Antiplatelet or Anticoagulant Therapy for Abdominal Aortic Aneurysms: Growth and Clinical Outcomes

BACKGROUND

Intraluminal thrombi in the abdominal aortic aneurysms (AAA) were demonstrated to increase aneurysm growth. The effect of treatments on thrombus reduction upon AAA enlargement and clinical endpoints is uncertain Therefore, this study aimed to investigate the effect of antiplatelet and anticoagulant therapy on AAA growth and clinical outcomes.

METHOD

A total of 357 patients with AAAs were enrolled in this study. They were divided into 2 groups based on their medical therapies. Patients on antiplatelet and anticoagulant therapy were assigned to group 1 (n = 234) and group 2 (n = 92), respectively.

RESULTS

The greatest reduction in thrombus diameter change was observed in patients with anticoagulant therapy (group 1, -2.26 mm; group 2, -8.16 mm; P =.001). The greatest aneurysmal enlargement was found in patients with antiplatelet therapy. There was less AAA progression with anticoagulant therapy than with the other therapy (group 1, 2.08 mm; group 2, 1.31 mm P =.027. The more operational need was observed in patients with antiplatelet therapy than in patients with anticoagulant therapy ( group 1 67, group 2 16, P =.036) Conclusion: In our study, it was revealed that anticoagulant therapy has been associated with decreased thrombus diameter and less aneurysmal enlargement compared with antiplatelet therapy. Furthermore, this beneficial effect on the thrombus size and aneurysmal diameter decreased the operational need in patients with anticoagulant therapy.

Oral Anticoagulants Beyond Warfarin

Direct oral anticoagulants (DOACs) have largely replaced vitamin K antagonists, mostly warfarin, for the main indications for oral anticoagulation, prevention and treatment of venous thromboembolism, and prevention of embolic stroke in atrial fibrillation. While DOACs offer practical, fixed-dose anticoagulation in many patients, specific restrictions or contraindications may apply. DOACs are not sufficiently effective in high-thrombotic risk conditions such as antiphospholipid syndrome and mechanical heart valves. Patients with cancer-associated thrombosis may benefit from DOACs, but the bleeding risk, particularly in those with gastrointestinal or urogenital tumors, must be carefully weighed. In patients with frailty, excess body weight, and/or moderate-to-severe chronic kidney disease, DOACs must be cautiously administered and may require laboratory monitoring. Reversal agents have been developed and approved for life-threatening bleeding. In addition, the clinical testing of potentially safer anticoagulants such as factor XI(a) inhibitors is important to further optimize anticoagulant therapy in an increasingly elderly and frail population worldwide.

N, N'-disubstituted Ureas as Novel Antiplatelet Agents: Synthesis, Pharmacological Evaluation and In Silico Studies

INTRODUCTION

Thrombotic disorders are among the leading causes of morbidity and mortality worldwide. Drugs used in the prevention and treatment of atherothrombosis have pharmacokinetic limitations and adverse effects such as hemorrhagic conditions, highlighting the importance of developing more effective antiplatelet agents. ethod: In this work, we synthesized N,N'-disubstituted ureas 3a-3j and evaluated their antiplatelet profiles through in vitro, ex vivo, and in silico studies. The synthesized derivatives exhibited a selective inhibitory profile against platelet aggregation induced by arachidonic acid (AA) in vitro, without significantly affecting other aspects of primary hemostasis and blood coagulation. The compounds that showed inhibition greater than 85% were submitted to the analysis of their potency by calculating the concentration required to inhibit 50% of platelet aggregation induced by AA (IC50). Urea derivative 3a was the most potent with IC50 of 1.45 μM. Interestingly, this derivative inhibited more than 90% of platelet aggregation induced by AA ex vivo, with a similar effect to acetylsalicylic acid. In the hemolysis assay, most of the urea derivatives presented values below 10% suggesting good hemocompatibility. Additionally, the compounds tested at 100 μM also showed no cytotoxic effects in HepG2 and Vero cells.

RESULT

The in silico results suggested that compound 3a may bind to the key residue of COX-1 similar to AA and known COX-1 inhibitors, and the results are also in agreement with our SAR, which suggests that the inhibition of this enzyme is the most likely mechanism of antiplatelet activity.

CONCLUSION

Therefore, these results demonstrated that N,N'-disubstituted ureas are promising candidates for the development of novel antiplatelet agents.

Intraluminal Thrombus of the Extracranial Cerebral Arteries in Acute Ischemic Stroke: Manifestations, Treatment Strategies, and Outcome

Background

Intraluminal thrombus (ILT) of the cervical arteries is an uncommon finding that can lead to acute or recurrent ischemic stroke. Currently, antithrombotic therapy in the form of antiplatelet and/or anticoagulation is considered the mainstay of treatment, but evidence of which one has a better outcome is lacking.

Methods

A retrospective cohort study included 28 patients diagnosed with acute stroke or transient ischemic attack with ILT of the extracranial arteries from 2013 to 2022. The primary efficacy outcome was assessed as recurrent stroke, and the primary safety outcome was assessed as hemorrhagic complications. Secondary outcomes were assessed as the resolution of thrombi by CT angiography (CTA) and clinical improvement by the Modified Rankin Scale (mRS) and NIH Stroke Scale (NIHSS).

Results

Out of 28 patients, more than half (57.1%; n = 16) were males with a mean age of 57.8 ± 9.5 years and an average BMI of 26.9 ± 4.5 kg/m2. As initial treatment, twenty-four patients received anticoagulation and four received antiplatelet agents. Recurrent strokes were found in four patients (14.29%), and all were initially treated with anticoagulation. One patient in the anticoagulation group had a significant retroperitoneal hemorrhage. None of the patients in the antiplatelets group had a recurrent stroke or bleeding event. Initial treatment with antiplatelet agents significantly improved the NIHSS on day 7 (P = 0.017). A significant improvement in NIHSS on day 90 was observed in the anticoagulant group (P = 0.011). In the follow-up CTA performed on 24 patients, 18 (75%) showed complete resolution (3 out of 3 (100%) in the antiplatelet group and 15 out of 21 (71.43%) in the anticoagulant group).

Conclusion

Initial treatment with anticoagulants improves neurologic outcomes in patients with ILT-induced acute ischemic stroke but carries the risk of recurrent stroke and bleeding. However, initial treatment with dual antiplatelet agents appears to have comparable efficacy without sequelae, particularly in atherosclerosis-induced ILT.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Patients With Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

Thrombocyte transfusion and rebleeding rate in patients using antiplatelet agents before aneurysmal subarachnoid hemorrhage

OBJECTIVE

The reason for a rebleed after an initial hemorrhage in patients with aneurysmal subarachnoid hemorrhage (aSAH) is considered multifactorial. Antiplatelet use is one of the factors that has been related to early rebleed and worse outcome after aSAH. Thrombocyte transfusion overcomes the inhibitory effects of antiplatelet agents by increasing the number of functional thrombocytes, but its impact on the rebleed rate and clinical outcome remains unknown. The aim of this study was to assess the effect of thrombocyte transfusion on rebleeding and clinical outcome in patients with aSAH and prehemorrhage antiplatelet use, considering confounding factors.

METHODS

Data were prospectively collected at a single tertiary reference center for aSAH in Zurich, Switzerland. Patients with aSAH and prehemorrhage antiplatelet use were divided into "thrombocyte transfusion" and "nontransfusion" groups based on whether they did or did not receive any thrombocyte transfusion in the acute stage of aSAH after hospital admission and before the exclusion of the bleeding source. Using multivariate logistic regression analysis, the impact of thrombocyte transfusion on the rebleed rate and on clinical outcome (defined as Glasgow Outcome Scale score 1-3) was calculated.

