DNA methylation and stroke prognosis: an epigenome-wide association study.

BACKGROUND AND AIMS: Stroke is the leading cause of adult-onset disability. Although clinical factors influence stroke outcome, there is a significant variability among individuals that may be attributed to genetics and epigenetics, including DNA methylation (DNAm). We aimed to study the association between DNAm and stroke prognosis. METHODS AND RESULTS: To that aim, we conducted a two-phase study (discovery-replication and meta-analysis) in Caucasian patients with ischemic stroke from two independent centers (BasicMar [discovery, N = 316] and St. Pau [replication, N = 92]). Functional outcome was assessed using the modified Rankin Scale (mRS) at three months after stroke, being poor outcome defined as mRS > 2. DNAm was determined using the 450K and EPIC BeadChips in whole-blood samples collected within the first 24 h. We searched for differentially methylated positions (DMPs) in 370,344 CpGs, and candidates below p-value < 10-5 were subsequently tested in the replication cohort. We then meta-analyzed DMP results from both cohorts and used them to identify differentially methylated regions (DMRs). After doing the epigenome-wide association study, we found 29 DMPs at p-value < 10-5 and one of them was replicated: cg24391982, annotated to thrombospondin-2 (THBS2) gene (p-valuediscovery = 1.54·10-6; p-valuereplication = 9.17·10-4; p-valuemeta-analysis = 6.39·10-9). Besides, four DMRs were identified in patients with poor outcome annotated to zinc finger protein 57 homolog (ZFP57), Arachidonate 12-Lipoxygenase 12S Type (ALOX12), ABI Family Member 3 (ABI3) and Allantoicase (ALLC) genes (p-value < 1·10-9 in all cases). DISCUSSION: Patients with poor outcome showed a DMP at THBS2 and four DMRs annotated to ZFP57, ALOX12, ABI3 and ALLC genes. This suggests an association between stroke outcome and DNAm, which may help identify new stroke recovery mechanisms.

Blood DNA Methylation Analysis Reveals a Distinctive Epigenetic Signature of Vasospasm in Aneurysmal Subarachnoid Hemorrhage.

Vasospasm is a potentially preventable cause of poor prognosis in patients with aneurysmal subarachnoid hemorrhage (aSAH). Epigenetics might provide insight on its molecular mechanisms. We aimed to analyze the association between differential DNA methylation (DNAm) and development of vasospasm. We conducted an epigenome-wide association study in 282 patients with aSAH admitted to our hospital. DNAm was assessed with the EPIC Illumina chip (> 850 K CpG sites) in whole-blood samples collected at hospital admission. We identified differentially methylated positions (DMPs) at the CpG level using Cox regression models adjusted for potential confounders, and then we used the DMP results to find differentially methylated regions (DMRs) and enriched biological pathways. A total of 145 patients (51%) experienced vasospasm. In the DMP analysis, we identified 31 CpGs associated with vasospasm at p-value < 10-5. One of them (cg26189827) was significant at the genome-wide level (p-value < 10-8), being hypermethylated in patients with vasospasm and annotated to SUGCT gene, mainly expressed in arteries. Region analysis revealed 13 DMRs, some of them annotated to interesting genes such as POU5F1, HLA-DPA1, RUFY1, and CYP1A1. Functional enrichment analysis showed the involvement of biological processes related to immunity, inflammatory response, oxidative stress, endothelial nitric oxide, and apoptosis. Our findings show, for the first time, a distinctive epigenetic signature of vasospasm in aSAH, establishing novel links with essential biological pathways, including inflammation, immune responses, and oxidative stress. Although further validation is required, our results provide a foundation for future research into the complex pathophysiology of vasospasm.

The Role of Epigenetics in Brain Aneurysm and Subarachnoid Hemorrhage: A Comprehensive Review.

