Risk Of Incident Ischemic Stroke Research Articles

Correction to: Head Injury and Risk of Incident Ischemic Stroke in Community-Dwelling Adults.

Correction to: Head Injury and Risk of Incident Ischemic Stroke in Community-Dwelling Adults.

Association between physical activity changes and risk of incident ischemic stroke following cancer diagnosis: A nationwide retrospective cohort study.

Physical inactivity is prevalent after cancer treatment, which could increase ischemic stroke risk in cancer survivors. This study investigated the association between physical activity change from pre- to post-diagnosis and ischemic stroke risk among cancer survivors. Using data from the Korean National Health Insurance Service database, 269,943 cancer survivors (mean [SD] age, 56.3 [12.1] years; 45.7% male) with no history of cardiovascular disease were evaluated based on changes in physical activity from pre- to post-diagnosis. Using the Fine-Gray model, subdistribution hazard ratios (sHRs) and 95% confidence intervals (CIs) for ischemic stroke risk were calculated, considering death as a competing risk. After cancer diagnosis, 62.0% remained inactive, 10.1% remained active, 16.6% became active, and 11.4% became inactive. During a mean (SD) follow-up of 4.1 (2.0) years, being active both pre- and post-diagnosis was associated with a 15% decreased risk of ischemic stroke (sHR, 0.85; 95% CI, 0.75-0.96), compared with those who remained inactive. Cancer survivors who became active and inactive post-diagnosis showed a 16% and 11% lower ischemic stroke risk (sHR, 0.84; 95% CI, 0.75-0.93; sHR, 0.89; 95% CI, 0.79-0.99), respectively, than those who remained inactive. Analysis by the primary cancer site did not substantially differ from the main findings. Physical activity is associated with reduced ischemic stroke risk among cancer survivors. The potential benefits of physical activity are not limited to individuals who were physically active before cancer diagnosis, thus preventive strategies against ischemic stroke should emphasize physical activity throughout the cancer journey.

Head Injury and Risk of Incident Ischemic Stroke in Community-Dwelling Adults.

While stroke is a recognized short-term sequela of traumatic brain injury, evidence about long-term ischemic stroke risk after traumatic brain injury remains limited. The Atherosclerosis Risk in Communities Study is an ongoing prospective cohort comprised of US community-dwelling adults enrolled in 1987 to 1989 followed through 2019. Head injury was defined using self-report and hospital-based diagnostic codes and was analyzed as a time-varying exposure. Incident ischemic stroke events were physician-adjudicated. We used Cox regression adjusted for sociodemographic and cardiovascular risk factors to estimate the hazard of ischemic stroke as a function of head injury. Secondary analyses explored the number and severity of head injuries; the mechanism and severity of incident ischemic stroke; and heterogeneity within subgroups defined by race, sex, and age. Our analysis included 12 813 participants with no prior head injury or stroke. The median follow-up age was 27.1 years (25th-75th percentile=21.1-30.5). Participants were of median age 54 years (25th-75th percentile=49-59) at baseline; 57.7% were female and 27.8% were Black. There were 2158 (16.8%) participants with at least 1 head injury and 1141 (8.9%) participants with an incident ischemic stroke during follow-up. For those with head injuries, the median age to ischemic stroke was 7.5 years (25th-75th percentile=2.2-14.0). In adjusted models, head injury was associated with an increased hazard of incident ischemic stroke (hazard ratio [HR], 1.34 [95% CI, 1.12-1.60]). We observed evidence of dose-response for the number of head injuries (1: HR, 1.16 [95% CI, 0.97-1.40]; ≥2: HR, 1.94 [95% CI, 1.39-2.71]) but not for injury severity. We observed evidence of stronger associations between head injury and more severe stroke (National Institutes of Health Stroke Scale score ≤5: HR, 1.31 [95% CI, 1.04-1.64]; National Institutes of Health Stroke Scale score 6-10: HR, 1.64 [95% CI, 1.06-2.52]; National Institutes of Health Stroke Scale score ≥11: HR, 1.80 [95% CI, 1.18-2.76]). Results were similar across stroke mechanism and within strata of race, sex, and age. In this community-based cohort, head injury was associated with subsequent ischemic stroke. These results suggest the importance of public health interventions aimed at preventing head injuries and primary stroke prevention among individuals with prior traumatic brain injuries.

Contemporary trends in incident ischemic stroke, intracranial hemorrhage, and mortality in individuals with atrial fibrillation.

