Platelet function in stroke/transient ischemic attack patients treated with tocotrienol.
Ontology highlight
ABSTRACT:
SUBMITTER: Slivka A
PROVIDER: S-EPMC7815323 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:BACKGROUND:Patients with ischemic stroke or transient ischemic attack (TIA) are at increased risk for future cardiovascular events despite current preventive therapies. The identification of insulin resistance as a risk factor for stroke and myocardial infarction raised the possibility that pioglitazone, which improves insulin sensitivity, might benefit patients with cerebrovascular disease. METHODS:In this multicenter, double-blind trial, we randomly assigned 3876 patients who had had a recent ischemic stroke or TIA to receive either pioglitazone (target dose, 45 mg daily) or placebo. Eligible patients did not have diabetes but were found to have insulin resistance on the basis of a score of more than 3.0 on the homeostasis model assessment of insulin resistance (HOMA-IR) index. The primary outcome was fatal or nonfatal stroke or myocardial infarction. RESULTS:By 4.8 years, a primary outcome had occurred in 175 of 1939 patients (9.0%) in the pioglitazone group and in 228 of 1937 (11.8%) in the placebo group (hazard ratio in the pioglitazone group, 0.76; 95% confidence interval [CI], 0.62 to 0.93; P=0.007). Diabetes developed in 73 patients (3.8%) and 149 patients (7.7%), respectively (hazard ratio, 0.48; 95% CI, 0.33 to 0.69; P<0.001). There was no significant between-group difference in all-cause mortality (hazard ratio, 0.93; 95% CI, 0.73 to 1.17; P=0.52). Pioglitazone was associated with a greater frequency of weight gain exceeding 4.5 kg than was placebo (52.2% vs. 33.7%, P<0.001), edema (35.6% vs. 24.9%, P<0.001), and bone fracture requiring surgery or hospitalization (5.1% vs. 3.2%, P=0.003). CONCLUSIONS:In this trial involving patients without diabetes who had insulin resistance along with a recent history of ischemic stroke or TIA, the risk of stroke or myocardial infarction was lower among patients who received pioglitazone than among those who received placebo. Pioglitazone was also associated with a lower risk of diabetes but with higher risks of weight gain, edema, and fracture. (Funded by the National Institute of Neurological Disorders and Stroke; ClinicalTrials.gov number, NCT00091949.).
| S-EPMC4887756 | biostudies-literature
Project description:BACKGROUND:The IRIS trial (Insulin Resistance Intervention After Stroke) demonstrated that pioglitazone reduced the risk for both cardiovascular events and diabetes mellitus in insulin-resistant patients. However, concern remains that pioglitazone may increase the risk for heart failure (HF) in susceptible individuals. METHODS:In IRIS, patients with insulin resistance but without diabetes mellitus were randomized to pioglitazone or placebo (1:1) within 180 days of an ischemic stroke or transient ischemic attack and followed for ?5 years. To identify patients at higher HF risk with pioglitazone, we performed a secondary analysis of IRIS participants without HF history at entry. HF episodes were adjudicated by an external review, and treatment effects were analyzed using time-to-event methods. A baseline HF risk score was constructed from a Cox model estimated using stepwise selection. Baseline patient features (individually and summarized in risk score) and postrandomization events were examined as possible modifiers of the effect of pioglitazone. Net cardiovascular benefit was estimated for the composite of stroke, myocardial infarction, and hospitalized HF. RESULTS:Among 3851 patients, the mean age was 63 years, and 65% were male. The 5-year HF risk did not differ by treatment (4.1% pioglitazone, 4.2% placebo). Risk for hospitalized HF was low and not significantly greater in pioglitazone compared with placebo groups (2.9% versus 2.3%, P=0.36). Older age, atrial fibrillation, hypertension, obesity, edema, high C-reactive protein, and smoking were risk factors for HF. However, the effect of pioglitazone did not differ across levels of baseline HF risk (hazard ratio [95% CI] for pioglitazone versus placebo for patients at low, moderate, and high risk: 1.03 [0.61-1.73], 1.10 [0.56-2.15], and 1.08 [0.58-2.01]; interaction P value=0.98). HF risk was increased in patients with versus those without incident myocardial infarction in both groups (pioglitazone: 31.4% versus 2.7%; placebo: 25.7% versus 2.4%; P<0.0001). Edema, dyspnea, and weight gain in the trial did not predict HF hospitalization but led to more study drug dose reduction with a lower mean dose of pioglitazone versus placebo (29±17 mg versus 33±15 mg, P<0.0001). Pioglitazone reduced the composite outcome of stroke, myocardial infarction, or hospitalized HF (hazard ratio, 0.78; P=0.007). CONCLUSIONS:In IRIS, with surveillance and dose adjustments, pioglitazone did not increase the risk of HF and conferred net cardiovascular benefit in patients with insulin resistance and cerebrovascular disease. The risk of HF with pioglitazone was not modified by baseline HF risk. The IRIS experience may be instructive for maximizing the net benefit of this therapy. CLINICAL TRIAL REGISTRATION:URL: https://www.clinicaltrials.gov . Unique identifier: NCT00091949.
