Recovery time of platelet function after aspirin withdrawal

Acute-to-chronic subdural hematoma: radiographic and clinical progression from acute subdural hematoma

INTRODUCTION

The pathogenesis of chronic subdural hematoma (CSDH) has not been completely understood. However, different mechanisms can result in space-occupying subdural fluid collections, one pathway can be the transformation of an original trauma-induced acute subdural hematoma (ASDH) into a CSDH.

MATERIALS AND METHODS

All patients with unilateral CSDH, requiring burr hole trephination between 2018 and 2023 were included. The population was distributed into an acute-to-chronic group (group A, n = 41) and into a conventional group (group B, n = 282). Clinical and radiographic parameters were analyzed. In analysis A, changes of parameters after trauma within group A are compared. In analysis B, parameters between the two groups before surgery were correlated.

RESULTS

In group A, volume and midline shift increased significantly during the progression from acute-to-chronic (p < 0.001, resp.). Clinical performance (modified Rankin scale, Glasgow Coma Scale) dropped significantly (p = 0.035, p < 0.001, resp.). Median time between trauma with ASDH and surgery for CSDH was 12 days. Patients treated up to the 12th day presented with larger volume of ASDH (p = 0.012). Before burr hole trephination, patients in group A presented with disturbance of consciousness (DOC) more often (p = 0.002), however less commonly with a new motor deficit (p = 0.014). Despite similar midline shift between the groups (p = 0.8), the maximal hematoma width was greater in group B (p < 0.001).

CONCLUSION

If ASDH transforms to CSDH, treatment may become mandatory early due to increase in volume and midline shift. Close monitoring of these patients is crucial since DOC and rapid deterioration is common in this type of SDH.

Perioperative management and outcomes in patients receiving low-dose rivaroxaban and/or aspirin: a subanalysis of the Cardiovascular Outcomes for People Using Anticoagulation Strategies (COMPASS) trial

BACKGROUND

No study has investigated the perioperative management and clinical outcomes in patients who are receiving rivaroxaban 2.5 mg twice a day and acetylsalicylic acid (ASA) 81 to 100 mg daily.

OBJECTIVE

To assess perioperative management and outcomes in patients who are receiving low-dose rivaroxaban, 2.5 mg twice-daily, and low-dose ASA, 81 to 100 mg daily. To assess perioperative management and outcomes in patients who are receiving low-dose rivaroxaban, 2.5 mg twice-daily, and low-dose ASA, 81 to 100 mg daily.

METHODS

Subanalysis of the Cardiovascular Outcomes for People Using Anticoagulation Strategies (COMPASS) trial was performed to assess perioperative management and clinical outcomes in patients with stable coronary or peripheral artery disease who were randomized to receive rivaroxaban 2.5 mg twice a day plus ASA 100 mg daily, rivaroxaban 5 mg twice a day, or ASA 100 mg daily. Patients studied required a surgery/procedure during the trial. The study outcomes, which included myocardial infarction, angina, stroke, acute limb ischemia, bleeding, and death, were assessed according to treatment allocation.

RESULTS

There were 2632 patients studied (mean age, 68 years; 80% male) who had a surgery/procedure, comprising percutaneous coronary interventions (∼43%), carotid or other arterial angioplasty (∼15%), pacemaker or internal cardiac defibrillator implantation (∼9%), and coronary artery bypass graft surgery (∼7%). Perioperative study drug management varied, with about one-third of patients not interrupting study drug and the remainder interrupting it between 1 and ≥10 days preprocedure. The incidences of adverse outcomes across treatment groups were 12.7% to 15.3% for myocardial ischemia, 0.8% to 1.2% for stroke, 0.1% to 0.2% for venous thromboembolism, and 3.1% to 4.2% for any bleeding. There was no statistically significant difference in outcome rates across treatment groups.

CONCLUSION

In patients in the COMPASS trial who required a surgery/procedure, there was no significant difference in perioperative adverse outcomes whether patients were receiving rivaroxaban 2.5 mg twice a day and ASA 100 mg daily, rivaroxaban 5 mg twice a day, or ASA alone.