RESULTS

One hundred fifty-seven patients were included, 87 (55.4%) of whom received thrombocyte transfusion. Eighteen (11.5%) of 157 patients had a rebleed during the hospital stay. The rebleed risk was 6.9% in the thrombocyte transfusion group and 17.1% in the nontransfusion group. After adjusting for confounders, thrombocyte transfusion showed evidence for a reduction in the rebleed rate (adjusted OR [aOR] 0.29, 95% CI 0.10-0.87). Fifty-seven patients (36.3%) achieved a poor outcome at 6 months' follow-up. Among those 57 patients, 31 (54.4%) underwent at least one thrombocyte transfusion. Thrombocyte transfusion was not associated with poor clinical outcome at 6 months' follow-up (aOR 0.91, 95% CI 0.39-2.15).

CONCLUSIONS

Thrombocyte transfusion in patients with aSAH and prehemorrhage antiplatelet use is independently associated with a reduction in rebleeds but shows no impact on clinical outcome at 6 months' follow-up. Larger and randomized studies are needed to investigate the impact of thrombocyte transfusion on rebleed and outcome.

Comparison of the Efficacy and Safety Profiles of Different P2Y12 Inhibitors in Patients With ST-Segment Elevation Myocardial Infarction in the COVID-19 Era

BACKGROUND/AIM

Coronavirus Disease 2019 (COVID-19) is characterized by an increased risk of thrombotic and hemorrhagic events resulting from endothelial dysfunction. In patients with ST-elevation myocardial infarction (STEMI), the dual antiplatelet therapy used to reduce mortality may increase the risk of bleeding. The study aimed to compare the efficacy and safety profiles of P2Y12 inhibitors used during the COVID-19 era.

MATERIALS AND METHODS

Three hundred and ninety patients who underwent primary percutaneous intervention for STEMI between January 1, 2020, and December 31, 2021, were included in this study, retrospectively. The patients were divided into groups according to their COVID-19 history and all-cause mortality, cardiac mortality, stent thrombosis, and bleeding complications during hospitalization and at one-year follow-up were compared.

RESULTS

The mean age of the patients was 64.3 years and the mean follow-up period was 10.2 months; 80% of the patients were male and 44.6% had a history of COVID-19 infection. The in-hospital mortality rate was 11.3%. Cardiac mortality was significantly higher in the clopidogrel group compared to the other groups, regardless of COVID-19 history (21.9% in the clopidogrel group, 1.6% in the prasugrel group, and 6.7% in the ticagrelor group (p<0.001)). There was no significant difference between the groups in terms of bleeding complications and relation to COVID-19.

CONCLUSION

In STEMI patients treated with different P2Y12 inhibitors, there was no significant difference in mortality, bleeding, stroke, and thrombotic complications, regardless of the presence or absence of COVID-19 infection.

Daily Aspirin Reduced the Incidence of Hepatocellular Carcinoma and Overall Mortality in Patients with Cirrhosis

BACKGROUND

Cirrhosis is the primary risk factor for hepatocellular carcinoma (HCC) and gastrointestinal bleeding (GI). We aimed to assess the efficacy and safety of daily aspirin on HCC occurrence, overall survival, and GI bleeding in cirrhotic patients.

METHODS

A total of 35,898 eligible cases were enrolled for analyses from an initial 40,603 cirrhotic patients without tumor history. Patients continuously treated with aspirin for at least 84 days were in the therapy group, whereas those without treatment were controls. A 1:2 propensity score matching by age, sex, comorbidities, drugs, and significant clinical laboratory tests with covariate assessment was used.

RESULTS

Multivariable regression analyses revealed that daily aspirin use was independently associated with a reduced risk of HCC (three-year HR 0.57; 95% CI 0.37-0.87; p = 0.0091; five-year HR 0.63, 95% CI 0.45-0.88; p = 0.0072) inversely correlated with the treatment duration [3-12 months: HR 0.88 (95% CI 0.58-1.34); 12-36 months: HR 0.56 (0.31-0.99); and ≥ 36 months: HR 0.37 (0.18-0.76)]. Overall mortality rates were significantly lower among aspirin users compared with untreated controls [three-year HR 0.43 (0.33-0.57); five-year HR 0.51 (0.42-0.63)]. Consistent results were obtained when the laboratory data were included in the propensity score for matching.

CONCLUSIONS

Long-term aspirin use significantly reduced the incidence of HCC and overall mortality without increasing gastrointestinal bleeding in cirrhotic patients.

Species Differences in Platelet Protease-Activated Receptors

Protease-activated receptors (PARs) are a class of integral membrane proteins that are cleaved by a variety of proteases, most notably thrombin, to reveal a tethered ligand and promote activation. PARs are critical mediators of platelet function in hemostasis and thrombosis, and therefore are attractive targets for anti-platelet therapies. Animal models studying platelet PAR physiology have relied heavily on genetically modified mouse strains, which have provided ample insight but have some inherent limitations. The current review aims to summarize the notable PAR expression and functional differences between the mouse and human, in addition to highlighting some recently developed tools to further study human physiology in mouse models.

Prevalence of venous thromboembolism in patients undergoing diagnostic venous ultrasound during the first SARS-CoV-2 pandemic

Background: Venous thromboembolism appears to be associated with severe COVID-19 infection than in those without it. However, this varies considerably depending on the cohort studied. The aims of this single-centre, multi-site retrospective cross-sectional study were to assess the number of all venous scans performed in the first month of pandemic in a large university teaching hospital, to evaluate the incidence of deep venous thrombosis (DVT), and assess the predictive ability of the clinical information available on the electronic patient record in planning work-up for DVT and prioritising ultrasound scans. Patients and methods: All consecutive patients undergoing venous ultrasound for suspected acute DVT between 1st of March and 30th of April 2020 were considered. Primary outcome was the proportion of scans positive for DVT; the secondary outcomes included association of a positive SARS-CoV-2 PCR test, demographic, clinical factors, and Wells scores. Results: 819 ultrasound scans were performed on 762 patients across the Trust in March and April 2020. This number was comparable to the corresponding pre-pandemic cohort from 2019. The overall prevalence of DVT in the studied cohort was 16.1% and was higher than before the pandemic (11.5%, p=.047). Clinical symptoms consistent with COVID-19, irrespective of the SARS-CoV-2 PCR test result (positive_COVID_PCR OR 4.97, 95%CI 2.31-10.62, p<.001; negative_COVID_PCR OR 1.97, 95%CI 1.12-3.39, p=.016), a history of AF (OR 0.20, 95%CI 0.03-0.73, p=.037), and personal history of venous thromboembolism (VTE) (OR 1.95, 95%CI 1.13-3.31, p=.014), were independently associated with the diagnosis of DVT on ultrasound scan. Wells score was not associated with the incidence of DVT. Conclusions: Amongst those referred for the DVT scan, SARS-CoV-2 PCR test was associated with an increased risk of VTE and should be taken into consideration when planning DVT work-up and prioritising diagnostic imaging. We postulate that the threshold for imaging should possibly be lower.

Advances in the available pharmacotherapy for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation

INTRODUCTION

Non-ST-segment elevation acute coronary syndromes (NSTE-ACS), including non-ST-segment-elevation myocardial infarction (NSTEMI) and unstable angina, represent a leading cause of mortality worldwide, with important socio-economic consequences. NSTEMI accounts for the majority of acute coronary syndromes and usually develops on the background of a nonocclusive thrombus. We searched for relevant literature in the field in PubMed and clinicaltrials.gov as of July 2022.

AREAS COVERED

A number of pharmacotherapies are currently available for treatment and secondary prevention, mainly including antithrombotic, lipid-lowering and anti-inflammatory drugs. Pretreatment with aspirin, anticoagulant and statin therapy is of key importance in the preprocedural phase, while pretreating with an oral P2Y12 inhibitor is not routinely indicated in patients undergoing early invasive management. For patients undergoing percutaneous coronary revascularization, pharmacotherapy essentially consists of antithrombotic drugs, which should be carefully selected. Finally, antithrombotic, lipid-lowering and anti-inflammatory drugs are important components of long-term secondary prevention after a NSTE-ACS.