| S-EPMC6202153 | biostudies-literature
Project description:BACKGROUND:Patients with a recent ischemic stroke have a higher risk of recurrent stroke compared to (ocular) transient ischemic attack (TIA) patients. Plaque microvasculature is considered as a feature of plaque vulnerability and can be quantified with carotid dynamic contrast-enhanced MRI (DCE-MRI). The purpose of this cross-sectional study was to explore the association between plaque microvasculature and the type of recent cerebrovascular events in symptomatic patients with mild-to-moderate carotid stenosis. METHODS:A total of 87 symptomatic patients with a recent stroke (n = 35) or (ocular) TIA (n = 52) underwent carotid DCE-MRI examination. Plaque microvasculature was studied in the vessel wall and adventitia using DCE-MRI and the pharmacokinetic modeling parameter Ktrans. Statistical analysis was performed with logistic regression, correcting for associated clinical risk factors. RESULTS:The 75th percentile adventitial (OR 1.97, 95% CI 1.18-3.29) Ktrans was significantly associated with a recent ischemic stroke compared to (ocular) TIA in multivariate analysis, while clinical risk factors were not significantly associated with the type of event. CONCLUSIONS:This study indicates a positive association of leaky plaque microvasculature with a recent ischemic stroke compared to (ocular) TIA. Prospective longitudinal studies are needed to investigate whether Ktrans or other plaque characteristics may serve as an imaging marker for predicting (the type of) future cerebrovascular events.
| S-EPMC5804829 | biostudies-literature
Project description:Background and purposeLow biological response to Clopidogrel prescribed after non cardioembolic ischemic stroke or transient ischemic attack (TIA) is a major clinical problem and could explain the recurrence of vascular events. Platelet α2-adrenoreceptors are involved in the high residual platelet reactivity in stable coronary artery disease patients on dual antiplatelet therapy. In the present study we investigated the impact of platelet α2-adrenoreceptors on ADP-induced platelet aggregation and on ADP-induced platelet membrane CD62P (P-selectin) expression, a marker of platelet activation on blood samples from patients hospitalized at the acute phase of a non cardioembolic ischemic stroke or TIA.Methods72 consecutive patients were prospectively recruited over the course of two years in a monocentric study. Patients received a daily 75 mg-dose of Clopidogrel. ADP-induced platelet aggregation was measured alone, with low dose epinephrine or with atipamezole, a selective α blocker of α2-adrenoreceptors, by Light Transmittance Aggregometry (LTA). Platelet membrane expression of P-selectin was measured by flow cytometry with either ADP alone or combined with epinephrine.ResultsEpinephrine at low dose stimulated ADP-induced platelet membrane expression of CD62P whereas Atipamezole significantly inhibited 10 µM ADP-induced platelet aggregation.ConclusionsOur study showed the role of platelet α2-adrenoreceptors in biological low response to Clopidogrel for patients hospitalized for a non-cardioembolic ischemic stroke or TIA. Atipamezole could improve the status of biological response to Clopidogrel.