Aspirin 15cH has Different Effects on Morphology and Function of Lipopolysaccharide-Challenged RAW 264.7 Macrophages In Vitro Compared to a Pharmacological Dose of Aspirin

INTRODUCTION

 Aspirin is one of the most commonly used drugs worldwide. It is known to present antipyretic, anti-inflammatory and anti-thrombotic actions, making it extremely useful in a wide range of clinical contexts. Interestingly, homeopathically prepared Aspirin 15cH has been found to have a pro-thrombotic effect in rats, raising the hypothesis that Aspirin 15cH could also modulate the activity of inflammatory cells in different pathological processes.

OBJECTIVE

 Our objective was to assess what effect Aspirin 15cH has on RAW 264.7 macrophages in vitro.

METHODS

 The effects of Aspirin 15cH on biochemical and morphological activities of lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages were evaluated. These effects were compared with unchallenged macrophages (negative control), untreated LPS-stimulated macrophages, macrophages treated with succussed water (vehicle control), or aspirin 200 µg/mL (pharmacological inhibitor of LPS activity). Cell morphology (adhered cell area and cytoskeleton arrangements), cell viability, toll-like receptor-4 (TLR-4) expression, and the production of nitric oxide, cytokines and intracellular reactive oxygen species were assessed.

RESULTS

 Aspirin 15cH reduced the number of cells expressing TLR-4 on the surface (p = 0.03) and induced a "columnar" morphology of macrophage pseudopods, indicating changes in cytoskeleton arrangement. When cells were treated with both Aspirin 15cH and LPS, cell morphology became heterogeneous, suggesting that sub-populations of cells had differing sensitivities to LPS or Aspirin 15cH. Exposure of the cells to LPS alone, succussed water or aspirin 200 µg/mL produced effects consistent with the literature.

CONCLUSION

 Aspirin 15cH, aspirin 200 µg/mL, LPS and succussed water appear to act as independent stimuli able to induce different patterns of macrophage response. Aspirin 15cH induced changes suggestive of M2 polarization of the macrophages (i.e., toward a wound healing or tissue repair, rather than inflammatory, phenotype). These preliminary findings need to be confirmed in further specific studies.

Perioperative Management of Oral Anticoagulants and Antiplatelet Therapy in Hand and Wrist Surgery

There is wide variability in the management of patients on antithrombotic therapy requiring surgery of the hand and wrist. There are no specific guidelines regarding whether to temporarily cease or continue oral anticoagulants and antiplatelet agents. Discontinuation of these medications before surgery can lead to perioperative thromboembolic or ischemic events. On the other hand, continuation can lead to intraoperative or postoperative bleeding complications. This review discusses various anticoagulants and antiplatelet agents with special considerations for their management, analyzes the current literature, summarizes current recommendations, and provides direction for additional research.

Aspirin vs Clopidogrel: Antiplatelet Agent of Choice for Those With Recent Bleeding or at Risk for Gastrointestinal Bleed

Antiplatelet agents are used worldwide mainly for primary and secondary prevention of cardiovascular events on a long-term basis for mortality benefit. Gastrointestinal bleeding is a well-known adverse effect. Various factors are to be considered while choosing antiplatelet agents to prevent the risk of bleed and rebleed incidents. These range from deciding on the agent, timing of therapy, underlying indications, coadministration of proton pump inhibitor, etc. At the same time, one must weigh the risks of cardiovascular events secondary to the stoppage of antiplatelet therapy. With this review, we have tried to guide the clinician on decision-making regarding the care of patients on management of acute upper and lower gastrointestinal bleeding, stoppage, restarting of agents, and measures to prevent a recurrence. We have focused on aspirin and clopidogrel as they are among the most widely used antiplatelet agents.

Estimation of Platelet Count and Bleeding Time of Mice Treated with Musa paradisiaca var. sapientum (L.) Kuntze Extract

Objective

The aim of this study was to estimate the platelet count and bleeding time on peripheral blood smear of mice tail wound using Musa paradisiaca var. sapientum (L.) Kuntze (ambonese banana stem extract).

Design

Randomized post-test-only control group design.

Materials and Methods

Twenty-four male mice (Mus Musculus) were randomly divided into 4 groups. A negative control group was treated with carboxymethyl cellulose (CMC), a positive control group (K+) treated aspirin 100 mg/kg body weight, group P1 treated with aspirin 100 mg/kg body weight and tranexamic acid 50 mg/kg body weight, and group P2 treated with 30% of ambonese banana stem extract (ABSE). The mean and standard deviation data of platelet counts and bleeding time were analyzed by one-way ANOVA statistical software.

