Sex Differences in Stroke Survival: 10-Year Follow-up of the Copenhagen Stroke Study Cohort

A Novel Needle Mouse Model of Vascular Cognitive Impairment and Dementia

Bilateral common carotid artery (CCA) stenosis (BCAS) is a useful model to mimic vascular cognitive impairment and dementia (VCID). However, current BCAS models have the disadvantages of high cost and incompatibility with magnetic resonance imaging (MRI) scanning because of metal implantation. We have established a new low-cost VCID model that better mimics human VCID and is compatible with live-animal MRI. The right and the left CCAs were temporarily ligated to 32- and 34-gauge needles with three ligations, respectively. After needle removal, CCA blood flow, cerebral blood flow, white matter injury (WMI) and cognitive function were measured. In male mice, needle removal led to ∼49.8% and ∼28.2% blood flow recovery in the right and left CCA, respectively. This model caused persistent and long-term cerebral hypoperfusion in both hemispheres (more severe in the left hemisphere), and WMI and cognitive dysfunction in ∼90% of mice, which is more reliable compared with other models. Importantly, these pathologic changes and cognitive impairments lasted for up to 24 weeks after surgery. The survival rate over 24 weeks was 81.6%. Female mice showed similar cognitive dysfunction, but a higher survival rate (91.6%) and relatively milder white matter injury. A novel, low-cost VCID model compatible with live-animal MRI with long-term outcomes was established.SIGNIFICANCE STATEMENT Bilateral common carotid artery (CCA) stenosis (BCAS) is an animal model mimicking carotid artery stenosis to study vascular cognitive impairment and dementia (VCID). However, current BCAS models have the disadvantages of high cost and incompatibility with magnetic resonance imaging (MRI) scanning due to metal implantation. We established a new asymmetric BCAS model by ligating the CCA to various needle gauges followed by an immediate needle removal. Needle removal led to moderate stenosis in the right CCA and severe stenosis in the left CCA. This needle model replicates the hallmarks of VCID well in ∼90% of mice, which is more reliable compared with other models, has ultra-low cost, and is compatible with MRI scanning in live animals. It will provide a new valuable tool and offer new insights for VCID research.

[Sex differences in stroke mortality in Thailand : A National cohort study]

BACKGROUND

Over half of the growing global stroke-mortality burden is accounted for by the East-Asian-subcontinent alone. Sex differences in stroke-mortality in the Asian population is yet to be assessed in the literature. We aimed to assess the sex-differences in mortality following stroke in a large cohort of Thai-patients.

METHOD

All stroke admissions between 2004-2015 were included from the Thailand public-health-insurance-database. The association between sex and mortality was assessed in-hospital, at 1 month, 1 year and 5 years, using multivariable Cox-regressions, separately for ischaemic-stroke (IS), haemorrhagic-stroke (HS) and stroke-of-undetermined-type(SUT), adjusting for confounders.

RESULTS

608,890 patients were included: 370,527 patients with IS(60.9%), 173,236 with HS(28.5%) and 65,127 with SUT(10.6%). Women were older than men in all three groups and had higher prevalence of comorbidities. Adjusted hazard-ratios(HRs) of mortality showed women had higher mortality post-IS compared to men (in-hospital: HR: 1.20; 95% CI: 1.17-1.23; 1 month: HR: 1.17; 95% CI: 1.15-1.20; 1 year: HR: 1.10; 95% CI: 1.09-1.12 and 5 years: HR: 1.02; 95% CI: 1.01-1.03). Women also had higher mortality after HS (in-hospital: HR: 1.02; 95% CI: 1.00-1.04; 1 month: HR: 1.08; 95% CI: 1.06-1.10; 1 year: HR: 1.04; 95% CI: 1.03-1.06 and 5 years: HR: 1.09; 95% CI: 1.08-1.11), and SUT (in-hospital: HR: 1.04; 95% CI: 1.03-1.06; 1 month: HR: 1.20; 95% CI: 1.14-1.27; 1 year: HR: 1.14; 95% CI: 1.09-1.18 and 5 years: HR: 1.06; 95% CI: 1.03-1.10).

