Pharmacologic dissection of the overlapping impact of heat shock protein family members on platelet function

BACKGROUND

Platelets play a pivotal role in hemostasis, wound healing, and inflammation, and are thus implicated in a variety of diseases, including cancer. Platelet function is associated with release of granule content, cellular shape change, and upregulation of receptors that promote establishment of a thrombus and maintenance of hemostasis.

OBJECTIVES

The role of heat shock proteins (Hsps) in modulating platelet function has been studied for a number of years, but comparative roles of individual Hsps have not been thoroughly examined.

METHODS

We utilized a panel of specific inhibitors of Hsp40, Hsp70, Hsp90, and Grp94 (the endoplasmic reticulum homolog of Hsp90) to assess their impact on several aspects of platelet function.

RESULTS

Inhibition of each of the aforementioned Hsps reduced alpha granule release. In contrast, there was some selectivity in impacts on dense granule release. Thromboxane synthesis was impaired after exposure to inhibitors of Hsp40, Hsp90, and Grp94, but not after inhibition of Hsp70. Both expression of active glycoprotein IIb/IIIa (GPIIb/IIIa) and fibrinogen-induced platelet shape change were diminished by our inhibitors. In contrast, aggregation was selectively abrogated after inhibition of Hsp40 or Hsp90. Lastly, activated platelet-cancer cell interactions were reduced by inhibition of both Hsp70 and Grp94.

CONCLUSIONS

These data suggest the importance of Hsp networks in regulating platelet activity.

Stroke prevention in atrial fibrillation changes after dabigatran availability in China: The GLORIA-AF registry

Background

Until the approval of dabigatran etexilate, treatment choices for stroke prevention in patients with atrial fibrillation (AF) were vitamin K antagonists (VKAs) or antiplatelet drugs. This analysis explored whether availability of non-vitamin K antagonist oral anticoagulants post-dabigatran approval was associated with changing treatment patterns in China.

Methods

Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation (GLORIA-AF) collected data on antithrombotic therapy choices for patients with newly diagnosed nonvalvular AF at risk for stroke. In China, enrollment in phase 1 (before dabigatran approval) and phase 2 (after dabigatran approval) occurred from 2011 to 2013 and 2013 to 2014, respectively. Analyses were restricted to sites within China that contributed patients to both phases. The weighted average of the site-specific results was estimated for standardization. Sensitivity analyses used multiple regression.

Results

Thirteen sites participated in both phase 1 (419 patients) and phase 2 (276 patients), 76.1% and 16.0% were known to be at high risk for stroke (CHA₂DS₂-VASc ≥2) and bleeding (HAS-BLED ≥3); 55.5% were male. In phase 1, 16.7%, 61.6%, and 21.7% of patients were prescribed oral anticoagulants (OACs), antiplatelet agents, and no treatment, respectively. Respective proportions were 26.4%, 40.6%, and 33.0% in phase 2. The absolute increase in the site-standardized proportion of patients prescribed OACs after dabigatran availability was 9.9% (95% confidence interval [CI]: 3.7%-16.0%). There was a standardized 17.3% (95% CI: -24.3% to -10.4%) absolute decrease in antiplatelet agent use.

Conclusions

There was an increase in OAC and decrease in antiplatelet agent prescription since dabigatran availability in China. However, a large proportion of AF patients at risk for stroke remained untreated.

P2Y12 Inhibition beyond Thrombosis: Effects on Inflammation

The P2Y₁₂ receptor is a key player in platelet activation and a major target for antithrombotic drugs. The beneficial effects of P2Y₁₂ receptor antagonists might, however, not be restricted to the primary and secondary prevention of arterial thrombosis. Indeed, it has been established that platelet activation also has an essential role in inflammation. Additionally, nonplatelet P2Y₁₂ receptors present in immune cells and vascular smooth muscle cells might be effective players in the inflammatory response. This review will investigate the biological and clinical impact of P2Y₁₂ receptor inhibition beyond its platelet-driven antithrombotic effects, focusing on its anti-inflammatory role. We will discuss the potential molecular and cellular mechanisms of P2Y₁₂-mediated inflammation, including cytokine release, platelet–leukocyte interactions and neutrophil extracellular trap formation. Then we will summarize the current evidence on the beneficial effects of P2Y₁₂ antagonists during various clinical inflammatory diseases, especially during sepsis, acute lung injury, asthma, atherosclerosis, and cancer.

