Antiplatelet Therapy for Secondary Prevention of Vascular Disease Complications

Continuous aspirin treatment improves cardiovascular events and all-cause mortality in hemodialysis patients with peripheral artery disease

BACKGROUND

Hemodialysis (HD) patients with peripheral arterial disease (PAD) are at heightened risk of adverse vascular events, and aspirin positively affects those outcomes. We aimed to investigate the association between different patterns of aspirin use and clinical vascular events in chronic HD patients with PAD.

METHODS

This retrospective nationwide cohort study enrolled 758 chronic HD patients who had been diagnosed with PAD between January 1, 2008, and December 31, 2012, and followed up until the end of 2020. Patients were divided into three groups according to medication possession ratio (MPR) and continued use of aspirin (i.e., low MPR, high MPR but discontinuous prescription, and high MPR and continuous prescription). Percutaneous transluminal angioplasty (PTA), surgical bypass, lower leg amputation, cardiovascular events, cerebrovascular events, and all-cause mortality were evaluated.

RESULTS

High MPR and continuous aspirin use had the lowest incidence of all-cause mortality and cardiovascular events compared with the two other groups, and it was significantly associated with low risk of PTA, surgical bypass, cardiovascular events, and all-cause mortality (aHR: 0.58 [0.41-0.83], 0.49 [0.25-0.95], 0.57 [0.40-0.81], and 0.70 [0.55-0.88], respectively). Kaplan-Meier analysis revealed that event-free rates of PTA, cardiovascular events, and all-cause mortality of patients with high MPR and continuous aspirin treatment were the highest among the three groups (p < 0.05).

CONCLUSION

Among HD patients with PAD, high MPR and continuous aspirin use significantly reduced the risk of PTA, surgical bypass, cardiovascular events, and all-cause mortality and improved the event-free rates of PTA, cardiovascular events, and all-cause mortality during long-term follow-up.

Clinical recurrence and antiplatelet drug resistance among patients with lower limb ischemia

There is a high prevalence rate of peripheral artery disease worldwide, with estimated cases exceeding 200 million. Most patients are under-diagnosed and under-treated, and there is a lack of knowledge regarding the best therapeutic regimen and therapy duration, which leads to many cases of recurrence, complications, and amputations. This study aims to explore clinical recurrence, which was defined as the worsening of chronic peripheral artery disease requiring hospital admission, and its relationship with antiplatelet drug resistance among patients with lower limb ischemia. This cohort study includes both retrospective and prospective recruitment of patients with chronic lower limb ischemia. Platelet aggregation tests were offered to the patients. Between February 2018 and November 2020, 147 patients were recruited from King Abdullah University Hospital and followed up for at least 1 year. Platelet aggregation tests were done for 93 patients who agreed to participate in this part of the study. The prevalence of chronic lower limb ischemia was higher in young male patients who are current smokers with co-morbid diseases such as hypertension, diabetes mellitus, and/or dyslipidemia. There was a significant association only of clinical recurrence with younger age (P = .011) and with low platelets count in severe stages of the disease (P = .047). No significant association was found in terms of laboratory resistance. The clinical recurrence rates of chronic lower limb ischemia were higher in younger patients and among those with low platelet counts in the severe stages of the disease. Despite the laboratory responsiveness to anti-platelet therapy, we observed significant clinical resistance and increased recurrence rates.

Anticoagulation and Antiplatelet Agents in Peripheral Arterial Interventions

Effective revascularization of peripheral artery disease relies on periprocedural pharmacological regulation of the clotting cascade. Patient-specific factors such as cardiovascular risk factors, contraindications, and individual psychosocial factors must be considered when initiating post revascularization management. Management with anticoagulant and antiplatelet agents is discussed to guide the interventionalist on which therapy may be appropriate for their patient. While exact treatment may be institution and provider dependent, the interventionist must be familiar with the available classes of medications and how they can be prescribed in the postprocedural setting to improve cardiovascular outcomes.

