Association between antithrombotic therapy and mortality in patients hospitalized for COVID‑19

BACKGROUND

The prothrombotic state is a common abnormality in patients with coronavirus disease 2019 (COVID-19). However, there is controversy over the use of anticoagulants, especially oral anticoagulants (OAC) due to limited studies. We sought to evaluate the association between antithrombotic therapy on mortality and clinical outcomes in patients hospitalized for COVID-19 through propensity score matching (PSM) analysis.

METHODS

A retrospective cohort study was performed to include adult patients with COVID-19 in a university hospital. The primary outcome was in-hospital mortality. Secondary outcomes included intensive care unit (ICU) admission, mechanical ventilation, and acute kidney injury (AKI) during hospitalization. PSM was used as a powerful tool for matching patients' baseline characteristics. Adjusted odds ratios (aOR) with 95% confidence intervals (CI) were calculated from the models.

RESULTS

Of 4,881 COVID-19 patients during the study period, 690 (14.1%) patients received antithrombotic therapy and 4,191 (85.9%) patients were under no antithrombotic therapy. After adjustment with multivariate regression analysis, patients receiving OAC, compared with those who did not receive any antithrombotic therapy, had significantly lower odds for in-hospital mortality (aOR: 0.46. 95% CI: 0.24 to 0.87; P= 0.017). PSM analysis observed similar results (aOR: 0.35. 95% CI: 0.19 to 0.61; P< 0.001). Moreover, in critically ill patients who received mechanical ventilation, antithrombotic treatment (aOR: 0.54. 95% CI: 0.32 to 0.89; P= 0.022) was associated with reduced risk of mortality.

CONCLUSIONS

The application OACs was associated with reduced hospital mortality and mechanical ventilation requirement in COVID-19 patients. Besides, antithrombotic treatment was associated with a reduction in in-hospital mortality among critically ill COVID-19 patients who required mechanical ventilation.

Synthesis and bioevaluation of Scutellarein-Tertramethylpyrazine hybrid molecules for the treatment of ischemic stroke

Ischemic stroke caused by insufficient blood supply to the brain may produce a sequence of cascade reactions, leading to oxidative stress and ultimately inducing nerve cell damage. Therefore, hybrid molecules with multiple therapeutic effects have irreplaceable advantages for the treatment of ischemic stroke. Based on the previous works, two types of Scutellarein and Tertramethylpyrazine hybrid molecules were designed and synthesized according to the PepT 1-based design. After systematic research, all synthesized hybrid molecules exhibited more excellent neuroprotective effect and antiplatelet activity compared to the original drugs. Among them, the selected compound 1e with superior neuroprotective and antiplatelet effects could significantly enhance the permeability on the Caco-2 monolayer membrane and inhibit the Gly-Sar uptake on Caco-2 cells. Meanwhile, the result of intestinal perfusion has also confirmed that the absorption of the selected compound 1e is indeed increased. Further, the selected compound 1e significantly reduce the cerebral infarction volume of middle cerebral artery occlusion/reperfusion rats. Especially, the cerebral infarction volume of the high-dose 1e group reduced to one fourth of the model group. Meanwhile, results of hematoxylin-eosin staining also indicated that the damage in the hippocampus CA1 region was significantly alleviated after treatment with the compound 1e. Accordingly, molecular hybridization strategy is one of the simple and feasible ways to improve the therapeutic effect of single targeted drug.

Long-term prognostic significance of history of cancer and atrial fibrillation in coronary artery disease

Background

Limited data exist on the prognostic significance of a history of cancer and atrial fibrillation (AF) in patients with coronary artery disease (CAD). This study aimed to evaluate the associations among a history of cancer, AF, and long-term prognosis in patients with CAD.

Methods

We studied 3,233 patients with CAD (69 ± 11 years; women, 23%) in a multicenter hospital-based cohort study, the CHART-2 and related a history of cancer and AF to cardiovascular outcomes with a median follow-up of 10.8 years.

Results

Of the 3,233 patients enrolled, 10.7% and 11.2% had a history of cancer and AF, respectively, while 2.8% had both. Patients with AF and a history of cancer were characterized by older age, male sex, and higher BNP levels. Anticoagulant use with warfarin or direct oral anticoagulants increased from 43% at baseline to 56% at 10 years in patients with CAD with AF and no history of cancer and increased from 49% to 83% in those with both. Patients with CAD with both comorbidities had a higher risk of a composite outcome including stroke, thrombosis, and major bleeding (Hazard Ratio [HRadjusted], 2.26; 1.50-3.40, P < 0.001). Furthermore, patients with both comorbidities had a higher risk of all-cause death (1.55; 95% confidence interval [CI] 1.12-2.12, P = 0.007) including cancer death (2.62; 1.51-4.54, P = 0.001), and new-onset heart failure (HF) requiring hospitalization (2.47; 1.54-3.96, P < 0.001).

Conclusions

These results demonstrate that CAD patients with a history of cancer and AF have an increased risk of composite outcomes, including stroke, systemic thrombosis, major bleeding, all-cause death, cancer-related death, and new-onset HF.