Platelet Adhesion and Thrombus Formation in Microchannels: The Effect of Assay-Dependent Variables

Microfluidic flow chambers (MFCs) allow the study of platelet adhesion and thrombus formation under flow, which may be influenced by several variables. We developed a new MFC, with which we tested the effects of different variables on the results of platelet deposition and thrombus formation on a collagen-coated surface. Methods: Whole blood was perfused in the MFC over collagen Type I for 4 min at different wall shear rates (WSR) and different concentrations of collagen-coating solutions, keeping blood samples at room temperature or 37 °C before starting the experiments. In addition, we tested the effects of the antiplatelet agent acetylsalicylic acid (ASA) (antagonist of cyclooxygenase-1, 100 µM) and cangrelor (antagonist of P2Y₁₂, 1 µM). Results: Platelet deposition on collagen (I) was not affected by the storage temperature of the blood before perfusion (room temperature vs. 37 °C); (II) was dependent on a shear rate in the range between 300/s and 1700/s; and (III) was influenced by the collagen concentration used to coat the microchannels up to a value of 10 µg/mL. ASA and cangrelor did not cause statistically significant inhibition of platelet accumulation, except for ASA at low collagen concentrations. Conclusions: Platelet deposition on collagen-coated surfaces is a shear-dependent process, not influenced by the collagen concentration beyond a value of 10 µg/mL. However, the inhibitory effect of antiplatelet drugs is better observed using low concentrations of collagen.

Perioperative Management of Antiplatelet Therapy in Ophthalmic Surgery

Many patients undergoing ophthalmic surgery are elderly with comorbidities requiring antiplatelet therapy to prevent thromboembolic or atherothrombotic events. The use of antiplatelet therapy has expanded over the years, predisposing these patients to hemorrhagic complications perioperatively. The risk of hemorrhagic complications must be weighed against the risk of thromboembolic events with cessation of antiplatelet therapy. The decision to continue or interrupt antiplatelet therapy in the setting of ophthalmic surgery is based upon various factors, including the type of surgery and each patient’s comorbidities. This review examines the risks of thrombotic complications versus hemorrhagic complications in different types of ophthalmic surgeries with the use of antiplatelet medications and provides evidence-based recommendations regarding perioperative management of antiplatelet therapy

Anticoagulation and Spine Surgery

STUDY DESIGN

Literature review.

OBJECTIVE

Preoperative management of therapeutic anticoagulation in spine surgery is critical to minimize risk of thromboembolic events yet prevent postsurgical complications. Limited research is available, and most guidelines are based on drug half-lives. We aim to clarify current guidelines and available evidence for safe practice of spine surgery in this patient population.

METHODS

A literature search in PubMed was done encompassing comprehensive search terms to locate published literature on anticoagulation and spine surgery. Predefined inclusion and exclusion criteria were applied and data extraction was performed.

RESULTS

A total of 17 articles met the final inclusion criteria. Of these, 12 articles were retrospective chart reviews, 3 were prospective observational studies, and 2 were systematic reviews. Current practice suggests holding warfarin until international normalized ratio <1.4, anti-Xa drugs for 48 to 72 hours, 12 to 24 hours for low-molecular-weight heparin, and 4 to 24 hours for heparin, before surgery. Antiplatelet agents can be stopped for 1 to 3 days prior to operation (81-500 mg) but must be stopped for 1 week for doses >1 g/d. For Plavix, 5 to 7 days of discontinuation advised to prevent complications.

CONCLUSIONS

This review provides an overview of main anticoagulation agents seen in preoperative setting for spine patients. Although data is mixed and no true randomized control trials are available, there is growing evidence suggesting the aforementioned guidelines are needed to optimize anticoagulation in setting of spine surgery. Further studies are needed to elucidate risk of complications while operating under therapeutic levels of anticoagulation for a variety of comorbid conditions.

Establishing a reference range for thromboelastography maximum amplitude in patients administrating with antiplatelet drugs

Objective

We aimed to establish the reference range of thromboelastograph (TEG) maximum amplitude (MA) in patients taking antiplatelet drugs.