EXPERT OPINION

This article reviews the evidence supporting recommendation on pharmacotherapy in patients presenting with a NSTE-ACS. Several randomized clinical trials are still ongoing and are expected to further inform scientific knowledge and clinical practice, with the final aim to improve the treatment of NSTE-ACS patients.

Antithrombotic Management in AF Patients Following Percutaneous Coronary Intervention: A European Perspective

AF is a highly prevalent disease, often requiring long-term oral anticoagulation to prevent stroke or systemic embolism. Coronary artery disease, which is common among AF patients, is often referred for myocardial revascularisation by percutaneous coronary intervention (PCI), which requires dual antiplatelet therapy to minimise the risk of stent-related complications. The overlap of AF and PCI is a clinical conundrum, especially in the early post-procedural period, when both long-term oral anticoagulation and dual antiplatelet therapy are theoretically indicated as a triple antithrombotic therapy. However, stacking drugs is not a desirable option because of the increased bleeding risk. Several strategies have been investigated to mitigate this concern, including shortening triple antithrombotic therapy duration and switching to a dual antithrombotic regimen. This review analyses the mechanisms underlying thrombotic complications in AF-PCI, summarises evidence surrounding antithrombotic therapy regimens and reports and comments on the latest European guidelines.

Platelet-Mimicking Nanosponges for Functional Reversal of Antiplatelet Agents

BACKGROUND

During long-term antiplatelet agents (APAs) administration, patients with thrombotic diseases take a fairly high risk of life-threatening bleeding, especially when in need of urgent surgery. Rapid functional reversal of APAs remains an issue yet to be efficiently resolved by far due to the lack of any specific reversal agent in the clinic, which greatly restricts the use of APAs.

METHODS

Flow cytometry analysis was first applied to assess the dose-dependent reversal activity of platelet-mimicking perfluorocarbon-based nanosponges (PLT-PFCs) toward ticagrelor. The tail bleeding time of mice treated with APAs followed by PLT-PFCs was recorded at different time points, along with corresponding pharmacokinetic analysis of ticagrelor and tirofiban. A hemorrhagic transformation model was established in experimental stroke mice with thrombolytic/antiplatelet therapy. Magnetic resonance imaging was subsequently applied to observe hemorrhage and thrombosis in vivo. Further evaluation of the spontaneous clot formation activity of PLT-PFCs was achieved by clot retraction assay in vitro.

RESULTS

PLT-PFCs potently reversed the antiplatelet effect of APAs by competitively binding with APAs. PLT-PFCs showed high binding affinity comparable to fresh platelets in vitro with first-line APAs, ticagrelor and tirofiban, and efficiently reversed their function in both tail bleeding and postischemic-reperfusion models. Moreover, the deficiency of platelet intrinsic thrombotic activity diminished the risk of thrombogenesis.

CONCLUSIONS

This study demonstrated the safety and effectiveness of platelet-mimicking nanosponges in ameliorating the bleeding risk of different APAs, which offers a promising strategy for the management of bleeding complications induced by antiplatelet therapy.

P2Y12 Inhibition Suppresses Proinflammatory Platelet-Monocyte Interactions

BACKGROUND

 Monocyte-platelet aggregates (MPAs) represent the crossroads between thrombosis and inflammation, and targeting this axis may suppress thromboinflammation. While antiplatelet therapy (APT) reduces platelet-platelet aggregation and thrombosis, its effects on MPA and platelet effector properties on monocytes are uncertain.

OBJECTIVES

 To analyze the effect of platelets on monocyte activation and APT on MPA and platelet-induced monocyte activation.

METHODS

 Agonist-stimulated whole blood was incubated in the presence of P-selectin, PSGL1, PAR1, P2Y12, GP IIb/IIIa, and COX-1 inhibitors and assessed for platelet and monocyte activity via flow cytometry. RNA-Seq of monocytes incubated with platelets was used to identify platelet-induced monocyte transcripts and was validated by RT-qPCR in monocyte-PR co-incubation ± APT.

RESULTS

 Consistent with a proinflammatory platelet effector role, MPAs were increased in patients with COVID-19. RNA-Seq revealed a thromboinflammatory monocyte transcriptome upon incubation with platelets. Monocytes aggregated to platelets expressed higher CD40 and tissue factor than monocytes without platelets (p < 0.05 for each). Inhibition with P-selectin (85% reduction) and PSGL1 (87% reduction) led to a robust decrease in MPA. P2Y12 and PAR1 inhibition lowered MPA formation (30 and 21% reduction, p < 0.05, respectively) and decreased monocyte CD40 and TF expression, while GP IIb/IIIa and COX1 inhibition had no effect. Pretreatment of platelets with P2Y12 inhibitors reduced the expression of platelet-mediated monocyte transcription of proinflammatory SOCS3 and OSM. CONCLUSIONS:  Platelets skew monocytes toward a proinflammatory phenotype. Among traditional APTs, P2Y12 inhibition attenuates platelet-induced monocyte activation.

Reinitiation and Subsequent Discontinuation of Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers among New and Prevalent Users Aged 65 Years or More with Peripheral Arterial Disease

Angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin-receptor blockers (ARBs) are recommended in the treatment of arterial hypertension in patients with peripheral arterial disease (PAD). The aims of our study were: (a) to analyse the extent of reinitiation and subsequent discontinuation in older hypertensive PAD patients non-persistent with ACEIs/ARBs; (b) to determine patient and medication factors associated with reinitiation and subsequent discontinuation; and (c) to compare these factors between prevalent and new users. The analysis of reinitiation was performed on a sample of 1642 non-persistent patients aged ≥65 years with PAD newly diagnosed in 2012. Patients reinitiating ACEIs/ARBs were used for the analysis of subsequent discontinuation identified according to the treatment gap period of at least 6 months without any prescription of ACEI/ARB. In the group of non-persistent patients, 875 (53.3%) patients reinitiated ACEIs/ARBs during a follow-up (24.8 months on average). Within this group, subsequent discontinuation was identified in 414 (47.3%) patients. Being a new user was associated with subsequent discontinuation, but not with reinitiation. Myocardial infarction during non-persistence and after reinitiation was associated with reinitiation and lower likelihood of subsequent discontinuation, respectively. Being a prevalent or a new user is associated with the use of medication also after initial discontinuation.

[Cognitive impairment in patients with atrial fibrillation]

Atrial fibrillation (AF) is a serious medical and social problem, being a common cause of ischemic stroke (IS) and cognitive impairment (CI), often reaching the degree of dementia. The most common cause of CI in patients with AF is transferred IS or repeated IS. In a significant part of patients with AF who have undergone IS, CI is detected directly in the acute period of the disease and progresses subsequently. In addition, the risk of developing CI is increased even in patients with AF who have not experienced IS before. The review discusses the data on the relationship between CI and AF, provides information on the possible causes of the development of CI in the considered group of patients. The main difficulties of managing a patient with AF and CI are considered.

[Modern strategies for the management of patients who have suffered ischemic stroke or transient ischemic attack]

Modern strategies for secondary prevention of ischemic stroke (IS) are based on long-term use of drugs from three main pharmaceutical groups (antihypertensive, lipid-lowering and antithrombotic drugs). In practical terms, the most difficult thing for a practitioner is the choice of antithrombotic therapy with anticoagulants or antiplatelet agents. Antithrombotic therapy for patients with acute cerebrovascular accidents has changed significantly in recent years. Clinical guidelines mention traditional and new oral anticoagulants, and the family of antiplatelet agents that can be used in clinical practice has expanded. The possibilities of differentiated antithrombotic therapy depending on the pathogenetic subtype of IS have expanded. The concept of early secondary prevention, new in angioneurology, suggests the possibility of more aggressive management of patients using a combination of antithrombotic drugs. In connection with the increase in life expectancy of patients who have suffered a IS, the issues of choosing drugs with good efficacy and a better safety profile have become relevant. The article discusses the practical aspects of managing patients in the acute period of the disease, during the period of early secondary prevention (90 days), if long-term use of basic treatment strategies is necessary (years).