The prognosis for atrial fibrillation (AF) patients is based on data that is decades old. Given evolving standards of clinical practice, we sought to evaluate temporal trends in clinically important outcomes among patients with AF. California's Department of Health Care Access and Information databases were used to identify adults aged≥18 years with AF receiving hospital-based care in California. We compared 3 time-periods: 2005-2009, 2010-2014, and 2015-2019. ICD codes were used to identify chronic diseases and acute events. The outcomes were incident ischemic stroke, intracranial hemorrhage, and overall mortality. We included 2009832 patients with AF (52.7% males, 70.7% Whites, and mean age of 75.0 years), divided in 3 cohorts: 2005-2009 (n=738954), 2010-2014 (n=609447), and 2015-2019 (n=661431). Each outcome became substantially less common with time: compared to 2005-2009, AF patients diagnosed in 2015-2019 experienced a 34% (adjusted hazard ratio [HR] 0.66, 95% CI 0.64-0.69), 22% (HR 0.78, 0.75-0.82), and 24% (HR 0.76, 0.75-0.77) reduction in risk of incident ischemic stroke, intracranial hemorrhage, and mortality, respectively. Between 2005-2009 and 2015-2019, patients aged≥65 years experienced more reductions in each outcome compared to younger patients (p<0.001 for all), and declines in each outcome were significantly lower for Hispanics and Blacks compared to white patients. The risks of stroke, intracranial hemorrhage, and death have significantly declined among AF patients, although differences in the magnitude of improvement of these outcomes by demographic groups were observed. Commonly described estimates of the prognosis for AF patients should be updated to reflect contemporary care.

Abstract MP24: Contemporary Trends in Incident Ischemic Stroke, Intracranial Hemorrhage, and Mortality in Individuals With Atrial Fibrillation

Background: The prognosis for atrial fibrillation (AF) patients is based on data that is decades old. Given evolving standards of clinical practice that may now include lifestyle factor modification, catheter ablation, and DOACs, we evaluated temporal trends in clinically important outcomes among patients with AF. Methods: California’s Department of Health Care Access and Information databases were used to identify adults aged ≥18 years with AF receiving hospital-based care in California. We compared 3 time-periods in this population-based cohort corresponding to 2005-2009, 2010-2014, and 2015-2019. The outcomes were incident ischemic stroke, intracranial hemorrhage, and mortality. Results: We included 1,859,901 patients with AF (52.7% males, 71.0% Whites, and mean age of 74.8 years), divided in 3 cohorts: 2005-2009 (n=680,872), 2010-2014 (n=558,365), and 2015-2019 (n=620,664). Each of these outcomes became substantially less common with time: compared to 2005-2009 ( Figure 1A ), AF patients diagnosed in 2015-2019 experienced a 42% (adjusted hazard ratio [HR] 0.58, 95% CI 0.57-0.60), 17% (HR 0.83, 95% CI 0.80-0.88), and 28% (HR 0.72, 95% CI 0.71-0.73) reduction in risk of incident ischemic stroke, intracranial hemorrhage, and mortality, respectively. Between 2005-2009 and 2015-2019, the decline in the incidence rate of adverse outcomes was greater in patients aged ≥65 years (p&lt;.001), females (p=.02), and Whites (p&lt;.001) for ischemic stroke; more pronounced in patients aged ≥65 years (p=.008), females (p=.02), and Whites and Asians (p=.005) for intracranial hemorrhage; and greater in patients aged ≥65 years (p&lt;.001), in males (p=.04), and in Whites (p&lt;.001) for mortality ( Figure 1B ). Conclusion: The risk of stroke, intracranial hemorrhage, and mortality have significantly declined among AF patients, although significant disparities in the magnitude of improvement of these outcomes by demographic groups were observed. Estimates of the prognosis for AF patients should be updated to reflect contemporary care.

Abstract 47: Estimated Remnant Lipoprotein Particle Cholesterol, Very Low-Density Lipoprotein Cholesterol, and Incident Ischemic Stroke Risk - The Cardiovascular Health Study

