platelet-leukocyte aggregates have been found in patients with thrombotic or inflammatory diseases. This article reviews the latest research on the formation, function, and detection methods of platelet-leukocyte aggregates and their role in the onset of Kawasaki disease, so as to provide new ideas for studying the pathogenesis of Kawasaki disease.

Anticoagulation management in haemodialysis patients with atrial fibrillation: evidence and opinion.

In the absence of robust evidence to guide clinical decision-making, the optimal approach to prevent stroke and systemic embolism in haemodialysis (HD) patients with atrial fibrillation (AF) remains moot. In this position paper, studies on oral anticoagulation (OAC) in HD patients with AF are highlighted, followed by an evidence-based conclusion, a critical analysis to identify sources of bias and practical opinion-based suggestions on how to manage anticoagulation in this specific population. It remains unclear whether AF is a true risk factor for embolic stroke in HD. The currently employed cut-off values for the CHA2DS2-VASc score do not adequately discriminate dialysis patients deriving a net benefit from those suffering a net harm from OAC. Anticoagulation initiation should probably be more restrictive than currently advocated by official guidelines. Recent evidence reveals that the superior benefit-risk profile of direct oral anticoagulants (DOACs) versus vitamin K antagonists (VKAs) observed in the general population and in moderate chronic kidney disease can be extended to the HD population. VKA may be especially harmful in dialysis patients and should therefore be avoided, in particular in patients with a high bleeding risk and labile international normalized ratio. Dose-finding studies of DOACs suggest that rivaroxaban 10 mg daily and apixaban 2.5 mg twice daily are appropriate choices in dialysis patients. Combined treatment with oral anticoagulants and antiplatelet agents should be reserved for strong indications and limited in time. Left atrial appendage occlusion is a potential attractive solution to reduce the risk of stroke without increasing bleeding propensity, but it has not been properly studied in dialysis patients.

Risk of post-polypectomy bleeding after endoscopic mucosal resection in patients receiving antiplatelet medication: comparison between the continue and hold groups.

BACKGROUND: Current guidelines recommend continuing aspirin and discontinuing clopidogrel for colon polypectomy, but evidence for endoscopic mucosal resection (EMR) is insufficient. We aimed to assess post-polypectomy bleeding (PPB) in patients receiving antiplatelet agents and underwent EMR for various polyp sizes. METHODS: A single-center, prospective observational study was performed. Patients who underwent at least one EMR for polypectomy and those who received aspirin or clopidogrel were included. We compared PPB between the antiplatelet hold group (stopped antiplatelet therapy at least 5 days before the procedure) and continue group (antiplatelet therapy was maintained or stopped within 5 days before the procedure). RESULTS: Among patients who underwent EMR, 305 took aspirin (hold group 257, continue group 48) and 77 took clopidogrel (hold group 66, continue group 11). The mean number of polyps was four, and the mean size was 8.6 mm. There was no difference in the major PPB rate between the hold and continue groups among aspirin users (2.0% vs. 4.2%, P = 0.30), but it was significantly higher in the continue group than in the hold group among clopidogrel users (18.2% vs. 0%, P = 0.02). In patient- and polyp-based logistic regression analysis of clopidogrel users, the number of EMRs (OR 2.12, 95% CI 1.16-3.88), polyp size (OR 1.26, 95% CI 1.06-1.49), and continuing clopidogrel (OR 9.75, 95% CI 1.99-47.64) were independent risk factors for PPB. CONCLUSION: Continuous administration of antiplatelet agents was significantly associated with higher PPB in clopidogrel users, but not in aspirin users. Endoscopists should consider holding clopidogrel if the EMR includes polypectomy.

Using overlapping low-profile visualized intraluminal support stent-assisted coil embolization for treating blood blister-like aneurysms of the internal carotid artery.

Blood blister-like aneurysm (BBA) of the internal carotid artery (ICA) is highly challenging to treat owing to its variable morphology and tendency for rupture and regrowth. In this study, we attempted to discuss the key techniques for overlapping low-profile visualized intraluminal support (LVIS) stent-assisted coil embolization, which is used for treating BBAs in our center. Clinical characteristics, endovascular treatment details, outcomes, and follow-up results of 13 patients with BBA treated at our center were retrospectively evaluated in this study. Overlapping LVIS stent-assisted coil embolization was successfully performed in all 13 patients of ruptured BBAs located in the ICAs. Recurrence of aneurysm was observed in 4 cases (30.8%) during the angiographic follow-up; in 2 of these cases, spontaneous healing was observed after discontinuation of antiplatelet therapy. Further, 2 patients with recurrence underwent endovascular treatment with complete obliteration of the aneurysm in one and occlusion of the parent artery after Onyx embolization and stent placement in the other. The overall obliteration rate of the BBAs was 92.3% (12/13). One patient (7.7%) developed intraoperative rupture of the aneurysm with coils protruding outside; however, no severe hemorrhage or neurological dysfunction occurred owing to timely embolization. Overlapping LVIS stent-assisted coil embolization is effective for management of BBA of the ICA. Appropriate adjustment in antiplatelet therapy may improve healing in recurrent cases.

