Association of Antithrombotic Drug Use With Incident Intracerebral Hemorrhage Location.

BACKGROUND AND OBJECTIVES: Few population-based studies have assessed associations between the use of antithrombotic (platelet antiaggregant or anticoagulant) drugs and location-specific risks of spontaneous intracerebral hemorrhage (s-ICH). In this study, we estimated associations between antithrombotic drug use and the risk of lobar vs nonlobar incident s-ICH. METHODS: Using Danish nationwide registries, we identified cases in the Southern Denmark Region of first-ever s-ICH in patients aged 50 years or older between 2009 and 2018. Each verified case was classified as lobar or nonlobar s-ICH and matched to controls in the general population by age, sex, and calendar year. Prior antithrombotic use was ascertained from a nationwide prescription registry. We calculated odds ratios (aORs) for associations between the use of clopidogrel, aspirin, direct oral anticoagulants (DOACs) or vitamin K antagonists (VKA), and lobar and nonlobar ICH in conditional logistic regression analyses that were adjusted for potential confounders. RESULTS: A total of 1,040 cases of lobar (47.9% men, mean age [SD] 75.2 [10.7] years) and 1,263 cases of nonlobar s-ICH (54.2% men, mean age 73.6 [11.4] years) were matched to 41,651 and 50,574 controls, respectively. A stronger association with lobar s-ICH was found for clopidogrel (cases: 7.6%, controls: 3.5%; aOR 3.46 [95% CI 2.45-4.89]) vs aspirin (cases: 22.9%, controls: 20.4%; aOR 2.14 [1.74-2.63; p = 0.019). Corresponding estimates for nonlobar s-ICH were not different between clopidogrel (cases: 5.4%, controls: 3.4%; aOR 2.44 [1.71-3.49]) and aspirin (cases: 20.7%, controls: 19.2%; aOR 1.77 [1.47-2.15]; p = 0.12). VKA use was associated with higher odds of both lobar (cases: 14.3%, controls: 6.1%; aOR 3.66 [2.78-4.80]) and nonlobar (cases: 15.4%, controls: 5.5%; aOR 4.62 [3.67-5.82]) s-ICH. The association of DOAC use with lobar s-ICH (cases: 3.5%, controls: 2.7%; aOR 1.66 [1.02-2.70]) was weaker than that of VKA use (p = 0.006). Corresponding estimates for nonlobar s-ICH were not different between DOACs (cases: 5.1%, controls: 2.4%; aOR 3.44 [2.33-5.08]) and VKAs (p = 0.20). DISCUSSION: Antithrombotics were associated with higher risks of s-ICH, but the strength of the associations varied by s-ICH location and drug, which may reflect differences in the cerebral microangiopathies associated with lobar vs nonlobar hemorrhages and the mechanisms of drug action.

Temporal trends in use of antisecretory agents among patients administered clopidogrel-based dual antiplatelet therapy after percutaneous coronary intervention.

BACKGROUND: Antisecretory drugs are commonly prescribed with clopidogrel-based dual antiplatelet therapy (DAPT) to prevent gastrointestinal bleeding in high-risk patients after percutaneous coronary intervention (PCI). However, omeprazole and esomeprazole (inhibiting proton pump inhibitors [PPIs]) may increase cardiovascular event rates on co-administration with clopidogrel. This study aimed to examine trends in the use of antisecretory agents in patients administered clopidogrel-based DAPT and the concomitant use of clopidogrel and inhibiting PPIs. METHODS: We used National Inpatient Sample data compiled by the Health Insurance Review & Assessment Service from 2009 to 2020. Further, we identified patients who were prescribed clopidogrel-based DAPT after PCI and investigated the concomitant use of antisecretory agents with clopidogrel. To verify the annual trend of drug utilization, we used the Cochran-Armitage trend test. RESULTS: From 2009 to 2020, the percentage of H2 receptor antagonist users decreased steadily (from 82.5% in 2009 to 25.3% in 2020); instead, the percentage of PPI users increased (from 23.7% in 2009 to 82.0% in 2020). The use of inhibiting PPI also increased (from 4.2% in 2009 to 30.7% in 2020). Potassium competitive acid blockers (P-CABs) were rarely used before 2019; however, in 2020, it accounted for 7.8% of the antisecretory users. CONCLUSIONS: Our study demonstrates that the use of inhibiting PPIs increased steadily in patients administered clopidogrel-based DAPT therapy. This is a major concern since the concomitant use of inhibiting PPIs with clopidogrel could increase the risk of cardiovascular events.

