Proteogenomic Data Integration Reveals CXCL10 as a Potentially Downstream Causal Mediator for IL-6 Signaling on Atherosclerosis.

BACKGROUND: Genetic and experimental studies support a causal involvement of IL-6 (interleukin-6) signaling in atheroprogression. Although trials targeting IL-6 signaling are underway, any benefits must be balanced against an impaired host immune response. Dissecting the mechanisms that mediate the effects of IL-6 signaling on atherosclerosis could offer insights about novel drug targets with more specific effects. METHODS: Leveraging data from 522 681 individuals, we constructed a genetic instrument of 26 variants in the gene encoding the IL-6R (IL-6 receptor) that proxied for pharmacological IL-6R inhibition. Using Mendelian randomization, we assessed its effects on 3281 plasma proteins quantified with an aptamer-based assay in the INTERVAL cohort (n=3301). Using mediation Mendelian randomization, we explored proteomic mediators of the effects of genetically proxied IL-6 signaling on coronary artery disease, large artery atherosclerotic stroke, and peripheral artery disease. For significant mediators, we tested associations of their circulating levels with incident cardiovascular events in a population-based study (n=1704) and explored the histological, transcriptomic, and cellular phenotypes correlated with their expression levels in samples from human atherosclerotic lesions. RESULTS: We found significant effects of genetically proxied IL-6 signaling on 70 circulating proteins involved in cytokine production/regulation and immune cell recruitment/differentiation, which correlated with the proteomic effects of pharmacological IL-6R inhibition in a clinical trial. Among the 70 significant proteins, genetically proxied circulating levels of CXCL10 (C-X-C motif chemokine ligand 10) were associated with risk of coronary artery disease, large artery atherosclerotic stroke, and peripheral artery disease, with up to 67% of the effects of genetically downregulated IL-6 signaling on these end points mediated by decreases in CXCL10. Higher midlife circulating CXCL10 levels were associated with a larger number of cardiovascular events over 20 years, whereas higher CXCL10 expression in human atherosclerotic lesions correlated with a larger lipid core and a transcriptomic profile reflecting immune cell infiltration, adaptive immune system activation, and cytokine signaling. CONCLUSIONS: Integrating multiomics data, we found a proteomic signature of IL-6 signaling activation and mediators of its effects on cardiovascular disease. Our analyses suggest the interferon-γ-inducible chemokine CXCL10 to be a potentially causal mediator for atherosclerosis in 3 vascular compartments and, as such, could serve as a promising drug target for atheroprotection.

Deep Resequencing of the 1q22 Locus in Non-Lobar Intracerebral Hemorrhage.

OBJECTIVE: Genome-wide association studies have identified 1q22 as a susceptibility locus for cerebral small vessel diseases, including non-lobar intracerebral hemorrhage (ICH) and lacunar stroke. In the present study, we performed targeted high-depth sequencing of 1q22 in ICH cases and controls to further characterize this locus and prioritize potential causal mechanisms, which remain unknown. METHODS: A total of 95,000 base pairs spanning 1q22, including SEMA4A, SLC25A44, and PMF1/PMF1-BGLAP were sequenced in 1,055 spontaneous ICH cases (534 lobar and 521 non-lobar) and 1,078 controls. Firth regression and Rare Variant Influential Filtering Tool analysis were used to analyze common and rare variants, respectively. Chromatin interaction analyses were performed using Hi-C, chromatin immunoprecipitation followed by sequencing, and chromatin interaction analysis with paired-end tag databases. Multivariable Mendelian randomization assessed whether alterations in gene-specific expression relative to regionally co-expressed genes at 1q22 could be causally related to ICH risk. RESULTS: Common and rare variant analyses prioritized variants in SEMA4A 5'-UTR and PMF1 intronic regions, overlapping with active promoter and enhancer regions based on ENCODE annotation. Hi-C data analysis determined that 1q22 is spatially organized in a single chromatin loop, and that the genes therein belong to the same topologically associating domain. Chromatin immunoprecipitation followed by sequencing and chromatin interaction analysis with paired-end tag data analysis highlighted the presence of long-range interactions between the SEMA4A-promoter and PMF1-enhancer regions prioritized by association testing. Multivariable Mendelian randomization analyses demonstrated that PMF1 overexpression could be causally related to non-lobar ICH risk. INTERPRETATION: Altered promoter-enhancer interactions leading to PMF1 overexpression, potentially dysregulating polyamine catabolism, could explain demonstrated associations with non-lobar ICH risk at 1q22, offering a potential new target for prevention of ICH and cerebral small vessel disease. ANN NEUROL 2024;95:325-337.

Age- and Sex-Specific Analysis of Stroke Hospitalization Rates, Risk Factors, and Outcomes From German Nationwide Data.