Multifaceted highly targeted sequential multidrug treatment of early ambulatory high-risk SARS-CoV-2 infection (COVID-19).

The SARS-CoV-2 virus spreading across the world has led to surges of COVID-19 illness, hospitalizations, and death. The complex and multifaceted pathophysiology of life-threatening COVID-19 illness including viral mediated organ damage, cytokine storm, and thrombosis warrants early interventions to address all components of the devastating illness. In countries where therapeutic nihilism is prevalent, patients endure escalating symptoms and without early treatment can succumb to delayed in-hospital care and death. Prompt early initiation of sequenced multidrug therapy (SMDT) is a widely and currently available solution to stem the tide of hospitalizations and death. A multipronged therapeutic approach includes 1) adjuvant nutraceuticals, 2) combination intracellular anti-infective therapy, 3) inhaled/oral corticosteroids, 4) antiplatelet agents/anticoagulants, 5) supportive care including supplemental oxygen, monitoring, and telemedicine. Randomized trials of individual, novel oral therapies have not delivered tools for physicians to combat the pandemic in practice. No single therapeutic option thus far has been entirely effective and therefore a combination is required at this time. An urgent immediate pivot from single drug to SMDT regimens should be employed as a critical strategy to deal with the large numbers of acute COVID-19 patients with the aim of reducing the intensity and duration of symptoms and avoiding hospitalization and death.

Assessing guideline adherence in patients with non-variceal upper gastrointestinal bleeding receiving antiplatelet and anticoagulant therapy.

Background & aims: Non-variceal upper gastrointestinal bleeding (NVUGIB) occurs frequently and is associated with a significant morbidity and mortality, especially in patients receiving antiplatelet or anticoagulant therapy (APT and ACT, respectively). We aimed to evaluate adherence to guideline recommendations published by European Society of Gastrointestinal Endoscopy (ESGE).Methods: Retrospective analysis of patients with NVUGIB und prior exposition to APT or ACT at a single university hospital between 01 January 2016 and 31 December 2017.Results: 270 patients were identified (70.4% male, median age 72 years). 6/17 (35.3%) patients receiving APT for primary cardiovascular prophylaxis, 39/71 (54.9%) and 35 (49.3%) patients receiving APT for secondary cardiovascular prophylaxis (using strict and liberal definition, respectively) and 13/25 (52%) patients receiving dual antiplatelet therapy (DAPT) were not managed according to current recommendations. Management of ACT for secondary thromboembolic prophylaxis did not follow guideline recommendations in 59/93 (63.4%) and 34/93 (36.6%) patients (using strict and liberal definition, respectively). 23.7% of patients with NVUGIB were exposed to combined APT and ACT for whom no guideline recommendations exist. Mortality for any reason was twice as high in patients who were not managed according to guideline recommendations (18.8% vs. 8% using strict definition, 20.5% vs. 10.2% using liberal definition), which did not remain significant after adjusting for comorbidities, whereas cardiovascular events were observed at similar rates.Conclusion: A significant number of patients with NVUGIB receiving APT or ACT is not managed according to current ESGE guideline recommendations. Strategies to implement these guidelines into daily practice need to be developed.

Prevention of Stent Thrombosis in Rats by a Direct Oral Factor Xa Inhibitor Edoxaban.

BACKGROUND/AIMS: Stent thrombosis is a serious complication after percutaneous coronary intervention and femoropopliteal endovascular intervention. The aim of this study was to determine the antithrombotic effects of a direct factor Xa inhibitor edoxaban alone or in combination with antiplatelet agents in a rat model of stent thrombosis. METHODS: Stainless steel stents (4 stents per rat) were placed in an extracorporeal arteriovenous shunt. The shunt was inserted into the carotid artery and the jugular vein in each rat to circulate blood. Stent thrombosis was induced by exposing the stents to arterial blood for 30 min. Protein content of the thrombus was measured. Edoxaban and antiplatelet agents (aspirin, clopidogrel, and ticagrelor) were orally administered before the thrombus induction. RESULTS: Edoxaban (0.3-3 mg/kg), clopidogrel (1-10 mg/kg), aspirin (10-100 mg/kg), and ticagrelor (0.3-3 mg/kg) exerted significant and dose-dependent antithrombotic effects in a rat stent thrombosis model. The effect of edoxaban was comparable to that of antiplatelet agents. The combination of submaximal doses of edoxaban and clopidogrel or aspirin significantly potentiated the antithrombotic effects compared with antiplatelet agents alone. CONCLUSION: These results suggest that edoxaban alone and in combination with clopidogrel or aspirin are promising antithrombotic therapies for the prevention of stent thrombosis.

