CYP metabolic pathway related gene polymorphism increases the risk of embolic and atherothrombotic stroke and vulnerable carotid plaque in southeast China.

OBJECTIVE: To investigate the association of CYP metabolic pathway-related genetic polymorphisms with the susceptibility to ischemic stroke and stability of carotid plaque in southeast China. METHODS: We consecutively enrolled 294 acute ischemic stroke patients with carotid plaque and 282 controls from Wenling First People's Hospital. The patients were divided into the carotid vulnerable plaque group and stable plaque group according to the results of carotid B-mode ultrasonography. Polymorphisms of CYP3A5 (G6986A, rs776746), CYP2C9*2 (C430T, rs1799853), CYP2C9*3 (A1075C, rs1057910), and EPHX2 (G860A, rs751141) were determined using polymerase chain reaction and mass spectrometry analysis. RESULTS: EPHX2 GG may reduce the susceptibility to ischemic stroke (OR = 0.520, 95% CI: 0.288 ∼ 0.940, P = 0.030) and AA+AG may increase the risk for ischemic stroke (OR = 1.748, 95% CI: 1.001 ∼ 3.052, P = 0.050). The distribution of CYP3A5 genotypes showed significant differences between the vulnerable plaque and stable plaque groups (P = 0.026). Multivariate logistic regression analysis found that CYP3A5 GG could reduce the risk of vulnerable plaques (OR = 0.405, 95% CI: 0.178 ∼ 0.920, P = 0.031). CONCLUSION: EPHX2 G860A polymorphism may reduce the stroke susceptibility, while other SNPs of CYP genes are not associated with ischemic stroke in southeast China. Furthermore CYP3A5 polymorphism was related with carotid plaque instability.

20-hydroxyeiscosatetraenoic acid may be as a predictor of malignant middle cerebral artery infarction in patients with massive middle cerebral artery infarction.

BACKGROUND: Early identification of massive middle cerebral artery infarction (MCAI) at risk for malignant MCAI (m-MCAI) may be useful in selecting patients for aggressive therapies. The aim of this study was to determine whether CYP metabolites may help to predict impending m-MCAI. METHODS: This is a prospective, two-center observational study in 256 patients with acute massive MCAI. Plasma levels of 20-hydroxyeicosatetraenoic acid (20-HETE), epoxyeicosatrienoic acids, and dihydroxyeicosatrienoic acids were measured at admission. Brain computed tomography (CT) was performed at admission and repeated between day 3 and 7, or earlier if there was neurological deterioration. The primary outcome was m-MCAI. The m-MCAI was diagnosed when follow-up brain CT detected a more than two-thirds space-occupying MCAI with midline shift, compression of the basal cisterns, and neurological worsening. RESULTS: In total of 256 enrolled patients, 77 (30.1%) patients developed m-MCAI. Among the 77 patients with m-MCAI, 60 (77.9%) patients died during 3 months of stroke onset. 20-HETE level on admission was significantly higher in patients with m-MCAI than those without m-MCAI. There was an increase in the risk of m-MCAI with increase of 20-HETE levels. The third and fourth quartiles of 20-HETE levels were independent predictors of m-MCAI (OR: 2.86; 95% CI: 1.16 - 6.68; P = 0.025, and OR: 4.23; 95% CI: 1.35 - 8.26; P = 0.002, respectively). CONCLUSIONS: Incidence of m-MCAI was high in patients with massive MCAI and the prognosis of m-MCAI is very poor. Elevated plasma 20-HETE may be as a predictor for m-MCAI in acute massive MCAI, and it might useful in clinical practice in therapeutic decision making.

Early amantadine treatment reduces the risk of death in patients with large hemisphere infarctions:a Chinese hospital-based study.