CONCLUSIONS

Compared to men, women were older at time of stroke-diagnosis and had higher burden of stroke risk-factors. Women also had higher mortality after stroke regardless of stroke-type or duration since stroke-onset. Post-IS, excess stroke-mortality in women was greatest during the in-hospital period, whereas excess stroke-mortality increased with time in women who had HS. No clear relationship was found between duration since stroke-onset and mortality in patients who had SUT.

Gender differences in mortality of hospitalised stroke patients. Systematic review and meta-analysis

OBJECTIVE

Gender differences in mortality after stroke remains unclear in the current literature. We therefore aimed to systematically review the gender differences in mortality up to five years after ischaemic (IS) or haemorrhagic stroke (HS) to address this evidence gap.

METHODS

The literature was systematically searched using Ovid EMBASE, Ovid Medline, and Web of Science databases, from inception-November 2021. The quality of evidence was appraised using the CASP Cohort-study checklist. Unadjusted and adjusted odds and hazard ratios were meta-analysed, separately for IS and HS and a subgroup analysis of age-stratified mortality data was conducted.

RESULTS

Forty-one studies were included (n = 8,128,700; mean-age 68.5 yrs; 47.1% female). 37 studies were included in meta-analysis (n = 8, 8008, 110). Compared to men, women who had an IS had lower mortality risk in-hospital (0.94; 95%CI 0.91-0.97), at one-month (0.87; 95%CI 0.77-0.98), 12-months (0.94; 95%CI 0.91-0.98) and five-years (0.93 95%CI 0.90-0.96). The subgroup analysis showed that this gender difference in mortality was present in women ≥ 70 years up to one-month post-IS (in-hospital: 0.94; 95%CI 0.91-0.97; one-month: 0.87; 95% CI 0.77-0.98), however, in women < 70 years this difference was no longer present. Nevertheless, analysis of crude data showed women were at higher risk of mortality in-hospital, at 12-months and five-years (in-hospital: 1.05; 95%CI 1.03-1.07, 12-months: 1.10; 95%CI 1.06-1.14, five-years: 1.06; 95%CI 1.02-1.10). After HS, women had higher mortality risk in-hospital (1.03; 95%CI 1.01-1.04) however, no gender differences were found post-discharge.

CONCLUSION

The gender differences in post-stroke mortality differ by stroke type, age group and follow-up. Crude stroke mortality in women is higher than in men and this appears to be driven by pre-existing comorbidities. In adjusted models, women have a lower mortality risk following IS, independent of duration of follow-up. After HS, women had higher mortality in hospital however, no gender differences after hospital discharge were found.

Sex differences in recovery of motor function in a rhesus monkey model of cortical injury

BACKGROUND

Stroke disproportionately affects men and women, with women over 65 years experiencing increased severity of impairment and higher mortality rates than men. Human studies have explored risk factors that contribute to these differences, but additional research is needed to investigate how sex differences affect functional recovery and hence the severity of impairment. In the present study, we used our rhesus monkey model of cortical injury and fine motor impairment to compare sex differences in the rate and degree of motor recovery following this injury.

METHODS

Aged male and female rhesus monkeys were trained on a task of fine motor function of the hand before undergoing surgery to produce a cortical lesion limited to the hand area representation of the primary motor cortex. Post-operative testing began two weeks after the surgery and continued for 12 weeks. All trials were video recorded and latency to retrieve a reward was quantitatively measured to assess the trajectory of post-operative response latency and grasp pattern compared to pre-operative levels.

RESULTS

Postmortem analysis showed no differences in lesion volume between male and female monkeys. However, female monkeys returned to their pre-operative latency and grasp patterns significantly faster than males.