First-in-human study to assess the safety, pharmacokinetics, and pharmacodynamics of BMS-986141, a novel, reversible, small-molecule, PAR4 agonist in non-Japanese and Japanese healthy participants

BMS-986141 is a novel, oral, protease-activated, receptor 4 (PAR4)-antagonist that exhibited robust antithrombotic activity and low bleeding risk in preclinical studies. The pharmacokinetic, pharmacodynamic, and tolerability profiles of BMS-986141 in healthy participants were assessed in a randomized, double-blind, placebo-controlled, single-ascending-dose (SAD; N = 60) study; a multiple-ascending-dose (MAD; N = 32) study; and a Japanese MAD (JMAD; N = 32) study. Exposure was dose-proportional for BMS-986141 2.5 mg and 150 mg; maximum concentrations were 17.6 ng/mL and 958 ng/mL; and areas under the curve (AUC) to infinity were 183 h* × ng/mL and 9207 h* × ng/mL, respectively. Mean half-life ranged from 33.7 to 44.7 hours across dose panels. The accumulation index following once-daily administration for 7 days suggested a 1.3- to 2-fold AUC increase at steady state. In the SAD study, BMS-986141 75 and 150 mg produced ≥80% inhibition of 25-100 µM PAR4 agonist peptide (AP)-induced platelet aggregation, without affecting PAR1-AP-induced platelet aggregation, through ≥24 hours postdose. In the MAD and JMAD studies, BMS-986141 doses ≥10 mg completely inhibited 12.5 μM and 25 μM PAR4-AP-induced platelet aggregation through 24 hours. This study found BMS-986141 was safe and well tolerated, with dose-proportional pharmacokinetics and concentration-dependent pharmacodynamics in healthy participants over a wide dose range. ClinicalTrials.gov ID: NCT02341638.

Low dose intravenous cangrelor versus glycoprotein IIb/IIIa inhibitors in endovascular treatment of tandem lesions

OBJECTIVES

Intravenous (IV) periprocedural antiplatelet therapy (APT) for patients undergoing acute carotid stenting during mechanical thrombectomy (MT) is not fully investigated. We aimed to compare the safety profile of IV low dose cangrelor versus IV glycoprotein IIb/IIIa (GP-IIb/IIIa) inhibitors in patients with acute tandem lesions (TLs).

MATERIALS AND METHODS

We retrospectively identified all cases of periprocedural administration of IV cangrelor or GP-IIb/IIIa inhibitors during acute TLs intervention from a multicenter collaboration. Patients were divided in two groups according to the IV APT regimen at the time of MT procedure: 1) cangrelor and 2) GP-IIb/IIIa inhibitors (tirofiban and eptifibatide). Safety outcomes included rates of symptomatic intracranial hemorrhage (sICH), parenchymal hematoma type 1 and 2 (PH1-PH2), and hemorrhagic infarction type 1 and 2 (HI1-HI2).

RESULTS

Sixty-three patients received IV APT during MT, 30 were in the cangrelor group, and 33 were in the GP-IIb/IIIa inhibitors group. There were no significant differences in the rates of sICH (3.3% vs. 12.1%, aOR=0.21, 95%CI 0.02-2.18, p=0.229), HI1-HI2 (21.4% vs 42.4%, aOR=0.21, 95%CI 0.02-2.18, p=0.229), and PH1-PH2 (17.9% vs. 12.1%, aOR=1.63, 95%CI 0.29-9.83, p=0.577) between both treatment groups. However, there was a trend toward reduced hemorrhage rates with cangrelor. Cangrelor was associated with increased odds of complete reperfusion (aOR=5.86; 95%CI 1.57-26.62;p=0.013).

CONCLUSIONS

In this retrospective non-randomized cohort study, our findings suggest that low dose cangrelor has similar safety and increased rate of complete reperfusion compared to IV GP-IIb/IIIa inhibitors. Further prospective studies are warranted to confirm this association.

Clinical outcomes for patients on antiplatelet and anticoagulants in thoracoabdominal trauma

Introduction

Trauma outcomes can be greatly affected by antiplatelet and anticoagulant (AP/AC) use. The goal of this study was to compare outcomes in trauma patients on AP/AC undergoing emergent surgery for thoracoabdominal trauma at 35 level 1 and 2 trauma centers from 2014 to 2021.

Methods

This was a retrospective cohort study of 2460 adult patients with a chest, abdomen, or pelvis abbreviated injury score (AIS) of 2 or more who underwent surgery within 24 h of admission. These patients were segregated into four main cohorts based on antiplatelet/anticoagulation use: those not on AP/AC, those taking direct-acting oral anticoagulants (DOACs), those taking clopidogrel, and those taking warfarin. Patients were excluded if they had surgery >24 h after presentation, were dead on arrival, or had any other body system AIS score of 3 or higher.

Results

The mean injury severity score (ISS) in all four groups ranged from 16.3 to 18.6 (p = 0.834) with a mean time to operating room from 208 to 478 min (p < 0.001). Laparotomy was performed in 60 to 71 % (p > 0.01) of patients, regardless of AP/AC status, and thoracic procedures were performed in 3.1 to 9.3 % (p = 0.42) of patients. In-hospital mortality and hospice rates were highest in the clopidogrel group at 21.9 %, followed by warfarin at 13 %, DOACs at 15 %, and no AP/AC at 7.63 % (p = 0.008). Serious complications occurred in 61 % of patients on warfarin, 50 % of those on DOACs, and 44 % of those on clopidogrel. All of these groups demonstrated significantly higher complication rates than patients in the no AP/AC control group at 25 % (p < 0.001). Total transfusion of packed red blood cells and fresh frozen plasma did not differ significantly between the groups; however, 24-h platelet transfusion did. Patients on clopidogrel received 14 packs of platelets, while those on warfarin and DOACs received 8 and 13 packs respectively (p = 0.011). Patients on warfarin had the longest hospital length of stay (LOS) at 13 days and ICU LOS at 9 days, compared to those on DOACs (8 and 4), those on clopidogrel (7 and 3), and those not taking AC/AP (7 and 4) (hospital LOS p = 0.03, ICU LOS p = 0.019). Those on AC/AP were also noted to be significantly older than those on neither, with those taking these medications averaging out to be approximately 69 years old and those not on these medications averaging 37 years old (p < 0.001).

Conclusion

There was significantly higher mortality in patients on clopidogrel and increased length of stay and risk of serious complications in patients taking DOACs and warfarin. In patients on AP/AC there was also a significantly longer time to surgery than in those not taking either. Given these associations trauma surgeons should consider intervening sooner on patients taking AP/AC on admission, as the delay to intervention may contribute to the risks for trauma patients and result in worse outcomes as well as higher rates of mortality.