| S-EPMC6129516 | biostudies-literature
Project description:ObjectiveTo discover, by using metabolomics, novel candidate biomarkers for stroke recurrence (SR) with a higher prediction power than present ones.MethodsMetabolomic analysis was performed by liquid chromatography coupled to mass spectrometry in plasma samples from an initial cohort of 131 TIA patients recruited <24 hours after the onset of symptoms. Pattern analysis and metabolomic profiling, performed by multivariate statistics, disclosed specific SR and large-artery atherosclerosis (LAA) biomarkers. The use of these methods in an independent cohort (162 subjects) confirmed the results obtained in the first cohort.ResultsMetabolomics analyses could predict SR using pattern recognition methods. Low concentrations of a specific lysophosphatidylcholine (LysoPC[16:0]) were significantly associated with SR. Moreover, LysoPC(20:4) also arose as a potential SR biomarker, increasing the prediction power of age, blood pressure, clinical features, duration of symptoms, and diabetes scale (ABCD2) and LAA. Individuals who present early (<3 months) recurrence have a specific metabolomic pattern, differing from non-SR and late SR subjects. Finally, a potential LAA biomarker, LysoPC(22:6), was also described.ConclusionsThe use of metabolomics in SR biomarker research improves the predictive power of conventional predictors such as ABCD2 and LAA. Moreover, pattern recognition methods allow us to discriminate not only SR patients but also early and late SR cases.
| S-EPMC4336096 | biostudies-literature
Project description:A majority of patients with ischemic stroke present with mild deficits for which aggressive management is not often pursued. Comprehensive work-up and appropriate intervention for minor strokes and transient ischemic attacks (TIAs) point toward better patient outcomes, lower costs, and fewer cases of disability. Imaging is a key modality to guide treatment and predict stroke recurrence. Patients with large vessel occlusions have been found to suffer worse outcomes and could benefit from intervention. Whether intravenous thrombolytic therapy decreases disability in minor stroke patients and whether acute endovascular intervention improves functional outcomes in patients with minor stroke and known large vessel occlusion remain controversial. Studies are ongoing to determine ideal antiplatelet therapy for stroke and TIA, while ongoing statin therapy, surgical management for patients with carotid stenosis, and anticoagulation for patients with atrial fibrillation have all been proven to decrease the rate of stroke recurrence and improve outcomes. This review summarizes the current evidence and discusses the standard of care for patients with minor stroke and TIA.
| S-EPMC4901037 | biostudies-other
Project description:Introduction: Patients with transient ischemic attack (TIA) and minor stroke demonstrate cognitive impairment, and a four-fold risk of late-life dementia. Aim: To study the extent to which the rates of brain volume loss in TIA patients differ from healthy controls and how they are correlated with cognitive impairment. Methods: TIA or minor stroke patients were tested with a neuropsychological battery and underwent T1 weighted volumetric magnetic resonance imaging scans at fixed intervals over a 3 years period. Linear mixed effects regression models were used to compare brain atrophy rates between groups, and to determine the relationship between atrophy rates and cognitive function in TIA and minor stroke patients. Results: Whole brain atrophy rates were calculated for the TIA and minor stroke patients; n = 38 between 24 h and 18 months, and n = 68 participants between 18 and 36 months, and were compared to healthy controls. TIA and minor stroke patients demonstrated a significantly higher whole brain atrophy rate than healthy controls over a 3 years interval (p = 0.043). Diabetes (p = 0.012) independently predicted higher atrophy rate across groups. There was a relationship between higher rates of brain atrophy and processing speed (composite P = 0.047 and digit symbol coding P = 0.02), but there was no relationship with brain atrophy rates and memory or executive composite scores or individual cognitive tests for language (Boston naming, memory recall, verbal fluency or Trails A or B score). Conclusion: TIA and minor stroke patients experience a significantly higher rate of whole brain atrophy. In this cohort of TIA and minor stroke patients changes in brain volume over time precede cognitive decline.