BACKGROUND: Significant age and sex differences have been reported at each stage of the stroke pathway, from risk factors to outcomes. However, there is some uncertainty in previous studies with regard to the role of potential confounders and selection bias. Therefore, using German nationwide administrative data, we aimed to determine the magnitude and direction of trends in age- or sex-specific differences with respect to admission rates, risk factors, and acute treatments of ischemic and hemorrhagic stroke. METHODS: We obtained and analyzed data from the Research Data Centres of the Federal Statistical Office for the years 2010 to 2020 with regard to all acute stroke hospitalizations, risk factors, treatments, and in-hospital mortality, stratified by sex and stroke subtype. This database provides a complete national-level census of stroke hospitalizations combined with population census counts. All hospitalized patients ≥15 years with an acute stroke (diagnosis code: I60-64) were included in the analysis. RESULTS: Over the 11-year study period, there were 3 375 157 stroke events; 51.2% (n=1 728 954) occurred in men. There were higher rates of stroke admissions in men compared with women for both ischemic (378.1 versus 346.7/100 000 population) and hemorrhagic subtypes (75.6 versus 65.5/100 000 population) across all age groups. The incidence of ischemic stroke admissions peaked in 2016 among women (354.0/100 000 population) and in 2017 among men (395.8/100 000 population), followed by a consistent decline from 2018 onward. There was a recent decline in hemorrhagic stroke admissions observed for both sexes, reaching its nadir in 2020 (68.9/100 000 for men; 59.5/100 000 for women). Female sex was associated with in-hospital mortality for both ischemic (adjusted odds ratio, 1.11 [1.09-1.12]; P<0.001) and hemorrhagic stroke (adjusted odds ratio, 1.18 [95% CI, 1.16-1.20]; P<0.001). CONCLUSIONS: Despite improvements in stroke prevention and treatment pathways in the past decade, sex-specific differences remain with regard to hospitalization rates, risk factors, and mortality. Better understanding the mechanisms for these differences may allow us to develop a sex-stratified approach to stroke care.

Long-Term Outcomes in Patients With Spontaneous Cerebellar Hemorrhage: An International Cohort Study.

BACKGROUND: Spontaneous intracerebral hemorrhage (ICH) in the cerebellum has a poor short-term prognosis, whereas data on the long-term case fatality and recurrent vascular events are sparse. Herewith, we aimed to assess the long-term case fatality and recurrence rate of vascular events after a first cerebellar ICH. METHODS: In this international cohort study, we included patients from 10 hospitals (the United States and Europe from 1997 to 2017) aged ≥18 years with a first spontaneous cerebellar ICH who were discharged alive. Data on long-term case fatality and recurrence of vascular events (recurrent ICH [supratentoria or infratentorial], ischemic stroke, myocardial infarction, or major vascular surgery) were collected for survival analysis and absolute event rate calculation. RESULTS: We included 405 patients with cerebellar ICH (mean age [SD], 72 [13] years, 49% female). The median survival time was 67 months (interquartile range, 23-100 months), with a cumulative survival rate of 34% at 10-year follow-up (median follow-up time per center ranged: 15-80 months). In the 347 patients with data on vascular events 92 events occurred in 78 patients, after initial cerebellar ICH: 31 (8.9%) patients had a recurrent ICH (absolute event rate, 1.8 per 100 patient-years [95% CI, 1.2-2.6]), 39 (11%) had an ischemic stroke (absolute event rate, 2.3 [95% CI, 1.6-3.2]), 13 (3.7%) had a myocardial infarction (absolute event rate, 0.8 [95% CI, 0.4-1.3]), and 5 (1.4%) underwent major vascular surgery (absolute event rate, 0.3 [95% CI, 0.1-0.7]). The median time to a first vascular event during follow-up was 27 months (interquartile range, 8.7-50 months), with a cumulative hazard of 47% at 10 years. CONCLUSIONS: The long-term prognosis of patients who survive a first spontaneous cerebellar ICH is poor and comparable to that of patients who survive a first supratentorial ICH. Further identification of patients at high risk of vascular events following the initial cerebellar ICH is needed. Including patients with cerebellar ICH in randomized controlled trials on secondary prevention of patients with ICH is warranted.

Fibrinolytic Agents in Thromboembolic Diseases: Historical Perspectives and Approved Indications.

Fibrinolytic agents catalyze the conversion of the inactive proenzyme plasminogen into the active protease plasmin, degrading fibrin within the thrombus and recanalizing occluded vessels. The history of these medications dates to the discovery of the first fibrinolytic compound, streptokinase, from bacterial cultures in 1933. Over time, researchers identified two other plasminogen activators in human samples, namely urokinase and tissue plasminogen activator (tPA). Subsequently, tPA was cloned using recombinant DNA methods to produce alteplase. Several additional derivatives of tPA, such as tenecteplase and reteplase, were developed to extend the plasma half-life of tPA. Over the past decades, fibrinolytic medications have been widely used to manage patients with venous and arterial thromboembolic events. Currently, alteplase is approved by the U.S. Food and Drug Administration (FDA) for use in patients with pulmonary embolism with hemodynamic compromise, ST-segment elevation myocardial infarction (STEMI), acute ischemic stroke, and central venous access device occlusion. Reteplase and tenecteplase have also received FDA approval for treating patients with STEMI. This review provides an overview of the historical background related to fibrinolytic agents and briefly summarizes their approved indications across various thromboembolic diseases.

Impaired kidney function, cerebral small vessel disease and cognitive disorders: the Framingham Heart Study.