Results and Discussion

Tranexamic acid had no significant effect on platelets count compared to CMC group (p = 0.871), but administration of aspirin resulted in low platelets count significantly (p = 0.003). The platelet counts of ABSE and CMC groups were not significant different (p = 0.937). Aspirin has significantly shown prolonged bleeding time than CMC, tranexamic acid, and ABSE groups. However, there was no difference between the tranexamic acid and ABSE groups (p=0.934). The bleeding time of tranexamic acid and ABSE groups was similar, although the platelet count in the ABSE group was lower than in the CMC group.

Conclusion

This study proved that ambonese banana stem extract has a potency to shorten the bleeding time in mice tail wound without interfering to platelet count.

Aspirin, heparin and ischemia time in microvascular free flap surgery - their influence and an optimal anticoagulation protocol

BACKGROUND

Microvascular surgery has become a standardized technique for reconstruction of large tissue defects in Head and Neck Reconstructive Surgery. However, the main dreaded complications are thrombosis of blood vessels or major bleeding after surgery. Several different anticoagulation protocols have been established in the last decades to overcome these problems with varying degrees of success.

METHODS

Over a period of six years, a standardized anticoagulation protocol including acetylsalicylic acid (ASA) and unfractionated heparin (UFH) for direct intraoperative and postoperative administration was established, optimized and compared to a previously used non-standardized protocol. A total of 178 flap surgeries were included in the development and optimization process of the protocol.

RESULTS

ASA significantly increased the risk of complications when used for longer than 72 h (OR = 2.52; p = 0.002; 95% CI 1.39-4.59). Administration of UFH reduced flap loss (bolus: OR 0.68; p = 0.47; 95% CI 0.24-1.93; continuous UFH administration: OR = 0.61; p = 0.33; 95% CI 0.22-1.66), however doses greater than 500 IU/ h of UFH as continuous infusion increased the risk of complications. Reduction in ischemia time had no effect on the occurrence of complications.

CONCLUSION

Anticoagulation regimes in microvascular surgery can influence the postoperative complication rate. The optimal protocol should consist of a combination of ASA and UFH for the intraoperative and direct postoperative phase. Prolonged administration of ASA as well as doses &gt;500 IU/ h of UFH are to be avoided due to the increased complication rate.

Comparative effectiveness and safety of different combinations of antithrombotic regimens in atrial fibrillation patients with stent insertions

This study aims to compare the risks of major adverse cardiac events (MACEs), including cardiovascular death, myocardial infarction, ischemic stroke and transient ischemic attack, and major bleeding across different antithrombotic regimens in Asian atrial fibrillation (AF) patients with stent insertions. We conducted a retrospective cohort study using Taiwan's National Health Insurance Research Database and National Mortality Registry. A total of 10,208 nonvalvular AF patients who had undergone percutaneous coronary intervention (PCI) with stents for the first time in 2007-2017 were identified. Most patients (68.4%) were prescribed dual antiplatelet therapy (DAPT) at discharge. During follow-up, the use of anticoagulants increased, and double therapy (an antiplatelet plus an anticoagulant) was the most frequently prescribed therapy. The risks of MACEs were comparable in double therapy and had a similar risk of MACEs compared to DAPT (aHR 0.86; 95% CI 0.67-1.11). Triple therapy (DAPT plus an anticoagulant) also had similar effectiveness to double therapy (1.23; 0.84-1.80) or DAPT (1.06; 0.77-1.45). However, triple therapy was associated with a nearly twofold higher major bleeding risk than DAPT and double therapy (1.97; 1.31-2.94 and 1.80; 1.10-2.95, respectively). DAPT was the most frequently prescribed antithrombotic regimen at discharge for Asian AF patients who had undergone stent insertions. DAPT and double and triple therapy had comparable effectiveness, but triple therapy had a significantly higher major bleeding risk than either DAPT or double therapy.

