Effect of antiplatelet persistence on long-term mortality and predictors of non-persistence in ischemic stroke patients 75 years and older: a nationwide cohort study

Background

We aimed to provide real-world evidence on the benefit of persistence with antiplatelet therapy (APT) on long-term all-cause mortality (ACM) in ischemic stroke patients aged 75 years and older.

Methods

Newly diagnosed ischemic stroke patients aged 75 years and older who initiated aspirin or clopidogrel for the first time were chosen from 2003 to 2010 National Health Insurance Service-National Sample Cohort (NHIS-NSC) of Korea (n = 887), a random cohort sample accounting for 2.2% (n = 1,017,468) of total population (n = 46,605,433). Then subjects were divided into persistent (n = 556) and non-persistent (n = 321) groups according to the persistent status at 6 months. Survivor analysis was performed between the two groups and predictors of non-persistence were analyzed by multivariate logistic regression analysis. Patients were followed up until death or December 31, 2013.

Results

Non-persistence with APT was significantly associated with increased risk of ACM (adjusted hazard ration [aHR] 2.13, 95% confidence interval [CI] 1.72–2.65), cerebro-cardiovascular disease (CVD) mortality (aHR 2.26, 95% CI 1.57–3.24), and non-CVD mortality (aHR 2.06, 95% CI 1.5702.70). More comorbidities (Charlson comorbidity index score ≥ 6) (adjusted odds ratio [aOR], 2.56, 95% CI 1.43–4.55), older age (aOR 1.52, 95% CI 1.11–2.09 for 80–84 years, aOR 1.73, 95% CI 1.17–2.57 for ≥85 years), and less than 4 total prescribed drugs (aOR 1.54, 95% CI 1.08–2.21) were independent predictors of non-persistence.

Conclusions

Persistent with APT after ischemic stroke featured long-term mortality benefit even in patients aged 75 years and older. Thus, improving APT persistence for ischemic stroke patients in this age group is also recommended by understanding factors associated with non-persistence.

Prasugrel switching from clopidogrel after percutaneous coronary intervention for acute coronary syndrome in Taiwanese patients: an analysis of safety and efficacy

The recommended maintenance dose of prasugrel for East Asian populations (i.e., Japanese and Taiwanese) is 3.75 mg as part of dual antiplatelet therapy (DAPT) for the prevention of recurrent ischemia and stent thrombosis in acute coronary syndrome (ACS). This modified dosage regimen has been established in studies conducted in Japan; however, the efficacy and safety of switching from clopidogrel to prasugrel DAPT among Taiwanese patients remain to be explored. In this phase IV, multicenter, single-arm, open-label study, we evaluated the 4-week pharmacodynamic response, and the 48-week safety outcomes of prasugrel 3.75 mg after a switch from clopidogrel in Taiwanese ACS patients. A total of 203 prasugrel-naïve ACS patients (over 90% male) who had received post-PCI clopidogrel DAPT for at least 2 weeks were enrolled from ten medical centers in Taiwan and subsequently switched to prasugrel 3.75 mg DAPT. Four weeks after the switch, P2Y12 reaction unit (PRU) values were significantly decreased in the total cohort (mean − 18.2 ± 48.1; 95% confidence interval − 24.9 to − 11.5, p < 0.001), and there was an overall consistent antiplatelet response in the treated subjects. The proportion of patients with high on-treatment platelet reactivity (HPR; PRU > 208) dropped from 23.5 to 10% (p < 0.001). Female sex was associated with a greater PRU reduction with prasugrel, whereas HPR at baseline, age ≥ 65 years, and body mass index ≥ 25 best predicted HPR at Week 4. Throughout the 48-week treatment with prasugrel, the incidences of MACE (1.0%) and TIMI major bleeding (2.0%) were rather low, accompanying an acceptable safety profile of TIMI minor (6.4%) and non-major, non-minor clinically relevant bleeding (3.0%). Overall, switching to the maintenance dose of prasugrel (3.75 mg) was observed to be effective and well tolerated among post-PCI ACS patients in Taiwan. Clinical Trial Registration Number: NCT03672097.

Prognostic impact of antiplatelet therapy in Takotsubo syndrome: a systematic review and meta-analysis of the literature

While the most recent evidence suggests a lack of benefit, antithrombotic therapy is still extensively prescribed in patients with Takotsubo syndrome (TTS). The objective of this study was to determine whether patients with TTS benefit from anti-aggregation, in terms of either short-term or long-term outcomes. A systematic review and meta-analysis was conducted. A comprehensive search of the literature included MEDLINE, Cochrane Library, Clinicaltrials.gov, EU Clinical Trial Register, References, and contact with the authors. Methodological quality assessment and data extraction were systematically performed. The review adhered to the PRISMA framework guidelines. A total of 86 citations were identified, six being eligible for inclusion, for a total of 1997 patients. One of them considered both short-term and long-term outcomes. One reported outcomes during the index event, while the remaining four focused on potential long-term benefits. They were all retrospective cohort studies.