BACKGROUND: Amantadine hydrochloride is one of the most frequently prescribed drugs for patients with severe traumatic brain injury in restoring consciousness and accelerating the pace of functional recovery. However, there is a paucity of studies on the effectiveness of amantadine in patients with severe stroke especially large hemisphere infarction (LHI). The present study aimed to investigate whether amantadine treatment is associated with better clinical outcomes in conservatively treated LHI patients. METHODS: We retrospectively collected conservatively treated LHI patients according to inclusion/exclusion criteria. The patients were divided into two groups based on the treatment regimen, whether they did receive amantadine hydrochloride in addition to standard therapy (ST) or not. The primary outcomes were in-hospital death, 3-month mortality, and unfavorable outcome (defined as modified Rankin Scale score of 4 to 6). All outcomes were compared between the two groups before and after propensity score matching (PSM). Multivariate logistic regression was performed to identify the association between early amantadine hydrochloride treatment and clinical outcomes in LHI patients. RESULTS: Thirty-one LHI patients treated with amantadine combined with ST and 127 patients treated with ST were enrolled. Amantadine group had a shorter prehospital delay (median: 2 vs. 10 h), a higher baseline NIHSS score (21.71 ± 4.76 vs. 17.49 ± 5.84), and a higher rate of dominant hemisphere involvement (67.74% vs. 45.67%). After PSM, amantadine treatment significantly reduced the risk of in-hospital death (7.41% vs. 31.11%, p=0.019) and 3-month mortality (25.93% vs. 55.56%, p=0.008). Amantadine treatment yielded a significant decrease in death in-hospital (before PSM: OR 0.143, 95% CI 0.034 to 0.605; after PSM: OR 0.113, 95% CI 0.020 to 0.635) and 3-month mortality (before PSM: OR 0.214, 95% CI 0.077 to 0.598; after PSM: OR 0.176, 95% CI 0.053 to 0.586) in unmatched and matched multivariate analyses. CONCLUSION: The results of our study provide initial evidence that early amantadine treatment was associated with a decrease in death in conservatively treated LHI patients. Considering the limitations of observational study, randomized controlled trials with a large sample size may help provide a clearer picture of the utility of amantadine in LHI patients.

1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) Urea Exerts Neuro-Protective Effects Against Ischemic Injury via Suppressing JNK/p38 MAPK-Mediated Mitochondrial Apoptosis Pathway.

BACKGROUND: 1-trifluoromethoxyphenyl-3-(1- propionylpiperidin-4-yl) urea (TPPU) is a novel soluble epoxide hydrolase inhibitor which can protect against cerebral ischemic injury in middle cerebral artery occlusion rat model. However, the effects and potential mechanisms of TPPU on mitochondrial dysfunction are poorly understood. MATERIALS AND METHODS: In oxygen-glucose deprivation/reperfusion (OGD/R)-induced cortical neurons, the effect of TPPU on cell viability was measured by MTT assay and apoptosis was evaluated using TUNEL assay. Mitochondria were observed by transmission electron microscopy and Mitotracker green staining assay, mitochondrial membrane potential was determined by JC-1 staining assay, activities of mitochondrial respiratory chain complexes (MRCC) I-IV and ATPase were measured by MRCC Activity Assay Kits and spectrophotometer. Western blot was used to investigate the effects of TPPU on apoptosis-related proteins. RESULTS: TPPU treatment demonstrated significant protective effect on the OGD/R-induced cortical neurons by reducing cell death and number of apoptotic cells, stabilizing mitochondrial ultrastructure and morphology, increasing mitochondrial membrane potential and activities of MRCC I-IV and ATPase. Furthermore, TPPU treatment might effectively reverse the upregulation of caspase-3, Bax, p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal protein kinase (JNK), alleviate the inhibition of Bcl-2 in OGD/R-induced cortical neurons. CONCLUSIONS: TPPU exerts a marked neuroprotective effect against mitochondrial dysfunction after cerebral ischemia potentially via suppressing JNK/p38 MAPK-mediated mitochondrial apoptosis signal pathway, it may be a promising neuroprotective agent for cerebral ischemia.

Variants in clopidogrel-relevant genes and early neurological deterioration in ischemic stroke patients receiving clopidogrel.

BACKGROUND: Early neurological deterioration (END) is common in acute ischemic stroke (IS). However, the underlying mechanisms for END are unclear. The aim of this study was to evaluate the associations of 16 variants in clopidogrel-relevant genes and interactions among these variants with END in acute IS patients receiving clopidogrel treatment. METHODS: We consecutively enrolled 375 acute IS patients between June 2014 and January 2015. Platelet aggregation was measured on admission and after the 7-10 days of clopidogrel treatment. The 16 variants in clopidogrel-relevant genes were examined using mass spectrometry. The primary outcome was END within the 10 days of admission. Gene-gene interactions were analyzed by generalized multifactor dimensionality reduction (GMDR) methods. RESULTS: Among the 375 patients, 95 (25.3%) patients developed END within the first 10 days of admission. Among the 16 variants, only CYP2C19*2 (rs4244285) AA/AG was associated with END using single-locus analytical approach. GMDR analysis revealed that there was a synergistic effect of gene-gene interactions among CYP2C19*2 rs4244285, P2Y12 rs16863323, and GPIIIa rs2317676 on the risk for END. The high-risk interactions among the three variants were associated with the higher platelet aggregation and independent predictor for END after adjusting for the covariates (hazard ratio: 2.82; 95% confidence interval: 1.36-7.76; P = 0.003). CONCLUSIONS: END is very common in patients with acute IS. The mechanisms leading to END are most likely multifactorial. Interactions among CYP2C19*2 rs4244285, P2Y12 rs16863323, and GPIIIa rs2317676 may confer a higher risk for END. It was very important to modify clopidogrel therapy for the patients carrying the high-risk interactive genotypes. CLINICAL TRIAL REGISTRATION INFORMATION: The study described here is registered at http://www.chictr.org/ (unique Identifier: ChiCTR-OCH-14004724). The date of trial registration was May 30, 2014.

