Lower hazard ratio for death in women with cerebral hemorrhage

Sex Differences in Case Fatality of Aneurysmal Subarachnoid Hemorrhage: A Systematic Review

INTRODUCTION

Aneurysmal subarachnoid hemorrhage (SAH) is more common in women than in men, contrary to most cardiovascular diseases. However, it is unclear whether the case fatality rate (CFR) of SAH also differs by sex. Thus, we performed a systematic review to address the relationship between sex and SAH CFRs.

METHODS

We conducted a systematic literature search in PubMed, Scopus, and Cochrane library databases. We focused on population-based studies that included both nonhospitalized and hospitalized SAHs and had either reported 1-month (28-31 day) SAH CFRs separately for men and women or calculated risk estimates for SAH CFR by sex. For quality classification, we used the Cochrane Collaboration Handbook and Critical Appraisal Skills Program guidelines. We pooled the study cohorts and calculated relative risk ratios (RRs) with 95% confidence intervals (CIs) for SAH death between women and men using a random-effects meta-analysis model.

RESULTS

The literature search yielded 5,592 initial publications, of which 33 study cohorts were included in the final review. Of the 33 study cohorts, only three reported significant sex differences, although the findings were contradictory. In the pooled analysis of all 53,141 SAH cases (60.3% women) from 26 countries, the 1-month CFR did not differ (RR = 0.99 [95% CI: 0.93-1.05]) between women (35.5%) and men (35.0%). According to our risk-of-bias evaluation, all 33 study cohorts were categorized as low quality. The most important sources of bias risks were related to the absence of proper confounding control (all 33 study cohorts), insufficient sample size (27 of 33 study cohorts), and poor/unclear diagnostic accuracy (27 of 33 study cohorts).

CONCLUSION

Contrary to SAH incidence rates, the SAH CFRs do not seem to differ between men and women. However, since none of the studies were specifically designed to examine the sex differences in SAH CFRs, future studies on the topic are warranted.

Development of a 3D Brain Model to Study Sex-Specific Neuroinflammation After Hemorrhagic Stroke

Subarachnoid hemorrhage (SAH) accounts for 5% of stroke, with women having a decreased inflammatory response compared to men; however, this mechanism has yet to be identified. One hurdle in SAH research is the lack of human brain models. Studies in murine models are helpful, but human models should be used in conjunction for improved translatability. These observations lead us to develop a 3D system to study the sex-specific microglial and neuroglial function in a novel in vitro human SAH model and compare it to our validated in vivo SAH model. Our lab has developed a 3D, membrane-based in vitro cell culture system with human astrocytes, microglia, and neurons from both sexes. The 3D cultures were incubated with male and female cerebrospinal fluid from SAH patients in the Neuro-ICU. Furthermore, microglial morphology, erythrophagocytosis, microglial inflammatory cytokine production, and neuronal apoptosis were studied and compared with our murine SAH models. The human 3D system demonstrated intercellular interactions and proportions of the three cell types similar to the adult human brain. In vitro and in vivo models of SAH showed concordance in male microglia being more inflammatory than females via morphology and flow cytometry. On the contrary, both in vitro and in vivo models revealed that female microglia were more phagocytic and less prone to damaging neurons than males. One possible explanation for the increased phagocytic ability of female microglia was the increased expression of CD206 and MerTK. Our in vitro, human, 3D cell culture SAH model showed similar results to our in vivo murine SAH model with respect to microglial morphology, inflammation, and phagocytosis when comparing the sexes. A human 3D brain model of SAH may be a useful adjunct to murine models to improve translation to SAH patients.

Association of sex and age with in-hospital mortality and complications of patients with intracerebral hemorrhage: A study from the Chinese Stroke Center Alliance

BACKGROUND AND PURPOSE

The impact of sex and age on prognosis in patients with intracerebral hemorrhage (ICH) in the Chinese population remains unclear. Our study aimed to investigate the relationship between sex and age of Chinese ICH patients and adverse prognosis.

METHODS

We used the Chinese Stroke Center Alliance database with in-hospital mortality as the primary outcome and hospital complications as the secondary outcome. Patients were divided into four groups by sex and age. Logistic regression analyses were performed to assess the association between sex and age and the prognosis of ICH patients.