BACKGROUND AND HYPOTHESIS: It remains unclear whether the relation of chronic kidney disease (CKD) with cognitive dysfunction is independent of blood pressure (BP). We evaluated kidney function in relation to premorbid BP measurements, cerebral small vessel disease (CSVD), and incident mild cognitive impairment (MCI) and dementia in Framingham Offspring Cohort participants. METHODS: We included Framingham Offspring participants free of dementia, attending an examination during midlife (exam cycle 6, baseline) for ascertainment of kidney function status, with brain magnetic resonance imaging late in life (exam cycles 7-9), cognitive outcome data, and available interim hypertension and BP assessments. We related CKD (estimated glomerular filtration rate <60 ml/min/1.73 m2) and albuminuria (urine albumin-to-creatinine ratio ≥30 mg/g) to CSVD markers and cognitive outcomes using multivariable regression analyses. RESULTS: Among 2604 participants (mean age 67.4 ± 9.2, 64% women, 7% had CKD, and 9% albuminuria), albuminuria was independently associated with covert infarcts [adjusted OR, 1.55 (1.00-2.38); P = 0.049] and incident MCI and dementia [adjusted hazard ratio (HR), 1.68 (1.18-2.41); P = 0.005 and 1.71, (1.11-2.64); P = 0.015, respectively]. CKD was not associated with CSVD markers but was associated with a higher risk of incident dementia [HR, 1.53 (1.02-2.29); P = 0.041]. While albuminuria was predictive of the Alzheimer's disease subtype [adjusted HR = 1.68, (1.03-2.74); P = 0.04), CKD was predictive of vascular dementia [adjusted HR, 2.78 (1.16-6.68); P = 0.023]. CONCLUSIONS: Kidney disease was associated with CSVD and cognitive disorders in asymptomatic community dwelling participants. The relation was independent of premorbid BP, suggesting that the link between kidney and brain disease may involve additional mechanisms beyond BP-related injury.

Hypertension control after intracerebral hemorrhage among varying small vessel disease etiologies.

INTRODUCTION: Intracerebral hemorrhage (ICH) is attributable to cerebral small vessel disease (cSVD), which includes cerebral amyloid angiopathy (CAA) and hypertensive-cSVD (HTN-cSVD). HTN-cSVD includes patients with strictly deep ICH/microbleeds and mixed location ICH/microbleeds, the latter representing a more severe form of HTN-cSVD. We test the hypothesis that more severe forms of HTN-cSVD are related to worse hypertension control in long-term follow-up after ICH. METHODS: From consecutive non-traumatic ICH patients admitted to a tertiary care center, we classified the ICH as CAA, strictly deep ICH/microbleeds, and mixed-location ICH/microbleeds. CSVD burden was quantified using a validated MRI-based score (range: 0-6 points). We created a multivariable (linear mixed effects) model adjusting for age, sex, race, year of inclusion, hypertension, and antihypertensive medication usage to investigate the association of average systolic blood pressure (SBP) during follow-up with cSVD etiology/severity. RESULTS: 796 ICH survivors were followed for a median of 48.8 months (IQR 41.5-60.4). CAA-related ICH survivors (n = 373) displayed a lower median SBP (138 mmHg, IQR 133-142 mmHg) compared to those of strictly deep ICH (n = 222, 141 mmHg, IQR 136-143 mmHg, p = 0.04), and mixed location ICH/microbleeds (n = 201, 142 mmHg, IQR 135-144 mmHg, p = 0.02). In the multivariable analysis, mixed location ICH/microbleeds (effect: + 3.8 mmHg, SE: 1.3 mmHg, p = 0.01) and increasing cSVD severity (+ 1.8 mmHg per score point, SE: 0.8 mmHg, p = 0.03) were associated with higher SBP in follow-up. CONCLUSION: CSVD severity and subtype predicts long-term hypertension control in ICH patients.

ECG-Based Deep Learning and Clinical Risk Factors to Predict Atrial Fibrillation.

BACKGROUND: Artificial intelligence (AI)-enabled analysis of 12-lead ECGs may facilitate efficient estimation of incident atrial fibrillation (AF) risk. However, it remains unclear whether AI provides meaningful and generalizable improvement in predictive accuracy beyond clinical risk factors for AF. METHODS: We trained a convolutional neural network (ECG-AI) to infer 5-year incident AF risk using 12-lead ECGs in patients receiving longitudinal primary care at Massachusetts General Hospital (MGH). We then fit 3 Cox proportional hazards models, composed of ECG-AI 5-year AF probability, CHARGE-AF clinical risk score (Cohorts for Heart and Aging in Genomic Epidemiology-Atrial Fibrillation), and terms for both ECG-AI and CHARGE-AF (CH-AI), respectively. We assessed model performance by calculating discrimination (area under the receiver operating characteristic curve) and calibration in an internal test set and 2 external test sets (Brigham and Women's Hospital [BWH] and UK Biobank). Models were recalibrated to estimate 2-year AF risk in the UK Biobank given limited available follow-up. We used saliency mapping to identify ECG features most influential on ECG-AI risk predictions and assessed correlation between ECG-AI and CHARGE-AF linear predictors. RESULTS: The training set comprised 45 770 individuals (age 55±17 years, 53% women, 2171 AF events) and the test sets comprised 83 162 individuals (age 59±13 years, 56% women, 2424 AF events). Area under the receiver operating characteristic curve was comparable using CHARGE-AF (MGH, 0.802 [95% CI, 0.767-0.836]; BWH, 0.752 [95% CI, 0.741-0.763]; UK Biobank, 0.732 [95% CI, 0.704-0.759]) and ECG-AI (MGH, 0.823 [95% CI, 0.790-0.856]; BWH, 0.747 [95% CI, 0.736-0.759]; UK Biobank, 0.705 [95% CI, 0.673-0.737]). Area under the receiver operating characteristic curve was highest using CH-AI (MGH, 0.838 [95% CI, 0.807 to 0.869]; BWH, 0.777 [95% CI, 0.766 to 0.788]; UK Biobank, 0.746 [95% CI, 0.716 to 0.776]). Calibration error was low using ECG-AI (MGH, 0.0212; BWH, 0.0129; UK Biobank, 0.0035) and CH-AI (MGH, 0.012; BWH, 0.0108; UK Biobank, 0.0001). In saliency analyses, the ECG P-wave had the greatest influence on AI model predictions. ECG-AI and CHARGE-AF linear predictors were correlated (Pearson r: MGH, 0.61; BWH, 0.66; UK Biobank, 0.41). CONCLUSIONS: AI-based analysis of 12-lead ECGs has similar predictive usefulness to a clinical risk factor model for incident AF and the approaches are complementary. ECG-AI may enable efficient quantification of future AF risk.