Prevalence of stroke and stroke related risk factors: a population based cross sectional survey in southwestern China.

BACKGROUND: Stroke and its risk factors epidemiological survey can help identify individuals at higher risk and therefore promote stroke prevention strategies. The aim of this study was to estimate the current prevalence of stroke and high risk stroke population, and evaluate stroke associated risk factors in southwestern China. METHODS: This was a multi-center, cross sectional survey in southwestern China from May 2015 to September 2015. The eight communities were selected at random, and 17,413 residents aged ≥40 years volunteered to participate in this survey. Data were collected through face-to-face survey using a structured questionnaire. Five hundred twenty-one participants with incomplete questionnaires on stroke history or risk factors records were excluded. RESULTS: A total of 16,892 people included in analysis. The overall prevalence of stroke was 3.1% (95% CI 2.6-3.9%), 17.1% of participants were the high risk stroke population. After full adjustments, hypertension, diabetes, dyslipidemia, overweight, lack of exercise and family history of stroke were significantly associated with overall stroke and ischemic stroke. The largest contributor was hypertension (population-attributable risk 23.6%), followed by dyslipidemia, physical inactivity, family history of stroke, diabetes, and overweight. However, only hypertension (OR = 3.66, 95% CI 1.82-8.23) was significantly associated with hemorrhagic stroke. CONCLUSIONS: The prevalence of stroke and high risk stroke population was high among adults aged ≥40 years in southwestern China. Hypertension, dyslipidemia and lack of exercise were stronger contributors for stroke, these findings suggest that individual-level and population-level interventions for these leading risk factors are necessary to prevent stroke.

The TXA2R rs1131882, P2Y1 rs1371097 and GPIIIa rs2317676 three-loci interactions may increase the risk of carotid stenosis in patients with ischemic stroke.

BACKGROUND: The genetic risk factors for carotid stenosis are not fully understood. The aim of this study is to investigate the relationship between variants in platelet activation-relevant genes and carotid stenosis in patients with ischemic stroke (IS). METHODS: Eleven variants of platelet activation-relevant genes, aggregates of platelet-leukocyte, and platelet aggregation were examined in 236 IS patients with carotid stenosis and 378 patients without carotid stenosis. High-resolution B-mode ultrasound was used to assess carotid stenosis. Generalized multifactor dimensionality reduction (GMDR) methods were applied in analyzing gene-gene interactions to determine whether there was any interactive role of assessed variants in affecting risk of carotid stenosis. RESULTS: Platelet aggregation and aggregates of platelet-leukocyte showed higher value in patients with carotid stenosis, compared with patients without carotid stenosis. Excluding potential disturbance variables, these 11 variants were not associated with carotid stenosis. However, according to the GMDR analysis, gene-gene interactions among TXA2R rs1131882, P2Y1 rs1371097 and GPIIIa rs2317676 had a synergistic influence on carotid stenosis. The high-risk interactions between the three variants showed a relationship with higher platelet activation, and have independent associations with risk of carotid stenosis (OR = 2.72, 95% CI: 1.28-7.82, P = 0.001). CONCLUSION: The interactions among rs1131882, rs1371097 and rs2317676 perhaps increase the risk of symptomatic carotid stenosis, and maybe a potential marker for carotid stenosis. In this study, the combinatorial analysis made good use in elucidating complex risk factors in the heredity of carotid stenosis.

Influence of collateral circulation on cerebral blood flow and frontal lobe cognitive function in patients with severe internal carotid artery stenosis.