Endothelium, Platelets, and Coagulation Factors as the Three Vital Components for Diagnosing Bleeding Disorders: A Simplified Perspective with Clinical Relevance

Bleeding disorders are a major group of hematological disorders, which are highly prevalent in the world. Excessive bleeding can result in serious consequences including hypoperfusion and cardiac arrest. The body has its selfmechanism to control excessive bleeding which is termed hemostasis. Hemostasis is achieved in two major steps, the formation of the primary and secondary hemostatic plugs. Endothelium, platelets, and coagulation factors are three components involved in hemostasis. Endothelium and platelets have a major role in forming the primary hemostatic plug. Consequently, the first step in investigating a bleeding disorder is platelet count. Despite normal platelet count, abnormality in the primary hemostatic plug may arise due to functional defects of the platelets including adhesion, activation, and aggregation. Von Willebrand disease (VWD) is an endothelial defect and the most prevalent inherited defect in coagulation. Abnormalities in the secondary hemostatic plug are largely due to coagulation factor deficiencies, and, to a lesser extent, the presence of inhibitors. Techniques involving viscoelastics have been aiding in rapid diagnosis and are useful in point-of-care testing. This article discusses the investigation of bleeding disorders from the perspective of the endothelium, platelet, and coagulation factor physiology. These three components should be properly investigated to achieve the definitive diagnosis of bleeding disorders.

Impact of Preoperative Aspirin on Long-Term Outcomes in Diabetic Patients Following Coronary Artery Bypass Grafting: a Propensity Score Matched Study

Introduction

This study aimed to determine the effect of preoperative aspirin administration on early and long-term clinical outcomes in patients suffering from diabetes mellitus (DM) undergoing coronary artery bypass grafting (CABG).

Methods

In this observational study, a total of 315 patients were included and grouped according to the time interval between their last aspirin dose and the time of surgery; patients who had been continued aspirin intake with last administered dose ≤ 24-hours before CABG (n=144) and those who had been given the last dose of aspirin between 24 to 48 hours before CABG (n=171).

Results

Multivariable analysis showed that the continuation of preoperative aspirin intake ≤ 24 hours before CABG in patients with DM is associated with reduced incidence of 30-day major adverse cardiac and cerebral events (MACCE) (P=0.004) as well as reduced incidence of composite 30-day mortality/MACCE (P=0.012). During mean follow-up of 37±17.5 months, the unadjusted hazard ratio (HR) showed that aspirin ≤ 24 hours prior CABG in patients with DM significantly reduced the incidence of MACCE and composite of mortality/MACCE during follow-up (HR: 0.50; 95% confidence interval [CI]: 0.29-0.87; P=0.014 and HR: 0.61; 95% CI: 0.38-0.97; P=0.039, respectively). However, after propensity score (PS) matching, the PS-adjusted HR showed a non-significant trend towards the reduction of MACCE during follow-up (HR: 0.58; 95% CI: 0.31-1.06; P=0.081).

Conclusion

Continuation of preoperative aspirin intake ≤ 24 hours before CABG in patients with DM is associated with reduced incidence of early MACCE, but without significant influence on long-term outcomes.

Current-Induced Vasodilation Specifically Detects, and Correlates With the Time Since, Last Aspirin Intake: An Interventional Study of 830 Patients

BACKGROUND

Galvanic current-induced vasodilation (CIV) is impaired in patients under low-dose aspirin (ASA; ≤ 500 mg/day), but potential covariates and the impact of the time since the last ASA intake are unknown.

OBJECTIVES

We used tissue viability imaging (TiVi) in patients at risk of cardiovascular disease and examined its association with self-reported treatments.

PATIENTS/METHODS

We recorded the age, gender, height, weight, smoking status, and use of 14 different drug categories in 822 patients either with known peripheral artery disease or at risk thereof. The difference between TiVi arbitrary units (TAUs) where stimulation was applied and an adjacent skin area was recorded, as well as the time since the last ASA intake. Step-by-step regression analysis was used to determine the factors that affect CIV amplitude.

RESULTS AND CONCLUSIONS

CIV was 28.2 ± 22.9 vs. 14.6 ± 18.0 TAUs (P < 0.001) in patients treated with ASA (n = 287) and not treated with ASA (n = 535), respectively. The main determinants of CIV amplitude, by order of importance, were: aspirin intake, diabetes mellitus, age, and male sex. In ASA-treated patients, the main determinants were diabetes mellitus, time since the last ASA intake, male gender, and age. Non-invasive determination of the physiological effects of low-dose ASA is feasible in routine clinical practice. It could be a clinical approach to provide objective evidence of ASA intake, and potentially could be used to test adherence to treatment in ASA-treated patients.