In mild ischemic stroke or high-risk TIA, DAPT started ≤72 h after onset reduced new stroke and increased bleeding at 90 d.

SOURCE CITATION: Gao Y, Chen W, Pan Y, et al; INSPIRES Investigators. Dual antiplatelet treatment up to 72 hours after ischemic stroke. N Engl J Med. 2023;389:2413-2424. 38157499.

Prognostic Impact of CYP2C19 Genotypes on Long-Term Clinical Outcomes in Older Patients After Percutaneous Coronary Intervention.

BACKGROUND: Carriers of CYP2C19 loss-of-function alleles have increased adverse events after percutaneous coronary intervention, but limited data are available for older patients. We aimed to evaluate the prognostic impact of CYP2C19 genotypes on clinical outcomes in older patients after percutaneous coronary intervention. METHODS AND RESULTS: The study included 1201 older patients (aged ≥75 years) who underwent percutaneous coronary intervention and received clopidogrel-based dual antiplatelet therapy in South Korea. Patients were grouped on the basis of CYP2C19 genotypes. The primary outcome was 3-year major adverse cardiac events, defined as a composite of cardiac death, myocardial infarction, and stent thrombosis. Older patients were grouped into 3 groups: normal metabolizer (36.6%), intermediate metabolizer (48.1%), and poor metabolizer (15.2%). The occurrence of the primary outcome was significantly different among the groups (3.1, 7.0, and 6.2% in the normal metabolizer, intermediate metabolizer, and poor metabolizer groups, respectively; P=0.02). The incidence rate of all-cause death at 3 years was greater in the intermediate metabolizer and poor metabolizer groups (8.1% and 9.2%, respectively) compared with that in the normal metabolizer group (3.5%, P=0.03) without significant differences in major bleeding. In the multivariable analysis, the intermediate metabolizer and poor metabolizer groups were independent predictors of 3-year clinical outcomes. CONCLUSIONS: In older patients, the presence of any CYP2C19 loss-of-function allele was found to be predictive of a higher incidence of major adverse cardiac events within 3 years following percutaneous coronary intervention. This finding suggests a need for further investigation into an optimal antiplatelet strategy for older patients. REGISTRATION: URL: https://clinicaltrials.gov. Identifier: NCT04734028.

Trends in Dual Antiplatelet Therapy of Aspirin and Clopidogrel and Outcomes in Ischemic Stroke Patients Noneligible for POINT/CHANCE Trial Treatment.

BACKGROUND: Recent clinical trials established the benefit of dual antiplatelet therapy with aspirin and clopidogrel (DAPT-AC) in early-presenting patients with minor ischemic stroke. However, the impact of these trials over time on the use and outcomes of DAPT-AC among the patients with nonminor or late-presenting stroke who do not meet the eligibility criteria of these trials has not been delineated. METHODS AND RESULTS: In a multicenter stroke registry, this study examined yearly changes from April 2008 to August 2022 in DAPT-AC use for stroke patients ineligible for CHANCE/POINT (Clopidogrel in High-Risk Patients with Acute Nondisabling Cerebrovascular Events/Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke) clinical trials due to National Institutes of Health Stroke Scale >4 or late arrival beyond 24 hours of onset. A total of 32 118 patients (age, 68.1±13.1 years; male, 58.5%) with National Institutes of Health Stroke Scale of 4 (interquartile range, 1-7) were analyzed. In 2008, DAPT-AC was used in 33.0%, other antiplatelets in 62.7%, and no antiplatelet in 4.3%. The frequency of DAPT-AC was relatively unchanged through 2013, when the CHANCE trial was published, and then increased steadily, reaching 78% in 2022, while other antiplatelets decreased to 17.8% in 2022 (Ptrend<0.001). From 2011 to 2022, clinical outcomes nonsignificantly improved, with an average relative risk reduction of 2%/y for the composite of stroke, myocardial infarction, and all-cause mortality, both among patients treated with DAPT-AC and patients treated with other antiplatelets. CONCLUSIONS: Use of DAPT-AC in stroke patients with stroke ineligible for recent DAPT clinical trials increased markedly and steadily after CHANCE publication in 2013, reaching deployment in nearly 4 of every 5 patients by 2022. The secondary prevention in patients with ischemic stroke seems to be gradually improving, possibly due to the enhancement of risk factor control.