RESULTS

We enrolled 60,911 ICH patients, including 22,284 young and middle-aged males, 15,651 older males, 11,948 young and middle-aged females, and 11,028 older females. After adjusting for variables, older male patients had a higher mortality rate (OR = 1.21, 95% CI 1.01-1.45), combined with more frequent hematoma expansion (OR = 1.14, 95% CI 1.03-1.26), pneumonia (OR = 1.91, 95% CI 1.81-2.03), and hydrocephalus (OR = 1.28, 95% CI 1.04-1.59). Young and middle-aged female patients had a lower mortality rate (OR = 0.74, 95% CI 0.58-0.95) and less frequent combined pneumonia (OR = 0.81, 95% CI 0.75-0.87). In-hospital mortality was not significantly different in older females compared with young and middle-aged males, but the odds of deep vein thrombosis, swallowing disorders, urinary tract infections, and gastrointestinal bleeding were significantly higher.

CONCLUSION

Among young and middle-aged patients, females are related to a lower in-hospital mortality rate from ICH. Older patients are at an increased risk of ICH complications, with higher in-hospital mortality in older men.

Red Cell Microparticles Suppress Hematoma Growth Following Intracerebral Hemorrhage in Chronic Nicotine-Exposed Rats

Spontaneous intracerebral hemorrhage (sICH) is a disabling stroke sub-type, and tobacco use is a prominent risk factor for sICH. We showed that chronic nicotine exposure enhances bleeding post-sICH. Reduction of hematoma growth is a promising effective therapy for sICH in smoking subjects. Red-blood-cell-derived microparticles (RMPs) are hemostatic agents that limit hematoma expansion following sICH in naïve rats. Considering the importance of testing the efficacy of experimental drugs in animal models with a risk factor for a disease, we tested RMP efficacy and the therapeutic time window in limiting hematoma growth post-sICH in rats exposed to nicotine. Young rats were chronically treated with nicotine using osmotic pumps. sICH was induced in rats using an injection of collagenase in the right striatum. Vehicle/RMPs were administered intravenously. Hematoma volume and neurological impairment were quantified ≈24 h after sICH. Hematoma volumes in male and female nicotine-exposed rats that were treated with RMPs at 2 h post-sICH were significantly lower by 26 and 31% when compared to their respective control groups. RMP therapy was able to limit hematoma volume when administered up to 4.5 h post-sICH in animals of both sexes. Therefore, RMPs may limit hematoma growth in sICH patients exposed to tobacco use.

Chronic Nicotine Exposure Increases Hematoma Expansion Following Collagenase-Induced Intracerebral Hemorrhage in Rats

Spontaneous intracerebral hemorrhage (sICH) is a deadly stroke subtype, and tobacco use increases sICH risk. However epidemiological studies show that, there are no confirmatory studies showing the effect of tobacco use on sICH outcome. Therefore, we evaluated the effect of chronic nicotine exposure (as a surrogate for tobacco use) on outcomes following sICH. Young male and female rats were randomly assigned to either nicotine (4.5 mg/kg b.w. per day) or vehicle (saline) treatment (2–3 weeks) groups. sICH was induced by injecting collagenase into the right striatum. Neurological score and hematoma volume were determined 24 h post-sICH. The hematoma volumes in nicotine-treated male and female rats were significantly higher by 42% and 48% when compared to vehicle-treated male and female rats, respectively. Neurological deficits measured in terms of neurological score for the nicotine-treated male and female groups were significantly higher when compared to the respective vehicle-treated male and female groups. Our results show that chronic nicotine exposure increases hematoma volume post-sICH in rats of both sexes. Identifying the mechanism of nicotine-dependent increase in hematoma growth post-sICH will be crucial to understanding the detrimental effect of tobacco use on the severity of bleeding following intracerebral hemorrhage.

Clinical effect of minimally invasive aspiration and drainage of intracranial hematoma in the treatment of cerebral hemorrhage

Objectives:

To explore the clinical value of minimally invasive aspiration and drainage of intracranial hematoma in the treatment of cerebral hemorrhage.

Methods:

Seventy-eight patients with cerebral hemorrhage who were treated in the Taian City Central Hospital and the Second Affiliated Hospital of Shandong First Medical University between June 2018 and December 2019 were selected. The patients were randomly numbered and divided into two groups by drawing lots, 39 in each group. The control group was treated with the traditional internal medicine conservative therapy, and the observation group was treated with minimally invasive intracranial hematoma aspiration and drainage. The indexes of the two groups were compared.

Results:

The efficacy rate of the observation group was significantly higher than that of the control group, and the difference was statistically significant (P<0.05). The National Institutes of Health Stroke Scale (NIHSS) score of the observation group was lower than that of the control group after treatment, and the difference was statistically significant (P<0.05). After treatment, the good recovery rate of the observation group was higher compared to the control group, and the difference had statistical significance (P<0.05). The incidence of complications in the observation group was lower than that of the control group, with a statistically significant difference (P<0.05).