Based on our data, the long-term use of antiplatelet therapy (AT) led to a significantly higher incidence of the composite outcome (OR: 1.54; 95% CI 1.09–2.17; p = 0.014) and overall mortality (OR 1.72; 95% CI 1.07–2.77; p = 0.027). The analysis did not show a statistically significant difference in TTS recurrences, stroke/TIA, and MI or CAD worsening with AT compared with no anti-aggregation. The AT in this settings did not show any clear benefit in improving the long-term outcomes, and it may be even detrimental and it may be detrimental. These results warrant further future research and the design of adequately powered randomized controlled trials focusing on the impact of aspirin on the outcomes in patients presenting with TTS.

Is alteration in single drug anticoagulant/antiplatelet regimen necessary in patients who need minor oral surgery? A systematic review with meta-analysis

OBJECTIVE

This study aimed to systematically review literature about the effect of alteration of the pharmacological regimen in adult patients using anticoagulants or antiplatelets who need minor oral surgery.

MATERIAL AND METHODS

A search strategy was performed in three databases-PubMed-Medline, Scopus, and Embase-and included randomized clinical trials (either parallel or crossover), involving individuals under anticoagulant or antiplatelet therapy who underwent oral surgeries. Studies comprised two groups: those who stopped their medication prior to the dental procedure (control) or those who did not (test). Meta-analyses were conducted for the pooled risk ratio (RR) between the groups. Subgroup analyses were performed for anticoagulant and antiplatelet therapies.

RESULTS

Thirteen studies were included. It was found that patients who did not stop therapy had 157% higher intraoperative bleeding occurrences (95%CI: 1.40-4.71). In the subgroup analysis, warfarinazed patients showed significantly higher occurrences of intraoperative bleeding when compared with the control (RR: 1.79; 95%CI: 1.00-3.21). Conversely, there was no statistically significant difference in postoperative bleeding between the groups (RR: 0.81; 95%CI: 0.54-1.22; p = 0.42).

CONCLUSION

Minor oral surgeries can be safely performed in patients under antiplatelets or anticoagulants without drug regimen modification. Because these patients tend to bleed more during procedures, use of local hemostatic measures is strongly advised.

CLINICAL RELEVANCE

Management of patients under antiplatelet or anticoagulant drugs is still challenging in clinical practice. However, clinicians may perform minor oral surgeries safely without changing the pharmacological regimen. Use of local hemostatic measures is strongly advised during these procedures.

Office hysteroscopy safety and feasibility in women receiving anticoagulation and anti-platelet treatment

OBJECTIVES

More than 60,000 hysteroscopies are performed every year in the UK for common reasons such as heavy menstrual bleeding (HMB) or postmenopausal bleeding. A significant number of women requiring hysteroscopy receive oral anticoagulants and there is often a reluctance to perform these procedures due to bleeding concerns.

STUDY DESIGN

We are presenting the first proof of concept cohort of patients undergoing minor hysteroscopic procedures while on anticoagulant or antiplatelet medication. A variety of minor procedures such as cervical dilatation, targeted endometrial biopsies, Pipelle endometrial biopsies and insertion or removal of intrauterine contraceptive devices were performed alongside hysteroscopy.

RESULTS

Completion of planned procedures was feasible in all women due to minimal bleeding despite the ongoing anticoagulation or anti-platelet treatment.

CONCLUSION

More research is needed to establish the safety of performing diagnostic and operative hysteroscopies without bridging or interrupting anticoagulation or antiplatelet treatment.

Update on the perioperative management of antiplatelets and anticoagulants in ophthalmic surgery

INTRODUCTION

Anti-thrombotic drugs (antiplatelets and anticoagulants) are widely used for different clinical reasons. This means that there are an increasing number of patients undergoing elective ophthalmic surgery that are being treated with these drugs. A better knowledge of their implications and their peri-operative use may help to prevent surgical and secondary adverse events. There is often no firm recommendation on how to manage certain drugs in certain surgeries.

OBJECTIVE

To review the recommendations in the scientific literature as regards managing anti-thrombotic agents during the peri-operative period of ophthalmic surgery.

MATERIAL AND METHODS

A review was made of the relevant guidelines and studies using an antiplatelet and anticoagulant drugs approach for cataract, vitreo-retinal, glaucoma, oculoplastic, and strabismus surgeries.

RESULTS

Recommendations about whether to continue or discontinue anti-thrombotic drugs in the peri-operative period of different ophthalmic surgical fields are presented.

CONCLUSIONS

There are only firm recommendations of maintaining anti-thrombotic drugs as regards cataract surgery using phacoemulsification with topical anaesthesia. In other surgical fields, ophthalmologists should balance the risk of thromboembolic events and risks of haemorrhagic complications in order to carry out a proper management. A multi-disciplinary approach is recommended for complex cases. Additional studies should be performed to better characterise the peri-operative use of anti-thrombotic agents in order to prepare clinical guidelines for ophthalmic surgery.

Characteristics and antithrombotic treatment patterns of patients with concomitant coronary artery disease and atrial fibrillation from Thailand's COOL-AF registry

BACKGROUND

Concomitant coronary artery disease (CAD) and atrial fibrillation (AF) are common in clinical practice. The aim of this study was to investigate the characteristics and antithrombotic treatment patterns of patients with concomitant CAD and AF from the COhort of antithrombotic use and Optimal INR Level in patients with non-valvular atrial fibrillation in Thailand (COOL-AF Thailand) registry.