CONCLUSIONS

These findings demonstrate the need for additional studies to further investigate the role of estrogens and other sex hormones that may differentially affect recovery outcomes in the primate brain.

Thoracic Aortic Calcium for the Prediction of Stroke Mortality (from the Coronary Artery Calcium Consortium)

Thoracic aortic calcium(TAC) is an important marker of extracoronary atherosclerosis with established predictive value for all-cause mortality. We sought to explore the predictive value of TAC for stroke mortality, independent of the more established coronary artery calcium (CAC) score. The CAC Consortium is a retrospectively assembled database of 66,636 patients aged ≥18 years with no previous history of cardiovascular disease, baseline CAC scans for risk stratification, and follow-up for 12 ± 4 years. CAC scans capture the adjacent thoracic aorta, enabling assessment of TAC from the same images. TAC was available in 41,066 (62%), and was primarily analyzed as present or not present. To account for competing risks for nonstroke death, we utilized multivariable-adjusted Fine and Gray competing risk regression models adjusted for traditional cardiovascular risk factors and CAC score. The mean age of participants was 53.8 ± 10.3 years, with 34.4% female. There were 110 stroke deaths during follow-up. The unadjusted subdistribution hazard ratio (SHR) for stroke mortality in those who had TAC present compared with those who did not was 8.80 (95% confidence interval [CI]: 5.97, 12.98). After adjusting for traditional risk factors and CAC score, the SHR was 2.21 (95% CI:1.39,3.49). In sex-stratified analyses, the fully adjusted SHR for females was 3.42 (95% CI: 1.74, 6.73) while for males it was 1.55 (95% CI: 0.83, 2.90). TAC was associated with stroke mortality independent of CAC and traditional risk factors, more so in women. The presence of TAC appears to be an independent risk marker for stroke mortality.

Heterogeneity among women with stroke: health, demographic and healthcare utilization differentials

BACKGROUND

Although age specific stroke rates are higher in men, women have a higher lifetime risk and are more likely to die from a stroke. Despite this increased severity, most studies focus on male/female differences in stroke onset, patterns of care and stroke-related outcomes. Given that stroke presents differently in men and women, mixed sex studies fail to fully capture heterogeneity among women with stroke and the subsequent impact on their outcomes. This study examined the sociodemographic characteristics, factors related to stroke incidence and post-stroke functional status between young (< 60) and old (≥ 60) women with stroke.

METHODS

Using 5 years of data from the National Health Interview Survey (NHIS), a nationally representative sample of US adults, cohorts of young and old women with stroke were identified. A set of demographic/lifestyle, health services utilization and health status characteristics were used evaluate within gender heterogeneity in three ways. First, disparities in population characteristics were assessed using Chi-Square and t tests. Second, young and old women with stroke were matched with women without stroke in their respective cohorts to determine differences in factors related to stroke incidence. Finally, the determinants of post-stroke functional limitation for the two cohorts were determined.

RESULTS

Young women with stroke were more likely to be Black, smoke regularly and frequently consume alcohol than older women. Young women were also less likely to engage with their health provider regularly or receive preventative health screenings. Diabetes, high blood pressure, high cholesterol and high BMI were correlated with an increased relative likelihood of stroke among older women. In contrast, family size, smoking frequency, alcohol consumption and sleep were correlated with an increased prevalence of stroke among young women. Although factors correlated with stroke varied between young and old women, health status and receipt of healthcare were the most significant determinants of post-stroke functional status for both cohorts.

CONCLUSIONS

Health related characteristics were the primary correlates of stroke in older women, whereas post-stroke lifestyle and behaviors are the most significant correlates for younger stroke survivors. These findings suggest that while receipt of health services is essential for preventing stroke in both young and old women, providers should stress the importance of post-stoke lifestyle and behaviors to younger women at risk of stroke using approaches that may be different from older stroke women.