Impact of Society Guidelines on Trends in Use of Newer P2Y12 Inhibitors for Patients With Acute Coronary Syndromes Undergoing Percutaneous Coronary Intervention.

BACKGROUND: Over the past decade, major society guidelines have recommended the use of newer P2Y12 inhibitors over clopidogrel for those undergoing percutaneous coronary intervention for acute coronary syndrome. It is unclear what impact these recommendations had on clinical practice. METHODS AND RESULTS: All percutaneous coronary intervention procedures (n=534 210) for acute coronary syndrome in England and Wales (April 1, 2010, to March 31, 2022) were retrospectively analyzed, stratified by choice of preprocedural P2Y12 inhibitor (clopidogrel, ticagrelor, and prasugrel). Multivariable logistic regression models were used to examine odds ratios of receipt of ticagrelor and prasugrel (versus clopidogrel) over time, and predictors of their receipt. Overall, there was a significant increase in receipt of newer P2Y12 inhibitors from 2010 to 2020 (2022 versus 2010: ticagrelor odds ratio, 8.12 [95% CI, 7.67-8.60]; prasugrel odds ratio, 6.14 [95% CI, 5.53-6.81]), more so in ST-segment-elevation myocardial infarction than non-ST-segment-elevation acute coronary syndrome indication. The most significant increase in odds of receipt of prasugrel was observed between 2020 and 2022 (P<0.001), following a decline/plateau in its use in earlier years (2011-2019). In contrast, the odds of receipt of ticagrelor significantly increased in earlier years (2012-2017, Ptrend<0.001), after which the trend was stable (Ptrend=0.093). CONCLUSIONS: Over a 13-year-period, there has been a significant increase in use of newer P2Y12 inhibitors, although uptake of prasugrel use remained significantly lower than ticagrelor. Earlier society guidelines (pre-2017) were associated with the highest rates of ticagrelor use for non-ST-segment-elevation acute coronary syndrome and ST-segment-elevation myocardial infarction cases while the ISAR-REACT 5 (Prospective, Randomized Trial of Ticagrelor Versus Prasugrel in Patients With Acute Coronary Syndrome) trial and later society guidelines were associated with higher prasugrel use, mainly for ST-segment-elevation myocardial infarction indication.

Ticagrelor, but Not Clopidogrel, Attenuates Hepatic Steatosis in a Model of Metabolic Dysfunction-Associated Steatotic Liver Disease.

BACKGROUND: Previous studies have suggested that platelets are associated with inflammation and steatosis and may play an important role in liver health. Therefore, we evaluated whether antiplatelet agents can improve metabolic disorder-related fatty liver disease (MASLD). METHODS: The mice used in the study were fed a high-fat-diet (HFD) and were stratified through liver biopsy at 18 weeks. A total of 22 mice with NAFLD activity scores (NAS) ≥ 4 were randomly divided into three groups (HFD-only, clopidogrel (CLO; 35 mg/kg/day), ticagrelor (TIC; 40 mg/kg/day) group). And then, they were fed a feed mixed with the respective drug for 15 weeks. Blood and tissue samples were collected and used in the study. RESULTS: The TIC group showed a significantly lower degree of NAS and steatosis than the HFD group (p = 0.0047), but no effect on the CLO group was observed. Hepatic lipogenesis markers' (SREBP1c, FAS, SCD1, and DGAT2) expression and endoplasmic reticulum (ER) stress markers (CHOP, Xbp1, and GRP78) only reduced significantly in the TIC treatment group. Inflammation genes (MCP1 and TNF-α) also decreased significantly in the TIC group, but not in the CLO group. Nile red staining intensity and hepatic lipogenesis markers were reduced significantly in HepG2 cells following TIC treatment. CONCLUSION: Ticagrelor attenuated NAS and hepatic steatosis in a MASLD mice model by attenuating lipogenesis and inflammation, but not in the CLO group.