Continued Use of a Single Antiplatelet Agent Does Not Increase the Risk of Delayed Bleeding After Colorectal Endoscopic Submucosal Dissection.

BACKGROUND: With the aging of the population and rising incidence of thromboembolic events, the usage of antiplatelet agents is also increasing. There are few reports yet on the management of antiplatelet agents for patients undergoing colorectal endoscopic submucosal dissection (ESD). AIMS: The aim of this study is to evaluate whether continued administration of antiplatelet agents is associated with an increased rate of delayed bleeding after colorectal ESD. METHODS: A total of 1022 colorectal neoplasms in 927 patients were dissected at Yokohama City University Hospital and its three affiliate hospitals between July 2012 and June 2017. We included the data of 919 lesions in the final analysis. The lesions were divided into three groups: the no-antiplatelet group (783 neoplasms), the withdrawal group (110 neoplasms), and the continuation group (26 neoplasms). RESULTS: Among the 919 lesions, bleeding events occurred in a total of 31 (3.37%). The rate of bleeding after ESD was 3.3% (26/783), 4.5% (5/110), and 0% (0/26), respectively. There were no significant differences in the rate of bleeding after ESD among the three groups (the withdrawal group vs. the no-antiplatelet group, the continuation group vs. the no-antiplatelet group, and the withdrawal group vs. the continuation group). CONCLUSIONS: Continued administration of antiplatelet agents is not associated with any increase in the risk of delayed bleeding after colorectal ESD. Prospective, randomized studies are necessary to determine whether treatment with antiplatelet agents must be interrupted prior to colorectal ESD in patients who are at a high risk of thromboembolic events.

[Essential thrombocythemia complicated by intracranial thrombohemorrhagic events].

Although the life expectancy if patients with essential thrombocythemia (ET) is considered to be almost similar to that of the general population, advanced age, leukocytosis, and a previous history of thrombosis are poor prognostic factors, and it is important to prevent thrombohemorrhagic events, leukemic transformation, and secondary malignancies. We report an 85-year-old ET patient with a history of asymptomatic lacunar infarction, who developed symptomatic cerebral infarction and even chronic subdural hematoma. It is necessary to follow patients who have asymptomatic cerebral infarction or chronic ischemic change and to examine the necessity of brain imaging and treatment intervention at the time of diagnosis.

The aspirin story - from willow to wonder drug.

The story of the discovery of aspirin stretches back more than 3500 years to when bark from the willow tree was used as a pain reliever and antipyretic. It involves an Oxfordshire clergyman, scientists at a German dye manufacturer, a Nobel Prize-winning discovery and a series of pivotal clinical trials. Aspirin is now the most commonly used drug in the world. Its role in preventing cardiovascular and cerebrovascular disease has been revolutionary and one of the biggest pharmaceutical success stories of the last century.

Anti-GPVI Fab SAR264565 effectively blocks GPVI function in ex vivo human platelets under arterial shear in a perfusion chamber.

INTRODUCTION: Glycoprotein VI (GPVI) is the major platelet receptor for collagen-mediated platelet adhesion and activation. SAR264565 is an anti-GPVI-Fab, binds to GPVI with high affinity, and blocks GPVI function in human platelets in vitro. METHODS: The effect of SAR26456 on platelet responsiveness in the blood of 21 healthy male subjects was investigated using Sakariassen's ex vivo thrombogenesis perfusion chamber model on a collagen-coated surface under conditions mimicking arterial flow. Ex vivo effects of SAR264565 (10 and 100 µg/mL) were investigated before administration of aspirin or clopidogrel to study subjects (baseline), after aspirin (2× 300 mg) administration alone, and after combined aspirin (2× 300 mg)/clopidogrel (600 mg) administration. Additional ex vivo and in vitro platelet tests were also performed. RESULTS: Addition of SAR264565 to the perfusion chamber dose-dependently reduced platelet and fibrin deposition, reaching statistical significance at 100 µg/mL (415 ± 67 compared to 137 ± 36 platelets/cm2, [p < 0.01] and fibrin 0.095 ± 0.014 compared to 0.032 ± 0.008 µg/cm2, [p < 0.001]). Aspirin administration caused an additive and dose-dependent reduction of SAR264565-induced platelet and fibrin deposition. Combined aspirin/clopidogrel administration did not lead to additional SAR264565-induced inhibition of platelet or fibrin deposition. CONCLUSION: GPVI antagonism by the anti-GPVI-Fab fragment SAR264565 dose-dependently inhibits platelet adhesion and fibrin formation on a collagen surface under arterial shear. Additive inhibition is observed after prior aspirin administration with no further amplification on top of a combination of aspirin with clopidogrel. Ex vivo antiplatelet tests confirmed a selective inhibiting effect of SAR264565 on collagen-induced platelet activation.