Modeling Survival in Patients With Brain Stroke in the Presence of Competing Risks

Objectives

After heart disease, brain stroke (BS) is the second most common cause of death worldwide, underscoring the importance of understanding preventable and treatable risk factors for the outcomes of BS. This study aimed to model the survival of patients with BS in the presence of competing risks.

Methods

This longitudinal study was conducted on 332 patients with a definitive diagnosis of BS. Demographic characteristics and risk factors were collected by a validated checklist. Patients’ mortality status was investigated by telephone follow-up to identify deaths that may be have been caused by stroke or other factors (heart disease, diabetes, high cholesterol, etc.). Data were analyzed by the Lunn-McNeil approach at alpha=0.1.

Results

Older age at diagnosis (59–68 years: adjusted hazard ratio [aHR], 2.19; 90% confidence interval [CI], 1.38 to 3.48; 69–75 years: aHR, 5.04; 90% CI, 3.25 to 7.80; ≥76 years: aHR, 5.30; 90% CI, 3.40 to 8.44), having heart disease (aHR, 1.65; 90% CI, 1.23 to 2.23), oral contraceptive pill use (women only) (aHR, 0.44; 90% CI, 0.24 to 0.78) and ischemic stroke (aHR, 0.52; 90% CI, 0.36 to 0.74) were directly related to death from BS. Older age at diagnosis (59–68 years: aHR, 21.42; 90% CI, 3.52 to 130.39; 75–69 years: aHR, 16.48; 90% CI, 2.75 to 98.69; ≥76 years: aHR, 26.03; 90% CI, 4.06 to 166.93) and rural residence (aHR, 2.30; 90% CI, 1.15 to 4.60) were directly related to death from other causes. Significant risk factors were found for both causes of death.

Conclusions

BS-specific and non-BS-specific mortality had different risk factors. These findings could be utilized to prescribe optimal and specific treatment.

Carotid artery intima-media thickness, HDL cholesterol levels, and gender associated with poor visual acuity in patients with branch retinal artery occlusion

PURPOSE

To investigate factors associated with poor visual acuity (VA) in branch retinal artery occlusion (BRAO).

METHODS

This was a retrospective cross-sectional study of 72 eyes with BRAO of 72 patients. For statistical comparison, we divided the patients into worse-VA (decimal VA < 0.5) and better-VA (decimal VA > = 0.5) groups. We examined the association of clinical findings, including blood biochemical test data and carotid artery ultrasound parameters, with poor VA.

RESULTS

Median age, hematocrit, hemoglobin and high-density lipoprotein (HDL) differed significantly between the groups (P = 0.018, P < 0.01, P < 0.01, and P = 0.025). There was a tendency towards higher median IMT-Bmax in the worse-VA group (worse-VA vs. better-VA: 2.70 mm vs. 1.60 mm, P = 0.152). Spearman's rank correlation test revealed that logMAR VA was significantly correlated to IMT-Bmax (rs = 0.31, P < 0.01) and IMT-Cmax (rs = 0.24, P = 0.035). Furthermore, logMAR VA was significantly correlated to HDL level (rs = -0.33, P < 0.01). Multivariate logistic regression analysis revealed that IMT-Bmax (odds ratio [OR] = 2.70, P = 0.049), HDL level (OR = 0.91, P = 0.032), and female gender (OR = 15.63, P = 0.032) were independently associated with worse VA in BRAO.

CONCLUSIONS

We found that increased IMT-Bmax, decreased HDL, and female sex were associated with poor VA in BRAO patients. Our findings might suggest novel risk factors for visual dysfunction in BRAO and may provide new insights into the pathomechanisms underlying BRAO.