[Drug interactions in neurosurgical patients]

We analyzed literature data on the most common drug interactions in neurosurgical patients. Drug interactions are a potential cause of adverse and dangerous clinical events and outcomes. Awareness of nature of drug interactions is valuable to avoid negative consequences when using combination of several drugs. Polypharmacy in neurosurgical patients is caused by treatment of intracranial lesions (hormonal therapy, antiepileptic drugs, etc.) and concomitant somatic diseases that increases the risk of drug interactions.

The Effectiveness of Antiplatelet Therapy and the Factors Influencing It in Patients with Acute Coronary Syndrome before and during the COVID-19 Pandemic

Background and Objectives: Dual antiplatelet therapy (DAPT) is essential in the treatment of patients with acute coronary syndrome (ACS). The objective of this study was to evaluate the effectiveness of antiplatelet medication in our practice and to investigate the factors that influence it. Materials and Methods: A prospective cohort observational study was conducted, in which 193 patients with ACS were enrolled. The patients were stented in the catheterization laboratory between May 2019 and October 2020, before and during the COVID-19 pandemic, and were receiving DAPT. Their platelet functions were tested using a Multiplate Analyzer. In addition to this, clinical data, demographics, laboratory tests, and cardiovascular risk factors were also analyzed. Results: 43.46% of the patients treated with aspirin were found to be resistant to it. This phenomenon was more common in men (48.17% vs. 31.48%, p = 0.036), and it was associated with being under the age of 50 (OR: 2.08; 95% CI: 1.11-3.90) and weighing over 70 kg (OR: 3.00; 95% CI: 1.21-7.40). Most of the patients treated with clopidogrel were in the optimal treatment window, while about half of the patients treated with ticagrelor had an exaggerated pharmacological response. Among the laboratory parameters, leukocytosis and platelet count were found to be determinants of platelet reactivity for both the aspirin and ticagrelor treatments. Conclusions: Many patients treated with antiplatelet agents are outside of the treatment window. The results obtained showed that low doses of gastro-resistant aspirin tablets are ineffective, and their efficacy can be influenced by various clinical and laboratory factors. Patients receiving ticagrelor have significantly reduced platelet reactivity, influenced only by certain laboratory indicators. The pandemic significantly influenced the results of the platelet aggregation tests only in patients treated with clopidogrel.

Platelets and Their Role in Hemostasis and Thrombosis—From Physiology to Pathophysiology and Therapeutic Implications

Hemostasis is a physiological process critical for survival. Meanwhile, thrombosis is amongst the leading causes of death worldwide, making antithrombotic therapy one of the most crucial aspects of modern medicine. Although antithrombotic therapy has progressed tremendously over the years, it remains far from ideal, and this is mainly due to the incomplete understanding of the exceptionally complex structural and functional properties of platelets. However, advances in biochemistry, molecular biology, and the advent of 'omics' continue to provide crucial information for our understanding of the complex structure and function of platelets, their interactions with the coagulation system, and their role in hemostasis and thrombosis. In this review, we provide a comprehensive view of the complex role that platelets play in hemostasis and thrombosis, and we discuss the major clinical implications of these fundamental blood components, with a focus on hemostatic platelet-related disorders and existing and emerging antithrombotic therapies. We also emphasize a number of questions that remain to be answered, and we identify hotspots for future research.

Antithrombotic therapy after transcatheter aortic valve implantation

INTRODUCTION

Transcatheter aortic valve implantation (TAVI) is a treatment option for patients with symptomatic severe aortic stenosis across the entire spectrum of surgical risk. TAVI conveys some risk for thrombotic complications, requiring antithrombotic drugs for their prevention. Bleeding events represent the major drawback of antithrombotic therapy, which should be carefully tailored over the individual patient's risk profile.

AREAS COVERED

This review aimed at exploring the rationale for the adoption of a tailored antithrombotic therapy after successful TAVI, with a description and analysis of common complications and their impact on therapy selection. In addition, we aimed at reviewing and discussing current knowledge in this area, with a main focus on the high-quality evidence supporting latest guideline recommendations. Finally, ongoing studies and future directions on antithrombotic therapy after TAVI were outlined.

EXPERT OPINION

Initial experience with antithrombotic therapy after TAVI was derived from percutaneous coronary intervention practice. Accruing evidence in the field led to the current monotherapy paradigm, which prioritizes oral anticoagulant and single antiplatelet therapy in patients with or without an established indication for long-term anticoagulation, respectively. Future studies will investigate the role of alternative antithrombotic strategies to improve clinical outcomes of TAVI patients by minimizing both thrombotic and bleeding complications.

Antithrombotic treatment of retinal vein occlusion: a position statement from the Italian Society on Thrombosis and Haemostasis (SISET)

Retinal vein occlusion (RVO) represents a common cause of visual impairment and blindness. RVO may be associated with both local (e.g., hyperopia, glaucoma) and systemic (e.g., hypertension, diabetes, smoking, obesity, and dyslipidaemia) risk factors. The association with thrombophilia remains controversial. Data on the use of antithrombotic therapy for RVO are poor and inconsistent with most of the information being derived from observational studies. Here we provide a position statement from the Italian Society on Thrombosis and Haemostasis (SISET) to guide the clinical and therapeutic management of patients with RVO based on the available evidence and expert opinion.

Hospital-Level Variation in Ticagrelor Use in Patients With Acute Coronary Syndrome

Background

Despite improved outcomes associated with ticagrelor compared with clopidogrel in acute coronary syndrome (ACS), many studies have demonstrated slow adoption of ticagrelor in the United States because of its increased cost. Less is known about how ticagrelor is adopted when there is no added cost consideration. Our objectives were to determine patterns of use of ticagrelor, hospital‐level adoption of ticagrelor use, and factors associated with its use after ACS in a publicly funded health care system.

Methods and Results

We conducted a population‐based cohort study including patients (≥65 years) hospitalized with their first ACS from April 2014 to March 2018 in Ontario, Canada. We determined temporal trends in ticagrelor use and hospital‐level adoption of its use post‐ACS discharge. Using hierarchical regression models, we identified significant predictors of ticagrelor use. There were 23 962 patients with ACS (mean age 76.3 years, 59.7% men) hospitalized in 156 hospitals. Overall ticagrelor use increased from 32.6% in 2014/2015 to 51.8% in 2017/2018. There was substantial variation in ticagrelor use post‐ACS across hospitals, with hospital‐specific prescribing rates ranging from 0% to 83.6%. Lower odds of ticagrelor use was associated with advanced age and the presence of comorbidities. Besides patient factors, being admitted to a rurally located hospital more than halved the odds of being prescribed ticagrelor (odds ratio [OR], 0.49; 95% CI, 0.32–0.77). Being managed by a cardiologist during the index ACS hospitalization was associated with higher odds of having a ticagrelor prescription after ACS (OR, 2.80; 95% CI, 2.36–3.33).

Conclusions

Ticagrelor use rates varied substantially across hospitals and were strongly associated with physician and hospital factors independent of patient characteristics.

Successful Primary Percutaneous Coronary Intervention without Stenting: Insight from Optimal Coherence Tomography

For patients with acute myocardial infarction, current management guidelines recommend implantation of a drug-eluting stent, dual antiplatelet therapy (including potent P2Y12 inhibitors) for at least 1 year, and maintenance of life-long antiplatelet therapy. However, a pilot study showed favorable results with antithrombotic therapy without stent implantation when plaque erosion, not definite plaque rupture, was confirmed using optical coherence tomography (OCT), despite the patients having acute myocardial infarction. Here, we present a case where successful primary percutaneous coronary intervention was performed without stenting with the aid of OCT in a patient with ST-elevation myocardial infarction who developed thrombotic total occlusion of the right coronary artery.