This comprehensive review explores the emerging field of epigenetics in intracranial aneurysm (IA) and aneurysmal subarachnoid hemorrhage (aSAH). Despite recent advancements, the high mortality of aSAH needs an understanding of its underlying pathophysiology, where epigenetics plays a crucial role. This review synthesizes the current knowledge, focusing on three primary epigenetic mechanisms: DNA methylation, non-coding RNA (ncRNA), and histone modification in IA and aSAH. While DNA methylation studies are relatively limited, they suggest a significant role in the pathogenesis and prognosis of IA and aSAH, highlighting differentially methylated positions in genes presumably involved in these pathologies. However, methodological limitations, including small sample sizes and a lack of diverse population studies, temper these results. The role of ncRNAs, particularly miRNAs, has been more extensively studied, but there are still few studies focused on histone modifications. Despite methodological challenges and inconsistent findings, these studies underscore the involvement of miRNAs in key pathophysiological processes, including vascular smooth muscle regulation and the inflammatory response. This review emphasizes methodological challenges in epigenetic research, advocating for large-scale epigenome-wide association studies integrating genetic and environmental factors, along with longitudinal studies. Such research could unravel the complex mechanisms behind IA and aSAH, guiding the development of targeted therapeutic approaches.

The influence of epigenetic biological age on key complications and outcomes in aneurysmal subarachnoid haemorrhage.

BACKGROUND: We aimed to investigate the association between DNA-methylation biological age (B-age) calculated as age acceleration (ageAcc) and key aneurysmal subarachnoid haemorrhage (aSAH) complications such as vasospasm, delayed cerebral ischaemia (DCI), poor outcome, and mortality. METHODS: We conducted a prospective study involving 277 patients with aSAH. B-age was determined in whole blood samples using five epigenetic clocks: Hannum's, Horvath's, Levine's and both versions of Zhang's clocks. Age acceleration was calculated as the residual obtained from regressing out the effect of C-age on the mismatch between C-age and B-age. We then tested the association between ageAcc and vasospasm, DCI and 12-month poor outcome (mRS 3-5) and mortality using linear regression models adjusted for confounders. RESULTS: Average C-age was 55.0 years, with 66.8% being female. Vasospasm occurred in 143 cases (51.6%), DCI in 70 (25.3%) and poor outcomes in 99 (35.7%), with a mortality rate of 20.6%. Lower ageAcc was linked to vasospasm in Horvath's and Levine's clocks, whereas increased ageAcc was associated with 12-month mortality in Hannum's clock. No significant differences in ageAcc were found for DCI or poor outcome at 12 months with other clocks. CONCLUSIONS: Our study indicates that B-age is independently associated with vasospasm and 12-month mortality in patients with aSAH. These findings underscore the potential role of epigenetics in understanding the pathophysiology of aSAH-related complications and outcomes.

Sex and gender differences in acute stroke care: metrics, access to treatment and outcome. A territorial analysis of the Stroke Code System of Catalonia.

INTRODUCTION: Previous studies have reported differences in the management and outcome of women stroke patients in comparison with men. We aim to analyze sex and gender differences in the medical assistance, access to treatment and outcome of acute stroke patients in Catalonia. PATIENTS AND METHODS: Data were obtained from a prospective population-based registry of stroke code activations in Catalonia (CICAT) from January/2016 to December/2019. The registry includes demographic data, stroke severity, stroke subtype, reperfusion therapy, and time workflow. Centralized clinical outcome at 90 days was assessed in patients receiving reperfusion therapy. RESULTS: A total of 23,371 stroke code activations were registered (54% men, 46% women). No differences in prehospital time metrics were observed. Women more frequently had a final diagnosis of stroke mimic, were older and had a previous worse functional situation. Among ischemic stroke patients, women had higher stroke severity and more frequently presented proximal large vessel occlusion. Women received more frequently reperfusion therapy (48.2% vs 43.1%, p < 0.001). Women tended to present a worse outcome at 90 days, especially for the group receiving only IVT (good outcome 56.7% vs 63.8%; p < 0.001), but not for the group of patients treated with IVT + MT or MT alone, although sex was not independently associated with clinical outcome in logistic regression analysis (OR 1.07; 95% CI, 0.94-1.23; p = 0.27) nor in the analysis after matching using the propensity score (OR 1.09; 95% CI, 0.97-1.22). DISCUSSION AND CONCLUSION: We found some differences by sex in that acute stroke was more frequent in older women and the stroke severity was higher. We found no differences in medical assistance times, access to reperfusion treatment and early complications. Worse clinical outcome at 90 days in women was conditioned by stroke severity and older age, but not by sex itself.

Factors associated with migraine aura mimicking stroke in code stroke.