Management of acute cholecystitis in patients on anti-thrombotic therapy: A single center experience

Background

Acute cholecystitis in patients on anti-thrombotic therapy (ATT) presents a clinical dilemma at the intersection between conflicting guidelines, specifically between timing of early operative management (OM) versus time-to-reversal of certain ATT agents. With growing recognition that nonoperative management (NOM) is associated with considerable morbidity, and evidence in the literature that early OM in patients on ATT is safe, we reviewed our own practice to examine how we addressed these conflicting guidelines.

Materials and methods

We performed a retrospective review of patients with acute cholecystitis between December 2017 and March 2022. Patients were classified as ATT or non-ATT; ATT patients were subdivided into anticoagulation (AC) and antiplatelet (AP) groups. Rates of OM were compared.

Results

502 patients with acute cholecystitis were identified, 464 non-ATT and 38 ATT. 30 ATT patients were on AC, 7 on AP, and 1 on both. Non-ATT patients were significantly more likely to receive OM at index presentation compared to those on ATT: 89.9 % vs 63.2 % (p < 0.05). Subgroup analysis of the ATT group showed AP patients were significantly less likely to receive OM compared to those on AC, 12.5 % vs 77 % (p < 0.05).

Conclusions

At our institution, patients on ATT were significantly less likely to undergo OM for acute cholecystitis compared with non-ATT patients. Those on AC received OM significantly more than patients on AP. Further study is needed to better define the management of this growing population so that acute cholecystitis guidelines might address this issue in the future.

Pharmacodynamic Drug-Drug Interactions and Bleeding Outcomes in Patients with Atrial Fibrillation Using Non-Vitamin K Antagonist Oral Anticoagulants: a Nationwide Cohort Study

PURPOSE

Pharmacodynamic drug-drug interactions (PD DDIs) may influence the safety of non-vitamin K antagonist oral anticoagulants (NOACs), but the extent to which PD DDIs increase bleeding risks, remains unclear. Therefore, the impact of PD DDIs on bleeding outcomes in NOAC-treated patients with atrial fibrillation (AF) was investigated.

METHODS

Using Belgian nationwide data, NOAC-treated AF patients were included between 2013-2019. Concomitant use of PD interacting drugs when initiating NOAC treatment was identified.

RESULTS

Among 193,072 patients, PD DDIs were identified in 114,122 (59.1%) subjects. After multivariable adjustment, concomitant use of PD interacting drugs was associated with significantly higher risks of major or clinically-relevant non-major bleeding (adjusted hazard ratio (aHR) 1.19, 95% confidence interval (CI) (1.13-1.24)), gastrointestinal (aHR 1.12, 95%CI (1.03-1.22)), urogenital (aHR 1.21, 95%CI (1.09-1.35)) and other bleeding (aHR 1.28, 95%CI (1.20-1.36)), compared to NOAC-treated AF patients without PD interacting drug use. Increased bleeding risks were most pronounced with P2Y12 inhibitors (aHR 1.62, 95%CI (1.48-1.77)) and corticosteroids (aHR 1.53, 95%CI (1.42-1.66)), followed by selective serotonin or serotonin and norepinephrine reuptake inhibitors (SSRI/SNRI, aHR 1.26, 95%CI (1.17-1.35)), low-dose aspirin (aHR 1.14, 95%CI (1.08-1.20)) and non-steroidal anti-inflammatory drugs (NSAID, aHR 1.10, 95%CI (1.01-1.21)). Significantly higher intracranial bleeding risks in NOAC users were observed with SSRI/SNRIs (aHR 1.50, 95%CI (1.25-1.81)) and corticosteroids (aHR 1.49, 95%CI (1.21-1.84)).

CONCLUSION

Concomitant use of PD interacting drugs, especially P2Y12 inhibitors and corticosteroids, was associated with higher major, gastrointestinal, urogenital, and other bleeding risks in NOAC-treated AF patients. Remarkably, higher intracranial bleeding risks were observed with SSRI/SNRIs and corticosteroids.

Addition of aspirin to venous thromboembolism chemoprophylaxis safely decreases venous thromboembolism rates in trauma patients

Background

Trauma patients exhibit a multifactorial hypercoagulable state and have increased risk of venous thromboembolism (VTE). Despite early and aggressive chemoprophylaxis (CP) with various heparin compounds ("standard" CP; sCP), VTE rates remain high. In high-quality studies, aspirin has been shown to decrease VTE in postoperative elective surgical and orthopedic trauma patients. We hypothesized that inhibiting platelet function with aspirin as an adjunct to sCP would reduce the risk of VTE in trauma patients.

Methods

We performed a retrospective observational study of prospectively collected data from all adult patients admitted to an American College of Surgeons Level I Trauma center from January 2012 to June 2015 to evaluate the addition of aspirin (sCP+A) to sCP regimens for VTE mitigation. Cox proportional hazard models were used to assess the potential benefit of adjunctive aspirin for symptomatic VTE incidence.

Results

10,532 patients, median age 44 (IQR 28 to 62), 68% male, 89% blunt mechanism of injury, with a median Injury Severity Score (ISS) of 12 (IQR 9 to 19), were included in the study. 8646 (82%) of patients received only sCP, whereas 1886 (18%) patients received sCP+A. The sCP+A cohort displayed a higher median ISS compared with sCP (13 vs 11; p<0.01). The overall median time of sCP initiation was hospital day 1 (IQR 0.8 to 2) and the median day for aspirin initiation was hospital day 3 (IQR 1 to 6) for the sCP+A cohort. 353 patients (3.4%) developed symptomatic VTE. Aspirin administration was independently associated with a decreased relative hazard of VTE (HR 0.57; 95% CI 0.36 to 0.88; p=0.01). There were no increased bleeding or wound complications associated with sCP+A (point estimate 1.23, 95% CI 0.68 to 2.2, p=0.50).