Introduction: Serum remnant lipoprotein particle cholesterol (RLP-C), which includes very-low density lipoproteins (VLDL) and its lipolytic products, contributes to atherosclerotic plaque formation. Novel methods for estimating RLP-C and VLDL-cholesterol (VLDL-C) from a serum fasting lipid profile (FLP) have been proposed (Figure). 1,2,3 We evaluated the relationship of estimated serum RLP-C and VLDL-C with the risk of incident ischemic stroke (IS) in the Cardiovascular Health Study (CHS), a population-based longitudinal cohort of older adults. Methods: Eligible CHS participants were free of prevalent stroke and completed an FLP at the 1989-1990 or 1992-1993 baseline study visit. The relationships of a two-fold increase in RLP-C Varbo , RLP-C Sampson , and VLDL-C estimates with incident total IS were evaluated using Cox proportional hazards regression, adjusting for demographics and IS risk factors, including low-density and high-density lipoprotein cholesterol. Secondary analyses evaluated the relationship with incident cardioembolic IS, non-cardioembolic IS, and large artery atherosclerotic or lacunar IS. Results: Of 5,427 eligible participants, mean age was 72.8 (±5.6) years, 57.6% were women, and 15.7% were Black. Over a median follow-up of 12.4 years, 895 participants experienced an incident IS. RLP-C Varbo , RLP-C Sampson , and VLDL-C were each associated with incident total IS risk, non-cardioembolic IS risk, and large artery atherosclerotic or lacunar IS risk, after adjusting for confounders, but not with cardioembolic IS risk (Table). Conclusions: In older adults, RLP-C and VLDL-C are associated with IS risk, especially atherosclerotic IS.

Baseline Stroke Risk and Efficacy of Dual-Antiplatelet Therapy: A Post Hoc Analysis of the POINT Trial.

High-risk transient ischemic attacks and minor ischemic strokes are followed by a variable risk of ischemic stroke. We aimed to determine how baseline stroke risk modified the efficacy of clopidogrel-aspirin (referred to here as dual-antiplatelet therapy [DAPT]) for transient ischemic attack and minor ischemic stroke. We performed an unplanned secondary analysis of the POINT trial (Platelet-Oriented Inhibition in New Transient Ischemic Attack and Minor Ischemic Stroke). We first evaluated the associations of the CHA2DS2-VASc and stroke prognosis instrument II (SPI-II) scores with the risk of incident ischemic stroke and major hemorrhage (intracranial hemorrhage or major systemic hemorrhage). We then tested for heterogeneity of the relative and absolute treatment effect of DAPT relative to aspirin across low- and high-risk patient subgroups. A total of 4841 trial participants were included in this analysis, with 2400 participants assigned to treatment with short-term DAPT and 2430 participants to treatment with aspirin and placebo. The dichotomized SPI-II score, but not the CHA2DS2-VASc score (P=0.18), was associated with the risk of incident ischemic stroke. A high-risk SPI-II score (>3) was associated with greater risk of incident ischemic stroke (hazard ratio of incident ischemic stroke relative to low-risk SPI-II score of 1.84 [95% CI, 1.44-2.35]; P<0.001) and numerically greater risk of major hemorrhage though not meeting statistical significance (hazard ratio, 1.80 [95% CI, 0.90-3.57]; P=0.10). The relative risk reduction with DAPT was similar across SPI-II strata (Pinteraction=0.31). The absolute risk reduction for ischemic stroke with DAPT compared with aspirin was nearly 4-fold higher (2.80% versus 0.76%; number needed to treat, 31 versus 131) in the high-risk SPI-II stratum relative to the low-risk stratum. The absolute risk increase for major hemorrhage with DAPT compared with aspirin was 3-fold higher (0.84% versus 0.30%; number needed to harm, 119 versus 331) in the high-risk SPI-II stratum relative to the low-risk stratum. Stratification by baseline stroke risk identifies a patient subgroup that derives greater absolute benefit from treatment with DAPT. URL: https://www.clinicaltrials.gov; Unique identifier: NCT00991029.

Plasma levels of urea cycle related amino acids in association with risk of ischemic stroke: Findings from a nested case-control study

ObjectivesThe role of urea cycle related amino acids in the development of ischemic stroke (IS) remains unclear. The study aimed to evaluate the association of these amino acids with IS. Materials and MethodsWe conducted a case-control study nested within a cohort study in Changshu, Eastern China. A total of 321 cases and 321 controls matched by age and gender were finally included. Plasma levels of ornithine, arginine, spermidine, and proline were measured using ultra-high performance liquid chromatography–tandem mass-spectrometry (UHPLC–MS/MS). Odds ratios (ORs) and their 95 % confidence intervals (CIs) were calculated by conditional logistic regression analyses. ResultsPlasma ornithine was inversely associated with risk of IS [crude OR: 0.62 (95 % CI: 0.40-0.97)]. After adjustment for body mass index, smoking, hypertension, family history of stroke, estimated glomerular filtration rate, and total cholesterol, the corresponding ORs for the highest compared to the lowest quartiles was essentially unchanged [adjusted OR: 0.62 (95 % CI: 0.39-0.99)]. The risk association remained significant after repeating the analyses by excluding the first two years of follow-up. Plasma arginine, spermidine, and proline were not associated with the risk of IS. ConclusionWe observed that higher plasma levels of ornithine were associated with a lower risk of incident IS. Our novel findings suggest a protective role of ornithine in the pathogenesis of IS.

