A Multitrait Genetic Study of Hemostatic Factors and Hemorrhagic Transformation after Stroke Treatment

BACKGROUND: Thrombolytic recombinant tissue plasminogen activator (r-tPA) treatment is the only pharmacologic intervention available in the ischemic stroke acute phase. This treatment is associated with an increased risk of intracerebral hemorrhages, known as hemorrhagic transformations (HTs), which worsen the patient\u27s prognosis. OBJECTIVES: to investigate the association between genetically determined natural hemostatic factors\u27 levels and increased risk of HT after r-tPA treatment. METHODS: Using data from genome-wide association studies on the risk of HT after r-tPA treatment and data on 7 hemostatic factors (factor [F]VII, FVIII, von Willebrand factor [VWF], FXI, fibrinogen, plasminogen activator inhibitor-1, and tissue plasminogen activator), we performed local and global genetic correlation estimation multitrait analyses and colocalization and 2-sample Mendelian randomization analyses between hemostatic factors and HT. RESULTS: Local correlations identified a genomic region on chromosome 16 with shared covariance: fibrinogen-HT, P = 2.45 × 10 CONCLUSION: We identified 4 shared loci between hemostatic factors and HT after r-tPA treatment, suggesting common regulatory mechanisms between fibrinogen and VWF levels and HT. Further research to determine a possible mediating effect of fibrinogen on HT risk is needed

Single nucleotide variations in ZBTB46 are associated with post-thrombolytic parenchymal haematoma

Haemorrhagic transformation is a complication of recombinant tissue-plasminogen activator treatment. The most severe form, parenchymal haematoma, can result in neurological deterioration, disability, and death. Our objective was to identify single nucleotide variations associated with a risk of parenchymal haematoma following thrombolytic therapy in patients with acute ischaemic stroke. A fixed-effect genome-wide meta-analysis was performed combining two-stage genome-wide association studies (n = 1904). The discovery stage (three cohorts) comprised 1324 ischaemic stroke individuals, 5.4% of whom had a parenchymal haematoma. Genetic variants yielding a P-value < 0.05 1 x 10(-5) were analysed in the validation stage (six cohorts), formed by 580 ischaemic stroke patients with 12.1% haemorrhagic events. All participants received recombinant tissue-plasminogen activator; cases were parenchymal haematoma type 1 or 2 as defined by the European Cooperative Acute Stroke Study (ECASS) criteria. Genome-wide significant findings (P < 5 x 10(-8)) were characterized by in silica functional annotation, gene expression, and DNA regulatory elements. We analysed 7 989 272 single nucleotide polymorphisms and identified a genome-wide association locus on chromosome 20 in the discovery cohort; functional annotation indicated that the ZBTB46 gene was driving the association for chromosome 20. The top single nucleotide polymorphism was rs76484331 in the ZBTB46 gene [P = 2.49 x 10(-8); odds ratio (OR): 11.21; 95% confidence interval (CI): 4.82-26.55]. In the replication cohort (n = 580), the rs76484331 polymorphism was associated with parenchymal haematoma (P = 0.01), and the overall association after meta-analysis increased (P = 1.61 x 10(-8), OR: 5.84; 95% CI: 3.16-10.76). ZBTB46 codes the zinc finger and BTB domain-containing protein 46 that acts as a transcription factor. In silica studies indicated that ZBTB46 is expressed in brain tissue by neurons and endothelial cells. Moreover, rs76484331 interacts with the promoter sites located at 20q13. In conclusion, we identified single nucleotide variants in the ZBTB46 gene associated with a higher risk of parenchymal haematoma following recombinant tissue-plasminogen activator treatment.Peer reviewe

A multitrait genetic study of hemostatic factors and hemorrhagic transformation after stroke treatment