Methods

Between August 2015 and July 2018, a total of 4614 patients administrating with antiplatelet drugs (clopidogrel and aspirin) were retrospectively analyzed in this study. For MA_A parameter, we used the 10th and 90th percentiles to establish a reference range. The Spearman correlation was used for the correlation analysis among the inhibition rate of adenosine diphosphate (ADP%) and MA_ADP, inhibition rate of arachidonic acid (AA%) and MA_AA. Then, through receiver operating characteristic (ROC) curve analysis of the best cutoff point, the reference ranges of MA_ADP and MA_AA could be deduced. Consistency evaluation was performed by statistical analysis of ADP% and MA_ADP, AA% and MA_AA pairing for 4459 patients.

Results

The reference range of MA_A was 8.1‐25.8 mm. The reference range of MA_ADP was 19.8‐43.2 mm, and the corresponding sensitivity of two endpoints was 0.796, 0.856 and specificity were 0.897, 0.904, respectively. The reference range of MA_AA was 18.9‐37.7 mm, and the corresponding sensitivity of two endpoints was 0.819, 0.829 and specificity were 0.922, 0.896, respectively. The inconsistency rate of ADP% and MA_ADP, and AA% and MA_AA was 20.1% (898 cases) and 16.6% (738 cases), respectively.

Conclusions

The reference range of MA_ADP and MA_AA established by us were better in sensitivity and specificity. MA_ADP and MA_AA were more accurate than conventional inhibition rate analysis in guidance of antiplatelet therapy, especially in patients with excessive low MA or high MA_A.

Comparative effectiveness of different antiplatelet agents at reducing TNF-driven inflammatory responses in a mouse model

Antiplatelet drugs are conventionally used as treatments because of their anti-coagulation functions. However, their pleiotropic effects are of great significance to the treatment of ischaemic cardiovascular diseases. Many studies have reported that an excessive amount of inflammation driven by tumour necrosis factor (TNF) is closely related to the prevalence of atherosclerosis. As the drug selection criteria and evaluation methods related to the anti-TNF activity of antiplatelet drugs remain limited, our investigation of these drugs should prove beneficial. In this study, we compared the anti-TNF activity of three antiplatelet agents, namely clopidogrel, sarpogrelate, and cilostazol, using the TNF-induced inflammatory mouse model. After the oral administration of these drugs, acute inflammation was induced via injection of lipopolysaccharide (LPS) or D-galactosamine (D-gal) and TNF. Serum TNF levels, and the mRNA and protein expression levels of TNF in mouse heart tissue, macrophage accumulation in aortic lesions, and mouse survival were analysed to compare the anti-TNF effects of the three antiplatelet agents. Of the three antiplatelet agents, cilostazol significantly reduced the different levels under the most effective observation. In addition, cilostazol was found to attenuate the TNF-stimulated phosphorylation of mitogen-activated protein kinase (MAPK) and nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) p65 in the aortic vascular smooth muscle cell line, MOVAS-1 and the D-gal plus TNF-challenged heart tissue of mouse. Therefore, cilostazol is the most ideal of the three antiplatelet drugs for the treatment of TNF-mediated inflammatory disorders.

Discontinuation of Oral Antiplatelet Agents before Dental Extraction - Necessity or Myth?

BACKGROUND

The risk of excessive bleeding often prompts physicians to interrupt the antiplatelet agents as acetylsalicilyc acid and clopidogrel before dental extractions which puts patients at risk of adverse thrombotic events.

AIM

To assess the bleeding risk during dental extractions in patients with continued antiplatelet therapy.

MATERIALS AND METHODS

The study included 130 patients (64 men and 66 women) aged between 18 and 99 years old. Sixty-eight of the patients received 100 mg acetilsalicilic acid (ASA); these were divided into two groups: 34 patients continued taking ASA and 34 patients stopped it 72 hours before extraction. Sixty-two of the patients were treated with 75 mg clopidogrel; these were also divided into two groups: 31 continued taking clopidogrel and 31 patients stopped it 72 hours before extractions. Extraction was performed under local anaesthesia as no more than 3 teeth per visit were extracted. Local haemostasis with gelatine sponge and/or suturing was used to control bleeding.

RESULTS

Mild bleeding was observed most frequently in the first 30 minutes, successfully managed by local haemostasis. Only 1 patient in the control and 1 in the experimental group receiving ASA reported mild bleeding in the first 24 hours, controlled by compression with gauze. No major haemorrhage requiring emergency or more than local haemostasis occurred. No statistically significant difference in bleeding between two groups was found.