Antiplatelet therapy in cardiovascular disease: current status and future directions

Antiplatelet medications remain a cornerstone of therapy for atherosclerotic cardiovascular and cerebrovascular diseases. In primary prevention (patients with cardiovascular risk factors but no documented events, symptoms or angiographic disease), there is little evidence of benefit of any antiplatelet therapy, and such therapy carries the risk of excess bleeding. Where there is documented disease (secondary prevention), stable patients benefit from long-term antiplatelet monotherapy, aspirin being first choice in those with coronary heart disease and clopidogrel in those with cerebrovascular disease; moreover, recent evidence shows that low-dose rivaroxaban in combination with aspirin confers added benefit, in patients with stable cardiovascular and peripheral arterial disease. In patients with acute cerebrovascular disease, aspirin combined with clopidogrel reduces subsequent risk, while in acute coronary syndrome, dual antiplatelet therapy comprising aspirin and a P2Y₁₂ inhibitor (clopidogrel, prasugrel or ticagrelor) confers greater protection than aspirin monotherapy, with prasugrel and ticagrelor offering greater antiplatelet efficacy with faster onset of action than clopidogrel. Although greater antiplatelet efficacy is advantageous in preventing thrombotic events, this must be tempered by increased risk of bleeding which may be a particular issue in certain patient groups, as will be discussed. We will also discuss possible future approaches to personalisation of antiplatelet therapy.

Commentary: Prevention of saphenous vein graft disease remains elusive

One-year outcomes of Ticagrelor Antiplatelet Therapy to Reduce Graft Events and Thrombosis (TARGET), a randomized double-blinded clinical trial comparing post-coronary artery bypass surgery antiplatelet therapy with ticagrelor versus aspirin are published in this issue of the Journal. Although the authors did not detect statistically significant differences in their primary outcome (saphenous vein graft patency at 1 year) and major adverse cardiovascular events, their findings must be interpreted with caution given important limitations in the design and execution of the trial.

Association between osteoporosis or osteopenia and taking antiplatelet agents in general US population of NHANES

BACKGROUND

Osteoporosis (OP) and osteopenia are common bone disorders in old age, and lots of patients suffering from OP or osteopenia need to take antiplatelet agents to treat basic diseases. However, clinical data on the link between osteopenia or OP and antiplatelet agents are limited.

METHODS

Data in this study were collected and screened from the NHANES from 2013 to 2014 and 2017 to 2018. The variables were extracted from interviews and compared between OP or osteopenia participants and normal. The relationship between OP or osteopenia and taking antiplatelet drugs was analyzed by weighted multivariate logistic regression.

RESULTS

After excluding individuals who were not eligible and had invalid data, we finally identified 894 participants for inclusion in the study. We found a negative association between OP or osteopenia and taking antiplatelet agents (OR = 0.53; 95% CI, 0.33-0.84; p < 0.05). These results did not change on multiple imputations (OR = 0.32, 95% CI, 0.19-0.56; p <0.01). In the subgroup analyses, the associations were more significant in women (OR = 0.18, 95% CI, 0.05-0.62; p <0.05).

CONCLUSION

This study demonstrated that the association between OP or osteopenia and taking antiplatelet agents was significant. Therefore, it is necessary to confirm the result by extending further research.

Combined Antiplatelet Therapy Reduces the Proinflammatory Properties of Activated Platelets

The cause of atherothrombosis is rupture or erosion of atherosclerotic lesions, leading to an increased risk of myocardial infarction or stroke. Here, platelet activation plays a major role, leading to the release of bioactive molecules, for example, chemokines and coagulation factors, and to platelet clot formation. Several antiplatelet therapies have been developed for secondary prevention of cardiovascular events, in which anticoagulant drugs are often combined. Besides playing a role in hemostasis, platelets are also involved in inflammation. However, it is unclear whether current antiplatelet therapies also affect platelet immune functions. In this study, the possible anti-inflammatory effects of antiplatelet medications on chemokine release were investigated using enzyme-linked immunosorbent assay and on the chemotaxis of THP-1 cells toward platelet releasates. We found that antiplatelet medication acetylsalicylic acid (ASA) led to reduced chemokine (CC motif) ligand 5 (CCL5) and chemokine (CXC motif) ligand 4 (CXCL4) release from platelets, while leukocyte chemotaxis was not affected. Depending on the agonist, α _IIb β ₃ and P2Y ₁₂ inhibitors also affected CCL5 or CXCL4 release. The combination of ASA with a P2Y ₁₂ inhibitor or a phosphodiesterase (PDE) inhibitor did not lead to an additive reduction in CCL5 or CXCL4 release. Interestingly, these combinations did reduce leukocyte chemotaxis. This study provides evidence that combined therapy of ASA and a P2Y ₁₂ or PDE3 inhibitor can decrease the inflammatory leukocyte recruiting potential of the releasate of activated platelets.

Systemic antiplatelet agents and anticoagulants in eyes with branch retinal vein occlusion

Purpose

The purpose of this study was to investigate the effect of systemic antiplatelet agents and anticoagulants on the structural and functional outcomes of eyes with branch retinal vein occlusion (BRVO).

Methods

A retrospective longitudinal cohort study was performed on BRVO patients evaluated at a single tertiary care referral center between 2009 and 2017. Medical records were reviewed for antiplatelet agent and anticoagulant use including aspirin, clopidogrel, warfarin, rivaroxaban, apixaban, or dabigatran prior to BRVO onset. In addition, optical coherence tomography (OCT) parameters, clinical outcomes, and treatment patterns were also recorded.

Results

A total of 354 BRVO eyes were identified with a mean follow-up time of 36 months. Antiplatelet or anticoagulant use was associated with presence of cystoid macular edema (CME) at presentation after controlling for potential confounding variables in a multivariate logistic regression. Multivariate regression also revealed an association between foveal hemorrhage at presentation and use of antiplatelet or anticoagulant medications. There were no significant differences in visual acuity or prevalence of CME at the final visit in those with antiplatelet/anticoagulant use compared to those not on these agents.

Conclusion

Although the use of systemic antiplatelet or anticoagulant agents was associated with increased prevalence of CME and foveal hemorrhage at presentation of BRVO, the use of these medications was not associated with different visual or structural outcomes at the final visit.

Perioperative Antiplatelet and Anticoagulant Management with Endodontic Microsurgical Techniques

INTRODUCTION

The purpose of this study was to review evidence-based recommendations for the safe perioperative management of patients undergoing endodontic microsurgery who are currently taking antiplatelet or anticoagulant medications. Using the PICO (Population, Intervention, Comparison, Outcome) format, the following scientific question was asked: In patients taking anticoagulant or antiplatelet agents, what is the available evidence in the management of endodontic microsurgery?

METHODS

MEDLINE, Scopus, Cochrane Library, and ClinicalTrials.gov databases were searched to identify current recommendations regarding the management of antiplatelet and anticoagulant medications in the context of outpatient dental surgical procedures. Additionally, the authors hand searched the bibliographies of all relevant articles, the gray literature, and textbooks. Because of the lack of clinical studies and evidence on this subject, articles and guidelines from other organizations and association position statements were included.

RESULTS

Because any minor surgery can become a major surgery, the treating doctor needs to best assess the risk of bleeding, especially if the surgery is anticipated to take longer than 45 minutes. Every patient should be stratified on a case-by-case basis. Consultation with the patient's physician is highly recommended.