Investigation of smoking on the antiplatelet response to clopidogrel: Unravelling the smoker's paradox.

The intricate relationship between smoking and the effects of the antiplatelet drug clopidogrel has been termed the "smoker's paradox". This paradox details the enhanced efficacy of clopidogrel in smokers compared to non-smokers. This review begins with an exploration of the proposed mechanisms of the smoker's paradox, particularly drawing attention to the induction of cytochrome P450 (CYP) isoenzymes via tobacco smoke, specifically the enzymes CYP1A2 and CYP2C19. Moreover, an investigation of the effects of genetic variability on the smoker's paradox was undertaken from both clinical and molecular perspectives, delving into the effects of ethnicity and genetic polymorphisms. The intriguing role of CYP1A2 genotypes and the response to clopidogrel in smoking and non-smoking populations was examined conferring insight into the individuality rather than universality of the smoker's paradox. CYP1A2 induction is hypothesised to elucidate the potency of smoking in exerting a counteracting effect in those taking clopidogrel who possess CYP2C19 loss of function polymorphisms. Furthermore, we assess the comparative efficacies of clopidogrel and other antiplatelet agents, namely prasugrel and ticagrelor. Studies indicated that prasugrel and ticagrelor provided a more consistent effect and further reduced platelet reactivity compared to clopidogrel within both smoking and non-smoking populations. Personalised dosing was another focus of the review considering patient comorbidities, genetic makeup, and smoking status with the objective of improving the antiplatelet response of those taking clopidogrel. In summation, this review provides insight into multiple areas of research concerning clopidogrel and the smoker's paradox taking into account proposed mechanisms, genetics, other antiplatelet agents, and personalised dosing.

Genetic variability in stroke patients: CYP2C19 polymorphisms unraveled.

OBJECTIVE: To study the distribution characteristics of CYP2C19 polymorphisms in patients suffering from stroke in Han Chinese patients. METHOD: PCR and DNA microarray chip technology were used to detect the CYP2C19 genotype of 549 patients with stroke, and the genotype, allele frequency and metabolic type of patients with different sexes, ages and types of infarctions and the independent risk factors for clopidogrel resistance were analyzed. RESULTS: Six genotypes were detected in these 549 patients. A total of 233 (42.44%) patients had the heterozygous allele *1/*2, which was the most prevalent, followed by the homozygous wild-type allele *1/*1 (191, 34.79%). A total of 30 (5.46%) patients possessed the heterozygous allele *1/*3, and 65 (11.84%) patients had the homozygous mutant allele *2/*2. Twenty-nine (5.28%) patients had the compound heterozygous mutant allele *2/*3, and only 1 patient had the homozygous mutant allele *3/*3. The distribution of genotypes, alleles, and metabolic types did not change significantly (P > 0.05) by sex, age, or type of stroke. In addition, no independent risk factors for clopidogrel resistance were found in this analysis. CONCLUSION: The distribution of CYP2C19 genotypes, allele frequencies, and metabolic types in patients with stroke in Han Chinese patients were not correlated with sex, age, or infarction type. The possibilities of hyperglycemia, hypercholesterolemia, hypertriglyceridemia, hypo-HDL-cholesterolemia, hyper-LDL-cholesterolemia and high blood pressure were not statistically associated with CYP2C19 genotypes. CYP2C19 gene polymorphism detection is recommended for patients who are available, and during treatment, the CYP2C19 genotype can be used to guide personalized precise medication use in patients with stroke.

Influence of sex on the timing of coronary angiography and the prescription of antiplatelet therapy in patients with nonST-segment elevation myocardial infarction. / Impacto del sexo en los tiempos de cateterismo y en el uso de pretratamiento antiagregante plaquetario en pacientes con síndrome coronario agudo sin elevación del segmento ST (SCASEST).