Sex differences in stroke

Sex disparities within the field of stroke, including subarachnoid hemorrhages (SAHs), have been in focus during the last 2 decades. It is clear that stroke incidence is higher in men, and also that men have their first stroke earlier than women. On the other hand, women have more severe strokes, mainly because cardioembolic strokes are more common in women. This leads to higher case fatality and worse functional outcome in women. It has often been pointed out that women more often have nontraditional stroke symptoms, and therefore may seek medical help later. After discharge from the hospital, female stroke survivors live alone in many cases and are dependent on external care. Therefore, these women frequently rate their quality of life (QoL) lower than men do. Female spouses more often provide help to their male stroke survivors than the reverse, and they accept a heavier burden. These caregivers are at high risk for depression, low QoL, and low psychologic wellbeing. SAH is a special form of stroke, often caused by a ruptured aneurysm. It is about 20% more common in women. The case fatality is high, but does not differ between the sexes.

Neuroimaging evolution of ischemia in men and women: an observational study

Objective

We present an exploratory study for identification of sex differences in imaging biomarkers that could further refine selection of patients for acute reperfusion therapy and trials based on sex and imaging targets.

Methods

The Lesion Evolution in Stroke and Ischemia On Neuroimaging (LESION) study included consecutive acute stroke patients who underwent MRI within 24 h of time from last known well and prior to therapy. Those demonstrating a potential therapeutic target on imaging were identified by presence of: (1) arterial occlusion on angiography, (2) focal ischemic region on perfusion maps, or (3) a mismatch of perfusion versus diffusion imaging lesion size. The prevalence of imaging targets within clinically relevant time intervals was calculated for each patient and examined. The relationship of time from stroke onset to probability of detection of imaging targets was evaluated.

Results

Of 7007 patients screened, of which 86.7% were scanned with MRI, 1092 patients (477/615 men/women) were included in LESION. The probability of imaging target detection was significantly different between men and women, with women more likely to present with all assessed imaging targets, odds ratios between 1.36 and 1.59, P < 0.02, adjusted for NIHSS, age, and time from last known well to MRI scan. This trend held for the entire 24‐h studied.

Interpretation

Women present more often with treatable ischemic stroke than men. The greater probability of potentially viable and/or treatable imaging targets in women at all time points suggests that tissue injury is slower to evolve in women.

CCL2 and CXCL10 are associated with poor outcome after intracerebral hemorrhage

OBJECTIVE

Intracerebral hemorrhage carries a high mortality and survivors are frequently left with significant disability. Immunological mechanisms may play an important role in hemorrhage-induced brain injury, however, research linking these mechanisms with clinical outcome remains limited. We aim to identify serum inflammatory mediators that are associated with outcome after intracerebral hemorrhage in order to translate data from experimental models to a patient cohort and identify potential targets worthy of reverse translation.

METHODS

A prospective cohort study at two comprehensive stroke centers enrolled patients with spontaneous intracerebral hemorrhage. Peripheral blood was collected at 6, 24, and 72 h from onset. Functional outcome was assessed at 90 days using the modified Rankin Scale (mRS). Serum inflammatory mediators were measured using multiplex ELISA. Multivariable modeling identified serum biomarkers independently associated with functional outcome at 90 days.

RESULTS

115 patients completed the study. At 6 h after onset, patients with elevated CCL2 had worse mRS score at day 90 (OR 4.07, 95% CI 1.27-13.10, P = 0.02) after adjusting for age, gender, ICH volume, IVH, infratentorial location and NIHSS score. At 24 and 72 h after onset, elevation in CXCL10 was independently associated with worse 90 days mRS score (24 h: OR 8.08, 95% CI 2.69-24.30, P < 0.001; 72 h: OR 3.89, 95% CI 1.12-13.49, P = 0.03).

INTERPRETATION

Acute and subacute elevations in specific immune factors are associated with poor outcome, highlighting potential pathways that may contribute to ongoing brain injury in patients with intracerebral hemorrhage.