Genetically Proxied CRP (C-Reactive Protein) Levels and Lobar Intracerebral Hemorrhage Risk.

BACKGROUND: Recent evidence suggests that higher CRP (C-reactive protein) levels are associated with lower risk of Alzheimer disease, speculating that CRP might be involved in Aß clearance mechanisms. Testing this hypothesis, we explored whether genetically proxied CRP levels are also associated with lobar intracerebral hemorrhage (ICH), commonly caused by cerebral amyloid angiopathy. METHODS: We used 4 genetic variants within the CRP gene that explain up to 64% of the variance of circulating CRP levels and explored in 2-sample Mendelian randomization analyses associations with risk of any, lobar, and deep ICH (1545 cases and 1481 controls). RESULTS: Higher genetically proxied CRP levels were associated with lower odds of lobar ICH (odds ratio per SD increment in CRP, 0.45 [95% CI, 0.25-0.73]) but not deep ICH (odds ratio, 0.72 [95% CI, 0.45-1.14]). There was evidence of colocalization (posterior probability of association, 72.4%) in the signals for CRP and lobar ICH. CONCLUSIONS: Our results provide supportive evidence that high CRP levels may have a protective role in amyloid-related pathology.

Genetic Risk Score Improves Risk Stratification for Anticoagulation-Related Intracerebral Hemorrhage.

BACKGROUND: Intracerebral hemorrhage (ICH) is the most devastating adverse outcome for patients on anticoagulants. Clinical risk scores that quantify bleeding risk can guide decision-making in situations when indication or duration for anticoagulation is uncertain. We investigated whether integration of a genetic risk score into an existing risk factor-based CRS could improve risk stratification for anticoagulation-related ICH. METHODS: We constructed 153 genetic risk scores from genome-wide association data of 1545 ICH cases and 1481 controls and validated them in 431 ICH cases and 431 matched controls from the population-based UK Biobank. The score that explained the largest variance in ICH risk was selected and tested for prediction of incident ICH in an independent cohort of 5530 anticoagulant users. A CRS for major anticoagulation-related hemorrhage, based on 8/9 components of the HAS-BLED score, was compared with a combined clinical and genetic risk score incorporating an additional point for high genetic risk for ICH. RESULTS: Among anticoagulated individuals, 94 ICH occurred over a mean follow-up of 11.9 years. Compared with the lowest genetic risk score tertile, being in the highest tertile was associated with a two-fold increased risk for incident ICH (hazard ratio, 2.08 [95% CI, 1.22-3.56]). Although the CRS predicted incident ICH with a hazard ratio of 1.24 per 1-point increase (95% CI [1.01-1.53]), adding a point for high genetic ICH risk led to a stronger association (hazard ratio of 1.33 per 1-point increase [95% CI, 1.11-1.59]) with improved risk stratification (C index 0.57 versus 0.53) and maintained calibration (integrated calibration index 0.001 for both). The new clinical and genetic risk score showed 19% improvement in high-risk classification among individuals with ICH and a net reclassification improvement of 0.10. CONCLUSIONS: Among anticoagulant users, a prediction score incorporating genomic information is superior to a clinical risk score alone for ICH risk stratification and could serve in clinical decision-making.

Association of Depression Onset and Treatment With Blood Pressure Control After Intracerebral Hemorrhage.