CONCLUSION

Single and multiple dental extractions in patients receiving acetylsalicylic acid or clopidogrel can be safely performed without discontinuation of the therapy with provided appropriate local haemostasis.

Antiplatelet Therapy After Noncardioembolic Stroke

Background and Purpose- We assessed the efficacy and safety of antiplatelet agents after noncardioembolic stroke or transient ischemic attack and examined how these vary according to patients' demographic and clinical characteristics. Methods- We did a network meta-analysis (NMA) of data from 6 randomized trials of the effects of commonly prescribed antiplatelet agents in the long-term (≥3 months) secondary prevention of noncardioembolic stroke or transient ischemic attack. Individual patient data from 43 112 patients were pooled and reanalyzed. Main outcomes were serious vascular events (nonfatal stroke, nonfatal myocardial infarction, or vascular death), major bleeding, and net clinical benefit (serious vascular event or major bleeding). Subgroup analyses were done according to age, sex, ethnicity, hypertension, qualifying diagnosis, type of vessel involved (large versus small vessel disease), and time from qualifying event to randomization. Results- Aspirin/dipyridamole combination (RR_NMA-adj, 0.83; 95% CI, 0.74-0.94) significantly reduced the risk of vascular events compared with aspirin, as did clopidogrel (RR_NMA-adj, 0.88; 95% CI, 0.78-0.98), and aspirin/clopidogrel combination (RR_NMA-adj, 0.83; 95% CI, 0.71-0.96). Clopidogrel caused significantly less major bleeding and intracranial hemorrhage than aspirin, aspirin/dipyridamole combination, and aspirin/clopidogrel combination. Aspirin/clopidogrel combination caused significantly more major bleeding than aspirin, aspirin/dipyridamole combination, and clopidogrel. Net clinical benefit was similar for clopidogrel and aspirin/dipyridamole combination (RR_NMA-adj, 0.99; 95% CI, 0.93-1.05). Subgroup analyses showed no heterogeneity of treatment effectiveness across prespecified subgroups. The excess risk of major bleeding associated with aspirin/clopidogrel combination compared with clopidogrel alone was higher in patients aged <65 years than it was in patients ≥65 years (RR_NMA-adj, 3.9 versus 1.7). Conclusions- Results favor clopidogrel and aspirin/dipyridamole combination for long-term secondary prevention after noncardioembolic stroke or transient ischemic attack, regardless of patient characteristics. Aspirin/clopidogrel combination was associated with a significantly higher risk of major bleeding compared with other antiplatelet regimens.

[Therapeutic Strategies in Patients with Stable Coronary Artery Disease: The Role of Coronary Revascularization]

Therapeutic Strategies in Patients with Stable Coronary Artery Disease: The Role of Coronary Revascularization Abstract. Coronary artery disease is the leading cause of death worldwide. Prevention and optimal treatment of patients with coronary artery disease is therefore crucial. Lifestyle changes, optimal medical therapy and aggressive risk factor control represent key elements in the management of patients with stable coronary artery disease. Coronary revascularization of flow-limiting coronary artery stenoses is indicated to reduce myocardial ischemia and related symptoms. This review summarizes treatment strategies of patients with stable coronary artery disease, focusing on the 2018 European Society of Cardiology (ESC) guidelines of myocardial revascularization.

Consensus on the Rational Use of Antithrombotics in Veterinary Critical Care (CURATIVE): Domain 3-Defining antithrombotic protocols

OBJECTIVES

To systematically examine the evidence for use of a specific protocol (dose, frequency, route) of selected antithrombotic drugs, in comparisons to no therapy or to other antithrombotic therapies, to reduce the risk of complications or improve outcomes in dogs and cats at risk for thrombosis.

DESIGN

Standardized, systematic evaluation of the literature, categorization of relevant articles according to level of evidence (LOE) and quality (Good, Fair, or Poor), and development of consensus on conclusions via a Delphi-style survey for application of the concepts to clinical practice.

SETTINGS

Academic and referral veterinary medical centers.