INTRODUCTION: Migraine with aura (MA) is a frequent stroke simulator that can lead to erroneous diagnosis and subsequent unnecessary acute or secondary prevention treatments. We analyzed clinical and laboratory data of migraine with aura and ischemic stroke patients to detect differences that could help in the diagnosis. METHODS: Retrospective analysis of a consecutive register of code strokes between January 2005 and June 2020. Diagnosis of ischemic stroke or MA was collected. Multivariable logistic regression analyses were performed to test associations between clinical and blood data with ischemic stroke. RESULTS: Of 3140 code strokes, 2424 (77.2%) were ischemic strokes and 34 (1.1%) were MA. Migraine cases were younger, more frequently females and with lower prevalence of vascular risk factors. Initial NIHSS was lower in MA cases, but no differences were seen in fibrinolysis rate (30%). Blood test showed lower levels of glucose, D-dimer, and fibrinogen in MA cases. Multivariable model showed and independent association for ischemic stroke with age [OR, (95%CI): 1.09, (1.07-1.12, p < 0.001], male sex [OR, (95%CI): 4.47, (3.80-5.13), p < 0.001], initial NIHSS [OR, (95%CI): 1.21, (1.07-1.34), p < 0.01], and fibrinogen levels [OR, (95%CI): 1.01, (1.00-1.01), p < 0.05]. A model including sex male OR: 3.55 [2.882; 4.598], p < 0.001, and cutoff points (age > 65, OR: 7.953 [7.256; 8.649], p < 0.001, NIHSS > 6, OR: 3.740 [2.882; 4.598], p < 0.01, and fibrinogen > 400 mg/dL, OR: 2.988 [2.290; 3.686], p < 0.01) showed a good global discrimination capability AUC = 0.89 (95%CI: 0.88-0.94). CONCLUSIONS: In code stroke, a model including age, sex, NIHSS, and fibrinogen showed a good discrimination capability to differentiate between MA and Ischemic stroke. Whether these variables can be implemented in a diagnostic rule should be tested in future studies.

Machine Learning Approximations to Predict Epigenetic Age Acceleration in Stroke Patients.

Age acceleration (Age-A) is a useful tool that is able to predict a broad range of health outcomes. It is necessary to determine DNA methylation levels to estimate it, and it is known that Age-A is influenced by environmental, lifestyle, and vascular risk factors (VRF). The aim of this study is to estimate the contribution of these easily measurable factors to Age-A in patients with cerebrovascular disease (CVD), using different machine learning (ML) approximations, and try to find a more accessible model able to predict Age-A. We studied a CVD cohort of 952 patients with information about VRF, lifestyle habits, and target organ damage. We estimated Age-A using Hannum's epigenetic clock, and trained six different models to predict Age-A: a conventional linear regression model, four ML models (elastic net regression (EN), K-Nearest neighbors, random forest, and support vector machine models), and one deep learning approximation (multilayer perceptron (MLP) model). The best-performing models were EN and MLP; although, the predictive capability was modest (R2 0.358 and 0.378, respectively). In conclusion, our results support the influence of these factors on Age-A; although, they were not enough to explain most of its variability.

Evolution of quality indicators in acute stroke during the RACECAT Trial: Impact in the general population.