Abstract 13089: Plasma Proteomics and Risk of Incident Ischemic Stroke: Meta-Analysis of the Atherosclerosis Risk in Communities (ARIC) Study and the Cardiovascular Health Study (CHS)

Background: Proteomic profiling can screen large numbers of proteins to discover novel biomarkers related to ischemic stroke. However, prior studies have used a targeted approach or assessed a limited number of proteins (&lt;1300). Using data from the Atherosclerosis Risk in Communities (ARIC) study and the Cardiovascular Health Study (CHS), we examined the prospective association between 4954 plasma protein targets and incident ischemic stroke. Methods: Participants free of prevalent stroke at the time of proteomic profiling were included. Proteomics data were obtained from the 1990-92 exam in ARIC and the 1992-93 exam in CHS. Plasma proteins were quantified using the aptamer-based SOMAScan platform. Ischemic stroke events were ascertained and adjudicated through 2019 in ARIC and June 30, 2015 in CHS. Cox proportional hazards models adjusting for demographics, ischemic stroke risk factors, and estimated glomerular filtration rate were used. ARIC and CHS results were combined using fixed-effects meta-analysis. A Bonferroni-corrected p&lt;1.01e-5 was considered significant. Results: Median follow-up time in ARIC and CHS were 25 and 12 years, respectively. Among 10,856 ARIC participants (mean age 57 years, 56% female, 23% Black), 890 had an incident ischemic stroke. Among 3,283 CHS participants (mean age 74 years, 62% female, 18% Black), 507 had an incident ischemic stroke. In the meta-analysis, 44 proteins were significantly associated with incident ischemic stroke, of which 32 have not been previously reported ( Figure ). Of the 32, amyloid-like protein and kit ligand were the most strongly associated with ischemic stroke; each SD increment in log 2 (amyloid-like protein) and log 2 (kit ligand) were associated with 20% and 19% lower risk of ischemic stroke. Conclusion: In a meta-analysis of two community-based cohorts, we identified 32 novel protein associations with incident ischemic stroke. Further research is needed to determine causal associations.

Risk of ischemic stroke in patients recovered from COVID-19 infection: A systematic review and meta-analysis.

Data regarding the risk of ischemic stroke within 1 year after the post-acute phase of COVID-19 remain scant. We assess the risk of ischemic stroke in COVID-19 survivors after SARS-CoV-2 infection by performing a systematic review and meta-analysis of the available data. Following the PRISMA guidelines, we searched Medline and Scopus to locate all articles published up to February 11, 2023, reporting the risk of incident ischemic stroke in adult patients recovered from COVID-19 infection compared to non-infected patients (controls) defined as those who did not experience the infection over the same follow-up period. Ischemic stroke risk was evaluated using the Mantel-Haenszel random effects models with adjusted Hazard ratio (HR) as the effect measure with 95% confidence interval (CI) while heterogeneity was assessed using Higgins I2 statistic. Overall, 23,559,428 patients (mean age 56, 1 year, 54.3% males), of whom 1,595,984 had COVID-19, were included. Over a mean follow-up of 9.2 months, ischemic stroke occurred in 4.40 [95% CI: 4.36-4.43] out of 1000 patients survived to COVID-19 compared to 3.25 [95% CI:3.21-3.29] out of 1000 controls. Recovered COVID-19 patients presented a higher risk of ischemic stroke ((HR: 2.06, 95% CI: 1.75-2.41, p < 0.0001, I2 = 63.7%) compared to people who did not have COVID-19. COVID-19 patients hospitalized at the time of the infection have a subsequent higher risk of stroke during the follow-up compared to those non-hospitalized. Recovered COVID-19 patients have a higher risk of ischemic stroke compared to subjects from the general population within 9 months from the index infection.