Aspirin non-response in pregnant women at increased risk of pre-eclampsia

OBJECTIVES

Low dose aspirin (LDA) is recommended for women at increased risk of preeclampsia (PE), however it is not always effective. The study sought to determine the prevalence of non-response to LDA and to ascertain the effect of increasing aspirin dose in non-responders.

STUDY DESIGN

Single centre, cohort study of 166 women at increased risk of PE was conducted in a large maternity unit in the UK between 2013 and 2016. All women were prescribed 75 mg of aspirin and invited to attend study visits at 18-24 weeks' and 32-36 weeks' gestation. Non-response was defined as a serum thromboxane B2 (TXB₂) ≤10 ng/mL. Aspirin dose was increased to 150 mg if a bedside VerifyNow test suggested non-response (test value ≥ 550 arachidonic acid reactive units [ARU]) at 18-24 weeks. Adherence was assessed by self-report.

RESULTS

Based on serum TXB₂, response rates were 85.3 % at 18-24 weeks and 79.3 % at 32-36 weeks' gestation. Compared to serum TXB₂, the VerifyNow test demonstrated moderate test performance (AUC 0.79 95 % CI 0.71-0.88, p < 0.0001) to detect non-response. High prevalence of non-adherence (6/10) was evident in persistent non-response group. Dose change from 75 to 150 mg of aspirin in adherent participants improved response (VerifyNow: 598 [95 % CI 550-665] ARU at 18-24 weeks on 75 mg aspirin, 509 [95 % CI 350-667] at 32-36 weeks on 150 mg of aspirin, [p < 0.0001]).

CONCLUSIONS

Non-response to LDA is common in pregnancy but appears to be largely attributable to non-adherence. Dose change could be useful to improve response to LDA in this cohort.

Not all (N)SAID and done: Effects of nonsteroidal anti-inflammatory drugs and paracetamol intake on platelets

Platelets are key mediators of hemostasis and thrombosis and can be inhibited by nonsteroidal anti-inflammatory drugs (NSAIDs). As a result, platelet donors are temporarily deferred from donating if they have recently taken NSAIDs such as aspirin or ibuprofen. Despite these measures, a proportion of platelet donations show exposure to these drugs; however, little is known about the effect of NSAIDs and their metabolites on platelet quality in vivo and during storage. In this review, the effect of NSAIDs on platelet function is summarized, with a focus on the widely consumed over-the-counter (OTC) medications aspirin, ibuprofen, and the non-NSAID paracetamol. Aspirin and ibuprofen have well-defined antiplatelet effects. In comparison, studies regarding the effect of paracetamol on platelets report variable findings. The timing and order of NSAID intake is important, as concurrent NSAID use can inhibit or potentiate platelet activation depending on the drug taken. NSAID deferral periods and maximum platelet shelf-life is set by each country and are revised regularly. Reduced donor deferral periods and longer platelet storage times may affect the quality of platelet products, and it is therefore important to identify the possible impact of NSAID intake on platelet quality before and after storage.

Perioperative management of patients with rheumatoid arthritis undergoing orthopaedic surgery

Rheumatoid arthritis is an autoimmune disease which is characterised by systemic inflammation. In the recent decades, the advent of disease modifying anti-rheumatic drugs have reduced the need for orthopaedic procedures. However, there are numerous patients in which pharmacological treatment fails and these patients require surgical intervention. Complications can arise due to the underlying pathology and multitude of medications these patients can be on, specifically increased infection rates due to use of immunosuppressive agents. An understanding into the disease itself, as well as perioperative management, may improve overall patient outcomes and prevent future complications.

Effect of Acetylsalicylic Acid Dose and Time Discontinued Preoperatively on Outcomes After Total Knee and Hip Arthroplasty