BACKGROUND: Acute ischemic stroke patients not referred directly to a comprehensive stroke center (CSC) have reduced access to endovascular treatment (EVT). The RACECAT trial is a population-based cluster-randomized trial, designed to compare mothership and drip-and-ship strategies in acute ischemic stroke patients outside the catchment area of a CSC. AIMS: To analyze the evolution of performance indicators in the regions that participated in RACECAT. METHODS: This retrospective longitudinal observational study included all stroke alerts evaluated by emergency medical services in Catalonia between February 2016 and February 2020. Cases were classified geographically according to the nearest SC: local SC (Local-SC) and CSC catchment areas. We analyzed the evolution of EVT rates and relevant workflow times in Local-SC versus CSC catchment areas over three study periods: P1 (February 2016 to April 2017: before RACECAT initiation), P2 (May 2017 to September 2018), and P3 (October 2018 to February 2020). RESULTS: We included 20603 stroke alerts, 10,694 (51.9%) of which were activated within Local-SC catchment areas. The proportion of patients receiving EVT within Local-SC catchment areas increased (P1 vs. P3: 7.5% (95% confidence interval (CI), 6.4-8.7) to 22.5% (95% CI, 20.8-24.4) p < 0.001). Inequalities in the odds of receiving EVT were reduced for patients from CSC versus Local-SC catchment areas (P1: odds ratio (OR) 3.9 (95% CI, 3.2-5) vs. P3: OR 1.5 (95% CI, 1.3-1.7) In Local-SC, door-to-image (P1: 24 (interquartile range (IQR) 15-36), P2: 24 (15-35), P3: 21 (13-32) min, p < 0.001) and door-to-needle times (P1: 42 (31-60), P2: 41 (29-58), P3: 35 (25-50) p < 0.001) reduced. Time from Local-SC arrival to groin puncture also decreased over time (P1: 188 [151-229], P2: 190 (157-233), P3: 168 (127-215) min, p < 0.001). CONCLUSION: An increase in EVT rates in Local-SC regions with a significant decrease in workflow times occurred during the period of the RACECAT trial.

First pass effect in posterior circulation occlusions: Analysis from the CICAT registry.

BACKGROUND: The first pass effect (FPE) is an independent predictor of functional independence in patients with large vessel occlusion in anterior circulation ischemic strokes. However, whether it predicts outcome in posterior circulation large vessel occlusion (PC-LVO) is uncertain. We aimed to study the frequency, characteristics, and predictors of FPE and its association with clinical outcomes in PC-LVO. METHOD: We performed an analysis from the prospective CICAT Registry. All patients with PC-LVO who underwent endovascular therapy between January 2016 and January 2020 were included. A centrally assessed clinical follow-up was performed at 3 months by blinded investigators. FPE was defined as the achievement of modified Thrombolysis In Cerebral Infarction 3 in a single pass of the endovascular thrombectomy device, and multi-pass effect (MPE) if it was achieved in more than one pass. A multivariable analysis was performed to identify whether FPE is an independent predictor of functional independence defined as a modified Rankin Score of 0-2. RESULTS: We analyzed data from 265 patients in who FPE was achieved in 105 (39.6%). Patients with FPE were more likely to achieve functional independence compared to the non-FPE group (52.4% vs 25.1%, p < .001) and the MPE group (52.4% vs 26.7%, p < .001). FPE was independently associated with functional independence (adjusted odds ratio (aOR): 2.10, 95% confidence interval (CI) 1.01-4.37) but MPE was not (aOR: 0.92, 95% CI 0.40-2.13). Independent predictors of FPE were the use of direct aspiration, embolic mechanism of stroke, and the absence of general anesthesia (GA) use. CONCLUSIONS: FPE is an independent predictor of functional independence in PC-LVO and was associated with a significantly better outcome than MPE.

Determinants and Trends of the Use of Intravenous Thrombolysis for Minor Stroke: A Population-Based Study, 2016 to 2020.

BACKGROUND: We analyzed the main factors associated with intravenous thrombolysis (IVT) in patients with minor ischemic stroke. METHODS: Data were obtained from a prospective, government-mandated, population-based registry of stroke code patients in Catalonia (6 Comprehensive Stroke Centers, 8 Primary Stroke Centers, and 14 TeleStroke Centers). We selected patients diagnosed with ischemic stroke and National Institutes of Health Stroke Scale (NIHSS) ≤5 at hospital admission from January 2016 to December 2020. We excluded patients with a baseline modified Rankin Scale score of ≥3, absolute contraindication for IVT, unknown stroke onset, or admitted to hospital beyond 4.5 after stroke onset. The main outcome was treatment with IVT. We performed univariable and binary logistic regression analyses to identify the most important factors associated with IVT. RESULTS: We included 2975 code strokes; 1433 (48.2%) received IVT of which 30 (2.1%) had a symptomatic hemorrhagic transformation. Patients treated with IVT as compared to patients who did not receive IVT were more frequently women, had higher NIHSS, arrived earlier to hospital, were admitted to a Comprehensive Stroke Centers, and had large vessel occlusion. After binary logistic regression, NIHSS score 4 to 5 (odds ratio, 40.62 [95% CI, 31.73-57.22]; P<0.001) and large vessel occlusion (odds ratio, 16.39 [95% CI, 7.25-37.04]; P<0.001) were the strongest predictors of IVT. Younger age, female sex, baseline modified Rankin Scale score of 0, earlier arrival to hospital (<120 minutes after stroke onset), and the type of stroke center were also independently associated with IVT. The weight of large vessel occlusion on IVT was higher in patients with lower NIHSS. CONCLUSIONS: Minor stroke female patients, with higher NIHSS, arriving earlier to the hospital, presenting with large vessel occlusion and admitted to a Comprehensive Stroke Centers were more likely to receive intravenous thrombolysis.