The effects of ginsenosides on platelet aggregation and vascular intima in the treatment of cardiovascular diseases: From molecular mechanisms to clinical applications

Thrombosis initiated by abnormal platelet aggregation is a pivotal pathological event that precedes most cases of cardiovascular diseases (CVD). Recently, growing evidence indicates that platelet could be a potential target for CVD prevention. However, as the conventional antithrombotic management strategy, applications of current antiplatelet agents are somewhat limited by their various side effects, such as bleeding risk and drug resistance. Hence, efforts have been made to search for agents as complementary therapies. Ginsenoside, the principal active component extracted from Panax ginseng, has gained much attention for its regulations on multiple crucial events of platelet aggregation. From structural characteristics to clinical applications, this review anatomized the intrinsic structure-function relationship of antiplatelet potency of ginsenosides, and the involved signal pathways were specifically summarized. Additionally, the emphasis was placed on clinical studies that investigate the antithrombotic efficacy of ginsenosides in the treatment of CVD. Further, a broad overview of approaches for improving the bioavailability of ginsenosides was concluded. Limitations and prospects of current studies were also discussed. This study may provide some new insights into the systematic understanding of ginsenosides in CVD treatment and lay a foundation for future research.

Optical uncaging of ADP reveals the early calcium dynamics in single, freely moving platelets

Platelet activation is considered to be a cornerstone in pathogenesis of cardiovascular disease. The assessment of platelet activation at the single-cell level is a promising approach for the research of platelet function in physiological and pathological conditions. Previous studies used the immobilization of platelets on the surface, which significantly alters the activation signaling. Here we show that the use of photolabile "caged" analog of ADP allows one to track the very early stage of platelet activation in single, freely moving cells. In this approach, the diffusion step and ADP receptor ligation are separated in time, and a millisecond-timescale optical pulse may trigger the activation. The technique allows us to measure the delay (lag time) between the stimulus and calcium response in platelets. We also propose a simple model function for calcium peaks, which is in good agreement with the measured data. The proposed technique and model function can be used for in-depth studies of platelet physiology.

Treatment of stable ischaemic heart disease: the old and the new

Stable ischaemic heart disease is a frequent and very heterogeneous condition. Drug therapy is important, in these patients, for improving their prognosis and controlling their symptoms. The typical clinical manifestation of obstructive coronary disease is angina pectoris. This symptom can be improved by various classes of compounds, namely beta-blockers (BBs), calcium antagonist, and nitrates. More recently, ranolazine and ivabradine have been introduced. All these drugs have been proven to reduce significantly angina. On the other hand, there are no evidences supporting improvement in prognosis, besides for the use of BBs, in patients with previous myocardial infarction (MI) or systolic dysfunction. Besides drugs for symptoms control, these patients also receive antiplatelet drugs, specifically aspirin, and lipid lowering compounds such as statins. Furthermore, recent evidences supported the use of low doses direct anticoagulant, or a second antiplatelet agent in patients with previous MI. Similarly, a very low LDL cholesterol level, such as obtained with PCKS9 inhibitors, seems very beneficial in these patients. It is possible that in the near future a specific role for neo-angiogenesis factors and cellular therapies, could be proven, albeit, presently these treatments are not supported by solid evidences.

Role of Aspirin in Tuberculous Meningitis: A Systematic Review and Meta-analysis

Objectives

Aspirin is a drug that has been found to be useful in reducing the incidence of infarctions. This systemic is aimed at review evaluating the benefits of aspirin in the management of tuberculous meningitis.

Methods

A systematic literature search was performed using PubMed, Cochrane Central Register of Controlled Trials, and SCOPUS for articles published on or before September 22, 2018. The meta-register of controlled trials and bibliography was also searched. Randomized controlled trials wherein aspirin was used were included in the systematic review. The data was extracted using a predetermined format. The risk ratio (RR) for dichotomous data was calculated and a random-effects model was used to combine the data. Death and occurrence of new infarctions were considered as primary outcomes. The quality of evidence was assessed using the GRADE approach.

Results

Four trials including 546 patients were found eligible. The addition of aspirin to anti-tuberculosis drug regimens did not significantly reduce mortality [RR = 0.66 (0.42-1.02); low-quality evidence] but significantly reduced the risk of new infarctions [RR = 0.52 (0.29-0.92); moderate-quality evidence]. Aspirin did not differ from the placebo with regard to the adverse event outcome.