BACKGROUND: Blood pressure (BP) control represents a crucial intervention to improve long-term outcomes following spontaneous intracerebral hemorrhage (ICH). However, fewer than half of ICH survivors achieve target treatment goals. ICH survivors are also at very high risk for poststroke depression, which may contribute to inadequate BP control. We, therefore, sought to determine whether depressive symptoms after ICH are associated with inadequate BP control. We also investigated whether associations between depression after ICH and BP measurements were mediated by treatment with selective serotonin reuptake inhibitors or norepinephrine-serotonin reuptake inhibitors antidepressants. METHODS: We leveraged data from a single-center longitudinal study of ICH conducted at Massachusetts General Hospital (Boston, MA) between 2006 and 2018. We collected data from semiautomated review of electronic health records, baseline and follow-up interviews, and computed tomography imaging. Information on BP measurements, depression diagnoses, antidepressants medication use, and medical visits were collected longitudinally and analyzed using mixed effects models. Primary outcomes included systolic and diastolic BP measurements during long-term follow-up after ICH. RESULTS: We included 1243 consecutive ICH patients without pre-stroke depression history. Of these, 721 (58%) were diagnosed with incident depression over a median follow-up time of 52.8 months (interquartile range, 42.1-60.5). Depression onset was associated with subsequent increase in systolic (+8.3 mm Hg, SE, 2.4 mm Hg, P=0.012) and diastolic (+4.4 mm Hg, SE, 1.2 mm Hg) BP measurements. Resolution of depressive symptoms was associated with subsequent decrease in systolic (-5.9 mm Hg, SE, 1.4 mm Hg, P=0.031) and diastolic (-3.4 mm Hg, SE, 1.1 mm Hg, P=0.041) BP measurements. We also found associations between higher systolic BP measurements and use of selective serotonin reuptake inhibitor and noradrenaline-serotonin reuptake inhibitor antidepressants, independent of whether depression symptoms were active or not (all P<0.05). CONCLUSIONS: ICH survivors displayed increasing BP values after receiving a diagnosis of depression, followed by decreasing values among those experiencing resolution of depressive symptoms. Use of selective serotonin reuptake inhibitor and noradrenaline-serotonin reuptake inhibitor antidepressants was independently associated with higher systolic BP measurements. Clinicians ought to closely monitor BP for ICH survivors being treated for depression, especially using selective serotonin reuptake inhibitor and noradrenaline-serotonin reuptake inhibitor. Future studies will also be required to investigate the mechanisms underlying these associations.

A Genomic Risk Score Identifies Individuals at High Risk for Intracerebral Hemorrhage.

BACKGROUND: Intracerebral hemorrhage (ICH) has an estimated heritability of 29%. We developed a genomic risk score for ICH and determined its predictive power in comparison to standard clinical risk factors. METHODS: We combined genome-wide association data from individuals of European ancestry for ICH and related traits in a meta-genomic risk score ([metaGRS]; 2.6 million variants). We tested associations with ICH and its predictive performance in addition to clinical risk factors in a held-out validation dataset (842 cases and 796 controls). We tested associations with risk of incident ICH in the population-based UK Biobank cohort (486 784 individuals, 1526 events, median follow-up 11.3 years). RESULTS: One SD increment in the metaGRS was significantly associated with 31% higher odds for ICH (95% CI, 1.16-1.48) in age-, sex- and clinical risk factor-adjusted models. The metaGRS identified individuals with almost 5-fold higher odds for ICH in the top score percentile (odds ratio, 4.83 [95% CI, 1.56-21.2]). Predictive models for ICH incorporating the metaGRS in addition to clinical predictors showed superior performance compared to the clinical risk factors alone (c-index, 0.695 versus 0.686). The metaGRS showed similar associations for lobar and nonlobar ICH, independent of the known APOE risk locus for lobar ICH. In the UK Biobank, the metaGRS was associated with higher risk of incident ICH (hazard ratio, 1.15 [95% CI, 1.09-1.21]). The associations were significant within both a relatively high-risk population of antithrombotic medications users, as well as among a relatively low-risk population with a good control of vascular risk factors and no use of anticoagulants. CONCLUSIONS: We developed and validated a genomic risk score that predicts lifetime risk of ICH beyond established clinical risk factors among individuals of European ancestry. Whether implementation of the score in risk prognostication models for high-risk populations, such as patients under antithrombotic treatment, could improve clinical decision making should be explored in future studies.

Prevalence and Therapeutic Implications of Clonal Hematopoiesis of Indeterminate Potential in Young Patients With Stroke.

BACKGROUND: Undetermined stroke etiology hampers optimal secondary prevention in a large proportion of young patients. We explored whether genetic screening for clonal hematopoiesis of indetermined potential (CHIP), a novel risk factor for stroke, could identify patients with myeloid precursor lesions or covert myeloid neoplasm requiring specific treatment. METHODS: We performed targeted sequencing on 56 genes recurrently mutated in hematologic neoplasms in a prospective cohort of patients with acute brain ischemia between 18 and 60 years. CHIP prevalence was compared with age-matched healthy controls from the Nijmegen Biomedical Study (n=1604) and the UK Biobank (n=101 678). Patients with suspicion of high-risk CHIP or myeloid neoplasm were invited for further hematologic evaluation. RESULTS: We included 248 consecutive patients (39% women) of whom 176 (71%) had cryptogenic stroke etiology. Fifty-one (21%) patients had CHIP, 3-fold more than in the general population (7.7% versus 2.6% for the Nijmegen Biomedical Study and 11.9% versus 4.1% for UK Biobank; P<0.001 for both). Patients with CHIP were older (median [interquartile range], 53 [50-59] versus 51 [41-56] years; P<0.001), had higher carotid intima-media thickness (0.68 [0.58-0.80] versus 0.59 [0.51-0.73] mm; P=0.009), and had higher burden of atherosclerosis (29.4% versus 16.7%; P=0.04). We invited 11 patients (4.4%) for further hematologic assessment, which in 7 led to the diagnosis of high-risk CHIP and in 2 to the new diagnosis of a myeloproliferative neoplasm with indication for cytoreductive therapy. CONCLUSIONS: Using genetic screening for myeloid disorders in patients with stroke of predominantly undetermined etiology, we found a 3-fold higher CHIP prevalence than in the general population. We identified high-risk CHIP and previously covert myeloproliferative neoplasms as potential stroke etiologies in 4.4% and 1% of patients, respectively. Our findings demonstrate the diagnostic and therapeutic yield of genetic screening in young patients with stroke. Future studies should investigate the role of CHIP for stroke recurrence and optimal secondary prevention.