Conclusion:

In the treatment of cerebral hemorrhage, minimally invasive intracranial hematoma aspiration and drainage facilitates the recovery of patients, promotes the improvement of neurological function, and has a high safety profile and an ideal prognostic quality.

Sex differences in blood pressure after stroke: a systematic review and meta-analysis

OBJECTIVES

Evidence about sex differences in blood pressure (BP) at the time of acute stroke presentation is scarce. We aimed to summarize available data on sex differences in BP at the time of acute stroke presentation, including stratification by prior history of hypertension and stroke subtype.

METHODS

We performed a systematic literature search across MEDLINE and Embase, from inception to 21 December 2018, to identify all population-based observational studies that reported BP at the time of acute stroke presentation. We extracted data on patient demographics, stroke-type (ischaemic or haemorrhagic), stroke severity, vascular risk factors, and SBP and DBP at the time of stroke presentation. Wherever possible, data were pooled for meta-analysis with weighted mean difference (WMD) and corresponding 95% confidence intervals (CI) using random effects meta-analysis.

RESULTS

We included 128 138 stroke patients from 43 studies. Women had higher SBP at presentation than men (WMD, 1.46; 95% CI, 0.65-2.26); this difference was significant in ischaemic stroke (1.49; 0.25-2.72 mmHg), but not in intracerebral haemorrhage (0.19; -4.21 to 4.59 mmHg). Meta regression show that sex differences in SBP were consistent with increasing age, stroke severity, other comorbidities and medication history.

CONCLUSION

This systematic review and meta-analysis indicates that women have higher SBP at the time of presentation with acute stroke. These differences are consistent with sex differences in hypertension patterns in older age, and may be explained by the fact that women are more likely to have a premorbid hypertension. This highlights the need for effective sex-specific blood pressure control in patients at high risk for stroke.

Stroke in women - from evidence to inequalities

Stroke is the second largest cause of disability-adjusted life-years lost worldwide. The prevalence of stroke in women is predicted to rise rapidly, owing to the increasing average age of the global female population. Vascular risk factors differ between women and men in terms of prevalence, and evidence increasingly supports the clinical importance of sex differences in stroke. The influence of some risk factors for stroke - including diabetes mellitus and atrial fibrillation - are stronger in women, and hypertensive disorders of pregnancy also affect the risk of stroke decades after pregnancy. However, in an era of evidence-based medicine, women are notably under-represented in clinical trials - despite governmental actions highlighting the need to include both men and women in clinical trials - resulting in a reduced generalizability of study results to women. The aim of this Review is to highlight new insights into specificities of stroke in women, to plan future research priorities, and to influence public health policies to decrease the worldwide burden of stroke in women.

Higher ratio of ischemic stroke to hemorrhagic stroke in summer

BACKGROUND

The aim of this study was to investigate the seasonal variation of the ratio of hemorrhagic stroke to ischemic stroke. The working hypothesis is that the ratio may vary among seasons.

METHODS

A total of 13,788 patients registered in the Kyoto Stroke Registry from 1999 to 2009 were divided into 4 groups based on the season in which stroke developed. We calculated odds ratio (OR) for the incidence of stroke as a whole, cerebral infarction (CeI), cerebral hemorrhage (CH), and subarachnoid hemorrhage (SAH) in spring, autumn, and winter setting summer as a reference. Using a logistic regression, we evaluated the seasonal variation of ORs for CH/CeI and for SAH/CeI with adjustment for age, gender, and risk factors.

RESULTS

Incidence of CeI in autumn was lower than in summer (OR: 0.93; 0.87-0.98, P = 0.013). Incidence of CH was higher in spring (OR: 1.36; 1.23-1.49, P < 0.001), in autumn (OR: 1.16; 1.05-1.28, P = 0.004), and in winter (OR: 1.37; 1.25-1.51, P < 0.001) than in summer. Incidence of SAH was higher in spring (OR: 1.51; 1.28-1.79, P < 0.001) and in winter (OR: 1.44; 1.22-1.70, P < 0.001) than in summer. OR for CH/CeI in spring, autumn, and winter were 1.28 (1.13-1.45, P < 0.001), 1.26 (1.11-1.43, P < 0.001), and 1.35 (1.19-1.53, P < 0.001), respectively. ORs for SAH/CeI were 1.46 (1.19-1.79, P < 0.001), 1.34 (1.09-1.66, P = 0.007), and 1.50 (1.22-1.84, P < 0.001), respectively.