The purpose of this study was to determine if acetylsalicylic acid (ASA) dose or time discontinued preoperatively affected surgical outcomes in total joint arthroplasty (TJA). The authors hypothesized that ASA worsens surgical outcomes in patients receiving higher doses and in those who discontinue ASA closer to the operative date. A total of 2853 TJAs (1802 primary total knee arthroplasties and 1051 total hip arthroplasties) performed at a tertiary medical center were reviewed. Postoperative outcomes of patients receiving ASA prior to TJA, dosing of ASA (81 mg or 325 mg) preoperatively and postoperatively, and the time of preoperative discontinuation (no ASA, <4 days, <7 days, and 7 or more days) were compared. Preoperative ASA was a risk factor for readmission (odds ratio [OR], 1.86; P<.001) and 90-day postoperative events (OR, 1.26; P=.004). Among patients receiving ASA, the dose was not a risk factor for any of the studied outcomes. Discontinuing ASA 7 or more days prior to TJA was protective for hematomas (OR, 0.64; P=.038), emergency department visits (OR, 0.79; P=.006), readmission (OR, 0.65; P<.001), and 90-day postoperative events (OR, 0.72; P<.001). These outcomes had a time effect: the risk was greater for those who discontinued therapy closer to the operative date. Patients who discontinued ASA 7 or more days prior to TJA had a lower incidence of hematomas, emergency department visits, readmissions, and 90-day postoperative events. This study's findings support discontinuing ASA at least 7 days prior to TJA. [Orthopedics. 2019; 42(5):286-293].

The Safety of Continuing Antiplatelet Medication Among Elderly Patients Undergoing Urgent Hip Fracture Surgery

Elderly patients with hip fractures who are receiving antiplatelet therapy are commonly encountered in clinical practice. This study sought to elucidate the safety of urgent hip surgery without termination of antiplatelet medication among patients taking a combination of aspirin and dipyridamole, aspirin alone, or dipyridamole alone. This retrospective cohort study included 176 patients 55 years or older who had uncomplicated hip fractures and underwent surgery within 48 hours after admission. On the basis of the preoperative medication regimen, the patients were divided into the following 4 groups: those receiving aspirin and dipyridamole combined (n=29); those receiving aspirin alone (n=63); those receiving dipyridamole alone (n=28); and those not receiving antiplatelet medication (n=56). Main outcomes, including total blood loss, transfusion rate, and 1-year mortality, were analyzed. There was no significant difference in total blood loss, transfusion rate, or 1-year mortality among the 4 groups. The group receiving aspirin and dipyridamole combined preoperatively had increased intraoperative blood loss (mean, 309.14±189.15 mL) compared with the group not receiving antiplatelet medication (mean, 214.64±119.21 mL; P=.005). There was no significant difference in the hazard ratio (P>.05) for 1-year mortality among the 4 groups after adjusting for confounding covariates, including age, sex, Charlson Comorbidity Index, and duration of hospital stay. Patients receiving antiplatelet medication, including aspirin, dipyridamole, or both, who have uncomplicated hip fractures may undergo urgent surgery without a significant difference in total blood loss, transfusion rate, or 1-year mortality compared with patients not receiving anti-platelet medication. [Orthopedics. 2019; 42(5):268-274.].

The Effects of Exercise, Aspirin, and Celecoxib in an Atherogenic Environment

INTRODUCTION

Optimal vascular function is a hallmark of cardiovascular health. Specifically, the balance of vasoconstricting and vasodilating substances is recognized as a marker of vascular health. One of the greatest challenges to vascular health and vasodilatory balance is tumor necrosis factor alpha (TNFα)-mediated inflammation. Uncovering effective strategies that maintain a vascular environment that is more vasodilatory and antithrombotic in the face of an inflammatory challenge is favorable.

PURPOSE

To test the ability of various antithrombotic and provasodilatory treatments, as well as combinations thereof, to prevent unfavorable changes in markers of endothelial dysfunction in human umbilical vein endothelial cells when presented with an inflammatory challenge.

METHODS

Human umbilical vein endothelial cells were pretreated with exercise-like levels of laminar shear stress (LSS), aspirin, celecoxib, and their combination before a TNFα challenge. Western blot analysis as well as colorimetric assays were used to determine levels of endothelial nitric oxide synthase (eNOS) and prostacyclin (6-keto PGF1α)/thromboxane (TXB2) metabolite ratio, respectively.

RESULTS

Neither aspirin nor celecoxib were effective in preventing TNFα-induced reduction in eNOS. Further, aspirin was unable to maintain baseline levels of prostacyclin/thromboxane ratio in the face of the inflammatory challenge. Laminar shear stress, aspirin/LSS combination, and celecoxib/LSS combination were all able to prevent TNFα-induced alterations in eNOS levels and prostacyclin/thromboxane ratio.