Conclusion

In this large trauma cohort, adjunctive aspirin was independently associated with a significant reduction in VTE and may represent a potential strategy to safely mitigate VTE risk in trauma patients. Further prospective studies evaluating the addition of aspirin to heparinoid-based VTE chemoprophylaxis regimens should be sought.

Level of evidence

Level III/therapeutic.

The silent killer: Previously undetected pulmonary emboli that result in death after discharge

INTRODUCTION

Pulmonary embolism (PE) is a recognized cause of death in hospitalized trauma patients, yet less is known about PE after discharge.

PATIENTS & METHODS

All post-discharge, autopsy-demonstrated, fatal PE resulting from trauma within a large US county over six years were analyzed. Counts, percentages, mean values, SD, and IQR were calculated for all variables.

RESULTS

1848 trauma deaths were reviewed, of which 85% had an autopsy. Eighty-five patients died from PE after discharge from their initial injury. 53% were initially treated at non-trauma centers, and 9% did not seek medical assistance. 75% were injured by falling, and most injuries occurred in the lower extremities. 86% had an ISS <16, but 87% needed assistance or were bed-bound after injury, despite 75% having no mobility limitations before the injury. 53% died within one month of injury, and 91% within the first year. Before death, only 11% were prescribed chemical thromboprophylaxis or an antiplatelet agent, and only 8% were diagnosed with venous thromboembolism before death.

CONCLUSIONS

Fatal PE after discharge typically occurred following activity-limiting lower extremity injuries with an ISS<16.

Assessing mitochondria-targeted acyl hydroquinones on the mitochondrial platelet function and cytotoxic activity: Role of the linker length

INTRODUCTION

The use of triphenylphosphonium cation (TPP+) linked to phenolic compounds by alkyl chains has a significant relevance as a mitochondrial delivery strategy in biomedicine because it affects mitochondrial bioenergetics in models of noncommunicable diseases such as cancer and cardiovascular-related conditions. Studies indicate that a long alkyl chain (10-12 carbon) increases the mitochondrial accumulation of TPP+-linked drugs. In contrast, other studies show that these compounds are consistently toxic to micromolar concentrations (as observed in platelets). In the present study, we evaluated the in vitro effect of three series of triphenylphosphonium-linked acyl hydroquinones derivates on the metabolism and function of human platelets using 3-9 carbons for the alkyl linker. Those were assessed to determine the role of the length of the alkyl chain linker on platelet toxicity.

METHODS

Human platelets were exposed in vitro to different concentrations (2-40 μM) of every compound; cellular viability, phosphatidylserine exposition, mitochondrial membrane potential (ΔΨm), intracellular calcium release, and intracellular ROS generation were assessed by flow cytometry. An in silico energetic profile was generated with Umbrella sampling molecular dynamics (MD).

RESULTS AND CONCLUSIONS

There was an increase in cytotoxic activity directly related to the length of the acyl chain and lipophilicity, as seen by three techniques, and this was consistent with a decrease in ΔΨm. The in silico energetic profiles point out that the permeability of the mitochondrial membrane may be involved in the cytotoxicity of phosphonium salts. This information may be relevant for the design of new TPP+ -based drugs with a safe cardiovascular profile.

The impact of antiplatelet drugs on recurrent stroke in patients with intracerebral hemorrhage

Background

The influence of antiplatelet drugs on the risk of hemorrhagic stroke and the reduction of ischemic stroke in patients with intracerebral hemorrhage (ICH) remains unclear. This study aimed to elucidate the impact of antiplatelet therapy on the risk of recurrent stroke in ICH patients.

Methods

The study encompassed ICH survivors discharged from a central Taiwanese teaching hospital between January 1, 2013, and December 31, 2019. Patient hospitalization and treatment data were retrieved from electronic medical records. The primary endpoint was re-hospitalization due to ischemic or hemorrhagic stroke. Patients who continued antiplatelet drug use for over a month prior to stroke recurrence constituted the antiplatelet drug use group. Risk factors for recurrent hemorrhagic and ischemic strokes were evaluated using binary logistic regression.

Results

The study incorporated 407 ICH patients, each monitored for 4 years post-stroke. Recurrent stroke incidence showed no significant disparity between hemorrhagic and ischemic strokes. Hemorrhagic stroke recurrence stood at 5.16 % (21/407), and ischemic stroke recurrence was 4.42 % (18/407). In the non-antiplatelet group, hemorrhagic and ischemic stroke rates were 5.48 % (20/365) and 3.56 % (13/365) respectively. In the antiplatelet group, the rates were 2.38 % (1/42) for hemorrhagic and 11.9 % (5/42) for ischemic stroke, with a significantly higher ischemic stroke rate (p = 0.03). Hypertension emerged as a risk factor for recurrent hemorrhagic stroke, while diabetes mellitus was identified as a risk factor for ischemic stroke. Antiplatelet drug use did not escalate the risk of recurrent ICH.

Conclusion

Diabetes mellitus and hypertension are risk factors for recurrent ischemic and hemorrhagic strokes respectively in ICH patients. Antiplatelet therapy does not appear to elevate the risk of recurrent hemorrhagic stroke in these patients.

Risk of Postcolonoscopy Thromboembolic Events: A Real-World Cohort Study

BACKGROUND& AIMS

Although antithrombotic agents could increase the risk of postpolypectomy bleeding, interruption of these agents also increases the risk of thromboembolism (TE). We assessed the risks of postcolonoscopy TE events and their association with the interruption of antithrombotic agents.