| S-EPMC6389669 | biostudies-literature
Project description:ObjectiveTo determine if corneal confocal microscopy can identify corneal nerve and endothelial cell abnormalities and may be useful in the prognostication of patients with transient ischemic attack [1] or minor ischemic stroke (IS).MethodsThirty-six patients admitted with TIA (n = 14) or minor IS (n = 22) underwent transcranial Doppler evaluation and corneal confocal microscopy and were compared with 18 healthy controls.ResultsCorneal nerve fiber density (P = 0.002), branch density (P = 0.004) and fiber length (P = 0.004) were significantly lower in patients with TIA or minor IS compared to controls, with no difference between patients with TIA and minor IS. Endothelial cell density (P = 0.003) was lower and endothelial cell area (P = 0.003) and perimeter (P = 0.006) were significantly higher in patients with TIA or minor IS compared to controls, with no difference between patients with TIA and minor IS. There were no differences in corneal nerve or endothelial cell morphology between patients with and without abnormal cerebrovascular reactivity. HbA1c was independently associated with CNFL, and endothelial cell polymegathism and pleomorphism were associated with both HbA1c and total cholesterol.ConclusionCorneal confocal microscopy identifies corneal nerve fiber loss and endothelial cell abnormalities in patients with TIA and minor IS and independent associations with HbA1c and cholesterol.
| S-EPMC6420175 | biostudies-literature
Project description:Objective: To determine the association between serum phosphate level and 1-year clinical outcomes in patients with acute ischemic stroke and transient ischemic attack. Methods: We included 7,353 patients with acute ischemic stroke and transient ischemic attack from the China National Stroke Registry III for analysis. Participants were divided into 4 groups according to serum phosphate quartiles. Composite end point included recurrent stroke, myocardial infarction, other ischemic vascular events, and all-cause mortality. Poor functional outcome is defined as modified Rankin Scale score of 3 to 6. Multivariable Cox regression or logistic regression was used to evaluate the independent association of serum phosphate with 1-year all-cause mortality, recurrent stroke, composite end point and poor functional outcome. Results: The mean age of the included 7,353 patients was 62.5 years, and 68.6% of them were men. Plotting hazard ratios over phosphate levels suggested a U-shaped association especially for recurrent stroke and composite end point, and therefore the third quartile group was set as reference group. Compared with the third quartile of phosphate (1.06-1.20 mmol/L), the adjusted hazard ratios/odds ratios (95% CI) of the lowest quartile (<0.94 mmol/L) were 0.98 (0.67-1.42) for all-cause mortality, 1.31 (1.05-1.64) for stroke recurrence, 1.26 (1.02-1.57) for composite end point, and 1.27 (1.01-1.61) for poor functional outcome, and the adjusted odds ratio of the highest quartile (≥1.2 mmol/L) was 1.40 (1.11-1.77) for poor functional outcome. Conclusions: Serum phosphate may be an independent predictor of stroke recurrence, composite end point and poor functional outcome after ischemic stroke.
| S-EPMC8079723 | biostudies-literature
Project description:Background: Platelet endothelial aggregation receptor-1 (PEAR1) rs12041331 has been reported to affect agonist-stimulated platelet aggregation, but it remains unclear whether this variant plays a role in recurrent stroke. Here we assess the clinical relevance of PEAR1 rs12041331 in acute minor ischemic stroke (AMIS) and transient ischemic attack (TIA) Chinese patients treated with dual antiplatelet therapy (DAPT). Methods: We recruited 273 consecutive minor stroke and TIA patients, and Cox proportional hazard regression was used to model the relationship between PEAR1 rs12041331 and thrombotic and bleeding events. Results: Genotyping for PEAR1 rs12041331 showed 49 (18.0%) AA homozygotes, 129 (47.3%) GA heterozygotes, and 95 (34.7%) GG homozygotes. No association was observed between PEAR1 rs12041331 genotype and stroke or composite clinical vascular event rates (ischemic stroke, hemorrhagic stroke, TIA, myocardial infarction, or vascular death) or bleeding events regardless if individuals carried one or two copies of the A allele. Our results suggested that rs12041331 genetic polymorphism was not an important contributor to clinical events in AMIS and TIA patients in the setting of secondary prevention. Conclusions: Our data do provide robust evidence that genetic variation in PEAR1 rs12041331 do not contribute to atherothrombotic or bleeding risk in minor stroke and TIA patients treated with DAPT.
| S-EPMC8202184 | biostudies-literature