[Background] Thrombolytic recombinant tissue plasminogen activator (r-tPA) treatment is the only pharmacologic intervention available in the ischemic stroke acute phase. This treatment is associated with an increased risk of intracerebral hemorrhages, known as hemorrhagic transformations (HTs), which worsen the patient’s prognosis.[Objectives] To investigate the association between genetically determined natural hemostatic factors’ levels and increased risk of HT after r-tPA treatment.[Methods] Using data from genome-wide association studies on the risk of HT after r-tPA treatment and data on 7 hemostatic factors (factor [F]VII, FVIII, von Willebrand factor [VWF], FXI, fibrinogen, plasminogen activator inhibitor-1, and tissue plasminogen activator), we performed local and global genetic correlation estimation multitrait analyses and colocalization and 2-sample Mendelian randomization analyses between hemostatic factors and HT.[Results] Local correlations identified a genomic region on chromosome 16 with shared covariance: fibrinogen-HT, P = 2.45 × 10−11. Multitrait analysis between fibrinogen-HT revealed 3 loci that simultaneously regulate circulating levels of fibrinogen and risk of HT: rs56026866 (PLXND1), P = 8.80 × 10−10; rs1421067 (CHD9), P = 1.81 × 10−14; and rs34780449, near ROBO1 gene, P = 1.64 × 10−8. Multitrait analysis between VWF-HT showed a novel common association regulating VWF and risk of HT after r-tPA at rs10942300 (ZNF366), P = 1.81 × 10−14. Mendelian randomization analysis did not find significant causal associations, although a nominal association was observed for FXI-HT (inverse-variance weighted estimate [SE], 0.07 [−0.29 to 0.00]; odds ratio, 0.87; 95% CI, 0.75-1.00; raw P = .05).[Conclusion] We identified 4 shared loci between hemostatic factors and HT after r-tPA treatment, suggesting common regulatory mechanisms between fibrinogen and VWF levels and HT. Further research to determine a possible mediating effect of fibrinogen on HT risk is needed.This study is supported in part by the National Heart, Lung, and Blood Institute grants HL134894, HL139553, and HL141291. G.T.-S. is supported by the Pla Estratègic de Recerca i Innovació en Salut grant from the Catalan Department of Health for junior research personnel (SLT017/20/000100). M.S.-L. is supported by a Miguel Servet contract from the Instituto de Salud Carlos III (ISCIII) Spanish Health Institute (CPII22/00007) and cofinanced by the European Social Fund. E.M. is supported by a Río Hortega Contract (CM18/00198) from the ISCIII. J.C.-M. is supported by an Agència de Gestió d’Ajuts Universitaris i de Recerca Contract (FI_DGR 2020, grant number 2020FI_B1 00157) cofinanced by the European Social Fund. C.G.-F. is supported by a Sara Borrell Contract (CD20/00043) from ISCIII and Fondo Europeo de Desarrollo Regional (ISCIII- FEDER). M.L. is supported by a Contratos Predoctorales de Formación en Investigación en Salud Contract from the ISCIII (FI19/00309).Peer reviewe

Table_3_A Polygenic Risk Score Based on a Cardioembolic Stroke Multitrait Analysis Improves a Clinical Prediction Model for This Stroke Subtype.DOCX

[Background] Occult atrial fibrillation (AF) is one of the major causes of embolic stroke of undetermined source (ESUS). Knowing the underlying etiology of an ESUS will reduce stroke recurrence and/or unnecessary use of anticoagulants. Understanding cardioembolic strokes (CES), whose main cause is AF, will provide tools to select patients who would benefit from anticoagulants among those with ESUS or AF. We aimed to discover novel loci associated with CES and create a polygenetic risk score (PRS) for a more efficient CES risk stratification.[Methods] Multitrait analysis of GWAS (MTAG) was performed with MEGASTROKE-CES cohort (n = 362,661) and AF cohort (n = 1,030,836). We considered significant variants and replicated those variants with MTAG p-value < 5 × 10−8 influencing both traits (GWAS-pairwise) with a p-value < 0.05 in the original GWAS and in an independent cohort (n = 9,105). The PRS was created with PRSice-2 and evaluated in the independent cohort.[Results] We found and replicated eleven loci associated with CES. Eight were novel loci. Seven of them had been previously associated with AF, namely, CAV1, ESR2, GORAB, IGF1R, NEURL1, WIPF1, and ZEB2. KIAA1755 locus had never been associated with CES/AF, leading its index variant to a missense change (R1045W). The PRS generated has been significantly associated with CES improving discrimination and patient reclassification of a model with age, sex, and hypertension.[Conclusion] The loci found significantly associated with CES in the MTAG, together with the creation of a PRS that improves the predictive clinical models of CES, might help guide future clinical trials of anticoagulant therapy in patients with ESUS or AF.Peer reviewe