Clinical and Genetic Atrial Fibrillation Risk and Discrimination of Cardioembolic From Noncardioembolic Stroke.

BACKGROUND: Stroke is a leading cause of death and disability worldwide. Atrial fibrillation (AF) is a common cause of stroke but may not be detectable at the time of stroke. We hypothesized that an AF polygenic risk score (PRS) can discriminate between cardioembolic stroke and noncardioembolic strokes. METHODS: We evaluated AF and stroke risk in 26 145 individuals of European descent from the Stroke Genetics Network case-control study. AF genetic risk was estimated using 3 recently developed PRS methods (LDpred-funct-inf, sBayesR, and PRS-CS) and 2 previously validated PRSs. We performed logistic regression of each AF PRS on AF status and separately cardioembolic stroke, adjusting for clinical risk score (CRS), imputation group, and principal components. We calculated model discrimination of AF and cardioembolic stroke using the concordance statistic (c-statistic) and compared c-statistics using 2000-iteration bootstrapping. We also assessed reclassification of cardioembolic stroke with the addition of PRS to either CRS or a modified CHA2DS2-VASc score alone. RESULTS: Each AF PRS was significantly associated with AF and with cardioembolic stroke after adjustment for CRS. Addition of each AF PRS significantly improved discrimination as compared with CRS alone (P<0.01). When combined with the CRS, both PRS-CS and LDpred scores discriminated both AF and cardioembolic stroke (c-statistic 0.84 for AF; 0.74 for cardioembolic stroke) better than 3 other PRS scores (P<0.01). Using PRS-CS PRS and CRS in combination resulted in more appropriate reclassification of stroke events as compared with CRS alone (event reclassification [net reclassification indices]+=14% [95% CI, 10%-18%]; nonevent reclassification [net reclassification indices]-=17% [95% CI, 15%-0.19%]) or the modified CHA2DS2-VASc score (net reclassification indices+=11% [95% CI, 7%-15%]; net reclassification indices-=14% [95% CI, 12%-16%]) alone. CONCLUSIONS: Addition of polygenic risk of AF to clinical risk factors modestly improves the discrimination of cardioembolic from noncardioembolic strokes, as well as reclassification of stroke subtype. Polygenic risk of AF may be a useful biomarker for identifying strokes caused by AF.

Blood Pressure Control Targets and Risk of Cardiovascular and Cerebrovascular Events After Intracerebral Hemorrhage.

BACKGROUND: Intracerebral hemorrhage (ICH) survivors are at high risk for recurrent stroke and cardiovascular events. Blood pressure (BP) control represents the most potent intervention to lower these risks, but optimal treatment targets in this patient population remain unknown. We sought to determine whether survivors of ICH achieving more intensive BP control than current guideline recommendations (systolic BP <130 mmHg and diastolic BP <80 mmHg) were at lower risk of major adverse cardiovascular and cerebrovascular events and mortality. METHODS: We analyzed data for 1828 survivors of spontaneous ICH from 2 cohort studies. Follow-up BP measurements were recorded 3 and 6 months after ICH, and every 6 months thereafter. Outcomes of interest were major adverse cardiovascular and cerebrovascular events (recurrent ICH, incident ischemic stroke, myocardial infarction), vascular mortality (defined as mortality attributed to recurrent ICH, ischemic stroke, or myocardial infarction), and all-cause mortality. RESULTS: During a median follow-up of 46.2 months, we observed 166 recurrent ICH, 68 ischemic strokes, 69 myocardial infarction, and 429 deaths. Compared with survivors of ICH with systolic BP 120 to 129 mmHg, participants who achieved systolic BP <120 mmHg displayed reduced risk of recurrent ICH (adjusted hazard ratio [AHR], 0.74 [95% CI, 0.59-0.94]) and major adverse cardiovascular and cerebrovascular events (AHR, 0.69 [95% CI, 0.53-0.92]). All-cause mortality (AHR, 0.76 [95% CI, 0.57-1.03]) and vascular mortality (AHR, 0.68 [95% CI, 0.45-1.01]) did not differ significantly. Among participants aged >75 years or with modified Rankin Scale score 4 to 5, systolic BP <120 mmHg was associated with increased all-cause mortality (AHR, 1.38 [95% CI, 1.02-1.85] and AHR, 1.36 [95% CI, 1.03-1.78], respectively), but not vascular mortality. We found no differences in outcome rates between survivors of ICH with diastolic BP <70 versus 70 to 79 mmHg. CONCLUSIONS: Targeting systolic BP <120 mmHg in select groups of survivors of ICH could result in decreased major adverse cardiovascular and cerebrovascular events risk without increasing mortality. Our findings warrant investigation in dedicated randomized controlled trials.