Improved cardiorespiratory fitness is associated with lower incident ischemic stroke risk: Henry Ford FIT project

BackgroundChange in cardiorespiratory fitness (CRF) modulates vascular disease risk; however, it's unclear if this adds further prognostic information, particularly for ischemic stroke. The objective of this analysis is to describe the association between the change in CRF over time and subsequent incident ischemic stroke. MethodsThis is a retrospective, longitudinal, observational cohort study of 9,646 patients (age=55±11 years; 41% women; 25% black) who completed 2 clinically indicated exercise tests (> 12 months apart) and were free of any stroke at the time of test 2. CRF was expressed as metabolic-equivalents-of-task (METs). Incident ischemic stroke was identified using ICD codes. The adjusted hazard ratio (aHR) was determined for risk of ischemic stroke associated with change in CRF. ResultsMean time between tests was 3.7 years (IQR, 2.2, 6.0). During a median of 5.0 years (IQR, 2.7, 7.6 y) of follow-up, there were 873 (9.1%) ischemic stroke events. Each 1 MET increase between tests was associated with a 9% lower ischemic stroke risk (aHR 0.91 [0.88-0.94]; n = 9.646). There was an interaction effect by baseline CRF category, but not for sex or race. A sensitivity analysis which removed those who experienced an incident diagnosis known to be associated with an increased risk of ischemic vascular disease, validated our primary findings (aHR 0.91 [0.88, 0.95]; n= 6,943). ConclusionsImprovement in CRF over time is independently and inversely associated with a lower risk of ischemic stroke. Encouragement of regular exercise focused on improving CRF may reduce ischemic stroke risk.

Alpha globin gene copy number and incident ischemic stroke risk among Black Americans.

People with African ancestry have greater stroke risk and greater heritability of stroke risk than people of other ancestries. Given the importance of nitric oxide (NO) in stroke, and recent evidence that alpha globin restricts nitric oxide release from vascular endothelial cells, we hypothesized that alpha globin gene (HBA) deletion would be associated with reduced risk of incident ischemic stroke. We evaluated 8,947 participants self-reporting African ancestry in the national, prospective Reasons for Geographic And Racial Differences in Stroke (REGARDS) cohort. Incident ischemic stroke was defined as non-hemorrhagic stroke with focal neurological deficit lasting ≥ 24 hours confirmed by the medical record or focal or non-focal neurological deficit with positive imaging confirmed with medical records. Genomic DNA was analyzed using droplet digital PCR to determine HBA copy number. Multivariable Cox proportional hazards regression was used to estimate the hazard ratio (HR) of HBA copy number on time to first ischemic stroke. Four-hundred seventy-nine (5.3%) participants had an incident ischemic stroke over a median (IQR) of 11.0 (5.7, 14.0) years' follow-up. HBA copy number ranged from 2 to 6: 368 (4%) -α/-α, 2,480 (28%) -α/αα, 6,014 (67%) αα/αα, 83 (1%) ααα/αα and 2 (<1%) ααα/ααα. The adjusted HR of ischemic stroke with HBA copy number was 1.04; 95%CI 0.89, 1.21; p = 0.66. Although a reduction in HBA copy number is expected to increase endothelial nitric oxide signaling in the human vascular endothelium, HBA copy number was not associated with incident ischemic stroke in this large cohort of Black Americans.

Abstract 140: A Common, Racially Diverse Protease Activated Receptor 4 Functional Variant Impacts Ischemic Stroke Outcomes: Evidence For A Pharmacogenetic Effect

Black individuals have a higher incidence of ischemic stroke (IS) than White individuals. The platelet receptor PAR4 harbors a functional dimorphism: rs773902 A/G (encoding Thr120/Ala120, respectively), and the A allele is associated with greater ex vivo platelet aggregation. The A allele frequency is 0.6 in Black individuals and 0.2 in White subjects. However, it is unknown whether the A allele contributes to racial differences in IS. In a prospective cohort, the REGARDS study, a Black subject-only analysis of 487 IS cases and 7,133 controls was performed, examining if the A allele was a risk for incident IS and worse IS outcome. We used Cox proportional hazards models to calculate hazard ratios (HR) with 95% confidence intervals (CI) of incident IS for the rs773902 A allele. Models were adjusted for age, sex, the first 5 genetic principal components, smoking, hypertension and diabetes. To directly test the effect of this PAR4 variant on IS, we generated the first humanized PAR4 (hPAR4) mouse strains expressing either hPAR4 Thr120 or hPAR4 Ala120. In REGARDS, the A allele was a risk factor for incident IS (HR 1.24; CI 1.04-1.53, p=0.046) and worse IS outcome (HR 2.04; CI 1.10-3.79, p=0.025). In a murine stroke model, hPAR4 Thr120 mice had worse stroke outcomes compared to hPAR4 Ala120 mice (60% increase, p=0.001). This phenotype was mediated, in part, by enhanced platelet activation (p=0.002), platelet-neutrophil interactions (p=0.014), and neutrophil extracellular traps (p=0.001). Direct inhibition of PAR4 with BMS-986120 was equally effective in improving stroke outcomes in hPAR4 Ala120 and Thr120 mice. In contrast, ticagrelor treatment improved stroke outcomes in hPAR4 Ala120 mice (50% decrease, p=0.007), but was ineffective in hPAR4 Thr120 mice, even when combined with aspirin. Importantly, blocking platelet-neutrophil interactions downstream of PAR4 with a murine analog of the FDA-approved P-selectin inhibitor crizanlizumab improved stroke outcomes in hPAR4 Thr120 mice (55% decrease, p=0.004). These results support a causal role for PAR4 Thr120 in IS that may explain part of the racial disparity in stroke. Our findings further suggest that different anti-platelet therapies may be needed for patients expressing PAR4 Thr120.