METHODS

Registry enrollment criteria included patients aged ≥ 18 years who were diagnosed with AF for any duration at any of 27 public hospitals located across Thailand during 2014-2017. The That Clinical Trials Registry study registration number is TCTR20160113002. Statistical comparisons of characteristics and treatment strategies were performed between patients with and without CAD.

RESULTS

Of a total of 3461 AF patients, 557 had concomitant CAD (16.1%). Patients with concomitant CAD and AF were significantly older, more likely to be male, had more comorbidities, and had more cardiovascular implantable electronic devices. History of stroke/transient ischemic attack and prior bleeding was not significantly different between groups. CHA2DS2-VASc score and HAS-BLED score were both higher in patients with CAD than in patients without CAD (4.17 vs. 2.78, p < 0.001, and 2.01 vs. 1.45, p < 0.001, respectively). Utilization of oral anticoagulant was less in patients with CAD (76.0% vs. 84.3%, p < 0.001). Concomitant use of antiplatelet was found to be a major cause of oral anticoagulant (OAC) underutilization. Specifically, the rate of OAC prescription was 95.9% in patients without antiplatelet, and 43.7% in patients with antiplatelet. Among patients with CAD who were on OAC, the rate of concomitant antiplatelet prescription was still high. In this group, 63% of patients were on triple therapy when percutaneous coronary intervention (PCI) with drug eluting stent was performed within 1 year, and 32.2% of patients without prior PCI or acute coronary syndrome were taking at least one antiplatelet with OAC.

CONCLUSION

Among patients with concomitant CAD and AF, physicians were reluctant to discontinue antiplatelet. The use of antiplatelet discourages physicians from prescribing OAC. Underutilization of OAC may increase the risk of ischemic stroke, and an inappropriate combination of OAC and antiplatelet may increase the risk of bleeding. Trial registration The trial has been registered with the Thai Clinical Trials Registry (TCTR) which complied with WHO International Clinical Trials Registry Platform dataset. The Registration Number is TCTR20160113002 (05/01/2016).

Neurological complications of cardiovascular drugs

Cardiovascular drugs are used to treat arterial hypertension, hyperlipidemia, arrhythmias, heart failure, and coronary artery disease. They also include antiplatelet and anticoagulant drugs that are essential for prevention of cardiogenic embolism. Most neurologic complications of the cardiovascular drugs are minor or transient and are far outweighed by the anticipated benefits of treatment. Other neurologic complications are more serious and require early recognition and management. Overtreatment of arterial hypertension may cause lightheadedness or fatigue but often responds readily to dose adjustment or an alternative drug. Other drug complications may be more troublesome as in myalgia associated with statins or headache associated with vasodilators. The recognized bleeding risk of the antithrombotics requires careful calculation of risk/benefit ratios for individual patients. Many neurologic complications of cardiovascular drugs are well documented in clinical trials with known frequency and severity, but others are rare and recognized only in isolated case reports or small case series. This chapter draws on both sources to report the adverse effects on muscle, nerve, and brain associated with commonly used cardiovascular drugs.

Influence of PAR-1 in patients with non-valvular atrial fibrillation: The antiplatelet effect of dabigatran

INTRODUCTION

Dabigatran, a direct thrombin inhibitor, has been widely used in patients with non-valvular atrial fibrillation (NVAF) and is considered to have an antiplatelet effect. However, the mechanisms remain unclear. We evaluated protease-activated receptor-1 (PAR-1) expression and activation by thrombin on platelets from NVAF patients, before and after dabigatran treatment, in addition to the expression of platelet activation marker CD62P.

MATERIALS AND METHODS

The study included 18 NVAF patients. We used flow cytometry to measure the binding of PAR-1 monoclonal antibodies (SPAN12 and WEDE15) and the expression of CD62P with and without thrombin stimulation, before, 14 days after, and 28 days after treatment with dabigatran. Coagulation fibrinolysis markers were also measured.

RESULTS

PAR-1 expression was significantly lower in NVAF patients than in healthy controls (HC); it was further reduced by thrombin stimulation. CD62P expression was almost absent on the platelets in NVAF patients, but was significantly increased by thrombin stimulation. PAR-1 expression was not significantly different before and after treatment; CD62P expression was inhibited by dabigatran. The levels of coagulation markers were significantly higher in NVAF patients than in HC, and decreased after treatment.

CONCLUSIONS

Lower expression of PAR-1 in NVAF patients resulted from the cleavage of PAR-1 on some platelets, by exposure to small amounts of thrombin in vivo. The therapeutic effect of dabigatran in NVAF patients was demonstrated by inhibition of CD62P expression on the platelet upon thrombin stimulation in vitro. Our results indicate that dabigatran may reveal antithrombotic activity with antiplatelet and anticoagulant effects.