CONCLUSIONS

In order to maximize the effects of these medications (to prevent thrombosis) while minimizing the potential risks (procedural hemorrhage), clinicians should be aware of the best available evidence when considering continuation or discontinuation of antiplatelet and anticoagulant agents perioperatively for endodontic microsurgery. Ideally, a joint effort from an expert panel for microsurgery would be warranted.

Use of Antiplatelet Agents Decreases the Positive Predictive Value of Fecal Immunochemical Tests for Colorectal Cancer but Does Not Affect Their Sensitivity

Previous studies have evaluated the effects of antithrombotic agents on the performance of fecal immunochemical tests (FITs) for the detection of colorectal cancer (CRC), but the results were inconsistent and based on small sample sizes. We studied this topic using a large-scale population-based database. Using the Korean National Cancer Screening Program Database, we compared the performance of FITs for CRC detection between users and non-users of antiplatelet agents and warfarin. Non-users were matched according to age and sex. Among 5,426,469 eligible participants, 768,733 used antiplatelet agents (mono/dual/triple therapy, n = 701,683/63,211/3839), and 19,569 used warfarin, while 4,638,167 were non-users. Among antiplatelet agents, aspirin, clopidogrel, and cilostazol ranked first, second, and third, respectively, in terms of prescription rates. Users of antiplatelet agents (3.62% vs. 4.45%; relative risk (RR): 0.83; 95% confidence interval (CI): 0.78–0.88), aspirin (3.66% vs. 4.13%; RR: 0.90; 95% CI: 0.83–0.97), and clopidogrel (3.48% vs. 4.88%; RR: 0.72; 95% CI: 0.61–0.86) had lower positive predictive values (PPVs) for CRC detection than non-users. However, there were no significant differences in PPV between cilostazol vs. non-users and warfarin users vs. non-users. For PPV, the RR (users vs. non-users) for antiplatelet monotherapy was 0.86, while the RRs for dual and triple antiplatelet therapies (excluding cilostazol) were 0.67 and 0.22, respectively. For all antithrombotic agents, the sensitivity for CRC detection was not different between users and non-users. Use of antiplatelet agents, except cilostazol, may increase the false positives without improving the sensitivity of FITs for CRC detection.

Case Report: Effective Treatment for Acute Chlorpyrifos Poisoning Complicated by a Non-ST-Segment Elevation Myocardial Infarction

Background: Acute myocardial infarction (AMI) is a rare complication of acute organophosphorus pesticide poisoning. Although chlorpyrifos has been widely used as an organophosphate insecticide, a few cases of AMI complicated by chlorpyrifos poisoning have been reported thus far. Hence, a suitable treatment strategy remains to be explored.

Case Presentation: Based on the clinical manifestations, medical history, results of an auxiliary examination, and serum biomarkers, a 65-year-old male farmer with complaints of nausea, vomiting, chest tightness, and pain was clearly diagnosed as having a severe chlorpyrifos self-poisoning with acute non-ST-segment elevation MI. Because the patient and his family confirmedly refused a coronary intervention, conservative treatment was used instead. It should be noted that there were some conflicts of the management for chlorpyrifos poisoning and AMI. Although rapid atropinization would contribute to the relief of muscarinic symptoms, it would also lead to an increased heart rate and myocardial oxygen consumption in AMI. Furthermore, the reduction of platelet aggregation, which is necessary for coronary recanalization of an AMI patient, is known to aggravate the gastrointestinal injury caused by poisoning. In this case, these conflicts were properly addressed, which led to an excellent effect and prognosis of the patient.

Conclusions: To our knowledge, this is the first case report of acute chlorpyrifos poisoning with AMI. It is emphasized that patients with chest pain or coronary heart disease should be treated with atropine more cautiously because of the possible AMI. Moreover, proper resolution of conflicts in the management for chlorpyrifos poisoning and AMI played contributing roles in patient improvement.

Antithrombotic Therapy Recommendations in the European Society of Cardiology Guidelines: How Robust Are the Randomized Controlled Trials Underpinning Them?

Introduction  Criticisms have been raised against the sole use of p -value in interpreting results from randomized controlled trials (RCTs). Additional tools have been suggested, like the fragility index (FI), a measure of a trial's robustness/fragility, and derivative measures. The FI is the minimum number of patients who would have to be converted from nonevents to events, in the group with the least events, for a result to lose statistical significance. Objective  This study aimed to evaluate RCT supporting European Society of Cardiology (ESC) guidelines regarding antithrombotics, using the FI and FI-related measures. Methods  FI, fragility quotient (FQ), and FI minus LTF lost to follow-up (FI - LTF) were calculated for the RCT underpinning recommendations regarding antithrombotic therapy from the updated ESC guidelines. LTF was compared with FI. Results were calculated for the total group of studies, as per guideline and as per recommendation type. Results  Overall, 61 studies were included. The median FI was 24.5 (interquartile range [IQR]: 9.0-60.0) and median FQ was 0.0035 (IQR: 0.0019-0.0056). Median FI - LTF was 2.0 (IQR: 0.0-38.0). Twenty (32.8%) of the studies had one primary or main safety outcome with LTF exceeding FI. Peripheral arterial disease guideline and chronic coronary syndrome guideline had the lowest (2.5; IQR: 1.8-3.3) and the highest (48.5; IQR: 23.8-73.0) FI, respectively. Conclusion  The median FI suggests robustness of clinical trials evaluating antithrombotic drugs cited in the guidelines, but about one-third of them had LTF larger than FI. This emphasizes the need for assessing trials' robustness when constructing guidelines.

Incidence of Non-Traumatic Subconjunctival Hemorrhage in an Indian Rural Population

Purpose

To determine the incidence of non-traumatic subconjunctival hemorrhage (NTSH) in Indian rural population and analyze the associated risk factors.

Methods

The study included patients diagnosed having subconjunctival hemorrhage (SCH) who attended the out-patient department (OPD) of ophthalmology. Demographic characteristics of subjects included age, gender, medical and ocular history, and location of hemorrhage.

Results

The incidence rate of NTSH in this study was 3.07 per 1000 patients per year attending OPD. The men to women ratio for NTSH was 1.26 (95% CI). The commonest site of presentation was nasal side (n=36, 51.4%). Right eye (n= 37, 54.3%) was affected more than the left eye (n=28, 40%). The analysis showed 24 patients (34.3%) did not have any etiological factor attributable to SCH. Conjunctivochalasis (CCH) was associated in 15 patients (21.4%). An antiplatelet agent was associated with SCH in 7 patients (10%). Other factors associated with SCH were hypertension, leukemia, and anemia (n=6, 8.6%).

Conclusion

This study indicates that NTSH occurs in 3 out of 1000 individuals per year in the rural population presenting to the OPD. Nasal conjunctiva was commonly involved. CCH was associated with 15 patients. Use of antiplatelet agents, hypertension and blood disorders are associated with the risk of NTSH. Patients presenting for the first time with NTSH should be screened for systemic etiological factors.