OBJECTIVES: To assess differences in the clinical management of nonST-segment elevation myocardial infarction (NSTEMI), including in-hospital events, according to biological sex. MATERIAL AND METHODS: Prospective observational multicenter study of patients diagnosed with NSTEMI and atherosclerosis who underwent coronary angiography. RESULTS: We enrolled 1020 patients in April and May 2022; 240 (23.5%) were women. Women were older than men on average (72.6 vs 66.5 years, P .001), and more women were frail (17.1% vs 5.6%, P .001). No difference was observed in pretreatment with any P2Y12 inhibitor (prescribed in 68.8% of women vs 70.2% of men, P = .67); however, more women than men were prescribed clopidogrel (56% vs 44%, P = .009). Women prescribed clopidogrel were more often under the age of 75 years and not frail. Coronary angiography was performed within 24 hours less corooften in women (29.8% vs 36.9%, P = .03) even when high risk was recognized. Frailty was independently associated with deferring coronary angiography in the adjusted analysis; biological sex by itself was not related. The frequency and type of revascularization were the same in both sexes, and there were no differences in in-hospital cardiovascular events. CONCLUSION: Women were more often prescribed less potent antithrombotic therapy than men. Frailty, but not sex, correlated independently with deferral of coronary angiography. However, we detected no differences in the frequency of coronary revascularization or in-hospital events according to sex.

OBJETIVO: Evaluar las diferencias en el manejo clínico y eventos intrahospitalarios en una cohorte de pacientes con síndrome coronario agudo sin elevación del segmento ST (SCASEST) en función del sexo. METODO: Estudio observacional, prospectivo y multicéntrico que incluyó pacientes consecutivos con diagnóstico de SCASEST sometidos a coronariografía con enfermedad ateroesclerótica responsable. RESULTADOS: Entre abril y mayo de 2022 se incluyeron 1.020 pacientes; de ellos, 240 eran mujeres (23,5%). En comparación con los hombres, las mujeres fueron mayores (72,6 años vs 66,5 años; p 0,001) y más frágiles (17,1% vs 5,6%; p 0,001). No hubo diferencias en el pretratamiento con un inhibidor del receptor P2Y12 (68,8% vs 70,2%, p = 0,67), aunque las mujeres recibieron más pretratamiento con clopidogrel (56% vs 44%, p = 0,009), principalmente aquellas de edad 75 años y sin fragilidad. En las mujeres se realizaron menos coronariografías precoces (# 24 h) (29,8% vs 36,9%; p = 0,03) a pesar de presentar la misma indicación (criterios de alto riesgo). En el análisis ajustado, la fragilidad, pero no el sexo, se asoció de forma independiente con la realización de una coronariografía diferida. La tasa y el tipo de revascularización fue igual en ambos sexos, y no hubo diferencias en los eventos cardiovasculares intrahospitalarios. CONCLUSIONES: Las mujeres recibieron con mayor frecuencia un tratamiento antitrombótico menos potente. La fragilidad y no el sexo se asoció con la realización de coronariografía diferida. Sin embargo, no hubo diferencias en la tasa de revascularización coronaria ni en los eventos intrahospitalarios en función del sexo.

Safety of Clopidogrel vs. Ticagrelor in Dual Antiplatelet Therapy Regimens for High-Bleeding Risk Acute Coronary Syndrome Patients: A Comprehensive Meta-analysis of Adverse Outcomes.

INTRODUCTION: Patients of acute coronary syndrome (ACS) at a high-bleeding risk (HBR) often require dual antiplatelet therapy (DAPT) to reduce the risk of recurrent cardiovascular events. Clopidogrel and ticagrelor are the most commonly used antiplatelet agents in DAPT regimens. However, the safety profiles of these drugs in ACS patients at HBR remain a subject of ongoing debate. AIM: To investigate any difference between the safety of clopidogrel and ticagrelor used as a part of DAPT regimen in ACS patients at HBR. METHODS: A systematic search on PubMed, Cochrane Library, and Google Scholar was conducted to identify experimental and observational studies published up to the knowledge cutoff date in September 2023. Studies comparing the safety of clopidogrel and ticagrelor in ACS patients at HBR were included for analysis. The primary outcomes assessed were major bleeding events, stroke, and myocardial infarction (MI), while secondary outcomes included all-cause mortality, major adverse cardiac and cerebrovascular events (MACCE), and net adverse clinical and cerebral events (NACCE). RESULTS: We included a total of 8 observational studies in our meta-analysis. The pooled analysis revealed a statistically significant increase in the risk of MI (pooled RR = 1.43; 95% CI 1.12-1.83; P = 0.005) in the patients using clopidogrel. There were no statistically significant differences in major bleeding events (pooled RR = 0.94; 95% CI 0.82-1.09; P = 0.44), stroke (pooled RR = 1.36; 95% CI 0.86-2.14; P = 0.18), all-cause mortality (pooled RR = 1.17; 95% CI 0.97-1.41; P = 0.10), MACCE (pooled RR = 1.07; 95% CI 0.76-1.50; P = 0.69) and NACCE (pooled RR = 0.95; 95% CI 0.66-1.37; P = 0.78) between the two groups. Subgroup analyses based on region were performed. CONCLUSION: Both drugs are generally safe for treating ACS patients with HBR at baseline, although a higher risk of MI was observed with the use of clopidogrel. Nevertheless, drug choice should factor in regional variations, patient-specific characteristics, cost, accessibility, and potential drug interactions.