Antithrombotic strategies in elderly patients with acute coronary syndrome

Elderly patients represent a growing proportion of the acute coronary syndrome population in Western countries. However, their frequent atypical symptoms at presentation often lead to delays in management and to misdiagnosis. Furthermore, their prognosis is poorer than that of younger patients because of physiological changes in platelet function, haemostasis and fibrinolysis, but also a higher proportion of comorbidities and frailty, both of which increase the risk of recurrent thrombotic and bleeding events. This complex situation, with ischaemic and haemorrhagic risk factors often being intertwined, may lead to confusion about the required treatment strategy, sometimes resulting in inadequate management or even to therapeutic nihilism. It is therefore critical to provide a comprehensive overview of our understanding of the pathophysiological processes underlying acute coronary syndrome in elderly patients, and to summarise the results from the latest clinical trials to help decision making for these high-risk patients.

Antithrombotic therapy in patients with COVID-19? -Rationale and Evidence

In patients with severe or critical Coronavirus disease 2019 (COVID-19) manifestations, a thromboinflammatory syndrome, with diffuse microvascular thrombosis, is increasingly evident as the final step of pro-inflammatory cytokines storm. Actually, no proven effective therapies for novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection exist. Preliminary observations on anticoagulant therapy appear to be associated with better outcomes in moderate and severe COVID-19 patients with signs of coagulopathy and in those requiring mechanical ventilation. The pathophysiology underlying the prothrombotic state elicited by SARS-CoV-2 outlines possible protective mechanisms of antithrombotic therapy (in primis anticoagulants) for this viral illness. The indications for antiplatelet/anticoagulant use (prevention, prophylaxis, therapy) are guided by the clinical context and the COVID-19 severity. We provide a practical approach on antithrombotic therapy management for COVID-19 patients from a multidisciplinary point of view.

Low-dose antiplatelet therapy survey after intracerebral hemorrhage in China: a retrospective hospital-based study

Restarting of antiplatelet therapy (AT) for patients with a history of intracerebral hemorrhage (ICH) is still a clinical dilemma in China. We aimed to investigate the association between low-dose AT and the long-term clinical outcome in Chinese ICH patients. A total of 312 patients with a history of ICH were retrospectively enrolled and followed. The ischemic vascular events, recurrent ICH, and all-cause death were reviewed retrospectively. We explored the predictors of ischemic vascular events and recurrent ICH from all patients using Cox proportional hazard regression model. One hundred fifty-one (48.4%) patients were treated with low-dose AT, and the median duration of follow-up was 4.0 years (interquartile range, 2.5-5 years). Compared to 30 (19.8%) of 151 participants who restarted low-dose AT had ischemic vascular events, 51 (31.7%) of 161 participants who did not receive AT showed ischemic vascular events (p=0.025). Eighteen (11.9%) of 151 participants treated with low-dose AT had recurrent ICH and 21 (13.0%) of 161 in non-AT participants (p=0.830). Cox regression analysis also showed that diabetes mellitus was an independent risk factor for ischemic vascular events (p=0.029). Uncontrolled blood pressure (BP) was independently associated with the risk for both ischemic vascular events (p=0.025) and recurrent ICH (p=0.001). Atrial fibrillation (AF) was an independent risk factor for recurrent ICH among patients with a history of ICH (p=0.018). In a Chinese population of patients with predominantly deep, mild to moderate severity ICH, restarting of low-dose AT at a median of 6.2 months was associated with a lower risk of ischemic vascular events without increased risk of recurrent ICH.

Effect of antiplatelet treatments on patients with COVID-19 infection: A systematic review and meta-analysis

Despite the rationale that early anti-platelet would lower the risk of major organ dysfunction, the effectiveness of this approach remains controversial. Therefore, we perform a systematic review and meta-analysis to investigate the effect of antiplatelet treatments on patients with COVID-19 infection. An electronic search was carried out in Pubmed, Embase, Cochrane library, Web of Science, MEDLINE, Wanfang and China National Knowledge Infrastructure (CNKI). Meta-analysis and statistical analyses were completed with using the RevMan 5.3 and Stata 12.0. A total of 9 articles representing data from 5970 participants were included in this study. The meta-analysis showed antiplatelet agents were not associated with higher risk of severe COVID-19 disease (OR = 0.98, 95%CI: 0.64 to 1.50, P = 0.94; I 2 = 65%), while an adjusted analysis indicated that antiplatelet agents was not associated with an increased risk of mortality (OR = 0.65, 95%CI: 0.40 to 1.06, P = 0.498; I 2 = 0%). The results of this study reveal that while there is no significant benefit on mortality demonstrated with the use of antiplatelet agents, the upper bound of the confidence interval suggests that there is unlikely to be a compelling risk of harm associated with this practice. The benefit and risk of the use of antiplatelet agents should be fully considered especially in the presence of thrombocytopenia status in patients with COVID-19.

Antiplatelet therapy for the prevention of atherosclerosis in chronic kidney disease (ALTAS-CKD) patients: study protocol for a randomized clinical trial

BACKGROUND

Cardiovascular disease (CVD) is the most common complication and the leading cause of death in patients with chronic kidney disease (CKD). Accelerated atherosclerosis is a pathophysiological process that is vital to the occurrence of cardiovascular complications associated with CKD. Abnormal platelet activation is not only the leading cause of atherosclerosis but also plays a critical role in the occurrence of thrombotic events. Currently, antiplatelet drugs are commonly used as a secondary prevention strategy for high blood pressure, obesity, diabetes, and ischemic heart disease and can reduce the risk of CVD in the susceptible population. However, the benefits and evidence of using antiplatelet agents in patients with CKD remain controversial. This study aimed to determine whether antiplatelet therapy can safely prevent atherosclerosis in patients with CKD in the primary care setting.