CONCLUSIONS

Effective strategies to maintain a healthy endothelium, and therefore resistance vessel health, need to include exercise-levels of shear stress to be effective.

The Influence of Antiplatelet Drug Medication on Spine Surgery

Background

The incidence of cardiovascular and neurovascular diseases has been increasing with the aging of the population, and antiplatelet drugs (APDs) are more frequently used than in the past. With the average age of spinal surgery patients also increasing, there has been a great concern on the adverse effects of APD on spine surgery. To our knowledge, though there have been many studies on this issue, their results are conflicting. In this study, we aimed to determine the influence of APDs on spine surgery in terms of intraoperative bleeding and postoperative spinal epidural hematoma complication.

Methods

Patients who underwent posterior thoracolumbar decompression and instrumentation at our institution were reviewed. There were 34 APD takers (APDT group). Seventy-nine non-APD takers (NAPDT group) were selected as a control group in consideration of demographic and surgical factors. There were two primary endpoints of this study: the amount of bleeding per 10 minutes and cauda equina compression by epidural hematoma measured at the cross-sectional area of the thecal sac in the maximal compression site on the axial T2 magnetic resonance imaging scans taken on day 7.

Results

Both groups were homogeneous regarding age and sex (demographic factors), the number of fused segments, operation time, and primary/revision operation (surgical factors), and the number of platelets, prothrombin time, and activated partial thromboplastin time (coagulation-related factors). However, the platelet function analysis-epinephrine was delayed in the APDT group than in the NAPDT group (203.6 seconds vs. 170.0 seconds, p = 0.050). Intraoperative bleeding per 10 minutes was 40.6 ± 12.8 mL in the APDT group and 43.9 ± 9.9 mL in the NAPDT group, showing no significant difference between the two groups (p = 0.154). The cross-sectional area of the thecal sac at the maximal compression site by epidural hematoma was 120.2 ± 48.2 mm² in the APDT group and 123.2 ± 50.4 mm² in the NAPDT group, showing no significant difference between the two groups (p = 0.766).

Conclusions

APD medication did not increase intraoperative bleeding and postoperative spinal epidural hematoma. Therefore, it would be safer to perform spinal surgery without discontinuation of APD therapy in patients who are vulnerable to cardiovascular and neurovascular complications.

Management of antiplatelet therapy in patients undergoing elective invasive procedures. Proposals from the French Working Group on perioperative haemostasis (GIHP) and the French Study Group on thrombosis and haemostasis (GFHT). In collaboration with the French Society for Anaesthesia and Intensive Care Medicine (SFAR)

The French Working Group on Perioperative Haemostasis (GIHP) and the French Study Group on Haemostasis and Thrombosis (GFHT) in collaboration with the French Society for Anaesthesia and Intensive Care Medicine (SFAR) drafted up-to-date proposals for the management of antiplatelet therapy in patients undergoing elective invasive procedures. The proposals were discussed and validated by a vote; all proposals but one could be assigned with a high strength. The management of antiplatelet therapy is based on their indication and the procedure. The risk of bleeding related to the procedure can be divided into high, moderate and low categories depending on the possibility of performing the procedure in patients receiving antiplatelet agents (none, monotherapy and dual antiplatelet therapy respectively). If discontinuation of antiplatelet therapy is indicated before the procedure, a last intake of aspirin, clopidogrel, ticagrelor and prasugrel 3, 5, 5 and 7 days before surgery respectively is proposed. The thrombotic risk associated with discontinuation should be assessed according to each specific indication of antiplatelet therapy and is higher for patients receiving dual therapy for coronary artery disease (with further refinements based on a few well-accepted items) than for those receiving monotherapy for cardiovascular prevention, for secondary stroke prevention or for lower extremity arterial disease. These proposals also address the issue of the potential role of platelet functional tests and consider management of antiplatelet therapy for regional anaesthesia, including central neuraxial anaesthesia and peripheral nerve blocks, and for coronary artery surgery.