Stroke in-hospital survival and its predictors: the first results from Tabriz Stroke Registry of Iran

OBJECTIVE

The aim of this study was to determine the in-hospital survival of patients referred to the 2 stroke centers in North-West of Iran during a full seasonal year from April 2015.

METHODS

All the consecutive patients with stroke admitted to the 2 main stroke centers at Tabriz (Imam Reza University Hospital and Razi University Hospital) were recruited in this study. Stroke patients from both ischemic and hemorrhagic subtypes were selected based on the registry data and International Classification of Diseases, 10th edition. At admission, details of examination including vital signs, neurologic and systemic examination, Modified Rankin Scale, and Glasgow Coma Scale were recorded. Baseline hematological and biochemical parameter assessments as well as computerized tomographic scanning were conducted. Cox regression was used to investigate and detect potential predictors of in-hospital survival.

RESULTS

A total of 1,990 patients with stroke were studied. Males comprised 52.1% (1,036) of the subjects. The mean age of the patients was 65.8 years. Three hundred and fifty-seven (17.9%) patients had hemorrhagic stroke vs 1,633 (82.1%) with ischemic stroke. In-hospital case-fatality proportion was 12.5% (95% CI: 11.1-14). Based on modified Rankin Scale score at admission, 1,377 of 1,990 patients (69.2%) had a poor outcome (modified Rankin Scale score ≥3) at the admission time. The regression analysis showed that at least 7 variables could independently predict hospital survival of patients with stroke including age ≥65 years, higher admission modified Rankin Scale score, lower admission Glasgow Coma Scale score, hemorrhagic stroke nature, diabetes, having valvular heart disease, and having aspiration pneumonia.

CONCLUSION

The case-fatality of stroke in the present study setting is high and needs to be appropriately addressed through prevention or management of some of these factors such as diabetes, pneumonia, and valvular heart diseases.

Stroke Mortality in Kenya's Public Tertiary Hospitals: A Prospective Facility-Based Study

Background

Despite the increasing global burden of stroke, there are limited data on stroke from Kenya to guide in decision-making. Stroke occurrence in sub-Saharan Africa has been associated with poor health outcomes. This study sought to establish the stroke incidence density and mortality in Kenya's leading public tertiary hospitals for purposes of informing clinical practice and policy.

Methods

This is a prospective study conducted at Kenya's leading referral hospitals, namely, Kenyatta National Hospital (KNH) and Moi Teaching and Referral Hospital (MTRH). Adult patients with confirmed cases of stroke were recruited from February 2015 to January 2016 and followed up for a minimum period of 1 year. The WHO 2006 Stroke STEPS instrument was used to collect data on incidence and mortality at days 10 and 28 and every 3 months for 24 months. The person-time of follow-up was computed from admission to death, loss to follow-up, or the end of the study. A survival regression analysis was done using the Cox proportional hazards model.

Results

A total of 719 patients were recruited (KNH: n = 406 [56.5%]; MTRH: n = 313 [43.5%]). The mean age was 58.6 ± 18.7 years, and the male-to-female ratio was 1: 1.4. Ischemic stroke accounted for 56.1% of the stroke cases. The peak age for stroke was between 50 and 69 years, when 36.3% of the cases occurred. Mortality at day 10 and day 28 was 18.4 and 26.7%, respectively. The inpatient mortality rate was 21.6%. The stroke incidence density was 507 deaths per 1,000 person-years of follow-up. The mean survival time was significantly different between inpatients (13.9 months; 95% CI: 13.0–14.7) and outpatients (18.6 months; 95% CI: 17.2–19.9) (p < 0.001). A 1-year increase in age increased the hazard by 1.8%. Inpatients had a 3.9-fold increase in hazard compared to outpatients.

Conclusions

Mortality due to stroke is high, with poor survival observed in the first year after stroke. The risk of death increases with increasing age and duration of hospital stay. There is need for attention to quality of care and long-term needs of stroke patients to mitigate the high mortality rates observed. Public health initiatives aimed at early screening and diagnosis should be enhanced. Further research is recommended to establish the true burden of stroke at the community level to inform appropriate mitigation measures.