METHODS/DESIGN

The ALTAS-CKD study is a multicenter, prospective, randomized, double-blind, placebo-controlled trial of 554 adult patients with stage 3-5 non-dialysis-dependent CKD recruited from 10 territory medical centers in China. A secured web-based computer randomization system will be used to administer aspirin 100 mg once daily or a matching inactive placebo for 36 months. The primary endpoint will be the occurrence of atherosclerosis, as measured by carotid ultrasonography. The secondary endpoints will be combined cardiovascular events, all-cause mortality, and 50% decrease in the estimated glomerular filtration rate. TRIAL REGISTRATION {2A}: Current controlled trials number: ChiCTR1900021393 . Registered on 18 February 2019.

Association of Mortality with Antiplatelet Treatment in Patients with Stent Placement or Angioplasty: A Population-Based Nested Case-Control Study

PURPOSE

Antiplatelet drugs are essential in patients with cardiovascular disease who undergo stent placement. We hypothesized that risks of mortality would differ according to adherence to antiplatelet agents, number of antiplatelet agents, and antiplatelet regimens in patients undergoing stent placement or angioplasty.

MATERIALS AND METHODS

Between 2002 and 2013, we initially enrolled 8671 subjects who underwent stent placement or angioplasty in the National Health Insurance Service-National Sample Cohort in Korea. Using the International Classification of Diseases, 10th revision, the incidence of all-cause death, including cardiovascular disease, cerebrovascular disease, and cancer, was defined. Using a nested case-control study design, controls were matched to cases at a ratio of 4:1, and a total of 5415 subjects were eligible for this study.

RESULTS

During a median follow-up period of 3.51 years, the incidence rate of all-cause death was 40 per 1000 person-years. We found that adherence to antiplatelet monotherapy significantly decreased risk of death by cerebro-cardiovascular disease, compared with discontinuation of antiplatelets [adjusted odds ratio (OR) 0.62, 95% confidence interval (CI) (0.41-0.96)]. Compared with dual antiplatelet therapy (DAPT), aspirin and clopidogrel monotherapy significantly reduced death by cerebro-cardiovascular disease [adjusted OR 0.65, 95% CI (0.44-0.95) and adjusted OR 0.58, 95% CI (0.35-0.96), respectively]. There was no significant difference of mortality between aspirin monotherapy and clopidogrel monotherapy.

CONCLUSION

Our study demonstrated that adherence to antiplatelet therapy and antiplatelet monotherapy, compared with DAPT, in patients with stent placement or angioplasty may have a beneficial effect on mortality in cerebro-cardiovascular disease.

Comparison of anticoagulation and antiplatelet therapy for treatment of blunt cerebrovascular injury in children <10 years of age: a multicenter retrospective cohort study

PURPOSE

Blunt cerebrovascular injury (BCVI) is uncommon in the pediatric population. Among the management options is medical management consisting of antithrombotic therapy with either antiplatelets or anticoagulation. There is no consensus on whether administration of antiplatelets or anticoagulation is more appropriate for BCVI in children < 10 years of age. Our goal was to compare radiographic and clinical outcomes based on medical treatment modality for BCVI in children < 10 years.

METHODS

Clinical and radiographic data were collected retrospectively for children screened for BCVI with computed tomography angiography at 5 academic pediatric trauma centers.

RESULTS

Among 651 patients evaluated with computed tomography angiography to screen for BCVI, 17 patients aged less than 10 years were diagnosed with BCVI (7 grade I, 5 grade II, 1 grade III, 4 grade IV) and received anticoagulation or antiplatelet therapy for 18 total injuries: 11 intracranial carotid artery, 4 extracranial carotid artery, and 3 extracranial vertebral artery injuries. Eleven patients were treated with antiplatelets (10 aspirin, 1 clopidogrel) and 6 with anticoagulation (4 unfractionated heparin, 2 low-molecular-weight heparin, 1 transitioned from the former to the latter). There were no complications secondary to treatment. One patient who received anticoagulation died as a result of the traumatic injuries. In aggregate, children treated with antiplatelet therapy demonstrated healing on 52% of follow-up imaging studies versus 25% in the anticoagulation cohort.

CONCLUSION

There were no observed differences in the rate of hemorrhagic complications between anticoagulation and antiplatelet therapy for BCVI in children < 10 years, with a nonsignificantly better rate of healing on follow-up imaging in children who underwent antiplatelet therapy; however, the study cohort was small despite including patients from 5 hospitals.