CONCLUSIONS

Seasonal variations differed among stroke subtypes. The OR for CH/CeI and for SAH/CeI was lower in summer and higher in the rest of seasons independent of age, gender, and risk factors.

Influences of hyperlipidemia history on stroke outcome; a retrospective cohort study based on the Kyoto Stroke Registry

Background

Although hyperlipidemia is known as a risk factor of stroke, its effects on the outcome are unknown. The aim of the study is to clarify the influences of hyperlipidemia on the stroke early outcome by estimating odds ratio (OR) for sequelae requiring care and hazard ratio (HR) for death.

Methods

A total of 12617 stroke patients registered in the Kyoto Stroke Registry with information on a hyperlipidemia history. We compared patients who had hyperlipidemia history and patients who hadn’t. The OR for remaining sequelae requiring certain care on 30 day after stroke was calculated using a logistic regression in stroke as a whole and in each stroke subtype; cerebral infarction (CI), cerebral hemorrhage (CH) and subarachnoid hemorrhage (SAH). The HR for death within 30 day after stroke was estimated by the Cox regression.

Results

The OR (95% confidence interval) for remaining sequelae 30 days after stroke was 0.66 (0.60-0.73, p < 0.001) in patients with hyperlipidemia history compared with patients without hyperlipidemia history. After stratified by stroke subtypes, it was 0.75 (0.67-0.85, p < 0.001) in CI, 0.59 (0.45-0.77, p < 0.001) in CH and 0.77 (0.43-1.38, p = 0.767) in SAH. The HR (95% confidence interval) for death was 0.39 (0.31-0.48, p < 0.001) in patients with hyperlipidemia history comparing patients without hyperlipidemia history. After stratified by stroke subtypes, it was 0.45 (0.32-0.63, p < 0.001) in CI, 0.64 (0.44-0.93, p = 0.018) in CH and 0.76 (0.47-1.23, p = 0.264) in SAH. Each value was adjusted for age and sex.

Conclusions

This study suggests that the outcome is favorable for patients with hyperlipidemia history in terms of both remaining sequelae and HR for death. A factor which increases the incidence of the disease could influence on the severity of the disease in a favorable way.

Electronic supplementary material

The online version of this article (doi:10.1186/s12883-015-0297-1) contains supplementary material, which is available to authorized users.

Weekly variations of stroke occurrence: an observational cohort study based on the Kyoto Stroke Registry, Japan

OBJECTIVES

Understanding the temporal pattern of stroke onset and exploring the possible triggers are important strategies to reducing the incidence of stroke. If stroke occurs frequently on a specific day of the week, it is assumed that other factors, that is, 'triggering factors', induce stroke. The aim of the study is to investigate differences in the incidences of stroke among days of the week.

DESIGN

Hospital-based registry stroke over an 11-year period.

SETTING

Kyoto Prefecture, Japan.

PARTICIPANTS

A total of 13,788 patients with stroke identified from January 1999 to December 2009 inclusive in the entire Kyoto Prefecture and registered in the Kyoto Stroke Registry (KSR).

MAIN OUTCOME MEASURES

Patients with stroke were classified into seven groups based on the day of the week on which stroke developed. We confirmed the differences in the incidence among days using the χ(2) test and then performed multinomial logistic analysis referring to the stroke incidence on Sunday to calculate the OR and 95% CI of the stroke occurrence on each day of the week.

RESULTS

The OR (95% CI) for stroke occurring on Monday, Tuesday, Wednesday, Thursday, Friday and Saturday was 1.157 (1.030 to 1.293), 1.101 (0.981 to 1.236), 1.059 (0.943 to 1.188), 1.091 (0.972 to 1.225), 1.053 (0.938 to 1.205) and 1.074 (0.956 to 1.205), respectively. After stratification by stroke subtypes, cerebral infarction occurred more frequently on Monday than on Sunday (OR and 95% CI were 1.189 and 1.034 to 1.366, p=0.014) independent of age and gender. There was no significant day of the week variation in cerebral haemorrhage or subarachnoid haemorrhage.

CONCLUSIONS

Some factors that arise periodically appear to affect the incidence of cerebral infarction, which gradually develops over years, and this suggests an aetiological mechanism different from the conventional cumulative effect of risk factors due to long-term exposure. We propose a hypothesis that there is a 'triggering factor' for the development of cerebral infarction.