Conclusion

Aspirin reduces the risk of new infarctions in patients with tuberculous meningitis but does not affect mortality (moderate-to-low level of evidence).

Novel Locally Acting Dual Antiplatelet and Anticoagulant (APAC) Targets Multiple Sites of Vascular Injury in an Experimental Porcine Model

OBJECTIVES

Vascular binding of dual antiplatelet and anticoagulant (APAC) was assessed in surgically created femoral arteriovenous fistula (AVF) and iliac and carotid artery injury in porcine models.

METHODS

Three models of collagen exposing injury were used: 1) femoral AVF, 2) in vivo iliac and carotid artery balloon angioplasty injury, and 3) in vitro femoral artery endothelial denudation injury. Biotinylated APAC (0.5 mg/mL) was incubated with the injury site before releasing blood flow. APAC, von Willebrand factor (vWF), laminin, platelet endothelial cell adhesion molecule 1 (PECAM-1), and podocalyxin were detected in histological sections using immunofluorescence and confocal microscopy and Manders' co-localisation coefficient (M1).

RESULTS

APAC bound to AVF at anastomosis and to both in vivo and in vitro injured arteries. APAC co-localised with matrix vWF (M1 ≥ 0.66) and laminin (M1 ≥ 0.60), but less so if endothelial PECAM-1 or podocalyxin was present (M1 ≤ 0.25). APAC targeted and penetrated the injured vessel wall, especially the AVF vein.

CONCLUSIONS

APAC, compatible with its high negative charge, rapidly targets injured vessels co-localizing with matrix vWF and laminin, but not with endothelial PECAM-1 and podocalyxin. This localising feature may have potential antithrombotic implications for vascular interventions.

Aspirin for primary prevention: Is this the end of the road?

Aspirin is one of the oldest and most commonly used cardiovascular drugs. Despite there being high-quality evidence supporting the use of aspirin for patients with known cardiovascular disease, a definitive consensus regarding its use for patients at risk for cardiovascular disease (and without established cardiovascular disease) has never been reached. Many randomized control trials have produced conflicting results, and consequently, society guidelines have issued differring recommendations. Three major trials were published in 2018, which supplement the existing data on aspirin's role in primary prevention and provide further guidance on this contentious issue. This article reviews the history of aspirin through the last two decades, with special emphasis on these new trials.

Ticagrelor in the prevention of coronary and non-coronary atherothrombotic events: A comprehensive meta-analysis of 10 randomized trials

BACKGROUND AND AIMS

More potent antithrombotic strategies have significantly reduced the rate of recurrent ischemic events in cardiovascular disease. Ticagrelor, in particular, has significantly improved the outcome in patients with acute coronary syndromes, offering potential benefits also in terms of survival. In addition, more recent data have suggested that the advantages of ticagrelor could be extended also to non-coronary atherothrombotic disease, although with contrasting results, especially for mortality reduction. The aim of the present meta-analysis was to investigate the safety and effectiveness of a newer antiplatelet strategy with ticagrelor as compared to traditional antiplatelet regimens in patients with coronary or non-coronary atherothrombotic disease.

METHODS

Literature and main scientific session abstracts were searched for studies comparing a ticagrelor-based antiplatelet regimen vs. different antiplatelet agents in the secondary prevention of cardiac, cerebral or vascular atherothrombotic events. The primary efficacy endpoint was mortality, primary safety endpoint was the occurrence of major bleedings. Secondary endpoints were myocardial infarction and stroke.

RESULTS

We included 10 randomized clinical trials, for a total population of 73,121 patients, 54.9% randomized to ticagrelor. At a mean follow-up of 13.4 ± 12.6 months, a newer antiplatelet strategy based on ticagrelor was associated with a significant reduction in mortality as compared to a traditional therapy (OR[95%CI] = 0.92[0.86,0.99], p=0.02; phet = 0.14), however, such benefits were more evident in patients with coronary artery disease, while not in non-coronary trials, with a significant interaction between patients' setting and the prognostic impact of ticagrelor (p int = 0.03). A similar result was achieved for cardiovascular mortality, recurrent myocardial infarction, while for the risk of stroke, the largest advantages were observed in patients with a previous cerebrovascular accident. Major bleeding events were increased in ticagrelor treated patients (OR [95%CI] = 1.11 [1.02, 1.20], p=0.01; phet = 0.0003), although not affecting overall mortality, as confirmed by meta-regression analysis.