Anticoagulant and antiplatelet activities of novel serine protease purified from seeds of Cucumis maderaspatensis

In this study, we report the biochemical characterization of a novel serine protease from seeds of Cucumis maderaspatensis, aimed with assessing the anticoagulant and antiplatelet activities. The purified serine protease was obtained by subjecting the seed extract to ammonium sulphate precipitation followed by anion exchange and gel filtration chromatography. Twenty seven-fold purification with the specific activity of 884.2 U/mg of protease activity was obtained. The characterization of the novel protease enzyme activity for optimum temperature, pH and effect of different protease inhibitors and metal ions were measured using caseinolytic assay and casein zymogram. The relative molecular mass of the novel neutral serine protease (CmSP) is ~ 32 kDa. Its anticoagulant was determined by assessing the delay in plasma re-calcification time in both platelet-rich and platelet-poor plasma. The antiplatelet activity of serine protease was demonstrated by inhibition of agonists induced platelet aggregation; it was in the order of Epinephrine > Adenosine tri phosphate. Further studies would decipher the mechanism of action to understand its therapeutic potential as an antiplatelet and anticoagulant molecule.

Update on the perioperative management of antiplatelets and anticoagulants in ophthalmic surgery

INTRODUCTION

Anti-thrombotic drugs (antiplatelets and anticoagulants) are widely used for different clinical reasons. This means that there are an increasing number of patients undergoing elective ophthalmic surgery that are being treated with these drugs. A better knowledge of their implications and their peri-operative use may help to prevent surgical and secondary adverse events. There is often no firm recommendation on how to manage certain drugs in certain surgeries.

OBJECTIVE

To review the recommendations in the scientific literature as regards managing anti-thrombotic agents during the peri-operative period of ophthalmic surgery.

MATERIAL AND METHODS

A review was made of the relevant guidelines and studies using an antiplatelet and anticoagulant drugs approach for cataract, vitreo-retinal, glaucoma, oculoplastic, and strabismus surgeries.

RESULTS

Recommendations about whether to continue or discontinue anti-thrombotic drugs in the peri-operative period of different ophthalmic surgical fields are presented.

CONCLUSIONS

There are only firm recommendations of maintaining anti-thrombotic drugs as regards cataract surgery using phacoemulsification with topical anaesthesia. In other surgical fields, ophthalmologists should balance the risk of thromboembolic events and risks of haemorrhagic complications in order to carry out a proper management. A multi-disciplinary approach is recommended for complex cases. Additional studies should be performed to better characterise the peri-operative use of anti-thrombotic agents in order to prepare clinical guidelines for ophthalmic surgery.

Safety and efficacy of intravenous thrombolysis in stroke patients on prior antiplatelet therapy in the WAKE-UP trial

Background

One quarter to one third of patients eligible for systemic thrombolysis are on antiplatelet therapy at presentation. In this study, we aimed to assess the safety and efficacy of intravenous thrombolysis in stroke patients on prescribed antiplatelet therapy in the WAKE-UP trial.

Methods

WAKE-UP was a multicenter, randomized, double-blind, placebo-controlled clinical trial to study the efficacy and safety of MRI-guided intravenous thrombolysis with alteplase in patients with an acute stroke of unknown onset time. The medication history of all patients randomized in the WAKE-UP trial was documented. The primary safety outcome was any sign of hemorrhagic transformation on follow-up MRI. The primary efficacy outcome was favorable functional outcome defined by a score of 0–1 on the modified Rankin scale at 90 days after stroke, adjusted for age and baseline stroke severity. Logistic regression models were fitted to study the association of prior antiplatelet treatment with outcome and treatment effect of intravenous alteplase.

Results

Of 503 randomized patients, 164 (32.6%) were on antiplatelet treatment. Patients on antiplatelet treatment were older (70.3 vs. 62.8 years, p <  0.001), and more frequently had a history of hypertension, atrial fibrillation, diabetes, hypercholesterolemia, and previous stroke or transient ischaemic attack. Rates of symptomatic intracranial hemorrhage and hemorrhagic transformation on follow-up imaging did not differ between patients with and without antiplatelet treatment. Patients on prior antiplatelet treatment were less likely to achieve a favorable outcome (37.3% vs. 52.6%, p = 0.014), but there was no interaction of prior antiplatelet treatment with intravenous alteplase concerning favorable outcome (p = 0.355). Intravenous alteplase was associated with higher rates of favorable outcome in patients on prior antiplatelet treatment with an adjusted odds ratio of 2.106 (95% CI 1.047–4.236).

Conclusions

Treatment benefit of intravenous alteplase and rates of post-treatment hemorrhagic transformation were not modified by prior antiplatelet intake among MRI-selected patients with unknown onset stroke. Worse functional outcome in patients on antiplatelets may result from a higher load of cardiovascular co-morbidities in these patients.

Antiplatelet patterns and outcomes in patients with atrial fibrillation not prescribed an anticoagulant after stroke

BACKGROUND

To determine association of discharge antiplatelet therapy prescription with 1-year outcomes among patients with AF admitted with acute ischemic stroke and discharged without oral anticoagulation.

METHODS

In a retrospective cohort study from the Get With The Guidelines-Stroke registry, we identified all Medicare fee-for-service beneficiaries 65 years or older with AF or atrial flutter admitted with acute ischemic stroke and discharged without oral anticoagulation from April 2003 through December 2014, and we determined association of discharge antiplatelet therapy prescription with 1-year outcomes using Medicare claims data. Primary outcomes were 1-year mortality and composite endpoint of major adverse cardiovascular/neurologic/bleeding events (MACNBE).