Characteristics of hospitalizations due to acute stroke in the Silesian Province, Poland, between 2009 and 2015

INTRODUCTION

The available data on acute stroke (AS) in Poland come mainly from non-representative cohorts or are outdated. Therefore, the current study was done to access the most recent data on AS in the industrial region that covers 12% (4.6mln) of the country's population.

OBJECTIVE

To evaluate the epidemiological data of AS in the Silesian Province, Poland.

PATIENTS AND METHODS

Analysis of the data from stroke questionnaires, obligatory for all patients hospitalized due to AS and administered by the only public health insurer in Poland (the National Health Fund) between 2009 and 2015 (n=81,193).

RESULTS

The annual number of hospitalizations due to AS in the analyzed period was between 239 and 259 per 100,000 inhabitants of the Silesian Province. Haemorrhagic stroke constituted 13.3%, ischaemic stroke - 85.5%, and unspecified stroke - 1.2%. The average age of patients was 71.6±12.2 years (M 68.2±11.9, F 74.8±11.9, P<0.05). The mean duration of hospitalization was 17±16 days for haemorrhagic stroke, and 14±11 days for ischaemic stroke. Large-artery atherosclerosis (36.1%) and cardioembolism (18.7%) constituted the main causes of ischaemic stroke. Overall hospital mortality for AS was 18% (haemorrhagic - 40.8%, ischaemic - 14.9%). A decreasing trend in mortality was observed in ischaemic but not in haemorrhagic stroke. In-hospital mortality was significantly higher in women than in men (P<0.05).

CONCLUSIONS

This comprehensive long-term analysis of the epidemiological situation related to AS in the industrial region of Poland should encourage further development of educational and treatment programmes for improvement in the health status of the population.

Confounding by Pre-Morbid Functional Status in Studies of Apparent Sex Differences in Severity and Outcome of Stroke

BACKGROUND AND PURPOSE

Several studies have reported unexplained worse outcomes after stroke in women but none included the full spectrum of symptomatic ischemic cerebrovascular events while adjusting for prior handicap.

METHODS

Using a prospective population-based incident cohort of all transient ischemic attack/stroke (OXVASC [Oxford Vascular Study]) recruited between April 2002 and March 2014, we compared pre-morbid and post-event modified Rankin Scale score (mRS) in women and men and change in mRS score 1 month, 6 months, 1 year, and 5 years after stroke. Baseline stroke-related neurological impairment was measured with the National Institutes of Health Stroke Scale.

RESULTS

Among 2553 patients (50.6% women) with a first transient ischemic attack/ischemic stroke, women had a worse handicap 1 month after ischemic stroke (age-adjusted odds ratio for mRS score, 1.35; 95% confidence interval, 1.12-1.63). However, women also had a higher pre-morbid mRS score compared with men (age-adjusted odds ratio, 1.58; 95% confidence interval, 1.36-1.84). There was no difference in stroke severity when adjusting for age and pre-morbid mRS (odds ratio, 1.10; 95% confidence interval, 0.90-1.35) and no difference in the pre-/poststroke change in mRS at 1 month (age-adjusted odds ratio, 1.00; 95% confidence interval, 0.82-1.21), 6 months, 1 year, and 5 years. Women had a lower mortality rate, and there was no sex difference in risk of recurrent stroke.

CONCLUSIONS

We found no evidence of a worse outcome of stroke in women when adjusting for age and pre-morbid mRS. Failure to account for sex differences in pre-morbid handicap could explain contradictory findings in previous studies. Properties of the mRS may also contribute to these inconsistencies.

Intracerebral hemorrhage at young age: long-term prognosis

BACKGROUND AND PURPOSE

Intracerebral hemorrhage (ICH) is a devastating disorder associated with dismal outcomes. The long-term mortality and functional outcome of ICH in young patients was studied - areas so far poorly investigated.