Paracetamol, Ibuprofen, and Recurrent Major Cardiovascular and Major Bleeding Events in 19 120 Patients With Recent Ischemic Stroke.

BACKGROUND AND PURPOSE: The presumed safety of paracetamol in high-cardiovascular risk patients has been questioned. We determined whether paracetamol or ibuprofen use is associated with major cardiovascular events (MACE) or major bleeding in 19 120 patients with recent ischemic stroke or transient ischemic attack of mainly atherothrombotic origin included in the Prevention of cerebrovascular and cardiovascular events of ischemic origin with terutroban in patients with a history of ischemic stroke or transient ischemic attack (PERFORM) trial. METHODS: We performed 2 nested case-control analysis (2153 cases with MACE during trial follow-up and 4306 controls matched on Essen stroke risk score; 809 cases with major bleeding matched with 1616 controls) and a separate time-varying analysis. RESULTS: 12.3% were prescribed paracetamol and 2.5% ibuprofen. Median duration of treatment was 14 (interquartile range 5-145) days for paracetamol and 9 (5-30) days for ibuprofen. Paracetamol, but not ibuprofen, was associated with increased risk of MACE (odds ratio 1.21, 95% confidence interval [CI] 1.04-1.42) or a major bleeding (odds ratio 1.60, 95% CI 1.26-2.03), with no impact of daily dose and duration of paracetamol treatment. Time-varying analysis found an increased risk of MACE with both paracetamol (hazard ratio 1.22, 95% CI 1.05-1.43) and ibuprofen (hazard ratio 1.47, 95% CI 1.06-2.03) and of major bleeding with paracetamol (hazard ratio 1.95, 95% CI 1.45-2.62). CONCLUSIONS: There was a weak and inconsistent signal for association between paracetamol or ibuprofen and MACE or major bleeding, which may be related to either a genuine but modest effect of these drugs or to residual confounding. CLINICAL TRIAL REGISTRATION: http://www.isrctn.com. Unique identifier: ISRCTN66157730.

Antiplatelet and oral anticoagulant therapies in chronic hemodialysis patients: prescribing practices and bleeding risk.

PURPOSE: Results of previous studies assessing the risk of bleeding associated with prescription of antiplatelet (AP) and/or oral anticoagulant (AC) therapy to hemodialysis patients are conflicting. Our purpose was to describe practices for prescription of AP and AC in hemodialysis patients in the Lorraine region, and to assess their effect on the risk of major bleeding events. METHODS: All adults with chronic kidney disease who began a first renal replacement therapy by hemodialysis in 2009 or 2010 in one of the 12 dialysis centers in Lorraine were included in the Thrombosis and Hemorrhage in HemoDialysis patients (T2HD) study and followed up until 30 June 2013. The association of each treatment (AP, AC, AP + AC) with the risk of major bleeding was estimated by three Cox proportional hazard models with an inverse probability of treatment weighting on a propensity score, considering the untreated patients as the reference. RESULTS: Among 502 patients included, 227 (45.2%) received an AP, 68 (13.5%) an AC, 81 (16.1%) a combination AP + AC, and 126 (25.1%) were untreated. As compared with untreated patients, those given AP (HR 5.52, 95% CI [3.11-9.80]), AC (HR: 4.15, 95% CI: [3.46-4.99]), and AP + AC (HR: 5.59, 95% CI [2.62-11.91]) were at greater risk of major bleeding events. CONCLUSIONS: The risk of major bleeding is higher in patients receiving an oral AC compared with untreated patients and those receiving an AP agent. A combination of the two drugs does not seem to increase the risk. Copyright © 2016 John Wiley & Sons, Ltd.