METHODS

This was a retrospective cohort study including consecutive patients undergoing colonoscopy between January 2016 and March 2021. We determined the rates of postcolonoscopy TE events in patients taking various antithrombotic agents (with or without interruption), and in different patient groups according to indications for colonoscopy, underlying TE, and bleeding risks.

RESULTS

Of the 6220 patients, 1755 (28.2%) were on antithrombotics. Overall, 20 patients (0.32%) developed TE events, and 25 (0.80%) of 3134 patients with polypectomy experienced major episodes of bleeding. Among all patients on antithrombotic agents, the highest rates of TE events were observed in patients on dual-antiplatelet therapy (4.65%; adjusted odds ratio [aOR], 28.0; 95% CI, 3.77-142.1) and clopidogrel (2.78%; aOR, 12.2; 95% CI, 2.10-57.0), compared with 0.11% among those not on antithrombotics. In patients interrupting anti-thrombotic agents, the risk of TE was increased compared to those on no agent as follows: stopping 2 or more antithrombotic agents (4.55%; aOR, 22.5; 95% CI, 1.09-158.0), monotherapy with clopidogrel (3.06%; aOR, 15.5; 95% CI, 2.86-69.6), warfarin (1.33%; aOR, 6.96; 95% CI, 1.14-33.5), or direct-acting oral anticoagulants (0.87%; aOR, 6.23; 95% CI, 1.22-26.8). Having an underlying high TE risk (aOR, 16.8; 95% CI, 6.33-46.6) was associated with higher postcolonoscopy TE events.

CONCLUSIONS

The risk of post-colonoscopy thromboembolic events is low. However, the temporary interruption of antithrombotic agents, particularly stopping 2 or more agents, clopidogrel, warfarin, or direct-acting oral anticoagulants was associated with higher postcolonoscopy TE events, particularly in high-risk patients.

Regulation of mitochondrial function by hydroquinone derivatives as prevention of platelet activation

Platelet activation plays an essential role in the pathogenesis of thrombotic events in different diseases (e.g., cancer, type 2 diabetes, Alzheimer's, and cardiovascular diseases, and even in patients diagnosed with coronavirus disease 2019). Therefore, antiplatelet therapy is essential to reduce thrombus formation. However, the utility of current antiplatelet drugs is limited. Therefore, identifying novel antiplatelet compounds is very important in developing new drugs. In this context, the involvement of mitochondrial function as an efficient energy source required for platelet activation is currently accepted; however, its contribution as an antiplatelet target still has little been exploited. Regarding this, the intramolecular hydrogen bonding of hydroquinone derivatives has been described as a structural motif that allows the reach of small molecules at mitochondria, which can exert antiplatelet activity, among others. In this review, we describe the role of mitochondrial function in platelet activation and how hydroquinone derivatives exert antiplatelet activity through mitochondrial regulation.

Small-diameter PCL/PU vascular graft modified with heparin-aspirin compound for preventing the occurrence of acute thrombosis

The occurrence of acute thrombosis, directly related to platelet aggregation and coagulant system, is a considerable reason for the failure of small-diameter vascular grafts. Heparin is commonly used as a functional molecule for graft modification due to the strong anticoagulant effect. Unfortunately, heparin cannot directly resist the adhesion and aggregation of platelets. Therefore, we have prepared a heparin-aspirin compound by coupling heparin with aspirin, an antiplatelet drug, and covalently grafted it onto the surface of polycaprolactone/polyurethane composite tube. In this way, the graft not only showed a dual function of both anticoagulation and antiplatelet, but also effectively avoided the rapid drug release and excessive toxicity to other organs caused by simple blending the medicine with material matrix. The compound retained the original function of heparin, showing good hydrophilicity and biocompatibility, which could promote the adhesion and proliferation of endothelial cells (ECs) and facilitate the process of tissue regeneration. What's more, the compound showed more effective than heparin in reducing platelet activation and preventing thrombosis. The graft modified by this compound maintained completely unobstructed for one month of implantation, while severe obstruction or stenosis occurred in PCL/PU and PCL/PU-Hep lumen at the first week, verifying the effect of the compound on preventing acute thrombosis. In general, this study proposed a designing method for small-diameter vascular graft which could prevent acute thrombosis and promote intimal construction.

Antiplatelet therapy in aneurysmal subarachnoid hemorrhage: an updated meta-analysis

Antiplatelet therapy (AT) may serve to reduce the effects of aneurysmal subarachnoid hemorrhage (aSAH)-induced pro-coagulant state in the cerebral circulation. Several studies, however, have delivered conflicting conclusions on the efficacy of AT post aSAH. Systematic searches of Medline, Embase, and Cochrane Central were undertaken on 27th March 2023. The primary outcome was delayed cerebral ischaemia (DCI). Secondary outcomes were symptomatic and angiographic vasospasm, good functional outcome (modified Rankin Scale [mRS] with scores 0-2), hemorrhagic events, and in-hospital mortality. Twenty-two studies reporting 4378 patients with aSAH were included in the meta-analysis. AT was associated with lower rates of DCI (RR=0.62, 95% CI: 0.43; 0.89), symptomatic vasospasm (RR=0.63, 95% CI: 0.46; 0.86), and moderate/severe angiographic vasospasm (RR=0.74, 95% CI: 0.65; 0.84), with no effect on hemorrhagic complications (RR=1.36, 95% CI: 0.77; 2.41). When analyzing only post-ictal use of AT, AT additionally favored rates of good functional outcomes (RR=1.18, 95% CI: 1.10; 1.26) and in-hospital mortality (RR=0.56, 95% CI: 0.39; 0.80). In the subgroup treated with cilostazol, AT was associated with lower rates of DCI (RR=0.40, 95% CI: 0.32), symptomatic vasospasm (RR=0.47, 95% CI: 0.33; 0.65), moderate/severe angiographic vasospasm (RR=0.75, 95% CI: 0.57; 0.98) and good functional outcome (RR=1.24, 95% CI: 1.08; 1.43). In the surgically treated aSAH subgroup, AT favored rates of symptomatic vasospasm (RR=0.55, 95% CI: 0.30; 0.98), moderate/severe angiographic vasospasm (RR=0.70, 95% CI: 0.54; 0.90) and good functional outcome (RR=1.23, 95% CI: 1.09; 1.41). In the endovascularly treated aSAH subgroup, AT was associated with lower rates of in-hospital mortality (RR=0.60, 95% CI: 0.41; 0.88). In aSAH patients, post-ictal AT is associated with benefits in terms of rates of DCI, vasospasm, good functional outcomes, and in-hospital mortality without an increased risk of hemorrhagic events.