Determination of clopidogrel effect in cats using point-of-care Plateletworks ADP and shipped samples for PFA-200 analysis in a clinical practice setting.

OBJECTIVES: Clopidogrel is the recommended first-line antithrombotic in cats for a variety of conditions; however, it is ineffective in 15-20% of cats. The determination of clopidogrel effectiveness with platelet function assays has historically been limited to specialty centers; however, recent work has suggested that in-hospital or shipped analyses of samples may be feasible. The aim of the present study was to investigate the utility of an in-house analysis and shipping of blood samples collected in primary practices for the determination of clopidogrel effectiveness. METHODS: Citrated blood samples were collected from cats receiving clopidogrel therapy by veterinarians in clinical practices across Canada, a median of 304.4 km from the reference laboratory (range 8-4425). Samples were analyzed in-house using Plateletworks ADP and shipped for remote analysis using PFA-200 P2Y and COL/ADP cartridges. RESULTS: A total of 30 samples were collected from 25 cats. Of these, the percentage of samples analyzable for the presence or absence of the clopidogrel effect was 86% for Plateletworks ADP, 90% for PFA-200 P2Y and 87% for PFA-200 COL/ADP. There was no significant difference in the number of samples unable to be analyzed by each modality (P = 0.689) due to flow obstruction or other sample characteristics. The prevalence of absence of clopidogrel effectiveness on platelet function assays was 8% with the PFA-200 COL/ADP assay, 25% with the PFA-200 P2Y assay and 30% with the Plateletworks ADP assay. CONCLUSIONS AND RELEVANCE: The results of this study confirm that samples of feline blood can be collected in clinical practices and shipped to a reference laboratory for PFA-200 analysis with a high rate of success, comparable to point-of-care analysis.

Ticagrelor downregulates the expression of proatherogenic and proinflammatory miR125-b compared to clopidogrel: A randomized, controlled trial.

BACKGROUND: Platelet P2Y12 antagonist ticagrelor reduces cardiovascular mortality after acute myocardial infarction (AMI) compared to clopidogrel, but the underlying mechanism is unknown. Because activated platelets release proatherogenic and proinflammatory microRNAs, including miR-125a, miR-125b and miR-223, we hypothesized that the expression of these miRNAs is lower on ticagrelor, compared to clopidogrel. OBJECTIVES: We compared miR-125a, miR-125b and miR-223 expression in plasma of patients after AMI treated with ticagrelor or clopidogrel. METHODS: After percutaneous coronary intervention on acetylsalicylic acid and clopidogrel, 60 patients with first AMI were randomized to switch to ticagrelor or to continue with clopidogrel. Plasma expression of miR-223, miR-125a-5p, miR-125b was measured using quantitative polymerase chain reaction at baseline and after 72 h and 6 months of treatment with ticagrelor or clopidogrel in patients and one in 30 healthy volunteers. Multiple electrode aggregometry using ADP test was used to determine platelet reactivity in response to P2Y12 inhibitors. RESULTS: Expression of miR-125b was higher in patients with AMI 72 h and 6 months, compared to healthy volunteers (p = 0.001), whereas expression of miR-125a-5p and miR-223 were comparable. In patients randomized to ticagrelor, expression of miR-125b decreased at 72 h (p = 0.007) and increased back to baseline at 6 months (p = 0.005). Expression of miR-125a-5p and miR-223 was not affected by the switch from clopidogrel to ticagrelor. CONCLUSIONS: Ticagrelor treatment leads to lower plasma expression of miR-125b after AMI, compared to clopidogrel. Higher expression of miR-125b might explain recurrent thrombotic events and worse clinical outcomes in patients treated with clopidogrel, compared to ticagrelor.