RESULTS

Databases searched included Medline via PubMed and CAB abstracts. Eight different antithrombotic drugs were investigated using a standardized Patient, Intervention, Comparison, Outcome (PICO) question format both for dogs and cats, including aspirin, clopidogrel, warfarin, unfractionated heparin (UFH), dalteparin, enoxaparin, fondaparinux, and rivaroxaban, generating a total of 16 worksheets. Most studies identified were experimental controlled laboratory studies in companion animals (LOE 3) with only four randomized controlled clinical trials in companion animals (LOE 1).

CONCLUSIONS

Overall, evidence-based recommendations concerning specific protocols could not be formulated for most antithrombotic drugs evaluated, either because of the wide range of dosage reported (eg, aspirin in dogs) or the lack of evidence in the current literature. However, clopidogrel administration in dogs and cats at risk of arterial thrombosis, notably in cats at risk of cardiogenic thromboembolism, is supported by the literature, and specific protocols were recommended. Comparably, aspirin should not be used as a sole antithrombotic in cats with cardiomyopathy. Using the available safety profile information contained in the literature, the panel reached consensus on suggested dosage schemes for most antithrombotics. Significant knowledge gaps were highlighted, which will hopefully drive novel research.

Preventing arteriovenous shunt failure in hemodialysis patients: a population-based cohort study

Essentials Uncertainty remains about antiplatelets for vascular access patency in hemodialysis patients. 95 971 people under hemodialysis were followed in a claims database in Taiwan. Aspirin reduced vascular access failure rate and did not increase major bleeding rate. Clopidogrel, Aggrenox, and warfarin might increase major bleeding rate. SUMMARY: Background Dialysis adequacy is a major determinant of survival for patients with end-stage renal disease. Good vascular access is essential to achieve adequate dialysis. Objectives This study evaluated the impacts of different drugs on the vascular access failure rate of an arteriovenous fistula or an arteriovenous graft and the rate of major bleeding in hemodialysis patients. Patients and methods We studied patients with end-stage renal disease registered in the Taiwan National Health Insurance program from 1 January 1997 to 31 December 2012. A total of 95 971 patients were enrolled in our study. Vascular access dysfunction was defined as the need for thrombectomy or percutaneous angioplasty. Major bleeding was defined as emergency department visits or hospitalization with a primary diagnosis of gastrointestinal bleeding or intracerebral hemorrhage. The adjusted odds ratios between person-quarters with or without antiplatelet or oral anticoagulant use were calculated using a generalized estimating equation. Results The odds ratio of vascular access failure was 0.21 (0.11-0.39) for aspirin, 0.76 (0.74-0.79) for clopidogrel, 0.67 (0.59-0.77) for dipyridamole, 0.67 (0.53-0.86) for Aggrenox and 0.96 (0.90-1.03) for warfarin. The highest odds ratio for intracerebral hemorrhage was 5.33 (1.25-22.72) in younger patients using Aggrenox. The highest odds ratio for gastrointestinal bleeding was 1.34 (1.10-1.64) for clopidogrel. Conclusion Antiplatelet agents, but not warfarin, might reduce the vascular access thrombosis rate. The gastrointestinal bleeding rate was increased in the group using clopidogrel. Aggrenox should be used with caution in young individuals because it might increase the rate of intracerebral hemorrhage.

[Plasma D-dimer volume as a subclinical marker of thrombotic risk in elderly patients with atrial fibrillation.]

Aged patients with atrial fibrillation (AF) are at high risk of both thromboembolic and haemorrhagic complications of disease and of its treatment. A study was provided to assess the role of D-dimer plasma level as a marker of thrombosis in aged patients with AF having no clinical signs of active thrombosis depending on used treatment strategy and quantitative thrombotic and haemorrhagic risk of AF. The results show that D-dimer plasma levels correlate with scores of thromboembolic and haemorrhagic risks in group on antiplatelet agents but not anticoagulants, with the difference in D-dimer level driven by subgroup on CHA2DS2-VASc score ≥5. High D-dimer level was associated with in-hospital mortality and rhythm of AF at the moment of blood sample collection. Therefore, an accuracy of risk prognosis of fatal complications of AF for elderly patients may be increased by using the laboratory markers of thrombus formation such as D-dimer and by using the obtained results to guide an antithrombotic therapy.

Initiation And Persistence With Antiplatelet Agents Among The Patients With Acute Coronary Syndromes: A Retrospective, Observational Database Study In China

OBJECTIVES

To investigate the initiation and persistence of antiplatelet agents and the associated factors for patients with acute coronary syndromes (ACS) in Tianjin, China.