Antiplatelet and anticoagulant therapies in hereditary hemorrhagic telangiectasia: A large French cohort study (RETROPLACOTEL)

BACKGROUND

It is unclear whether hereditary hemorrhagic telangiectasia (HHT) patients can tolerate antithrombotic therapies (AT) including antiplatelet (AP) and/or anticoagulant (AC) agents.

OBJECTIVES

Primary endpoint was tolerance to AT in HHT. Secondary endpoints were to identify factors associated with major bleeding events (MBE) and premature discontinuation of AT.

METHODS

Retrospective multicenter study in French national HHT Registry patients exposed to AT.

RESULTS

We included 126 patients with 180 courses of AT. Median follow-up was 24 [11-52] months. Mean age was 65.6 ± 13.1 years. The first 3 months of AT exposure had an increased risk of hospitalization for hemorrhage (p < 0.001) and transfusions (p < 0.001). MBE (n = 63) occurred more frequently in the first 3 months of AT exposure (p < 0.001). Premature discontinuation of AT occurred in 61 cases. Rate of premature discontinuation was 29 % under both AP and AT therapy but significantly higher under dual AP therapy (n = 4/7, 57 % p = 0.008). Risk factors for MBE were: age ≥ 60 years (HR 2.34 [1.12;4.87], p = 0.023), prior hospitalization in the 3 months before starting AT for hemorrhage (HR 3.59 [1.93;6.66], p < 0.001) or transfusion (HR 3.15 [1.61;6.18], p = 0.001), previous history of gastro-intestinal bleeding (HR 2.71 [1.57;4.65], p < 0.001) or MBE (HR 4.62 [2.68;7.98], p < 0.001). Frequency of MBE did not differ between groups except for a higher risk in the dual AP group (HR 3.92 [1.37;11.22], p = 0.011).

CONCLUSION

Tolerance of AC or AP therapy was similar in HHT population but not dual AP therapy. We identified risk factors for MBE occurrence or premature discontinuation under AT.

Prospective observational registry of perioperative and periprocedural management of antithrombotic therapy in "real world": the REQXAA study

INTRODUCTION AND OBJECTIVES

There is scarce real-world evidence on the management of perioperative antithrombotic treatment according to current recommendations. The aim of this study was to analyze the management of antithrombotic treatment in patients undergoing surgery or another invasive intervention and to assess the consequences of this management on the occurrence thrombotic or bleeding events.

METHODS

This prospective, observational, multicenter and multispecialty study analyzed patients receiving antithrombotic therapy who underwent surgery or another invasive intervention. The primary endpoint was defined as the incidence of adverse (thrombotic and/or hemorrhagic) events after 30 days of follow-up with respect to management of perioperative antithrombotic drugs.

RESULTS

We included 1266 patients (male: 63.5%; mean age 72.6 years). Nearly half of the patients (48.6%) were under chronic anticoagulation therapy (mainly for atrial fibrillation; CHA2DS2-VASC: 3.7), while 53.3% of the patients were under chronic antiplatelet therapy (mainly for coronary artery disease). Low ischemic and hemorrhagic risk was found in 66.7% and 51.9%, respectively. Antithrombotic therapy management was in line with current recommendations in only 57.3% of the patients. Inappropriate management of antithrombotic therapy was an independent risk factor for both thrombotic and hemorrhagic events.

CONCLUSIONS

The implementation of recommendations on the perioperative/periprocedural management of antithrombotic therapy in real-world patients is poor. Inappropriate management of antithrombotic treatment is associated with an increase in both thrombotic and hemorrhagic events.

Hematuria and dietary supplements - A case report on pronounced bleeding following a minimally invasive urological intervention in a patient on long term garlic supplements

This report focuses on a patient encounter with suspected significant hematuria post operation occurring primarily due to garlic supplementation. A 65-year-old male underwent day case PVP. He had significant hematuria post operation requiring added use of bipolar coagulation. He was fit and well with no other past medical or drug history apart from dietary supplementation of garlic extracts. There are various mechanisms that components of garlic like allicin can produce antiplatelet effect on blood. This represents a novel case of unexpected bleeding in patient strongly attributed to dietary supplements for a less invasive technique with better hemostatic profile like PVP.

Ticagrelor plus aspirin in patients with minor ischemic stroke and transient ischemic attack: a network meta-analysis

BACKGROUND

Dual antiplatelet therapy (DAPT) with aspirin and clopidogrel was recommended as the secondary prevention of minor ischemic stroke or transient ischaemic attack (TIA). However, genetic polymorphisms of CYP2C19 had been identified as the major cause of poor responsiveness to clopidogrel. Ticagrelor, unlike clopidogrel, did not depend on metabolic activation, but it remained unclear whether ticagrelor was superior to clopidogrel in ischemic stroke. We performed a network meta-analysis to compare the efficacy and safety of ticagrelor, clopidogrel, and aspirin in the minor ischemic stroke and TIA populations.

METHODS

Databases of Cochrane Library, ClinicalTrials.gov, and PubMed were searched up to June 19, 2023. Randomized controlled trials (RCTs) assessing antiplatelet drugs for minor stroke or TIA were included. Statistical processing was conducted by using multivariate meta-analysis routines of STATA.