Genetic Architecture of Stroke of Undetermined Source: Overlap with Known Stroke Etiologies and Associations with Modifiable Risk Factors.

OBJECTIVE: Ischemic stroke etiology remains undetermined in 30% of cases. We explored the genetic architecture of stroke classified as undetermined to test if mechanisms and risk factors underlying large-artery atherosclerotic (LAAS), cardioembolic (CES), and small-vessel stroke (SVS) contribute to its pathogenesis. METHODS: We analyzed genome-wide data from 16,851 ischemic stroke cases and 32,473 controls. Using polygenic risk scores for LAAS, CES, and SVS, we assessed the genetic overlap with stroke of undetermined source and used pairwise genomewide association study (GWAS-PW) to search for shared loci. We then applied Mendelian randomization (MR) to identify potentially causal risk factors of stroke of undetermined source. RESULTS: Genetic risk for LAS, CES, and SVS was associated with stroke of undetermined source pointing to overlap in their genetic architecture. Pairwise analyses revealed 19 shared loci with LAAS, 2 with CES, and 5 with SVS that have been implicated in atherosclerosis-related phenotypes. Genetic liability to both carotid atherosclerosis and atrial fibrillation was associated with stroke of undetermined source, but the association with atrial fibrillation was attenuated after excluding cases with incomplete diagnostic workup. MR analyses showed effects of genetically determinants of blood pressure, diabetes, waist-to-hip ratio, inflammatory pathways (IL-6 signaling, MCP-1/CCL2 levels), and factor XI levels on stroke of undetermined source. INTERPRETATION: Stroke of undetermined source shares genetic and vascular risk factors with other stroke subtypes, especially LAAS, thus highlighting the diagnostic limitations of current subtyping approaches. The potentially causal associations with carotid atherosclerosis and atherosclerotic risk factors might have implications for prevention strategies targeting these mechanisms. ANN NEUROL 2022;91:640-651.

Genetically predicted on-statin LDL response is associated with higher intracerebral haemorrhage risk.

Statins lower low-density lipoprotein cholesterol and are widely used for the prevention of atherosclerotic cardiovascular disease. Whether statin-induced low-density lipoprotein reduction increases risk of intracerebral haemorrhage has been debated for almost two decades. Here, we explored whether genetically predicted on-statin low-density lipoprotein response is associated with intracerebral haemorrhage risk using Mendelian randomization. Using genomic data from randomized trials, we derived a polygenic score from 35 single nucleotide polymorphisms of on-statin low-density lipoprotein response and tested it in the population-based UK Biobank. We extracted statin drug and dose information from primary care data on a subset of 225 195 UK Biobank participants covering a period of 29 years. We validated the effects of the genetic score on longitudinal low-density lipoprotein measurements with generalized mixed models and explored associations with incident intracerebral haemorrhage using Cox regression analysis. Statins were prescribed at least once to 75 973 (31%) of the study participants (mean 57 years, 55% females). Among statin users, mean low-density lipoprotein decreased by 3.45 mg/dl per year [95% confidence interval (CI): (-3.47, -3.42)] over follow-up. A higher genetic score of statin response [1 standard deviation (SD) increment] was associated with significant additional reductions in low-density lipoprotein levels [-0.05 mg/dl per year, (-0.07, -0.02)], showed concordant lipidomic effects on other lipid traits as statin use and was associated with a lower risk for incident myocardial infarction [hazard ratio per SD increment 0.98 95% CI (0.96, 0.99)] and peripheral artery disease [hazard ratio per SD increment 0.93 95% CI (0.87, 0.99)]. Over a 11-year follow-up period, a higher genetically predicted statin response among statin users was associated with higher intracerebral haemorrhage risk in a model adjusting for statin dose [hazard ratio per SD increment 1.16, 95% CI (1.05, 1.28)]. On the contrary, there was no association with intracerebral haemorrhage risk among statin non-users (P = 0.89). These results provide further support for the hypothesis that statin-induced low-density lipoprotein reduction may be causally associated with intracerebral haemorrhage risk. While the net benefit of statins for preventing vascular disease is well-established, these results provide insights about the personalized response to statin intake and the role of pharmacological low-density lipoprotein lowering in the pathogenesis of intracerebral haemorrhage.

Loss of microRNA-21 protects against acetaminophen-induced hepatotoxicity in mice.