METHODS

Data were obtained from Tianjin Urban Employee Basic Medical Insurance database (2011-2015). Adult patients who were discharged alive after the first ACS-related hospitalization (index hospitalization) between January 2012 and December 2014 were included. Patients who initiated with antiplatelet therapy, including aspirin monotherapy, clopidogrel monotherapy, or dual antiplatelet with aspirin and clopidogrel at discharge or within the initial 30-day follow-up after discharge were further identified. Patients with no gaps of ≥30 days in antiplatelet therapy were deemed persistent. The logistic model and Cox model were used to explore the associated factors of initiation and persistence with antiplatelet agents, respectively.

RESULTS

In total, 21,450 patients (64.6±10.7 years; 46.0% female) were included. Only 70.3% (N=15,071) of them initiated with antiplatelet agents within the initial 30-day follow-up; 85.0% (N=12,809) of the initial users discontinued their antiplatelet therapy, and the average time to discontinuation was 117.4±119.7 days. The patients who had prior antiplatelet agents utilization (Odds ratio [95% CI]=1.93 [1.78-2.09]; hazard ratio [95% CI]=0.78 [0.74-0.81]), received percutaneous coronary intervention (PCI) during the baseline period (OR=1.47 [1.26-1.73]; HR=0.91 [0.84-0.97]) or index hospitalization (OR=22.40 [18.63-26.92]; HR=0.51 [0.49-0.53]) were more likely to initiate and persist with antiplatelet agents, while the female (OR=0.75 [0.70-0.81]; HR=1.22 [1.88-1.27]) patients were less likely to initiate and persist with antiplatelet agents.

CONCLUSION

The initiation and persistence with antiplatelet agents are poor among the ACS patients in Tianjin. Females are associated with poorer initiation and persistence, while prior antiplatelet agents use and receiving PCI during baseline period or index hospitalization are associated with better initial use and better persistence.

Antithrombotic treatment is associated with intraplaque haemorrhage in the atherosclerotic carotid artery: a cross-sectional analysis of The Rotterdam Study

Aims

Antithrombotic treatment plays a key role in stroke prevention, but their direct effects on the composition of carotid artery atherosclerotic plaques are unknown. To investigate the association of antithrombotic treatment with carotid artery plaque composition, with a specific focus on an intraplaque haemorrhage (IPH).

Methods and results

From the population-based Rotterdam Study, 1740 participants with carotid atherosclerosis on ultrasound (mean age 72.9 years, 46.0 women) underwent magnetic resonance imaging of the carotid arteries to assess plaque composition. Information on the use of oral anticoagulants [vitamin K antagonists (VKA)] and antiplatelet agents (salicylates), including duration of use and dosage, was obtained from pharmacy records for all participants. We used logistic regression models to assess the association between the use of anticoagulants and antiplatelet agents, and the different plaque components adjusting for confounders. Current and past use of VKA [adjusted odds ratio (OR): 1.88, 95% confidence interval (CI): 0.74-4.75 and OR 1.89, 95% CI: 0.91-3.93] and antiplatelet agents (OR: 1.22, 95% CI: 0.91-1.62), and (OR: 1.23, 95% CI: 0.86-1.75) showed positive trend with a higher presence of IPH. Also, a longer duration of use was associated with a higher frequency of IPH (OR: 3.15, 95% CI: 1.23-8.05) for the use of VKA, and longer duration of the use for antiplatelet agents showed a positive trend (OR: 1.21, 95% CI: 0.88-1.67). We also found that higher levels of international normalized ratio above 2.97 for VKA (OR: 1.48, 95% CI: 1.03-2.15) and higher daily defined dosage than 1.0 for antiplatelet agents (OR: 1.50, 95% CI: 1.21-1.87) were related to a higher frequency of IPH. We found no association with lipid core or calcification.

Conclusions

The use of antithrombotic treatment relates to a higher frequency of IPH in carotid atherosclerotic plaques.