PATJ Low Frequency Variants Are Associated with Worse Ischemic Stroke Functional Outcome: A Genome-Wide Meta-Analysis

RATIONALE: Ischemic stroke is among the leading causes of adult disability. Part of the variability in functional outcome after stroke has been attributed to genetic factors but no locus has been consistently associated with stroke outcome. OBJECTIVE: Our aim was to identify genetic loci influencing the recovery process using accurate phenotyping to produce the largest GWAS (genome-wide association study) in ischemic stroke recovery to date. METHODS AND RESULTS: A 12-cohort, 2-phase (discovery-replication and joint) meta-analysis of GWAS included anterior-territory and previously independent ischemic stroke cases. Functional outcome was recorded using 3-month modified Rankin Scale. Analyses were adjusted for confounders such as discharge National Institutes of Health Stroke Scale. A gene-based burden test was performed. The discovery phase (n=1225) was followed by open (n=2482) and stringent joint-analyses (n=1791). Those cohorts with modified Rankin Scale recorded at time points other than 3-month or incomplete data on previous functional status were excluded in the stringent analyses. Novel variants in PATJ (Pals1-associated tight junction) gene were associated with worse functional outcome at 3-month after stroke. The top variant was rs76221407 (G allele, β=0.40, P=1.70×10-9). CONCLUSIONS: Our results identify a set of common variants in PATJ gene associated with 3-month functional outcome at genome-wide significance level. Future studies should examine the role of PATJ in stroke recovery and consider stringent phenotyping to enrich the information captured to unveil additional stroke outcome loci

Reported prestroke physical activity is associated with vascular endothelial growth factor expression and good outcomes after stroke

Physical activity (PhA) prior to stroke has been associated with good outcomes after the ischemic insult, but there is scarce data on the involved molecular mechanisms. Methods: We studied consecutive acute ischemic stroke patients admitted to a single tertiary stroke center. Pre-stroke PhA was evaluated with the International Physical Activity Questionnaire (METS-minute/week). We studied several circulating angiogenic and neurogenic factors at different time-points: Vascular Endothelial Growth Factor (VEGF), Granulocyte Colony-Stimulating Factor (G-CSF) and Brain-Derived Neurotrophic Factor (BDNF) at admission, day 7, and at 3 months. We considered good functional outcome at 3 months (mRS = 2) as primary endpoint, and final infarct volume as secondary outcome. Results: We studied 83 patients with at least two time-point serum determinations (mean age 69.6 years, median NIHSS 17 at admission). Patients more physically active before stroke had a significantly higher increment of serum Vascular Endothelial Growth Factor (VEGF) at 7th day when compared to less active patients. This increment was an independent predictor of good functional outcome at 3 months and was associated with smaller infarct volume in multivariate analyses adjusted for relevant covariates. We did not find independent associations of G-CSF or BDNF levels neither with level of pre-stroke PhA nor with stroke outcomes. Conclusions: Although there are probably more molecular mechanisms by which physical activity exerts its beneficial effects in stroke outcomes, our observation regarding the potential role of VEGF is plausible and in line with previous experimental studies. Further research in this field is needed.Peer ReviewedPostprint (author's final draft