Do antiplatelet drugs increase the risk of bleeding after tooth extraction? A case-crossover study

The aim of this study was to assess the risk of bleeding after tooth extraction in patients taking aspirin or clopidogrel. This case-crossover study evaluated patients taking aspirin (80mg/day) or clopidogrel (75mg/day) and undergoing tooth extraction. In the first session, extraction was performed without discontinuing aspirin (group 1) or clopidogrel (group 2). In the second session, patients ceased using antiplatelet drugs 5days prior to tooth extraction. Bleeding was evaluated using a visual analogue scale (VAS) for 72h after tooth extraction. The platelet function assay (PFA) was performed for group 1 and flow cytometry assessment of vasodilator-stimulated phosphoprotein (VASP) was performed for group 2, in both sessions. Thirty-eight patients were studied: 20 in group 1 and 18 in group 2. Analysis of the data did not demonstrate any difference in bleeding severity between sessions 1 and 2 in either group (P>0.05). There was a significant difference between sessions 1 and 2 in group 1 for the mean collagen/epinephrine membrane closure time (PFA) (P=0.001). A significant difference in platelet reactivity index (flow cytometry for VASP) was noted between sessions 1 and 2 in group 2 (P=0.001). According to this case-crossover study, dental extraction can be performed safely without withdrawal of aspirin or clopidogrel.

Primary Prevention of Myocardial Infarction in Rheumatoid Arthritis Using Aspirin: A Case-crossover Study and a Propensity Score–matched Cohort Study

Objective.

Subjects with rheumatoid arthritis (RA) are at higher risk of developing cardiovascular disease, which is their leading cause of death. Conflicting evidence exists regarding the efficacy of aspirin (ASA) as primary prevention. We evaluated whether a protective association exists between ASA and myocardial infarction (MI) in RA subjects.

Methods.

In the United Kingdom, persons age ≥ 60 years receive free ASA by prescription and 75% of use is by prescription. Subjects ≥ 60 years with RA in the population-based The Health Improvement Network database constituted our study population. We excluded patients with history of MI, angina, stroke, peripheral vascular disease, or coronary artery procedures. Our main outcome was the occurrence of fatal and nonfatal MI. We performed a case-crossover study with each subject contributing a hazard period and a control period 90 days prior to the MI. In addition, to minimize confounding by indication, a propensity score (PS)–matched cohort study was performed, considering all patients with RA with an incident prescription of low-dose ASA as our exposed group.

Results.

We did not find a protective effect in the case-crossover study (OR 1.83, 95% CI 0.71–4.71), with 55 subjects exposed in the hazard period and 44 in the control period. Similarly, among 1836 subjects included in the PS-matched cohort study (918 ASA users and 918 ASA non-users), we did not find a protective effect of low ASA on MI (HR 1.39, 95% CI 0.87–2.23).

Conclusion.

We did not find a protective effect of ASA on MI in patients with RA when used as primary prophylaxis.

Aspirin as added prophylaxis for deep vein thrombosis in trauma: A retrospective case-control study

BACKGROUND

Current prophylaxis does not completely prevent deep vein thrombosis (DVT) in trauma patients. Recent data suggest that platelets may be a major contributor to hypercoagulability after trauma, indicating a potential role for antiplatelet medications in prophylaxis for DVT. We sought to determine if preinjury aspirin use was associated with a reduced incidence of lower extremity DVT in trauma patients.

METHODS

Using a retrospective case-control design, we matched 110 cases of posttrauma lower extremity DVT one-to-one with controls using seven covariates: age, admission date, probability of death, number of DVT risk factors, sex, mechanism of injury, and presence of head injury. Data collected included 26 risk factors for DVT, prehospital medications, and in-hospital prophylaxis. Logistic regression models were created to examine the relationship between prehospital aspirin use and posttrauma DVT.

RESULTS

Preinjury aspirin was used by 7.3% of cases (patients diagnosed with in-hospital DVT) compared with 13.6% of controls (p = 0.1). Aspirin was associated with a significant protective effect in multivariate analysis, with an odds ratio of 0.17 (95% confidence interval, 0.04-0.68; p = 0.012) in the most complete model. When stratified by other antithrombotic use, aspirin showed a significant effect only when used in combination with heparinoid prophylaxis (odds ratio, 0.35; 95% confidence interval, 0.13-0.93; p = 0.036).

CONCLUSION

Preinjury aspirin use seems to significantly lower DVT rate following injury. This association is strongest when heparinoid prophylaxis is prescribed after patients on preinjury aspirin therapy are admitted. Aspirin as added prophylaxis for DVT in trauma patients needs to be further evaluated.

LEVEL OF EVIDENCE

Prognostic and epidemiologic study, level III.