BACKGROUND: This study aimed to investigate the cerebral blood flow (CBF) and frontal lobe cognitive function in severe internal carotid artery (ICA) stenosis patients with different types of collateral circulation. METHODS: One hundred twenty-six patients with severe unilateral ICA stenosis were enrolled. Digital subtraction angiography (DSA) was performed to recruit patients with one of three common types of collateral circulation: anterior communicating artery (AcoA), posterior communicating artery (PcoA) and ophthalmic artery (OA). The hemodynamic parameters of the middle cerebral artery (MCA) were measured using transcranial Doppler (TCD), and the individual frontal lobe cognitive attention functions were evaluated using Word Fluency Test, Trail-Making Test (TMT), Digit Span, and Stroop Color Word Test (SCWT). The correlation between hemodynamic changes and the scores of all tasks was analyzed. RESULTS: On the side of arterial stenosis, the CBF velocities were highest in AcoA group and lowest in the OA group. All patients performed worse in TMT and Digit Span than the matched normal controls. The AcoA group exhibited a lower pulsatility index (PI) and a longer response time in the Stroop task, but had a higher accuracy rate in the Stroop task and higher scores in Word Fluency Test than the PcoA and OA groups. In all the three groups, PI was positively correlated with the accuracy rate for Stroop interference effects. CONCLUSIONS: Our findings suggested that the frontal lobe cognitive function of patients with ICA was impaired, and AcoA collaterals may be beneficial for selective attention functions, whereas OA collaterals may be associated with impairment of selective attention functions. Additionally, a high PI may be an indicator for identifying impaired selective attention in patients with severe ICA stenosis.

Preceding Antithrombotic Treatment is Associated With Acute Ischemic Stroke Severity and Functional Outcome at 90 Days Among Patients With Atrial Fibrillation.

BACKGROUND: Antithrombotic therapies are known to prevent ischemic stroke (IS) for patients with atrial fibrillation (AF), but are often underused in clinical practice. The aim of present study was to investigate the prevalence of patients with acute IS with known history of AF who were not receiving antithrombotic treatment before stroke and to evaluate the association of preceding antithrombotic treatment with stroke severity and outcomes at 90 days after admission. MATERIALS AND METHODS: This was a retrospective, multi-center, observational study of 748 patients with acute IS and known history of AF admitted to 6 participating hospitals between March 2016 and October 2017. The primary outcome was stroke severity at admission as assessed using National Institutes of Health Stroke Scale (NIHSS) score. The secondary outcome was functional outcome at 90 days after admission as measured by modified Rankin Scale (mRS) score. RESULTS: A total of 748 patients, 54 (7.2%) were receiving therapeutic warfarin (international normalized ratio [INR] ≥ 2) and 100 (13.4%) had subtherapeutic warfarin anticoagulation (INR < 2), 340 (45.5%) were receiving antiplatelet treatment, and 254 (34.0%) were not receiving any antithrombotic treatment prior to stroke. Compared with no antithrombotic treatment, therapeutic warfarin (OR: 0.64; 95% CI: 0.52-0.82; P = .022), and antiplatelet therapy only (OR: 0.89; 95% CI: 0.76-0.96; P = .041) were associated with lower odds ratio of moderate or severe stroke (NIHSS ≥ 16). Patients receiving preceding therapeutic warfarin (OR: 1.32; 95% CI: 1.22-3.57; P = .025), antiplatelet therapy only (OR: 1.13; 95% CI: 1.07-2.59; P = .043), and subtherapeutic warfarin with INR 1.5 to 1.99 (OR: 1.15; 95% CI: 1.10-2.66; P = .042) had higher odds ratio of better functional outcome (mRS ≤ 2) at 90 days. CONCLUSIONS: Among patients with AF who had experienced an acute IS, inadequate therapeutic warfarin preceding the stroke was very prevalent in China. Therapeutic warfarin was associated with less severe stroke and better functional outcome at 90 days.

Genetic Polymorphisms and Clopidogrel Efficacy for Acute Ischemic Stroke or Transient Ischemic Attack: A Systematic Review and Meta-Analysis.

BACKGROUND: The association of genetic polymorphisms and clopidogrel efficacy in patients with ischemic stroke or transient ischemic attack (TIA) remains controversial. We performed a systematic review and meta-analysis to assess the association between genetic polymorphisms, especially CYP2C19 genotype, and clopidogrel efficacy for ischemic stroke or TIA. METHODS: We conducted a comprehensive search of PubMed and EMBASE from their inceptions to June 24, 2016. Studies that reported clopidogrel-treated patients with stroke or TIA and with information on genetic polymorphisms were included. The end points were stroke, composite vascular events, and any bleeding. RESULTS: Among 15 studies of 4762 patients with stroke or TIA treated with clopidogrel, carriers of CYP2C19 loss-of-function alleles (*2, *3, and *8) were at increased risk of stroke in comparison with noncarriers (12.0% versus 5.8%; risk ratio, 1.92, 95% confidence interval, 1.57-2.35; P<0.001). Composite vascular events were also more frequent in carriers of CYP2C19 loss-of-function alleles than in noncarriers (13.7% versus 9.4%; risk ratio, 1.51, 95% confidence interval, 1.10-2.06; P=0.01), whereas bleeding rates were similar (2.4% versus 3.1%; risk ratio, 0.89, 95% confidence interval, 0.58-1.35; P=0.59). There was no evidence of statistical heterogeneity among the included studies for stroke, but there was for composite vascular events. Genetic variants other than CYP2C19 were not associated with clinical outcomes, with the exception that significant associations of PON1, P2Y12, and COX-1 with outcomes were observed in 1 study. CONCLUSIONS: Carriers of CYP2C19 loss-of-function alleles are at greater risk of stroke and composite vascular events than noncarriers among patients with ischemic stroke or TIA treated with clopidogrel.