RESULTS

Seven RCTs were included involving 41,745 participants. There was no significant difference between the two DAPTs in preventing stroke recurrence (OR, 1.16; 95% CI, 0.93-1.44), ischemic stroke recurrence (OR, 1.16; 95% CI, 0.93-1.45), and major hemorrhage (OR, 1.22; 95% CI, 0.62,2.39). Compared with aspirin alone, the two DAPT regimen reduced the risk of stroke recurrence (clopidogrel: OR, 0.69; 95% CI, 0.60-0.80, ticagrelor: OR, 0.66; 95% CI, 0.49-0.87) and ischemic stroke recurrence, but increased the incidence of major hemorrhage (clopidogrel: OR, 2.05; 95% CI, 1.22- 3.77; ticagrelor: OR, 2.55; 95% CI, 1.25-4.99). Despite being associated with a higher risk of any bleeding, ticagrelor did not impact the composite of vascular events or mortality. While ticagrelor and aspirin reduced the risk of ischemic stroke recurrence (OR, 0.77; 95% CI, 0.63- 0.92) without increasing the risk of major bleeding (OR 0.94; 95% CI 0.45-1.95) in the Asian population mainly Chinese.

CONCLUSIONS

DAPT was superior to aspirin in stroke prevention, but little difference existed between the two DAPT regimens. Asian population mainly Chinese may benefit from DAPT with aspirin and ticagrelor. But further head-to-head RCTs are needed to validate the study results.

P-Selectin mediates targeting of a self-assembling phototherapeutic nanovehicle enclosing dipyridamole for managing thromboses

Thrombotic vascular disorders, specifically thromboembolisms, have a significant detrimental effect on public health. Despite the numerous thrombolytic and antithrombotic drugs available, their efficacy in penetrating thrombus formations is limited, and they carry a high risk of promoting bleeding. Consequently, the current medication dosage protocols are inadequate for preventing thrombus formation, and higher doses are necessary to achieve sufficient prevention. By integrating phototherapy with antithrombotic therapy, this study addresses difficulties related to thrombus-targeted drug delivery. We developed self-assembling nanoparticles (NPs) through the optimization of a co-assembly engineering process. These NPs, called DIP-FU-PPy NPs, consist of polypyrrole (PPy), dipyridamole (DIP), and P-selectin-targeted fucoidan (FU) and are designed to be delivered directly to thrombi. DIP-FU-PPy NPs are proposed to offer various potentials, encompassing drug-loading capability, targeted accumulation in thrombus sites, near-infrared (NIR) photothermal-enhanced thrombus management with therapeutic efficacy, and prevention of rethrombosis. As predicted, DIP-FU-PPy NPs prevented thrombus recurrence and emitted visible fluorescence signals during thrombus clot penetration with no adverse effects. Our co-delivery nano-platform is a simple and versatile solution for NIR-phototherapeutic multimodal thrombus control.

Increased anti-thrombotic therapy is associated with decreased major adverse limb events in patients with low wound and foot infection scores

INTRODUCTION

The optimal anti-thrombotic management of patients after lower extremity bypass has yet to be fully elucidated, in part due to significant heterogeneity in patient presentation and practice patterns. The Wound, Ischemia, and foot Infection (WIfI) score is a validated scoring system to assist in the management of patients with chronic limb threatening ischemia (CLTI). We hypothesized that performing a restriction analysis based on WIFI scores would assist in the postoperative anti-thrombotic management of patients undergoing infrainguinal bypass.

METHODS

A retrospective cohort of infrainguinal bypass procedures completed at a single hospital system between January 2018 and January 2021 was selected, and preoperative WIfI scores were extracted for each patient. Patients with either Wound scores of 2 and 3, or Ischemia Scores of 0 and 1, or Foot Infection Scores of 3 were excluded. Based on the type of anti-thrombotic regimen on discharge, demographics, comorbidities, type of bypass, 30-day rates of graft occlusion, major amputation, mortality, and major adverse limb events (MALE) were analyzed. Statistical analysis included t-tests, chi square tests, and time-to-event survival analysis.

RESULTS

230 procedures were included in the study. 69 (30.0%) patients were discharged on single antiplatelet therapy (SAPT), compared to 161 (70.0%) who were discharged on either dual antiplatelet therapy or anticoagulation (DAPT/AC). There was a higher prevalence of bypasses using prosthetic conduit in the DAPT/AC group (45.9 vs 31.8%, p = .047); no other demographic or procedural variable analyzed had any significant differences. At 30-days postoperatively, there was no significant difference in postoperative reintervention rates, however, the DAPT/AC group had significantly lower rates of mortality (1.2 vs 7.2%, p = .01), major amputation (1.2% vs 5.8%, p = .04), and MALE (3.7 vs 13.0%, p < .01). There were no significant differences in bleeding complications. Survival analysis demonstrated that MALE-free survival was higher in the DAPT/AC group compared to the SAPT group (p < .01). On Cox regression analysis, DAPT/AC was associated with significantly decreased rates of MALE + mortality (Hazard Ratio (HR) 0.20 [0.06 - 0.66]).

CONCLUSION

Lower extremity bypasses patients with low Wound and low foot Infection scores who are discharged on DAPT/AC postoperatively have a significantly higher 30-day MALE-free survival rate compared to patients discharged on SAPT; consideration could be made to preferentially discharge such post-bypass patients on DAPT/AC.