RESULTS

Of 64,228 subjects (median [interquartile range] age, 84 [78-89] years; 62.5% female), 54,621 (85.0%) were discharged with antiplatelet therapy, and 9607 (15.0%) were discharged with no antithrombotic therapy. The unadjusted rates of 1-year mortality were lower among patients receiving antiplatelet therapy (37.3%) than among those receiving no antithrombotic therapy (48.1%); unadjusted rates of MACNBE were lower for those receiving antiplatelet therapy (45.5%) compared with those receiving no antithrombotic therapy (55.2%). After adjusting for potential confounders, antiplatelet therapy prescription was associated with reduced 1-year mortality (adjusted hazard ratio [HR] 0.64, 95% confidence interval [CI] 0.62-0.66, P < .001) and MACNBE (adjusted HR 0.69, 95% CI 0.67-0.71, P < .001).

CONCLUSIONS

Among Medicare beneficiaries with AF admitted for acute ischemic stroke but not discharged on oral anticoagulant therapy, antiplatelet therapy, compared with no antithrombotic therapy, was associated with reduced 1-year mortality and MACNBE.

Delayed vertebral artery dissection after mild trauma in a motor vehicle collision

Vertebral artery dissection can be insidious and is a leading cause of stroke in young patients, second only behind cardioembolic events [1]. We present the case of a 42-year-old patient who presented to the emergency department with diaphoresis and a complaint of neck pain one month after a low speed motor vehicle collision. The patient was transferred to a stroke center where cerebral angiography showed severe vertebral artery stenosis with likelihood of dissection after a noncontrast CT was negative for hemorrhage. She was definitively treated with antiplatelet therapy and discharged to rehab. By reviewing the most recent literature, we better define this illness. Most commonly, patients with arterial dissection present with head or neck pain, stroke, and Horner syndrome. It is now thought that vertebral artery dissection is a multifactorial disease process where certain intrinsic factors are present in the setting of an exacerbating extrinsic factor such as a low speed car accident, direct trauma, heavy lifting, or a rotational sports injury. And while our patient was treated with antiplatelet therapy and intravascular intervention, vertebral artery dissection is rare and further research is required to better guide treatment as there is no definitive data showing superiority of either anticoagulation or antiplatelet pharmaceutics.

Inhibitory effect on human platelet aggregation and coagulation and antioxidant activity of C. edulis Ker Gawl rhizome and its secondary metabolites

ETHNOPHARMACOLOGICAL RELEVANCE

Although Canna edulis Ker Gawl rhizome has been used in Traditional Vietnamese Medicine to prevent and treat heart diseases without thorough scientific evidence, limited intensive search for the bioactivities and useful substances has been done.

AIM OF THE STUDY

This study aims to investigate the antiplatelet aggregation, anticoagulant and antioxidant activity of extracts from C. edulis rhizome, separate and purify its compounds from the most active fraction and evaluate the antiplatelet aggregation, anticoagulant and antioxidant activity of isolated compounds.

MATERIALS AND METHODS

C. edulis rhizome was extracted with ethanol, then fractionated with n-hexane, ethyl acetate and water. The inhibitory effect on adenosine diphosphate- and collagen-induced human platelet aggregation was evaluated. Prothrombin time, activated partial thromboplastine time and thrombine time were measured to examine the anticoagulant activity. The free radical scavenging ability was assessed with DPPH and ABTS assays. The fraction that showed the most active was used to separate and purify compounds. The structures of compounds were elucidated by NMR and MS spectroscopic methods. Isolated compounds were also tested for antiplatelet, anticoagulant and antioxidant activity.

RESULTS

The ethyl acetate fraction showed the most potent antiplatelet aggregation, anticoagulant and antioxidant activity. Subsequent fractionation of this active fraction resulted in the isolation of seven known compounds: 5-hydroxy-6-methyl-2H-pyran-2-one (1), epimedokoreanone A (2), nepetoidin B (3), ferulic acid (4), caffeic acid (5), hydroxytyrosol (6), and 1H-indole-3-carboxaldehyde (7). Previous studies reported the antiplatelet, anticoagulant and antioxidant activity of ferulic acid (4), caffeic acid (5) and hydroxytyrosol (6) and the antioxidant activity of nepetoidin B (3). This study demonstrated that both epimedokoreanone A (2) and nepetoidine B (3) also exhibited good antiplatelet effect and epimedokoreanone A (2) also had effective anticoagulant and antioxidant activity, while 5-hydroxy-6-methyl-2H-pyran-2-one (1) showed weaker antiplatelet and antioxidant activity but no anticoagulant effect.

CONCLUSIONS

This is the first experimental study to demonstrate the potent dose-dependent antiplatelet aggregation, anticoagulant and antioxidant activity of C. edulis rhizome and its pure compounds, supporting the traditional use of this plant for the treatment of heart diseases. The C. edulis rhizome is a potential source of bioactive compounds or functional food for treatment and/or prevention of heart- and oxidative stress-related diseases and its bioactive compounds are good candidates for drug development of anti-thrombosis and antioxidant agents.