Factors associated with favourable outcome in large hemispheric infarctions.

BACKGROUND: Large hemispheric infarction (LHI) is a devastating condition with high mortality and poor functional outcome in most conservatively treated patients. The purpose of this study was to explore factors associated with favorable outcome in patients with LHI. METHODS: We prospectively enrolled consecutive patients with LHI. Favorable outcome was defined as a modified Rankin Scale (mRS) score of 0 to 3 at 90 days. Multivariate logistic regression analysis was employed to identify the independent factors associated with favorable outcome. RESULTS: Two hundred fifty-six cases with LHI were identified: 41 (16.0%) died during hospitalization, 94 (36.7%) died at 3 month, and 113 (44.1%) survived with favorable outcome at day 90. Compared with patients with unfavorable outcome, the favorable cases were younger (55.8 ± 14.7 vs. 66.2 ± 14.1), had less history of hypertension (38.9% vs. 59.3%), lower baseline NIHSS score (median NIHSS score 11 vs. 17), lower blood pressure on admission (systolic 134.7 ± 24.9 vs. 145.1 ± 26.1 mmHg; diastolic 80.2 ± 14.9 vs. 86.9 ± 16.2 mmHg; respectively), lower level of baseline serum glucose (7.2 ± 3.3 vs. 8.2 ± 3.3 mmol/L), a lower frequency of stroke-related complications (55.8% vs. 91.4%), more use of antiplatelets (93.8% vs. 57.1%) and statins (46.9% vs. 25.7%) in the acute phase of stroke, but less use of osmotic agents (69.9% vs. 89.3%), mechanical ventilation (1.8% vs. 20.0%) or decompressive hemicraniectomy (1.8% vs. 15.7%). Multivariable analysis identified the following factors associated with favorable outcome: age (odds ratio, OR 0.95, 95% confidence interval [CI] 0.92-0.98, p < 0.001), baseline NIHSS score (OR 0.90, 95% CI 0.84-0.96, p = 0.002), statins used in acute phase (OR 2.49, 95% CI 1.10-5.65, p = 0.029), brain edema (OR 0.05, 95% CI 0.01-0.21, p < 0.001) and pneumonia (OR 0.42, 95% CI 0.19-0.93, p = 0.032). CONCLUSION: More than one third of patients with LHI have relatively favorable clinical outcomes at 90 days. Younger age, lower baseline NIHSS score, absence of brain edema and pneumonia, and statins used in the acute phase were associated with favorable outcome of patients with LHI at 90 days.

Dual therapy with clopidogrel and aspirin prevents early neurological deterioration in ischemic stroke patients carrying CYP2C19*2 reduced-function alleles.

PURPOSE: To investigate the associations between CYP2C19 genotypes and early neurological deterioration (END), and to carry out a stratified analysis of the effectiveness of clopidogrel alone and dual antiplatelet therapy with clopidogrel and aspirin for prevention of END according to CYP2C19 genotypes in ischemic stroke (IS) patients. METHODS: This was a prospective, observational, two-center study. A total of 375 acute IS patients were enrolled. Platelet aggregation was measured before and after the 7- to 10-day treatment. Clopidogrel resistance (CR) was assessed by adenosine diphosphate-induced platelet aggregation. CYP2C19*2 (rs4244285) and CYP2C19*3 (rs4986893) genotypes were examined using mass spectrometry. The primary outcome was END during the 10 days after admission. RESULTS: Among the 375 patients, 144 patients received clopidogrel alone, 231 patients took clopidogrel plus aspirin, 153 patients (40.8%) had CR, 95 patients (25.3%) experienced END. Patients carrying CYP2C19*2 AG/AA (CYP2C19*2 reduced-function alleles) and CR were associated with a higher risk for END, and dual antiplatelet therapy was associated with a lower risk for END. Stratified analyses revealed that there was no significant difference in the incidence of END between patients not carryingCYP2C19*2 reduced-function alleles who received clopidogrel plus aspirin and those who received clopidogrel alone. However, dual antiplatelet therapy was more effective at reducing END and inhibiting platelet aggregation than clopidogrel alone for carriers of at least one CYP2C19*2 reduced-function allele. CONCLUSIONS: The frequency of END was very high after acute IS in the Chinese population. Dual therapy with clopidogrel and aspirin may be adequate for patients carrying CYP2C19*2 reduced-function alleles. Genetic testing may be useful to guide personalized and precise antiplatelet therapy. CLINICAL TRIAL REGISTRATION INFORMATION: The study described here is registered at http://www.chictr.org / (unique Identifier: ChiCTR-OCH-14004724).