Individualized antiplatelet therapy for non-cardiogenic ischemic stroke.

OBJECTIVE: This research aims to investigate the impact of individualized antiplatelet therapy guided by thromboelastography with platelet mapping (TEG-PM) on the clinical outcomes of patients with non-cardiogenic ischemic stroke. METHODS: Among a total of 1264 patients, 684 individuals diagnosed with non-cardiogenic ischemic stroke underwent TEG-PM testing. Based on the adjustment of antiplatelet medication, these patients were divided into individual and control groups. Within the individual group, in accordance with the TEG-PM test results, a Maximum amplitude (MA) value greater than 47mm was defined as high residual platelet reactivity (HRPR), while an MA value less than 31mm was defined as low residual platelet reactivity (LRPR). Patients with arachidonic acid (AA) less than 50% and adenosine diphosphate (ADP) less than 30% were classified as aspirin-resistant or clopidogrel-resistant. Treatment strategies for antiplatelet medication were subsequently adjusted accordingly, encompassing increment, decrement, or replacement of drugs. Meanwhile, the control group maintained their original medication regimen without alterations. RESULTS: The individual group included 487 patients, while the control group had 197. In the individual group, approximately 175 patients (35.9%) were treated with increased medication dosages, 89 patients (18.3%) with reduced dosages, and 223 patients (45.8%) switched medications. The results showed that the incidence rate of ischemic events in the individual group was lower than that of the control group (5.54% vs. 12.6%, P = 0.001), but no significant difference was observed in bleeding events. Cox regression analysis revealed age (hazard ratio, 1.043; 95% CI, 1.01-1.078; P = 0.011) and coronary heart disease (hazard ratio, 1.902; 95% CI, 1.147-3.153; P = 0.013) as significant risk factors for adverse events. CONCLUSION: Individualized antiplatelet therapy based on TEG-PM results can reduce the risk of ischemic events in patients with non-cardiogenic ischemic stroke without increasing the risk of bleeding events or mortality. Advanced age and coronary heart disease were identified as risk factors affecting the outcomes of individualized antiplatelet therapy.

Factors associated with clopidogrel resistance and clinical outcomes in ischemic cerebrovascular disease: A retrospective study.

OBJECTIVE: Clopidogrel resistance may lead to the recurrence of cerebrovascular diseases. We aimed to identify potential factors associated with clopidogrel resistance and evaluate the clinical outcomes of the patients. MATERIALS AND METHODS: In this retrospective study, patients with ischemic cerebrovascular disease treated with clopidogrel were included and classified into 2 groups according to the adenosine diphosphate (ADP)-induced platelet aggregation. Patients with the ADP inhibition rate of <30 % were included in clopidogrel resistance group, otherwise were included in clopidogrel sensitive group. CYP2C19 genotype and other clinical data were analyzed to identify factors and clinical features in the multivariate analysis. The outcomes were vascular events in 6 months. RESULTS: In total, 139 patients were enrolled with 81 (58.27 %) in clopidogrel sensitive group and 58 (41.73 %) in clopidogrel resistance group. Female and CYP2C19 *2*3 carrying were risk factors for clopidogrel resistance, and female was an independent risk factor (OR 2.481, 95 % CI 1.066-5.771, P=0.035). The clopidogrel resistance group showed a higher use rate of argatroban (P=0.030) and a lower arachidonic acid-induced inhibition of platelet aggregation (P=0.036). Clopidogrel resistance was related to the progressing stroke (HR 3.521, 95 % CI 1.352-9.170, P=0.010), but had no influence on the bleeding events (P>0.05). CONCLUSIONS: The risk of clopidogrel resistance increased significantly in female patients. Patients with clopidogrel resistance may have an increased incidence of stroke progression in the acute phase.

Impact of very low dose rivaroxaban in addition to dual antiplatelet therapy on endogenous fibrinolysis in acute coronary syndrome: The VaLiDate-R study.