Long-term vascular events after subarachnoid hemorrhage.

BACKGROUND: Spontaneous subarachnoid hemorrhage (SAH) long-term risk is not well known. Our aims are: describing long-term vascular event (VE) incidence rates in SAH survivors; describing VE: ischemic and/or hemorrhagic; identifying independent association of factors related to VE; and analyzing the usefulness of factors to increase predictive ability. METHODS: A prospective cohort study of consecutive patients admitted to Hospital del Mar with a diagnosis of SAH (n = 566) between January 2007 and January 2020 was carried out. They were followed up until January 2021. The study endpoint was a new VE in the follow-up. We calculated both incidence rates and cumulative rates at 5 years. Cox regression survival models including vascular risk factors with and without specific data of SAH disease were developed. We analyzed ROC curves of all multivariate models. RESULTS: The analyzed cohort included 423 non-fatal SAH cases. Total patient-years were 2468.16 years. The average follow-up was 70.03 ± 43.14; range: 1-180 months. There were 49 VE detected in 47 patients, as 2 of them had more than 1 VE. Incidence rate was 0.020 events_per_patient/year, cumulative incidence at 5 years was 11.11%. The more frequent VE that we found were cerebrovascular (28/49), mainly ischemic (21/28). Disability after SAH and the presence of multiple aneurysms were independently associated with a VE risk and improved the predictive capacity of multivariate models (AUC 0.679 vs 0.764; p = 0.0062). CONCLUSIONS: We reported a low vascular risk after SAH. We have shown the usefulness of SAH factors to identify patients with a higher risk of VE.

Genetics and Epigenetics of Spontaneous Intracerebral Hemorrhage.

Intracerebral hemorrhage (ICH) is a complex and heterogeneous disease, and there is no effective treatment. Spontaneous ICH represents the final manifestation of different types of cerebral small vessel disease, usually categorized as: lobar (mostly related to cerebral amyloid angiopathy) and nonlobar (hypertension-related vasculopathy) ICH. Accurate phenotyping aims to reflect these biological differences in the underlying mechanisms and has been demonstrated to be crucial to the success of genetic studies in this field. This review summarizes how current knowledge on genetics and epigenetics of this devastating stroke subtype are contributing to improve the understanding of ICH pathophysiology and their potential role in developing therapeutic strategies.

Patología asociada al consumo de metanfetamina cristalizada (shabú) en un centro hospitalario de tercer nivel / Emergencies associated with shabu — crystal methamphetamine — in a tertiary care hospital

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Prolonged Cardiac Monitoring and Stroke Recurrence: A Meta-analysis.

BACKGROUND AND OBJECTIVES: Prolonged poststroke cardiac rhythm monitoring (PCM) reveals a substantial proportion of patients with ischemic stroke (IS) with atrial fibrillation (AF) not detected by conventional rhythm monitoring strategies. We evaluated the association between PCM and the institution of stroke preventive strategies and stroke recurrence. METHODS: We searched MEDLINE and SCOPUS databases to identify studies reporting stroke recurrence rates in patients with history of recent IS or TIA receiving PCM compared with patients receiving conventional cardiac rhythm monitoring. Pairwise meta-analyses were performed under the random effects model. To explore for differences between the monitoring strategies, we combined direct and indirect evidence for any given pair of monitoring devices assessed within a randomized controlled trial (RCT). RESULTS: We included 8 studies (5 RCTs, 3 observational; 2,994 patients). Patients receiving PCM after their index event had a higher rate of AF detection and anticoagulant initiation in RCTs (risk ratio [RR] 3.91, 95% CI 2.54-6.03; RR 2.16, 95% CI 1.66-2.80, respectively) and observational studies (RR 2.06, 95% CI 1.57-2.70; RR 2.01, 95% CI 1.43-2.83, respectively). PCM was associated with a lower risk of recurrent stroke during follow-up in observational studies (RR 0.29, 95% CI 0.15-0.59), but not in RCTs (RR 0.72, 95% CI 0.49-1.07). In indirect analyses of RCTs, the likelihood of AF detection and anticoagulation initiation was higher for implantable loop recorders compared with Holter monitors and external loop recorders. DISCUSSION: PCM after an IS or TIA can lead to higher rates of AF detection and anticoagulant initiation. There is no solid RCT evidence supporting that PCM may be associated with lower stroke recurrence risk.