Safety and effectiveness of anticoagulation with non-vitamin K antagonist oral anticoagulants and warfarin in patients on tuberculosis treatment

Anti-tuberculosis treatment can cause significant drug-drug interaction and interfere with effective anticoagulation. However, there is a lack of evidence and conflicting data on the optimal oral anticoagulation in patients treated for tuberculosis. We investigated the safety and effectiveness of anticoagulation with non-vitamin K antagonist oral anticoagulants (NOACs) and warfarin in patients on anti-tuberculosis treatment. Patients on concomitant oral anticoagulation and anti-tuberculosis treatment including rifampin were identified from the Korean nationwide healthcare database. Subjects were censored at discontinuation of either anticoagulation or rifampin. The outcomes of interest were major bleeding, death, and ischemic stroke. A total 2090 patients (1153 on warfarin, 937 on NOAC) were included. NOAC users, compared to warfarin users, were older, had a lower prevalence of hypertension, heart failure, ischemic stroke, and aspirin use and a higher prevalence of cancer, with no significant differences in CHA2DS2-VASc or HAS-BLED scores. There were 18 major bleeding events, 106 deaths, and 50 stroke events during a mean follow-up of 2.9 months. After multivariable adjustment, the use of NOAC was associated with a lower risk of incident ischemic stroke (HR 0.51, 95% CI 0.27–0.94), while there was no significant difference in risk for major bleeding or death compared with warfarin. These results suggest that NOACs have better effectiveness for stroke prevention and similar safety compared with warfarin in patients on concomitant anti-tuberculosis treatment. This is the first study assessing the safety and effectiveness of NOACs compared to warfarin in this clinical scenario.

Stroke incidence and cognitive outcomes of intracranial atherosclerotic stenosis: study protocol for a multicenter, prospective, observational cohort study.

BackgroundIntracranial atherosclerotic stenosis (ICAS) is one of the leading causes of stroke worldwide. Current diagnostic evaluations and treatments remain insufficient to assess the vulnerability of intracranial plaques and reduce the recurrence of stroke in symptomatic ICAS. On the other hand, asymptomatic ICAS is associated with an increased risk of cognitive impairment. The pathogenesis of ICAS related cognitive decline is largely unknown. The aim of SICO-ICAS study (stroke incidence and cognitive outcomes of ICAS) is to elucidate the pathophysiology of stroke and cognitive impairment in ICAS population, comprehensively evaluating the complex interactions among life-course exposure, genomic variation, vascular risk factors, cerebrovascular burden and coexisting neurodegeneration.MethodsSICO-ICAS is a multicenter, prospective, observational cohort study. We aim to recruit 3,000 patients with symptomatic or asymptomatic ICAS (>50% or occlusion) who will be followed up for ≥12 months. All participants will undergo pre-designed magnetic resonance imaging packages, blood biomarkers testing, as well as detailed cognitive domains assessment. All participants will undergo clinical visits every 6 months and telephone interviews every 3 months. The primary outcome measurement is ischemic stroke or cognitive impairment within 12 months after enrollment.DiscussionThis study will establish a large prospective ICAS cohort, hopefully discover new biomarkers associated with vulnerable intracranial plaques, identify subjects at high risk for incident ischemic stroke or cognitive impairment, and eventually propose a precise diagnostic and treatment strategy for ICAS population.Trial RegistrationChinese Clinical Trials Register ChiCTR2200061938.