Reported prestroke physical activity is associated with vascular endothelial growth factor expression and good outcomes after stroke

Physical activity (PhA) prior to stroke has been associated with good outcomes after the ischemic insult, but there is scarce data on the involved molecular mechanisms. Methods: We studied consecutive acute ischemic stroke patients admitted to a single tertiary stroke center. Pre-stroke PhA was evaluated with the International Physical Activity Questionnaire (METS-minute/week). We studied several circulating angiogenic and neurogenic factors at different time-points: Vascular Endothelial Growth Factor (VEGF), Granulocyte Colony-Stimulating Factor (G-CSF) and Brain-Derived Neurotrophic Factor (BDNF) at admission, day 7, and at 3 months. We considered good functional outcome at 3 months (mRS = 2) as primary endpoint, and final infarct volume as secondary outcome. Results: We studied 83 patients with at least two time-point serum determinations (mean age 69.6 years, median NIHSS 17 at admission). Patients more physically active before stroke had a significantly higher increment of serum Vascular Endothelial Growth Factor (VEGF) at 7th day when compared to less active patients. This increment was an independent predictor of good functional outcome at 3 months and was associated with smaller infarct volume in multivariate analyses adjusted for relevant covariates. We did not find independent associations of G-CSF or BDNF levels neither with level of pre-stroke PhA nor with stroke outcomes. Conclusions: Although there are probably more molecular mechanisms by which physical activity exerts its beneficial effects in stroke outcomes, our observation regarding the potential role of VEGF is plausible and in line with previous experimental studies. Further research in this field is needed.Peer Reviewe

Early and delayed infarct growth in patients undergoing mechanical thrombectomy: a prospective, serial MRI study

BACKGROUND: We studied the evolution over time of diffusion weighted imaging (DWI) lesion volume and the factors involved on early and late infarct growth (EIG and LIG) in stroke patients undergoing endovascular treatment (EVT) according to the final revascularization grade. METHODS: This is a prospective cohort of patients with anterior large artery occlusion undergoing EVT arriving at 1 comprehensive stroke center. Magnetic resonance imaging was performed on arrival (pre-EVT), <2 hours after EVT (post-EVT), and on day 5. DWI lesions and perfusion maps were evaluated. Arterial revascularization was assessed according to the modified Thrombolysis in Cerebral Infarction (mTICI) grades. We recorded National Institutes of Health Stroke Scale at arrival and at day 7. EIG was defined as (DWI volume post-EVT–DWI volume pre-EVT), and LIG was defined as (DWI volume at 5d–DWI volume post-EVT). Factors involved in EIG and LIG were tested via multivariable lineal models. RESULTS: We included 98 patients (mean age 70, median National Institutes of Health Stroke Scale score 17, final mTICI=2b 86%). Median EIG and LIG were 48 and 63.3 mL in patients with final mTICI<2b, and 3.6 and 3.9 cc in patients with final mTICI=2b. Both EIG and LIG were associated with higher National Institutes of Health Stroke Scale at day 7 (¿=0.667; P<0.01 and ¿=0.614; P<0.01, respectively). In patients with final mTICI=2b, each 10% increase in the volume of DWI pre-EVT and each extra pass leaded to growths of 9% (95% CI, 7%–10%) and 14% (95% CI, 2%–28%) in the DWI volume post-EVT, respectively. Furthermore, each 10% increase in the volume of DWI post-EVT, each extra pass, and each 10 mL increase in TMax6s post-EVT were associated with growths of 8% (95% CI, 6%–9%), 9% (95% CI, 0%–19%), and 12% (95% CI, 5%–20%) in the volume of DWI post-EVT, respectively. CONCLUSIONS: Infarct grows during and after EVT, especially in nonrecanalizers but also to a lesser extent in recanalizers. In recanalizers, number of passes and DWI volume influence EIG, while number of passes, DWI, and hypoperfused volume after the procedure determine LIG.Postprint (author's final draft