Chronic Kidney Disease and Third-Generation P2Y12 Inhibitors Use in Patients With Acute Coronary Syndrome: Impact on the Prognosis at 1 Year

Chronic kidney disease (CKD) is associated with worse clinical outcomes in patients with acute coronary syndrome. However, they are underrepresented in clinical trials. We aimed to investigate differences in prognosis of acute coronary syndrome patients with and without CKD, focusing on the use of novel P2Y₁₂ receptor inhibitors. This multicenter registry involved patients with acute coronary syndrome from 3 tertiary institutions. After excluding anticoagulated patients and patients on antiplatelet monotherapy, 1280 patients remained. During 1 year of follow-up, we recorded all major adverse cardiovascular events (composite of cardiovascular death, nonfatal myocardial infarction, and nonfatal ischemic stroke), bleeds (Bleeding Academic Research Consortium classification) and deaths. Of 1280 patients, 325 (25.4%) had CKD; 55.5% of non-CKD patients and 22.7% of CKD patients were prescribed novel P2Y₁₂ inhibitors. During follow-up, CKD patients under novel P2Y₁₂ inhibitors showed a not statistically significant lower mortality and incidence of thrombotic events than clopidogrel-treated ones. In contrast, non-CKD patients taking novel P2Y₁₂ inhibitors had better outcomes in terms of major adverse cardiovascular events (4.72 vs 9.41; P = .006), all-cause mortality (1.32 vs 4.24; P = .006), and severe bleeding events (Bleeding Academic Research Consortium 3-5) (0.94 vs 2.82; P = .030), without differences for any bleeding (8.11 vs 8.47; P = .849). Bleeding risk was not increased by using third-generation P2Y₁₂ inhibitors in either group of patients. In conclusion, the use of third-generation P2Y₁₂ inhibitors among non-CKD patients was associated with better outcomes. CKD patients receiving third-generation P2Y₁₂ inhibitors treatment showed no statistically significant lower mortality and thrombotic events. Bleeding risk was not increased with the use of third-generation P2Y₁₂ inhibitors in either group of patients.

New antiplatelet drugs and new oral anticoagulants

In our daily anaesthetic practice, we are confronted with an increasing number of patients treated with either antiplatelet or anticoagulant agents. During the last decade, changes have occurred that make the handling of antithrombotic medication a challenging part of anaesthetic perioperative management. In this review, the authors discuss the most important antiplatelet and anticoagulant drugs, the perioperative management, the handling of bleeding complications, and the interpretation of some laboratory analyses related to these agents.

Periprocedural Antithrombotic Treatment During Acute Mechanical Thrombectomy for Ischemic Stroke: A Systematic Review

BACKGROUND

More than one-third of the patients with ischemic stroke caused by an intracranial large vessel occlusion do not recover to functional independence despite fast and successful recanalization by acute mechanical thrombectomy (MT). This may partially be explained by incomplete microvascular reperfusion. Some antithrombotics, e.g., antiplatelet agents and heparin, may be able to restore microvascular reperfusion. However, antithrombotics may also increase the risk of symptomatic intracranial hemorrhage (sICH). The aim of this review was to assess the potential safety and functional outcome of periprocedural antiplatelet or heparin use during acute MT for ischemic stroke.

METHODS

We systematically searched PubMed, Embase, Medline, Web of Science, and Cochrane for studies investigating the safety and functional outcome of periprocedural antiplatelet or heparin treatment during acute MT for ischemic stroke. The primary outcome was the risk for sICH. Secondary outcomes were functional independence after 3-6 months (modified Rankin Scale 0-2) and mortality within 6 months.

RESULTS

837 studies were identified through the search, of which 19 studies were included. The sICH risks of the periprocedural use of antiplatelets ranged from 6 to 17%, and for heparin from 5 to 12%. Two of four studies reporting relative effects of the use of antithrombotics are pointing toward an increased risk of sICH. Among patients treated with antiplatelet agents, functional independence varied from 23 to 60% and mortality from 18 to 33%. For heparin, this was, respectively, 19-54% and 19-33%. The three studies presenting relative effects of antiplatelets on functional independence showed neutral effects. Both studies reporting relative effects of heparin on functional independence found it to increase this chance.

CONCLUSION

Randomized controlled trials investigating the effect of periprocedural antithrombotic treatment in MT are lacking. Some observational studies report a slight increase in sICH risk, which may be acceptable because they also suggest a beneficial effect on functional outcome. Therefore, randomized controlled trials are warranted to address the question whether the potentially higher risk of sICH could be outweighed by improved functional outcome.