Associations of plasma carnitine, lysine, trimethyllysine and glycine with incident ischemic stroke: Findings from a nested case-control study

Carnitine biosynthesis has been related to fatty acid oxidation, a process probably exerting neuroprotective effects. However, the role of carnitine biosynthesis in the development of ischemic stroke (IS) remains unclear. We aimed to examine the associations between plasma markers of carnitine biosynthesis and the IS risk. We performed a case-control study nested in a community-based cohort (2013-2018, n=16457). The study included 321 incident cases of IS and 321 controls matched by age and gender. Carnitine, lysine, trimethyllysine (TML), glycine, and their ratios were measured/calculated in the baseline plasma samples using ultra-high performance liquid chromatography-tandem mass-spectrometry (UHPLC-MS/MS). Conditional logistic regression analyses were used to calculate odds ratios (ORs) and their 95% confidence intervals (CIs). Plasma carnitine, lysine, TML, and glycine were not significantly associated with the IS risk, although a gradually reduced risk was observed across the increasing tertiles of glycine. Notably, the ratios of glycine/carnitine, glycine/lysine, and glycine/TML were all inversely associated with the IS risk. Compared to the lowest tertiles, the corresponding odds ratios for the highest tertiles were 0.60 (95% CI: 0.40-0.91), 0.63 (95% CI: 0.42-0.94), and 0.63 (95% CI: 0.42-0.95), respectively, after adjustment for body mass index, smoking, hypertension, family history of stroke, estimated glomerular filtration rate and total cholesterol. Repeating the analyses by excluding the first two years of follow-up did not materially alter the risk associations for the ratios of glycine/lysine and glycine/carnitine. Increased ratios of plasma glycine to carnitine, lysine, and TML were associated with a lower risk of incident IS. Our observational findings suggest that the homeostasis of circulating carnitine, lysine, TML, and glycine may involve in the pathogenesis of IS.

Circulating Interleukin-6 Levels and Incident Ischemic Stroke: A Systematic Review and Meta-analysis of Prospective Studies.

Human genetic studies support a key role of interleukin-6 (IL-6) in the pathogenesis of ischemic stroke. However, there are only limited data from observational studies exploring circulating IL-6 levels as a risk factor for ischemic stroke. We set out to perform a systematic review and meta-analysis of aggregate data on cohort studies to determine the magnitude and shape of the association between circulating IL-6 levels and risk of incident ischemic stroke in the general population. Following the PRISMA guidelines, we systematically screened the PubMed search engine from inception to March 2021 for population-based prospective cohort studies exploring the association between circulating IL-6 levels and risk of incident ischemic stroke. We pooled association estimates for ischemic stroke risk with random-effects models and explored nonlinear effects in dose-response meta-analyses. Risk of bias was assessed with the Newcastle-Ottawa Scale (NOS). We used funnel plots and trim-to-fill analyses to assess publication bias. We identified 11 studies (n = 27,411 individuals; 2,669 stroke events) meeting our eligibility criteria. Mean age of all included participants was 60.5 years and 54.8% were female. Overall, quality of the included studies was high (median 8 out of 9 NOS points, interquartile range 7-9). In meta-analyses, 1 SD increment in circulating log-transformed IL-6 levels was associated with a 19% increase in risk of incident ischemic stroke over a mean follow-up of 12.4 years (relative risk 1.19; 95% confidence interval 1.10 to 1.28). A dose-response meta-analysis showed a linear association between circulating IL-6 levels and ischemic stroke risk. There was only moderate heterogeneity and the results were consistent in sensitivity analyses restricted to studies of low risk of bias and studies fully adjusting for demographic and vascular risk factors. The results also remained stable following adjustment for publication bias. Higher circulating IL-6 levels in community-dwelling individuals are associated with higher long-term risk of incident ischemic stroke in a linear pattern and independently of conventional vascular risk factors. Along with findings from genetic studies and clinical trials, these results provide additional support for a key role of IL-6 signaling in ischemic stroke.

Metabolomic Profiles Associated With Incident Ischemic Stroke.