Efficacy and Safety of Antiplatelet Agents for Adult Patients With Ischemic Moyamoya Disease

Background: The use of antiplatelet agents in ischemic moyamoya disease (MMD) is controversial. This study aimed to investigate the effectiveness and safety of antiplatelet therapy compared with conservative treatment and surgical revascularization in ischemic MMD patients. Methods: Ischemic MMD patients were retrospectively enrolled from eight clinical sites from January 2013 to December 2018. Follow-up was performed through clinical visits and/or telephone interviews from first discharge to December 2019. The primary outcome was the episodes of further ischemic attacks, and the secondary outcome was the individual functional status. Risk factors for future stroke were identified by the LASSO-Cox regression model. Propensity score matching was applied to assemble a cohort of patients with similar baseline characteristics using the TriMatch package. Results: Among 217 eligible patients, 159 patients were included in the analyses after a 1:1:1 propensity score matching. At a mean follow-up of 33 months, 12 patients (7.5%) developed further incident cerebral ischemic events (surgical:antiplatelet:conservative = 1:3:8; p = 0.030), 26 patients (16.4%) developed a poor functional status (surgical:antiplatelet:conservative = 7:12:7; p = 0.317), and 3 patients (1.8%) died of cerebral hemorrhage (surgical:antiplatelet:conservative = 1:2:0; p = 0.361). The survival curve showed that the risk of further cerebral ischemic attacks was lowest with surgical revascularization, while antiplatelet therapy was statistically significant for preventing recurrent risks compared with conservative treatment (χ² = 8.987; p = 0.011). No significant difference was found in the functional status and bleeding events. The LASSO-Cox regression model revealed that a family history of MMD (HR = 6.93; 95% CI: 1.28-37.52; p = 0.025), a past history of stroke or transient ischemic attack (HR = 4.35; 95% CI: 1.09-17.33; p = 0.037), and treatment (HR = 0.05; 95% CI: 0.01-0.32; p = 0.001) were significantly related to the risk of recurrent strokes. Conclusions: Antiplatelet agents were effective and safe in preventing further cerebral ischemic attacks in adult patients with ischemic MMD. They may be a replacement therapy for patients with surgical contraindications and for patients prior to revascularization.

Validation of an HPLC-MS/MS Method for the Determination of Plasma Ticagrelor and Its Active Metabolite Useful for Research and Clinical Practice

Ticagrelor is an antiplatelet agent which is extensively metabolized in an active metabolite: AR-C124910XX. Ticagrelor antagonizes P2Y12 receptors, but recently, this effect on the central nervous system has been linked to the development of dyspnea. Ticagrelor-related dyspnea has been linked to persistently high plasma concentrations of ticagrelor. Therefore, there is a need to develop a simple, rapid, and sensitive method for simultaneous determination of ticagrelor and its active metabolite in human plasma to further investigate the link between concentrations of ticagrelor, its active metabolite, and side effects in routine practice. We present here a new method of quantifying both molecules, suitable for routine practice, validated according to the latest Food and Drug Administration (FDA) guidelines, with a good accuracy and precision (<15% respectively), except for the lower limit of quantification (<20%). We further describe its successful application to plasma samples for a population pharmacokinetics study. The simplicity and rapidity, the wide range of the calibration curve (2–5000 µg/L for ticagrelor and its metabolite), and high throughput make a broad spectrum of applications possible for our method, which can easily be implemented for research, or in daily routine practice such as therapeutic drug monitoring to prevent overdosage and occurrence of adverse events in patients.

The role of pharmacogenetics for antithrombotic therapy management: new achievements and barriers yet to overcome

BACKGROUND

Pharmacogenetics investigates the response to pharmacological treatments based on individual genetic background. Actually, numerous pharmacogenetic tests help to predict the response to drugs used in different medical areas, contributing to the so-called personalized medicine.

OBJECTIVE

This review aims to update the available data on the genotype-guided treatment with both the anticoagulant and antiplatelet agents. Moreover, it shed light on the pitfalls still contrasting the implementation of cardiovascular pharmacogenetics.

METHODS

A review of the literature on the studies investigating the effects of the genotype-guided anticoagulant and antiplatelet treatment was performed.

RESULTS

Considering the large use of antithrombotic drugs, pharmacogenetics has particular importance in this field. Several polymorphisms influence the response to both anticoagulant and antiplatelet agents, and tests, based on their identification, are now available.

CONCLUSIONS

Recent randomized clinical trials demonstrated that pharmacogenetics might successfully contribute to optimizing the antiplatelet therapy also in patients particularly complicated to treat. However, despite accumulating evidence on the utility and feasibility of some pharmacogenetics tests, several barriers still contrast their implementation into clinical practice.

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.

Impact of Diabetes Mellitus on Antithrombotic Management Patterns and Long-Term Clinical Outcomes in Patients With Acute Coronary Syndrome: Insights From the EPICOR Asia Study

Background

Long‐term use of antiplatelet agents after acute coronary syndrome in diabetic patients is not well known. Here, we describe antiplatelet use and outcomes in such patients enrolled in the EPICOR Asia (Long‐Term Follow‐up of Antithrombotic Management Patterns in Acute Coronary Syndrome Patients in Asia) registry.

Methods and Results

EPICOR Asia is a prospective, observational study of 12 922 patients with acute coronary syndrome surviving to discharge, from 8 countries/regions in Asia. The present analysis included 3162 patients with diabetes mellitus (DM) and 9602 patients without DM. The impact of DM on use of antiplatelet agents and events (composite of death, myocardial infarction, and stroke, with or without any revascularization; individual components, and bleeding) was evaluated. Significant baseline differences were seen between patients with DM and patients without DM for age, sex, body mass index, cardiovascular history, angiographic findings, and use of percutaneous coronary intervention. At discharge, ≈90% of patients in each group received dual antiplatelet therapy. At 2‐year follow‐up, more patients with DM tended to still receive dual antiplatelet therapy (60% versus 56%). DM was associated with increased risk from ischemic but not major bleeding events. Independent predictors of the composite end point of death, myocardial infarction, and stroke in patients with DM were age ≥65 years and use of diuretics at discharge.

Conclusions

Antiplatelet agent use is broadly comparable in patients with DM and patients without DM, although patients with DM are more likely to be on dual antiplatelet therapy at 2 years. Patients with DM are at increased risk of ischemic events, suggesting an unmet need for improved antithrombotic treatment.

Registration

URL: https://www.clini​caltr​ials.gov; Unique identifier: NCT01361386.

An evaluation of ticagrelor for the treatment of sickle cell anemia

INTRODUCTION

Ticagrelor is an antiplatelet agent approved for the treatment of patients with an acute coronary syndrome or a history of myocardial infarction. Considering the evidence demonstrating that ticagrelor-mediated inhibition of platelet activation and aggregation have beneficial effects in the treatment of thrombotic conditions, clinical studies have been conducted to evaluate the use of this drug for the treatment of sickle cell disease (SCD), demonstrating satisfactory tolerability and safety.

AREAS COVERED

Clinical investigation has characterized the pharmacokinetic and pharmacodynamical profile, as well as the efficacy and safety of ticagrelor to prevent painful vaso-occlusive crisis (painful episodes and acute chest syndrome) in SCD patients.

EXPERT OPINION

While phase 1 and 2 clinical trials demonstrated satisfactory tolerability and safety, the conclusion of phase 3 clinical trials is crucial to prove the efficacy of ticagrelor as a therapeutic option for the treatment of SCD. Thus, it is expected that ticagrelor, especially in combination with other drugs, will improve the clinical profile and quality of life of patients with SCD.

Management of Bleeding Events Associated with Antiplatelet Therapy: Evidence, Uncertainties and Pitfalls

Bleeding complications are common in patients treated with antiplatelet agents (APA), but their management relies on poor evidence. Therefore, practical guidelines and guidance documents are mainly based on expert opinion. The French Working Group on Perioperative Haemostasis provided proposals in 2018 to enhance clinical decisions regarding the management of APA-treated patients with a bleeding event. In light of these proposals, this review discusses the evidence and uncertainties of the management of patients with a bleeding event while on antiplatelet therapy. Platelet transfusion is the main option as an attempt to neutralise the effect of APA on primary haemostasis. Nevertheless, efficacy of platelet transfusion to mitigate clinical consequences of bleeding in patients treated with APA depends on the type of antiplatelet therapy, the time from the last intake, the mechanism (spontaneous versus traumatic) and site of bleeding and the criteria of efficacy (in vitro, in vivo). Specific antidotes for APA neutralisation are needed, especially for ticagrelor, but are not available yet. Despite the amount of information that platelet function tests are expected to give, little data support the clinical benefit of using such tests for the management of bleeding events in patients treated or potentially treated with APA.