Acetaminophen (APAP)-induced Acute Liver Failure (ALF) is recognized as the most common cause of ALF in Western societies. APAP-induced ALF is characterized by coagulopathy, hepatic encephalopathy, multi-organ failure, and death. MicroRNAs are small, non-coding RNAs that regulate gene expression at the post-transcriptional level. MicroRNA-21 (miR-21) is dynamically expressed in the liver and is involved in the pathophysiology of both acute and chronic liver injury models. We hypothesize that miR-21genetic ablation attenuates hepatotoxicity following acetaminophen intoxication. Eight-week old miR-21knockout (miR21KO) or wild-type (WT) C57BL/6N male mice were injected with acetaminophen (APAP, 300 mg/kg BW) or saline. Mice were sacrificed 6 or 24 h post-injection. MiR21KO mice presented attenuation of liver enzymes ALT, AST, LDH compared with WT mice 24 h post-APAP treatment. Moreover, miR21KO mice had decreased hepatic DNA fragmentation and necrosis than WT mice after 24 h of APAP treatment. APAP-treated miR21KO mice showed increased levels of cell cycle regulators CYCLIN D1 and PCNA, increased autophagy markers expression (Map1LC3a, Sqstm1) and protein (LC3AB II/I, p62), and an attenuation of the APAP-induced hypofibrinolytic state via (PAI-1) compared with WT mice 24 post-APAP treatment. MiR-21 inhibition could be a novel therapeutic approach to mitigate APAP-induced hepatotoxicity and enhance survival during the regenerative phase, particularly to alter regeneration, autophagy, and fibrinolysis. Specifically, miR-21 inhibition could be particularly useful when APAP intoxication is detected at its late stages and the only available therapy is minimally effective.

Research Priorities in Atrial Fibrillation Screening: A Report From a National Heart, Lung, and Blood Institute Virtual Workshop.

Clinically recognized atrial fibrillation (AF) is associated with higher risk of complications, including ischemic stroke, cognitive decline, heart failure, myocardial infarction, and death. It is increasingly recognized that AF frequently is undetected until complications such as stroke or heart failure occur. Hence, the public and clinicians have an intense interest in detecting AF earlier. However, the most appropriate strategies to detect undiagnosed AF (sometimes referred to as subclinical AF) and the prognostic and therapeutic implications of AF detected by screening are uncertain. Our report summarizes the National Heart, Lung, and Blood Institute's virtual workshop focused on identifying key research priorities related to AF screening. Global experts reviewed major knowledge gaps and identified critical research priorities in the following areas: (1) role of opportunistic screening; (2) AF as a risk factor, risk marker, or both; (3) relationship between AF burden detected with long-term monitoring and outcomes/treatments; (4) designs of potential randomized trials of systematic AF screening with clinically relevant outcomes; and (5) role of AF screening after ischemic stroke. Our report aims to inform and catalyze AF screening research that will advance innovative, resource-efficient, and clinically relevant studies in diverse populations to improve the diagnosis, management, and prognosis of patients with undiagnosed AF.

Clinical Application of a Novel Genetic Risk Score for Ischemic Stroke in Patients With Cardiometabolic Disease.

BACKGROUND: Genome-wide association studies have identified single-nucleotide polymorphisms that are associated with an increased risk of stroke. We sought to determine whether a genetic risk score (GRS) could identify subjects at higher risk for ischemic stroke after accounting for traditional clinical risk factors in 5 trials across the spectrum of cardiometabolic disease. METHODS: Subjects who had consented for genetic testing and who were of European ancestry from the ENGAGE AF-TIMI 48 (Effective Anticoagulation with Factor Xa Next Generation in Atrial Fibrillation), SOLID-TIMI 52 (Stabilization of Plaques Using Darapladib), SAVOR-TIMI 53 (Saxagliptin Assessment of Vascular Outcomes Recorded in Patients with Diabetes Mellitus), PEGASUS-TIMI 54 (Prevention of Cardiovascular Events in Patients With Prior Heart Attack Using Ticagrelor Compared to Placebo on a Background of Aspirin), and FOURIER (Further Cardiovascular Outcomes Research With PCSK9 Inhibition in Patients With Elevated Risk) trials were included in this analysis. A set of 32 single-nucleotide polymorphisms associated with ischemic stroke was used to calculate a GRS in each patient and identify tertiles of genetic risk. A Cox model was used to calculate hazard ratios for ischemic stroke across genetic risk groups, adjusted for clinical risk factors. RESULTS: In 51 288 subjects across the 5 trials, a total of 960 subjects had an ischemic stroke over a median follow-up period of 2.5 years. After adjusting for clinical risk factors, a higher GRS was strongly and independently associated with increased risk for ischemic stroke (P trend=0.009). In comparison with individuals in the lowest third of the GRS, individuals in the middle and top tertiles of the GRS had adjusted hazard ratios of 1.15 (95% CI, 0.98-1.36) and 1.24 (95% CI 1.05-1.45) for ischemic stroke, respectively. Stratification into subgroups revealed that the performance of the GRS appeared stronger in the primary prevention cohort with an adjusted hazard ratio for the top versus lowest tertile of 1.27 (95% CI, 1.04-1.53), in comparison with an adjusted hazard ratio of 1.06 (95% CI, 0.81-1.41) in subjects with previous stroke. In an exploratory analysis of patients with atrial fibrillation and CHA2DS2-VASc score of 2, high genetic risk conferred a 4-fold higher risk of stroke and an absolute risk equivalent to those with CHA2DS2-VASc score of 3. CONCLUSIONS: Across a broad spectrum of subjects with cardiometabolic disease, a 32-single-nucleotide polymorphism GRS was a strong, independent predictor of ischemic stroke. In patients with atrial fibrillation but lower CHA2DS2-VASc scores, the GRS identified patients with risk comparable to those with higher CHA2DS2-VASc scores.