CONCLUSIONS

Based on the current meta-analysis, a newer antiplatelet strategy based on ticagrelor is associated with a significant reduction in mortality and recurrent cardiovascular events, as compared to a traditional treatment, among patients treated for coronary disease but not among those with non-coronary atherothrombotic disease. However, ticagrelor therapy was associated with a significant increase in major bleeding complications.

Design and rationale for the ASSOS study: Appropriateness of aspirin use in medical outpatients a multicenter and observational study

OBJECTIVE

The aim of this study was to describe the current status of aspirin use and the demographic characteristics of patients on aspirin for primary and secondary prevention of cardiovascular diseases.

METHODS

The Appropriateness of Aspirin Use in Medical Outpatients: A Multicenter, Observational Study (ASSOS) trial was a multicenter, cross-sectional, and observational study conducted in Turkey. The study was planned to include 5000 patients from 14 cities in Turkey. The data were collected at one visit, and the current clinical practice regarding aspirin use was evaluated (ClinicalTrials.gov number NCT03387384).

RESULTS

The study enrolled all consecutive patients who were admitted to the outpatient cardiology clinics from March 2018 until June 2018. Patients should be at least 18 years old, have signed written informed consent, and on aspirin (80-325 mg) therapy within the last 30 days. Cardiologists from the hospital participates in the study. Patients were divided into 2 categories according to presence or absence of atherosclerotic cardiovascular disease, namely secondary prevention group and primary prevention group, respectively. The appropriate use of aspirin in the primary and secondary prevention groups was assessed according to the European Society of Cardiology guidelines and US Preventive Services Task Force. The patients' gastrointestinal bleeding risk factors and colorectal cancer risk were evaluated.

CONCLUSION

The ASSOS registry will be the most comprehensive and largest study in Turkey evaluating the appropriateness of aspirin use. The results of this study help understand the potential misuse of aspirin in a real-world setting.

Thromboelastography-derived parameters for the prediction of acute thromboembolism following non-steroidal anti-inflammatory drug-induced gastrointestinal bleeding: A retrospective study

Efficacy of thromboelastography (TEG)-derived parameters for the prediction of acute thromboembolism (AT) in patients with non-steroidal anti-inflammatory drug (NSAID)-induced gastrointestinal bleeding (GIB) remains to be determined. A retrospective propensity score matching (PSM) study was performed to evaluate this efficacy. Patients with NSAID-induced GIB (98 with AT; 830 without AT) were matched for age, sex and history of cardiovascular and cerebrovascular diseases using PSM. Multivariate logistic regression was used to determine the efficacy of TEG-derived predictors of AT. Mean Decrease Gini (MDG) coefficients were used to rank the importance of the variables from random forest algorithm results. Univariate analysis indicated that the following indexes were significantly different between the two groups: Reaction time (R value), coagulation forming time, solidification angle, maximum amplitude (MA), coagulation index (CI), hemoglobin levels, D-dimer levels, platelet aggregation test (pAgt) results, fibrinogen levels and Acute Physiology and Chronic Health Evaluation II score (all P<0.001). Multifactor logistic regression analysis indicated that the R value (P=0.010), solidification angle (P=0.004), MA (P=0.038), D-dimer levels (P=0.012) and pAgt results (P=0.015) were independent predictors of AT in patients with NSAID-induced GIB, achieving an area under the curve of 0.999 in receiver operating characteristic curve analyses. The five most important parameters according to the MDG scores (MDGS) were: Solidification angle (MDGS=58.14), R value (MDGS=20.42), pAgt results (MDGS=15.61), D-dimer levels (MDGS=12.78) and CI (MDGS=12.61). The results of the present study indicated that TEG-derived parameters including the R value, solidification angle, MA and CI, as well as D-dimer levels and pAgt score were significant predictors of AT in patients with NSAID-induced GIB.