Impact of Age, Multimorbidity and Frailty on the Prescription of Preventive Antiplatelet Therapy in Older Population

Platelet aggregation inhibitors (PAI) have widely proven their efficiency for the prevention of ischemic cardiovascular events. We aimed to describe PAI prescription in an elderly multimorbid population and to determine the factors that influence their prescription, including the impact of age, comorbidities and frailty, evaluated through a comprehensive geriatric assessment. This cross-sectional study included all patients admitted to the acute geriatric department of a university hospital from November 2016 to January 2017. We included 304 consecutive hospitalized patients aged 88.7 ± 5.5 years. One third of the population was treated with PAI. A total of 133 (43.8%) patients had a history of cardiovascular disease, 77 of whom were on PAI. For 16 patients, no indication was identified. The prescription or the absence of PAI were consistent with medical history in 61.8% of patients. In the multivariate analysis, among the 187 patients with an indication for PAI, neither age (odds ratio (OR) = 1.00; 95% confidence interval (CI): [0.91-1.08], per year of age), nor comorbidities (OR = 0.97; 95% CI: [0.75-1.26], per point of Charlson comorbidity index), nor cognitive disorders (OR = 0.98; 95% CI [0.91-1.06] per point of Mini Mental State Examination), nor malnutrition (OR = 1.07; 95% CI [0.96-1.18], per g/L of albumin) were significantly associated with the therapeutic decision. PAI were less prescribed in primary prevention situations, in patients taking anticoagulants and in patients with a history of bleeding. In conclusion, a third of our older comorbid population of inpatients was taking PAI. PAI prescription was consistent with medical history for 61.8% of patients. Age, multimorbidity and frailty do not appear to have a significant influence on therapeutic decision-making. Further research is needed to confirm such a persistence of cardiovascular preventive strategies in frail older patients from other settings and to assess whether these strategies are associated with a clinical benefit in this specific population.

Perspective on CYP2C19 genotyping test among patients with acute coronary syndrome - a qualitative study

Aim: Identify factors patients consider regarding CYP2C19 genotyping test to guide choice of antiplatelet therapy. Patients & methods: Patient's perception and attitude toward use of CYP2C19 genotyping test was gathered according to an interview guide. Thematic analysis was conducted. Results: A total of 14 patients were interviewed. The main factors found to influence uptake of CYP2C19 genotyping test are, convenience of genotyping test (n = 4), physician's recommendation (n = 11), prior explanation of genetic testing by medical personnel (n = 5) and inclination toward clopidogrel, with three sub-factors; less frequent dosing (n = 3), lower cost (n = 7) and lower risk of bleeding (n = 9). Conclusion: This study provided the information needed to develop a discrete choice experiment to empirically quantify patients' preference and willingness to pay for genetic testing and to simulate uptake.

Effect of Preinjury Oral Anticoagulants on Outcomes Following Traumatic Brain Injury from Falls in Older Adults

BACKGROUND

Warfarin has been the oral anticoagulant of choice for the treatment of thromboembolic disease. However, upward of 50% of all new anticoagulant prescriptions are now for direct oral anticoagulants (DOAC). Despite this, outcome data evaluating preinjury anticoagulants remain scarce following traumatic brain injury (TBI). Our study objective is to determine the effects of preinjury anticoagulation on outcomes in older adults with TBI.

METHODS

Patient data were obtained from 29 level 1 and 2 trauma centers from 2012 to June 30, 2018. Overall, 8312 patients who were aged 65 years or older, suffering a ground level fall, and with an Abbreviated Injury Scale (AIS) head score of ≥ 3 were identified. Patients were excluded if they presented with no signs of life or a traumatic mechanism besides ground level fall. Statistical comparisons were made using multivariable analyses with anticoagulant/antiplatelet use as the independent variable.

RESULTS

Of the total patients with TBI, 3293 were on antiplatelet agents (AP), 669 on warfarin, 414 on warfarin + AP, 188 on DOACs, 116 on DOAC + AP, and 3632 on no anticoagulant. There were 185 (27.7%) patients on warfarin and 43 (22.9%) on a DOAC with a combined outcome of mortality or hospice as compared to 575 (15.8%) in the no anticoagulant group (p<0.001). After adjusting for patient factors, there was an increased risk of mortality or hospice in the warfarin (OR 1.60; 95% CI 1.27-2.01) and DOAC group (OR 1.67; 95% CI 1.07-2.59) as compared to no anticoagulant. Warfarin + AP was associated with an increased risk of mortality or hospice (OR 1.61; 95% CI 1.18-2.21) that was not seen with DOAC + AP (OR 0.93; 95% CI 0.46-1.87) as compared to no anticoagulant.

CONCLUSIONS

In older adults with TBI, preinjury treatment with warfarin or DOACs resulted in an increased risk of mortality or hospice whereas preinjury AP therapy did not increase risk. Future studies are needed with larger sample sizes to directly compare TBI outcomes associated with preinjury warfarin versus DOAC use.

Antiplatelet Agents Have a Distinct Efficacy on Platelet Aggregation Induced by Infectious Bacteria

Platelets are the cornerstone of hemostasis. However, their exaggerated aggregation induces deleterious consequences. In several diseases, such as infectious endocarditis and sepsis, the interaction between platelets and bacteria leads to platelet aggregation. Despite platelet involvement, no antiplatelet therapy is currently recommended in these infectious diseases. We aimed here, to evaluate, in vitro, the effect of antiplatelet drugs on platelet aggregation induced by two of the bacterial pathogens most involved in infectious endocarditis, Staphylococcus aureus and Streptococcus sanguinis. Blood samples were collected from healthy donors (n = 43). Treated platelet rich plasmas were incubated with three bacterial strains of each species tested. Platelet aggregation was evaluated by Light Transmission Aggregometry. CD62P surface exposure was evaluated by flow cytometry. Aggregate organizations were analyzed by scanning electron microscopy. All the strains tested induced a strong platelet aggregation. Antiplatelet drugs showed distinct effects depending on the bacterial species involved with different magnitude between strains of the same species. Ticagrelor exhibited the highest inhibitory effect on platelet activation (p <0.001) and aggregation (p <0.01) induced by S. aureus. In the case of S. sanguinis, platelet activation and aggregation were better inhibited using the combination of both aspirin and ticagrelor (p <0.05 and p <0.001 respectively). Aggregates ultrastructure and effect of antiplatelet drugs observed by scanning electron microscopy depended on the species involved. Our results highlighted that the effect of antiplatelet drugs depended on the bacterial species involved. We might recommend therefore to consider the germ involved before introduction of an optimal antiplatelet therapy.

The Role of Antithrombotic Therapy in Heart Failure

Heart failure is a major contributor to global morbidity and mortality burden affecting approximately 1-2% of adults in developed countries, mounting to over 10% in individuals aged >70 years old. Heart failure is characterized by a prothrombotic state and increased rates of stroke and thromboembolism have been reported in heart failure patients compared with the general population. However, the impact of antithrombotic therapy on heart failure remains controversial. Administration of antiplatelet or anticoagulant therapy is the obvious (and well-established) choice in heart failure patients with cardiovascular comorbidity that necessitates their use, such as coronary artery disease or atrial fibrillation. In contrast, antithrombotic therapy has not demonstrated any clear benefit when administered for heart failure per se, i.e. with heart failure being the sole indication. Randomized studies have reported decreased stroke rates with warfarin use in patients with heart failure with reduced left ventricular ejection fraction, but at the expense of excessive bleeding. Non-vitamin K oral anticoagulants have shown a better safety profile in heart failure patients with atrial fibrillation compared with warfarin, however, current evidence about their role in heart failure with sinus rhythm is inconclusive and further research is needed. In the present review, we discuss the role of antithrombotic therapy in heart failure (beyond coronary artery disease), aiming to summarize evidence regarding the thrombotic risk and the role of antiplatelet and anticoagulant agents in patients with heart failure.