Interaction among COX-2, P2Y1 and GPIIIa gene variants is associated with aspirin resistance and early neurological deterioration in Chinese stroke patients.

BACKGROUND: The effect of genetic variants on aspirin resistance (AR) remains controversial. We sought to assess the association of genetic variants with AR and early clinical outcomes in patients with acute ischemic stroke (IS). METHODS: A total of 850 acute IS patients were consecutively enrolled. Platelet aggregation was measured before and after a 7-10 day aspirin treatment. The sequences of 14 variants of COX-1, COX-2, GPIb, GPIIIa, P2Y1 and P2Y12 were determined using matrix-assisted laser desorption/ionization time of flight mass spectrometry. Gene-gene interactions were analyzed using generalized multifactor dimensionality reduction (GMDR). The primary outcome was early neurological deterioration (END) within 10 days of admission. The secondary outcome was a composite of early recurrent ischemic stroke (ERIS), myocardial infarction (MI) and death within 10 days of admission. RESULTS: 175 (20.6%) patients were AR, 45 (5.3%) were aspirin semi-resistant, 121 (14.2%) developed END, 17 (0.2%) had ERIS, 2 (0.2%) died, and 6 (0.7%) had MI. Single locus analysis indicated that only rs1371097 was associated with AR. However, GMDR analysis indicated that the following three sets of gene-gene interactions were significantly associated with AR: rs20417CC/rs1371097TT/rs2317676GG; rs20417CC/rs1371097TT/rs2317676GG; rs20417CC/rs1371097CT/rs2317676AG. END occurred significantly more frequently in patients with AR or high-risk interactive genotypes. Moreover, AR and high-risk interactive genotypes were independently associated with END. CONCLUSION: Sensitivity of IS patients to aspirin and END may be multifactorial and is not significantly associated with a single gene polymorphism. Combinational analysis may useful for further insight into the genetic risks for AR.

Platelet receptor Gene (P2Y12, P2Y1) and platelet glycoprotein Gene (GPIIIa) polymorphisms are associated with antiplatelet drug responsiveness and clinical outcomes after acute minor ischemic stroke.

PURPOSE: Patients with minor ischemic stroke (MIS) are at high risk of recurrent ischemic stroke (RIS). The aim of this study was to evaluate the effects of platelet receptor gene (P2Y12, P2Y1) and glycoprotein gene (GPIIIa) polymorphisms, as well as their interactions, on antiplatelet drug responsiveness and clinical outcomes in patients with acute MIS. METHODS: We prospectively enrolled 426 patients with acute MIS who had been receiving combined aspirin and clopidogrel treatment for at least 3 months. Prevalence of seven variants in P2Y12, P2Y1, and GPIIIa genes were examined using mass spectrometry. Gene-gene interactions were evaluated using generalized multifactor dimensionality reduction (GMDR) analysis. Antiplatelet drug responsiveness was assessed by platelet aggregation assay. All patients were followed for 90 days. Primary outcomes were defined as a composite of RIS, myocardial infarction (MI), and death. RESULTS: The incidence of primary outcomes was 10.8% (46/426; 40 had RIS, 2 died, and 4 had MI) during the first 90 days after stroke. No significant differences were found regarding genotype frequencies of the seven variants between those with and without incidence of primary outcomes. However, we observed significant gene-gene interaction between rs16863323 and rs2317676 polymorphisms. The high-risk interactive genotypes were independently associated with poor antiplatelet drug responsiveness and increased risk of primary outcomes. CONCLUSION: Responsiveness to antiplatelet drugs and the risks for adverse clinical events in this MIS cohort appear to be multifactorial since the outcomes were not mediated by single gene polymorphisms.

CYP Genetic Variants, CYP Metabolite Levels, and Neurologic Deterioration in Acute Ischemic Stroke in Chinese Population.