Antiplatelet Agents and Anticoagulants: From Pharmacology to Clinical Practice

Thrombosis is the formation of potentially deadly blood clots in the artery (arterial thrombosis) or vein (venous thrombosis). Since thrombosis is one of the main causes of death worldwide, the development of antithrombotic agents is a global medical priority. They are subdivided into antiplatelet agents and anticoagulants. Antiplatelet agents inhibit clot formation by preventing platelet activation and aggregation, while anticoagulants primarily inhibit the coagulation cascade and fibrin formation. Therapeutics within each category differs with respect to the mechanism of action, time to onset, duration of effect and route of administration. In this review, we critically discuss their main pharmacodynamic and pharmacokinetic characteristics as well as recent advances in daily clinical practice.

Preventing recurrent events in survivors of acute coronary syndromes in Australia: consensus recommendations using the Delphi process

OBJECTIVE

There remain substantial gaps in implementation of evidence-based care in patients with acute coronary syndromes (ACS) in Australia, which contribute to high recurrent event rates. Improved translation of evidence into effective action is a key health-care priority. We engaged cardiovascular experts from across Australia to develop straightforward, easily actionable recommendations on key medications to use following ACS.

METHODS

An eight-person steering committee (SC) reviewed the published evidence and developed an initial set of statements to be developed into consensus recommendations using a modified Delphi technique. A panel of 21 expert cardiologists in the ACS field (including the SC) voted on their level of agreement with the statements using a 6 point Likert scale. Statements that did not reach consensus (≥80% agreement) were reviewed by the SC, modified as appropriate based on input from the panel and circulated for re-voting.

RESULTS

Twenty-eight statements were developed by the SC across six classes of medication: low-density lipoprotein (LDL) cholesterol lowering agents, aspirin, dual antiplatelet therapy, renin-angiotensin-aldosterone system inhibitors, beta blockers and "other". Twenty-six recommendations were endorsed by the voting panel; two statements did not reach consensus.

CONCLUSIONS

Despite the extensive evidence base and detailed guidelines outlining best practice post ACS, there remain considerable gaps in translating these into everyday care. We used an internationally recognized technique to develop practical consensus recommendations on medical treatment following ACS. These simple, up-to-date recommendations aim to improve evidence-based medication use and thereby reduce the risk of future cardiovascular events for Australian patients with ACS.

External Validation of Risk Scores for Major Bleeding in a Population-Based Cohort of Transient Ischemic Attack and Ischemic Stroke Patients

BACKGROUND AND PURPOSE

The S₂TOP-BLEED score may help to identify patients at high risk of bleeding on antiplatelet drugs after a transient ischemic attack or ischemic stroke. The score was derived on trial populations, and its performance in a real-world setting is unknown. We aimed to externally validate the S₂TOP-BLEED score for major bleeding in a population-based cohort and to compare its performance with other risk scores for bleeding.

METHODS

We studied risk of bleeding in 2072 patients with a transient ischemic attack or ischemic stroke on antiplatelet agents in the population-based OXVASC (Oxford Vascular Study) according to 3 scores: S₂TOP-BLEED, REACH, and Intracranial-B₂LEED₃S. Performance was assessed with C statistics and calibration plots.

RESULTS

During 8302 patient-years of follow-up, 117 patients had a major bleed. The S₂TOP-BLEED score showed a C statistic of 0.69 (95% confidence interval [CI], 0.64-0.73) and accurate calibration for 3-year risk of major bleeding. The S₂TOP-BLEED score was much more predictive of fatal bleeding than nonmajor bleeding (C statistics 0.77; 95% CI, 0.69-0.85 and 0.50; 95% CI, 0.44-0.58). The REACH score had a C statistic of 0.63 (95% CI, 0.58-0.69) for major bleeding and the Intracranial-B₂LEED₃S score a C statistic of 0.60 (95% CI, 0.51-0.70) for intracranial bleeding. The ratio of ischemic events versus bleeds decreased across risk groups of bleeding from 6.6:1 in the low-risk group to 1.8:1 in the high-risk group.

CONCLUSIONS

The S₂TOP-BLEED score shows modest performance in a population-based cohort of patients with a transient ischemic attack or ischemic stroke. Although bleeding risks were associated with risks of ischemic events, risk stratification may still be useful to identify a subgroup of patients at particularly high risk of bleeding, in whom preventive measures are indicated.