BACKGROUND: Impaired endogenous fibrinolysis is adverse cardiovascular risk factor in acute coronary syndrome (ACS) patients. Addition of very low dose rivaroxaban (VLDR) to dual antiplatelet therapy (DAPT) reduces cardiovascular events but increases bleeding. OBJECTIVE: We aimed to assess whether addition of VLDR to DAPT can enhance endogenous fibrinolysis. METHODS: In a prospective, open-label trial, we assessed endogenous fibrinolysis in whole blood, in 549 patients with ACS using the Global Thrombosis Test (GTT) and Thromboelastography (TEG). Patients (n = 180) who demonstrated impaired endogenous fibrinolysis (lysis time [LT] >2000s with the GTT) were randomised 1:1:1 to (i) clopidogrel 75 mg daily; (ii) clopidogrel 75 mg daily plus rivaroxaban 2.5 mg twice daily; or (iii) ticagrelor 90 mg twice daily, for 30 days, in addition to aspirin. Fibrinolytic status was assessed at 0, 2, 4 and 8 weeks. The primary outcome was the change in LT from admission to week 4. We also measured thrombotic occlusion time (OT) at high shear, and rivaroxaban level. RESULTS: There was no difference between the groups with respect to LT or clot lysis with TEG, and no change in these parameters compared to baseline during study drug allocation. In the rivaroxaban plus clopidogrel group, OT was prolonged compared to the other groups, although rivaroxaban levels were low, suggesting non-compliance. CONCLUSION: Addition of rivaroxaban 2.5 mg twice daily to DAPT does not affect endogenous fibrinolysis of thrombus formed at either high or low shear. Further studies are needed to determine whether higher doses of rivaroxaban can favourably modulate fibrinolysis. CONDENSED ABSTRACT: Impaired endogenous fibrinolysis is a strong risk factor in ACS. We aimed to assess whether adding very low dose rivaroxaban (VLDR) to DAPT can enhance fibrinolysis. Fibrin and clot lysis were assessed in whole blood. ACS patients with impaired fibrinolysis were randomised 1:1:1 to clopidogrel 75 mg daily; clopidogrel 75 mg plus VLDR; or ticagrelor 90 mg twice daily, in addition to aspirin. At 30-days, there was no difference in lysis time between the groups, nor change from baseline. VLDR does not improve fibrinolysis at high or low shear. Further studies are needed to determine whether alternative antithrombotic regimens can enhance endogenous fibrinolysis.

Time interval of esomeprazole and dual antiplatelet therapy in patients with cardiocerebrovascular diseases.

Dual antiplatelet therapy (DAPT) with the combination of clopidogrel and aspirin is recommended for preventing secondary ischemic events in patients with acute coronary syndrome (ACS) or acute ischemic stroke (AIS). Proton pump inhibitors (PPIs) are suggested as preventive treatment for these patients. Due to clopidogrel-PPI interactions, separating their administration might be considered. However, a paucity of studies has been conducted to investigate the outcome differences between concurrent and interval-based use in ACS and AIS patients. Our study aimed to evaluate clinical outcomes based on administration timing. This study included patients with ACS or AIS onset or recurrence of within the last month. Patients who were expected to receive DAPT for at least 6 months and who were currently taking or planning to take esomeprazole were included. Patients were divided into Group 1 (interval administration group, IA group) and Group 2 (concurrent administration group, CA group) according to the interval between esomeprazole and DAPT administration. The time interval was based on 12 hours. The primary outcome was the occurrence of major adverse cardiocerebrovascular events (MACCEs), and safety outcomes were defined as major bleeding, minor bleeding and gastrointestinal bleeding and intracranial hemorrhage. A total of 3600 patients completed this study. The proportions of patients in the 2 groups were as follows: CA group, 99% (n = 3489) and IA group, 1% (n = 111). The primary outcome occurred in 0.9% of patients in the IA group and 1.8% of patients in the CA group (P = .51). There was no significant distinction in the overall bleeding risk of the CA group compared to that of the IA group (2.75% in the CA group and 2.70% in the IA group). Additionally, there was no significant difference observed between the 2 groups for safety outcomes. This multicenter, prospective, observational study that enrolled patients with ACS or AIS demonstrated that there was no significant difference in the occurrence of MACCEs and bleeding issues within 6 months according to the medication administration interval. The majority of patients with DAPT were taking PPIs simultaneously in real-world practice.