BACKGROUND: The mechanisms of neurologic deterioration (ND) are not fully understood. The aim of the present study was to evaluate the relationship between CYP genetic variants and CYP metabolite levels with ND in acute ischemic stroke patients. METHODS: Eleven single nucleotide polymorphisms (SNPs) of seven CYP genes were genotyped in 396 patients with acute ischemic stroke. The CYP plasma metabolite levels (20-hydroxyeicosatetraenoic acid [HETE], total epoxyeicosatrienoic acids [EETs], and dihydroxyeicosatrienoic acids [DiHETEs]) were also assessed. The primary outcome was ND within 10 days on admission. ND was defined as an increase of two or more points in the National Institutes of Health Stroke Scale score. RESULTS: Among 396 patients, 101 patients (25.5%) experienced ND. The plasma levels of 20-HETE and DiHETEs were significantly higher and the EET levels were significantly lower in patients with ND compared to patients without ND. Univariate analyses revealed that old age, diabetes mellitus (DM), higher fasting glucose, and higher hemoglobin A1c (HbA1c) were associated with ND. CYP2C8 rs17110453 CC, EPHX2 rs751141 GG, and CYP4A11 rs9333025 GG were independently associated with ND after adjusting age, DM, fasting glucose, and HbA1c (odds ratio [OR]: 1.60, 95% confidence interval [CI]: 1.02-3.72; OR: 3.01, 95% CI: 1.29-7.13; OR: 2.75, 95% CI: 1.17-6.24, respectively). Also, these polymorphisms were associated with CYP metabolite levels in patients with ND. CONCLUSIONS: ND is fairly common in acute ischemic stroke. Specific CYP gene SNPs are associated with CYP plasma metabolite levels, which may explain their associations with ND. Further studies are needed to validate our findings.

Statin and Aspirin Pretreatment Are Associated with Lower Neurological Deterioration and Platelet Activity in Patients with Acute Ischemic Stroke.

BACKGROUND: Aspirin and statin are recommended for the treatment of acute ischemic stroke. However, whether aspirin and statin pretreatment is associated with clinical outcomes has not been well addressed. This study aimed to evaluate the effect of pre-existing statin and aspirin use on platelet activation and clinical outcome in acute ischemic stroke patients. METHODS: We conducted a prospective, multicenter observational study in patients with acute ischemic stroke. Platelet aggregation and platelet-leukocyte aggregates were measured on admission and during 7-10 days after admission. The primary outcome of the study was neurological deterioration (ND) within 10 days after admission. The secondary outcome was a composite of recurrent ischemic stroke, myocardial infarction, and death during the first 3 months after admission. Physical disability was evaluated using the modified Rankin Scale score at 3 months after admission. RESULTS: Among 1124 enrolled patients, 270 (24%) experienced ND. Higher platelet aggregation and platelet-leukocyte aggregates on admission and during 7-10 days were associated with ND. Platelet aggregation and platelet-leukocyte aggregates on admission were significantly lower in the patients with pre-existing statin or aspirin use than those without treatment. Patients with prestroke concomitant statin and aspirin treatment had significantly lower incidence of ND than those without treatment. Diabetes mellitus, fasting glucose, platelet-leukocyte aggregates, and prestroke concomitant statin and aspirin use were independently associated with ND. CONCLUSIONS: Prestroke concomitant statin and aspirin use is associated with lower neurological deterioration and platelet activity in patients with acute ischemic stroke.

Interactions among Variants in Eicosanoid Genes Increase Risk of Atherothrombotic Stroke in Chinese Populations.

BACKGROUND: Eicosanoids are lipid mediators that may play a role in ischemic stroke (IS). However, the association of variants in eicosanoid genes and these interactions with IS risk has not been investigated. The aim of the present study was to investigate the association of 11 variants in eicosanoid genes with IS and to determine whether these gene-gene interactions increase the risk of IS. METHODS: Eleven variants in prostaglandin H synthase-1 (PTGS1), PTGS2, thromboxane A2 synthase (TBXAS1), prostacyclin synthase (PTGIS), and prostaglandin E synthase (PTGES) genes were examined using mass spectrometry method in 297 patients with atherothrombotic stroke and 291 controls. Gene-gene interactions were analyzed using generalized multifactor dimensionality reduction (GMDR) method. Platelet aggregation and platelet-leukocyte aggregates were measured on admission. RESULTS: There were no significant differences in the genotype distributions of the 11 variants between patients and controls. However, GMDR analysis showed a significant gene-gene interaction among rs20417, rs5602, and rs41708, which scored 10 for cross-validation consistency and 9 for the sign test (P = .014). Logistic regression analysis showed that high-risk interaction among rs20417, rs5602, and rs41708 was an independent risk factor for atherothrombotic stroke (OR = 2.45, 95% CI: 1.33-3.27, P = .019). The high-risk interactive genotypes were associated with higher platelet aggregation and platelet-leukocyte aggregates. CONCLUSIONS: PTGS2 rs20417, PTGIS rs5602, and TBXAS1 rs41708 three-locus interactions may confer a higher risk for atherothrombotic stroke. The combinatorial analysis used in this study may be helpful to elucidate complex genetic risk for IS.