Intravenously administered APAC, a dual AntiPlatelet AntiCoagulant, targets arterial injury site to inhibit platelet thrombus formation and tissue factor activity in mice

INTRODUCTION

Arterial thrombosis is the main underlying mechanism of acute atherothrombosis. Combined antiplatelet and anticoagulant regimens prevent thrombosis but increase bleeding rates. Mast cell-derived heparin proteoglycans have local antithrombotic properties, and their semisynthetic dual AntiPlatelet and AntiCoagulant (APAC) mimetic may provide a new efficacious and safe tool for arterial thrombosis. We investigated the in vivo impact of intravenous APAC (0.3-0.5 mg/kg; doses chosen according to pharmacokinetic studies) in two mouse models of arterial thrombosis and the in vitro actions in mouse platelets and plasma.

MATERIALS AND METHODS

Platelet function and coagulation were studied with light transmission aggregometry and clotting times. Carotid arterial thrombosis was induced either by photochemical injury or surgically exposing vascular collagen after infusion of APAC, UFH or vehicle. Time to occlusion, targeting of APAC to the vascular injury site and platelet deposition on these sites were assessed by intra-vital imaging. Tissue factor activity (TF) of the carotid artery and in plasma was captured.

RESULTS

APAC inhibited platelet responsiveness to agonist stimulation (collagen and ADP) and prolonged APTT and thrombin time. After photochemical carotid injury, APAC-treatment prolonged times to occlusion in comparison with UFH or vehicle, and decreased TF both in carotid lysates and plasma. Upon binding from circulation to vascular collagen-exposing injury sites, APAC reduced the in situ platelet deposition.

CONCLUSIONS

Intravenous APAC targets arterial injury sites to exert local dual antiplatelet and anticoagulant actions and attenuates thrombosis upon carotid injuries in mice. Systemic APAC provides local efficacy, highlighting APAC as a novel antithrombotic to reduce cardiovascular complications.

Optimal antiplatelet therapy for patients after antiplatelet therapy induced gastrointestinal bleeding: timing

Adjusting antiplatelet strategies after antiplatelet-associated gastrointestinal bleeding (GIB) is a complex clinical challenge. To assess the risk of outcomes at different times of resumption of antiplatelet therapy in an attempt to find the optimal time to resume therapy. The study analyzed consecutive patients with antiplatelet-associated GIB from Beijing Friendship Hospital Information System between October 2019 and June 2022. The primary outcomes were recurrent bleeding, major adverse cardiovascular and cerebrovascular events (MACE), and all-cause death. Multivariate-adjusted Cox proportional hazards models were used to evaluate the risks of these outcomes. The receiver operating characteristic curve was used to find the optimal time to resume treatment. Of the 617 patients with GIB after antiplatelet therapy successfully followed up, the median follow-up was 246 (interquartile range: 120-466) days, most patients (87.36%) interrupted therapy after GIB and 45.22% resumed within 90 days, of which 35.13% resumed within 7 days and 64.87% resumed after 7 days. Resumption therapy had a low risk of recurrent bleeding (uninterrupted as a reference: HR 0.32, 95% CI 0.15-0.67, p = 0.003), MACE (no resumption as a reference: HR 0.66, 95% CI 0.45-0.98, p = 0.037), and all-cause death (no resumption as a reference: HR 0.18, 95% CI 0.08-0.40, p < 0.001). And resuming therapy within 7 days had a lower risk of MACE (HR 0.18, 95% CI 0.08-0.44, p < 0.001) than after 7 days without a significantly higher risk of re-bleeding. The optimal time point for resuming therapy in this study was 8.5 days. Resuming antiplatelet therapy after GIB provides better clinical benefits compared to discontinued and uninterrupted therapy, especially compared with resuming after 7 days, resuming within 7 days is associated with a lower risk of MACE and a less significant increased risk of recurrent bleeding, leading to a higher net clinical benefit. China Clinical Trial Registration: ChiCTR2200064063.

Daily aspirin associated with a reduced risk of hepatocellular carcinoma in patients with non-alcoholic fatty liver disease: a population-based cohort study

Background

Emerging laboratory and animal studies suggest that aspirin may prevent non-alcoholic fatty liver disease (NAFLD)-related hepatocellular carcinoma (HCC), however clinical evidence remains lacking.

Methods

Using Taiwan's National Health Insurance Research Database, we screened 145,212 NAFLD patients from 1997 through 2011. After excluding any confounding conditions, 33,484 patients who continuously received a daily dose of aspirin for 90 days or more (treated group), along with 55,543 patients who had not received antiplatelet therapy (untreated group), were respectively recruited. Inverse probability of treatment weighting using the propensity score was applied to balance the baseline characteristics. Cumulative incidence of, and hazard ratio (HR) for HCC occurrence were analyzed after adjusting competing events. The high-risk patients, who were defined as age ≥ 55 years & elevated serum alanine aminotransferase, were further analyzed.

Findings

The 10-year cumulative incidence of HCC in the treated group was significantly lower than that in the untreated group (0.25% [95% CI, 0.19-0.32%] vs. 0.67% [95% CI, 0.54-0.81%]; P < 0.001). Aspirin therapy was significantly associated with a reduced HCC risk (adjusted HR [aHR] 0.48 [95% CI, 0.37-0.63]; P < 0.001). In the high-risk patients, the 10-year cumulative incidence of HCC in the treated group was significantly lower than that in the untreated group (3.59% [95% CI, 2.99-4.19%] vs. 6.54% [95% CI, 5.65-7.42%]; P < 0.001). Aspirin therapy remained associated with a reduced HCC risk (aHR 0.63 [95% CI, 0.53-0.76]; P < 0.001). Subgroup sensitivity analyses verified this significant association in nearly all subgroups. In the time-varying model amongst aspirin users, HCC risk was significantly lower through the use of aspirin for ≥ 3 years (aHR 0.64 [95% CI, 0.44-0.91]; P = 0.013), when compared with short-term use (< 1 year).

Interpretation

Daily aspirin therapy is significantly associated with a reduced HCC risk in NAFLD patients.

Funding

Ministry of Science and Technology, Ministry of Health and Welfare, and Taichung Veterans General Hospital, Taiwan.