Plasma levels of miRNA-1-3p are associated with subclinical atrial fibrillation in patients with cryptogenic stroke.

INTRODUCTION AND OBJECTIVES: Identifying biomarkers of subclinical atrial fibrillation (AF) is of most interest in patients with cryptogenic stroke (CrS). We sought to evaluate the circulating microRNA (miRNA) profile of patients with CrS and AF compared with those in persistent sinus rhythm. METHODS: Among 64 consecutive patients with CrS under continuous monitoring by a predischarge insertable monitor, 18 patients (9 with AF and 9 in persistent sinus rhythm) were selected for high-throughput determination of 754 miRNAs. Nine patients with concomitant stroke and AF were also screened to improve the yield of miRNA selection. Differentially expressed miRNAs were replicated in an independent cohort (n=46). Biological markers were stratified by the median and included in logistic regression analyses to evaluate their association with AF at 6 and 12 months. RESULTS: Eight miRNAs were differentially expressed between patients with and without AF. In the replication cohort, miR-1-3p, a gene regulator involved in cardiac arrhythmogenesis, was the only miRNA to remain significantly higher in patients with CrS and AF vs those in sinus rhythm and showed a modest association with AF burden. High (= above the median) miR-1-3p plasma values, together with a low left atrial ejection fraction, were independently associated with the presence of AF at 6 and 12 months. CONCLUSIONS: In this cohort, plasma levels of miR-1-3p were elevated in CrS patients with subsequent AF. Our results preliminarily suggest that miR-1-3p could be a novel biomarker that, together with clinical parameters, could help identify patients with CrS and a high risk of occult AF.

Risk factors analysis according to regional distribution of white matter hyperintensities in a stroke cohort.

OBJECTIVES: The spectrum of distribution of white matter hyperintensities (WMH) may reflect different functional, histopathological, and etiological features. We examined the relationships between cerebrovascular risk factors (CVRF) and different patterns of WMH in MRI using a qualitative visual scale in ischemic stroke (IS) patients. METHODS: We assembled clinical data and imaging findings from patients of two independent cohorts with recent IS. MRI scans were evaluated using a modified visual scale from Fazekas, Wahlund, and Van Swieten. WMH distributions were analyzed separately in periventricular (PV-WMH) and deep (D-WMH) white matter, basal ganglia (BG-WMH), and brainstem (B-WMH). Presence of confluence of PV-WMH and D-WMH and anterior-versus-posterior WMH predominance were also evaluated. Statistical analysis was performed with SPSS software. RESULTS: We included 618 patients, with a mean age of 72 years (standard deviation [SD] 11 years). The most frequent WMH pattern was D-WMH (73%). In a multivariable analysis, hypertension was associated with PV-WMH (odds ratio [OR] 1.79, 95% confidence interval [CI] 1.29-2.50, p = 0.001) and BG-WMH (OR 2.13, 95% CI 1.19-3.83, p = 0.012). Diabetes mellitus was significantly related to PV-WMH (OR 1.69, 95% CI 1.24-2.30, p = 0.001), D-WMH (OR 1.46, 95% CI 1.07-1.49, p = 0.017), and confluence patterns of D-WMH and PV-WMH (OR 1.62, 95% CI 1.07-2.47, p = 0.024). Hyperlipidemia was found to be independently related to brainstem distribution (OR 1.70, 95% CI 1.08-2.69, p = 0.022). CONCLUSIONS: Different CVRF profiles were significantly related to specific WMH spatial distribution patterns in a large IS cohort. KEY POINTS: • An observational study of WMH in a large IS cohort was assessed by a modified visual evaluation. • Different CVRF profiles were significantly related to specific WMH spatial distribution patterns. • Distinct WMH anatomical patterns could be related to different pathophysiological mechanisms.