Women have higher lifetime risk of stroke than men, and metabolic factors seem more strongly associated with stroke for women than men. However, few studies in either men or women have evaluated metabolomic profiles and incident stroke. We applied liquid chromatography-tandem mass spectrometry to measure 519 plasma metabolites in a discovery set of women in the Nurses' Health Study (NHS; 454 incident ischemic stroke cases, 454 controls) with validation in 2 independent, prospective cohorts: Prevención con Dieta Mediterránea (PREDIMED; 118 stroke cases, 791 controls) and Nurses' Health Study 2 (NHS2; 49 ischemic stroke cases, 49 controls). We applied logistic regression models with stroke as the outcome to adjust for multiple risk factors; the false discovery rate was controlled through the q value method. Twenty-three metabolites were significantly associated with incident stroke in NHS after adjustment for traditional risk factors (q < 0.05). Of these, 14 metabolites were available in PREDIMED and 3 were significantly associated with incident stroke: methionine sulfoxide, N6-acetyllysine, and sucrose (q < 0.05). In NHS2, one of the 23 metabolites (glucuronate) was significantly associated with incident stroke (q < 0.05). For all 4 metabolites, higher levels were associated with increased risk. These 4 metabolites were used to create a stroke metabolite score (SMS) in the NHS and tested in PREDIMED. Per unit of standard deviation of SMS, the odds ratio for incident stroke was 4.12 (95% confidence interval [CI] 2.26-7.51) in PREDIMED, after adjustment for risk factors. In PREDIMED, the area under the receiver operating characteristic curve (AUC) for the model including SMS and traditional risk factors was 0.70 (95% CI 0.75-0.79) vs the AUC for the model including the traditional risk factors only of 0.65 (95% CI 0.70-0.75), corresponding to a 5% improvement in risk prediction with SMS (p < 0.005). Metabolites associated with stroke included 2 amino acids, a carboxylic acid, and sucrose. A composite SMS including these metabolites was associated with ischemic stroke and showed improvement in risk prediction beyond traditional risk factors. This study provides Class II evidence that a SMS accurately predicts incident ischemic stroke risk.

Clonal Hematopoiesis Is Associated With Higher Risk of Stroke.

Clonal hematopoiesis of indeterminate potential (CHIP) is a novel age-related risk factor for cardiovascular disease-related morbidity and mortality. The association of CHIP with risk of incident ischemic stroke was reported previously in an exploratory analysis including a small number of incident stroke cases without replication and lack of stroke subphenotyping. The purpose of this study was to discover whether CHIP is a risk factor for ischemic or hemorrhagic stroke. We utilized plasma genome sequence data of blood DNA to identify CHIP in 78 752 individuals from 8 prospective cohorts and biobanks. We then assessed the association of CHIP and commonly mutated individual CHIP driver genes (DNMT3A, TET2, and ASXL1) with any stroke, ischemic stroke, and hemorrhagic stroke. CHIP was associated with an increased risk of total stroke (hazard ratio, 1.14 [95% CI, 1.03-1.27]; P=0.01) after adjustment for age, sex, and race. We observed associations with CHIP with risk of hemorrhagic stroke (hazard ratio, 1.24 [95% CI, 1.01-1.51]; P=0.04) and with small vessel ischemic stroke subtypes. In gene-specific association results, TET2 showed the strongest association with total stroke and ischemic stroke, whereas DMNT3A and TET2 were each associated with increased risk of hemorrhagic stroke. CHIP is associated with an increased risk of stroke, particularly with hemorrhagic and small vessel ischemic stroke. Future studies clarifying the relationship between CHIP and subtypes of stroke are needed.

Associations of coagulation factor X and XI with incident acute coronary syndrome and stroke: A nested case‐control study

BackgroundCoagulation cascade contributes to thrombotic and hemorrhagic diseases, but it remains unclear whether coagulation factors X (FX) and XI (FXI) levels are associated with cardiovascular diseases. ObjectiveTo evaluate prospective associations of FX and FXI levels with incident acute coronary syndrome (ACS), stroke, and their subtypes (acute myocardial infarction, unstable angina, ischemic stroke, and hemorrhagic stroke). MethodsWe performed a nested case‐control study (n = 1846) within the Dongfeng‐Tongji cohort from 2013 to 2016 matched on age (within 1 year), sex, and sampling date (within 1 month) by incidence density sampling, and measured plasma FX and FXI levels by enzyme‐linked immunosorbent assay. FX and FXI levels were categorized into three groups (low, <25th; middle, 25th to <75th; and high ≥75th percentiles) according to distributions, and conditional logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). ResultsAfter adjustment for traditional cardiovascular risk factors, compared with middle groups, the OR (95% CI) in high levels of FX and FXI were 1.11 (0.79–1.56) and 0.96 (0.68–1.36) for incident ACS, and 1.01 (0.63–1.62) and 1.72 (1.14–2.60) for incident stroke, respectively. As for subtypes of ACS and stroke, only high FXI levels were significantly associated with incident ischemic stroke (OR 1.66, 95% CI 1.05–2.65). Moreover, all associations remained steady after additional adjustment for platelet and leukocyte. ConclusionFXI levels were associated with a greater risk of incident ischemic stroke but not hemorrhagic stroke or ACS. FX levels were not associated with incident ACS or stroke.