Safety of temporary interruption of antiplatelet therapy in dengue fever with thrombocytopenia

Thrombocytopenia commonly occurs in dengue and may be complicated by bleeding. Dengue can occur in adults who may be on long term antiplatelet therapy for ischemic heart disease or stroke. In these cases, clinicians may temporarily discontinue antiplatelet therapy to minimize the risk of bleeding in the absence of clear guidelines. We conducted a retrospective cohort study of laboratory-confirmed adult dengue patients on antiplatelet therapy and evaluated participants whose antiplatelet therapy was continued versus discontinued. Primary outcome was a composite outcome of major adverse cardiac and cerebrovascular events (MACCE), and all-cause mortality in-hospital and for 1-year post discharge. Secondary outcomes were platelet and blood transfusion, and occurrence of dengue haemorrhagic fever (DHF), dengue shock syndrome, dengue with warning signs and severe dengue according to World Health Organization criteria. Discontinuation of antiplatelet therapy did not result in higher composite outcome (p=0.192). Continuation of antiplatelet therapy did not result in more platelet or blood transfusion (p=0.489 and p=0.567 respectively), DHF (p=0.923). Our results suggest that discontinuation or continuation of antiplatelet therapy based on clinical judgement in dengue with thrombocytopenia, is largely safe but further studies are needed.

Evaluating the safety of early surgery for ruptured intracranial aneurysms in patients with long-term aspirin use: a propensity score matching study

Background

Early microsurgical clipping is recommended for ruptured intracranial aneurysms to prevent rebleeding. However, dilemma frequently occurs when managing patients with current acetylsalicylic acid (aspirin) use. This study aimed to examine whether aspirin use was associated with worse outcomes after early surgery for aneurysmal subarachnoid hemorrhage (aSAH).

Methods

We retrieved a consecutive series of 215 patients undergoing early microsurgical clipping within 72 h after aneurysmal rupture from 2012 to 2018 in the neurosurgery department of Beijing Tiantan Hospital. The medical records of each case were reviewed. Twenty-one patients had a history of long-term aspirin use before the onset of aSAH, and 194 patients did not. To reduce confounding bias, propensity score matching (PSM) was performed to balance some characteristics of the two groups. The intraoperative blood loss, postoperative hemorrhagic events, postoperative hospital stay, and functional outcome at discharge were compared between aspirin and non-aspirin group.

Results

We matched all the 21 patients in aspirin group with 42 patients in non-aspirin group (1:2). Potential confounding factors were corrected between the two groups by PSM. No hospital mortality occurred after surgery. No significant differences were found in intraoperative blood loss (P = 0.540), postoperative hemorrhagic events (P > 0.999), postoperative hospital stay (P = 0.715), as well as functional outcome at discharge (P = 0.332) between the two groups.

Conclusions

Our preliminary results showed that long-term low-dose aspirin use was not associated with worse outcomes. Early surgery can be safe for ruptured intracranial aneurysms in patients with long-term aspirin use.

CYP2C19 Loss-of-Function is Associated with Increased Risk of Ischemic Stroke after Transient Ischemic Attack in Intracranial Atherosclerotic Disease

OBJECTIVES

Intracranial atherosclerotic disease (ICAD) is responsible for 8-10% of acute ischemic strokes, and resistance to antiplatelet therapy is prevalent. CYP2C19 gene loss-of-function (up to 45% of patients) causes clopidogrel resistance. For patients with asymptomatic ICAD and ICAD characterized by transient ischemic attack (TIA), this study measures the effect of CYP2C19 loss-of-function on ischemic stroke risk during clopidogrel therapy.

MATERIALS AND METHODS

From a deidentified database of medical records, patients were selected with ICD-9/10 code for ICAD, availability of CYP2C19 genotype, clopidogrel exposure, and established patient care. Dual-antiplatelet therapy patients were included. Patients with prior ischemic stroke, other neurovascular condition, intracranial angioplasty/stenting, or observation time <1 month were excluded. Time-to-event analysis using Cox regression was conducted to model first-time ischemic stroke events based on CYP2C19 loss-of-function allele and adjusted for age, gender, race, length of aspirin, length of concurrent antiplatelet/anticoagulant treatment, diabetes, coagulopathy, hypertension, heart disease, atrial fibrillation, and lipid disorder. Subset analyses were performed for asymptomatic and post-TIA subtypes of ICAD.

RESULTS

A total of 337 patients were included (median age 68, 58% male, 88% Caucasian, 26% CYP2C19 loss-of-function). A total of 161 (47.8%) patients had TIA at time of ICAD diagnosis, while 176 (52.2%) were asymptomatic. First-time ischemic stroke was observed among 20 (12.4%) post-TIA ICAD patients and 17 (9.7%) asymptomatic ICAD patients. Median observation time was 2.82 [IQR 1.13-5.17] years. CYP2C19 loss-of-function allele was associated with ischemic stroke event (HR 2.2, 95% CI 1.1-4.3, p=0.020) after adjustment. Post-TIA ICAD patients had a higher risk of ischemic stroke from CYP2C19 loss-of-function (HR 3.4, 95% CI 1.4-8.2, p=0.006).

CONCLUSIONS

CYP2C19 loss-of-function was associated with 3-fold increased risk of first-time ischemic stroke for ICAD patients treated with clopidogrel after TIA. This effect was not observed for asymptomatic ICAD. CYP2C19-guided antiplatelet selection may improve stroke prevention in ICAD after TIA.