Increased COVID-19 Mortality in People With Previous Cerebrovascular Disease: A Population-Based Cohort Study.

BACKGROUND: The aim of the study was to determine the association between previous stroke and mortality after coronavirus disease 2019 (COVID-19) according to sex, age groups, and stroke subtypes. METHODS: Prospective population-based cohort study including all COVID-19 positive cases between February 1 and July 31, 2020. Comorbidities and mortality were extracted using linked health administration databases. Previous stroke included transient ischemic attack, ischemic stroke, hemorrhagic stroke, spontaneous subarachnoid hemorrhage, and combined stroke for cases with more than one category. Other comorbidities were obesity, diabetes, hypertension, ischemic heart disease, atrial fibrillation, heart failure, chronic obstructive pulmonary disease, chronic kidney disease, cirrhosis, dementia, individual socioeconomic index, and deprivation index. Cases were followed up until December 31, 2020. Primary outcome was mortality of any cause after COVID-19 positivity. Cox proportional regression analysis adjusted for comorbidities was used. Stratified analyses were performed for sex and age (<60, 60-79, and ≥80 years). RESULTS: There were 91 629 COVID-19 cases. Previous strokes were 5752 (6.27%), of which 3887 (67.57%) were ischemic, 1237 (21.50%) transient ischemic attack, 255 (4.43%) combined, 203 (3.53%) hemorrhagic, and 170 (2.96%) subarachnoid hemorrhage. There were 9512 deaths (10.38%). Mortality was associated with previous stroke (hazard ratio [HR]=1.12 [95% CI, 1.06-1.18]; P<0.001), in both sexes separately (men=1.13 [1.05-1.22]; P=0.001; women=1.09 [1.01-1.18]; P=0.023), in people <60 years (HR=2.97 [1.97-4.48]; P<0.001) and 60 to 79 years (HR=1.32 [1.19-1.48]; P<0.001) but not in people ≥80 years (HR=1.02 [0.96-1.09]; P=0.437). Ischemic (HR=1.11 [1.05-1.18]; P=0.001), hemorrhagic (HR=1.53 [1.20-1.96]; P=0.001) and combined (HR=1.31 [1.05-1.63]; P=0.016) strokes were associated but not transient ischemic attack. Subarachnoid hemorrhage was associated only in people <60 years (HR=5.73 [1.82-18.06]; P=0.003). CONCLUSIONS: Previous stroke was associated with a higher mortality in people younger than 80 years. The association occurred for both ischemic and hemorrhagic stroke but not for transient ischemic attack. These data might help healthcare authorities to establish prioritization strategies for COVID-19 vaccination.

Epigenetic Clock Explains White Matter Hyperintensity Burden Irrespective of Chronological Age.

In this manuscript we studied the relationship between WMH and biological age (B-age) in patients with acute stroke. We included in this study 247 patients with acute stroke recruited at Hospital del Mar having both epigenetic (DNA methylation) and magnetic resonance imaging data. WMH were measured using a semi-automated method. B-age was calculated using two widely used methods: the Hannum and Horvath formulas. We used multiple linear regression models to interrogate the role of B-age on WMH volume after adjusting for chronological age (C-age) and other covariables. Average C-age of the sample was 68.4 (±11.8) and we observed a relatively high median WMH volume (median = 8.8 cm3, Q1-Q3 = 4.05-18.8). After adjusting for potential confounders, we observed a significant effect of B-ageHannum on WMH volume (ßHannum = 0.023, p-value = 0.029) independently of C-age, which remained significant (ßC-age = 0.021, p-value = 0.036). Finally, we performed a mediation analysis, which allowed us to discover that 42.7% of the effect of C-age on WMH is mediated by B-ageHannum. On the other hand, B-ageHoarvath showed no significant associations with WMH after being adjusted for C-age. In conclusion, we show for the first time that biological age, measured through DNA methylation, contributes substantially to explain WMH volumetric burden irrespective of chronological age.