Variants in COX-2, PTGIS, and TBXAS1 Are Associated with Carotid Artery or Intracranial Arterial Stenosis and Neurologic Deterioration in Ischemic Stroke Patients.

BACKGROUND: Eicosanoids may play a role in ischemic stroke (IS). However, the association of variants in eicosanoid genes with symptomatic carotid artery or intracranial arterial stenosis and neurologic deterioration (ND) is not fully understood. The aim of the present study was to investigate the association of 11 variants in eicosanoid genes with symptomatic carotid artery or intracranial arterial stenosis and ND. METHODS: Eleven variants in eicosanoid genes were examined using mass spectrometry method in 297 IS patients. The symptomatic carotid artery or intracranial arterial stenosis was assessed by computed tomographic angiography. Platelet aggregation and platelet-leukocyte aggregates were measured. The primary outcome was ND within 10 days of admission. ND was defined as an increase of 2 or more points in National Institutes of Health Stroke Scale score. RESULTS: Among 297 IS patients, 182 (61.3%) cases had symptomatic carotid artery or intracranial arterial stenosis, and 88 (29.6%) patients experienced ND within 10 days after admission. Symptomatic carotid artery or intracranial arterial stenosis was significantly associated with higher ND (P < .001). Rs20417CC, rs41708TT, and rs5629CC were independent risk factors for symptomatic carotid artery or intracranial arterial stenosis and ND, and associated with higher platelet aggregation and platelet-leukocyte aggregates. CONCLUSIONS: Symptomatic carotid artery or intracranial arterial stenosis was associated with higher ND. Rs20417CC, rs41708TT, and rs5629CC were not only independent risk factors for symptomatic carotid artery or intracranial arterial stenosis, but also independent risk predictors for ND.

20-Hydroxyeicosatetraenoic Acid as a Predictor of Neurological Deterioration in Acute Minor Ischemic Stroke.

BACKGROUND AND PURPOSE: The relationship between high plasma 20-hydroxyeicosatetraenoic acid (20-HETE) levels and neurological deterioration (ND) has not been investigated in patients with acute minor ischemic stroke. METHOD: We conducted a prospective, multicenter observational study in patients with acute minor ischemic stroke. Plasma levels of 20-HETE were measured at admission in all patients. The primary end point of the study was ND within 10 days after admission. The degree of disability was assessed using modified Rankin scale at 3 months after admission. RESULTS: A total of 322 patients were enrolled, of which 85 patients (26.4%) developed ND. Mean 20-HETE level was 1687±158 pmol/L. On multivariate analyses, high level (>1675 pmol/L) of 20-HETE was an independent predictor of ND (third and fourth quartiles). Neurological deterioration was associated with a higher risk of poor outcome (modified Rankin scale scores 3-6) at 3 months. CONCLUSIONS: ND is fairly common in acute minor ischemic stroke and is associated with poor prognosis. Elevated plasma level of 20-HETE may be a predictor for ND in acute minor ischemic stroke.

Interaction between COX-1 and COX-2 Variants Associated with Aspirin Resistance in Chinese Stroke Patients.

BACKGROUND: There have been conflicting results for the association between cyclooxygenase (COX) genetic variants and aspirin resistance (AR). The aim of this study was to investigate the association of the COX genetic variants and interaction among these variants with AR in patients with acute ischemic stroke (IS). METHODS: We consecutively enrolled 850 acute IS patients. Platelet aggregation activity was measured before and after a 7- to 10-day aspirin treatment. The four variants from COX genes were examined using mass spectrometry. Gene-gene interactions were analyzed using generalized multifactor dimensionality reduction (GMDR) methods. RESULTS: Among the 850 acute IS patients, 175 (20.6%) patients had AR, 45 (5.3%) patients had aspirin semiresistance (ASR), and 630 (74.1%) patients had aspirin sensitivity (AS). The genotype distributions of the 4 variants did not differ significantly between the ASR + AR group and the AS group using the single-locus analytical approach. However, the GMDR analysis showed a significant gene-gene interaction between COX-1 (rs3842787) and COX-2 (rs20417), and scored 10/10 for cross-validation consistency and 9 for the sign test (P = .0127). Individual patients with the combination of rs3842787CT and rs20417CC or rs3842787CT and rs20417GC had a significantly higher risk of ASR + AR than those with rs3842787CC and rs20417GG. The high-risk interactions between rs3842787 and rs20417 were independent predictors of ASR + AR, and were associated with lower reduction of platelet aggregation activity. CONCLUSIONS: The interactions of rs3842787 and rs20417 were associated with AR. The combinational analysis used in this study may provide further insight into the complex genetic risk of AR.