METHODS

A follow-up study was performed on a cohort of patients. Clinical and imaging data on ICH patients aged 16-49 were retrospectively obtained and linked with a nationwide cause-of-death register. The modified Rankin Scale (mRS) was evaluated for 30-day survivors at a visit 9.7 (7.0-12.0) years after ICH onset. Independent factors associated with mortality and unfavorable functional outcome (mRS 2-5) were sought by multivariate analysis.

RESULTS

Amongst the 268 1-month survivors, 1-year survival was 98.1% [95% confidence interval (CI) 96.2%-100%], 5-year survival 93.2% (89.3%-97.1%) and 10-year survival 88.8% (84.9%-92.7%). After adjustment for age and intraventricular hematoma extension, male sex [odds ratio (OR) 3.36, 95% CI 1.28-8.80] and diabetes (OR 2.64, 1.01-6.89) were associated with increased mortality. Unfavorable functional outcome emerged in 49%. After adjustment for confounders, age (OR 1.09 per 1 year, 95% CI 1.03-1.15), initial stroke severity (1.17 per one National Institutes of Health Stroke Scale score point, 1.08-1.27) and intraventricular hemorrhage (3.26, 1.11-9.55) were associated with unfavorable functional outcome.

CONCLUSIONS

Of every 10 survivors of acute phase ICH at a young age, one died within 10 years after onset, male sex and diabetes being associated with increased mortality. Half the survivors did not achieve a favorable functional outcome, which was predicted by increasing age, initial stroke severity and intraventricular hemorrhage.

Impact of gender-age interaction on the outcome of ischemic stroke in an Italian cohort of patients treated according to a standardized clinical pathway

BACKGROUND

Stroke outcome has been reported as worse in women, especially in terms of disability. As for mortality, the data are conflicting, with some reports suggesting a female advantage. Our objective was to explore such issues in an Italian cohort of patients managed by a standardized clinical pathway (CPW) and, as such, homogeneous in terms of clinical management.

METHODS

Data from a cohort of 1993 patients (987 women and 1006 men) with first-ever ischemic stroke, consecutively referred to an in-hospital Clinical Pathway Program from January 1, 2001 to December 31, 2009, were retrospectively analyzed. The relationship between female gender and one-month outcome was assessed with adjustment for age, stroke severity and premorbid disability.

RESULTS

The outcome was worse in women in terms of disability (age-adjusted odds ratio 2.03, 95% CI 1.69-2.46), while no difference was found for mortality. In multivariate models, female gender turned out to be associated with a lower case-fatality rate (adjusted hazard ratio 0.65, 95% CI 0.48-0.89, P=0.007), whereas the odds ratio for disability decreased but remained significant (OR 1.30; 95% CI 1.01-1.69). We found a significant interaction between gender and age in the case-fatality rate, and a female survival advantage was apparent only below 50 years.

CONCLUSIONS

Our study confirms the excess risk of disability after stroke in women, although it is mostly explained by the occurrence of the most severe clinical syndromes. As for mortality, female gender seems to play a protective role, at least in the short-term and in younger patients.

5-year survival and rehospitalization due to stroke recurrence among patients with hemorrhagic or ischemic strokes in Singapore

Background

Stroke is the 4th leading cause of death and 1st leading cause of disability in Singapore. However the information on long-term post stroke outcomes for Singaporean patients was limited. This study aimed to investigate the post stroke outcomes of 5-year survival and rehospitalization due to stroke recurrence for hemorrhagic and ischemic stroke patients in Singapore. The outcomes were stratified by age, ethnic group, gender and stroke types. The causes of death and stroke recurrence were also explored in the study.

Methods

A multi-site retrospective cohort study. Patients admitted for stroke at any of the three hospitals in the National Healthcare Group of Singapore were included in the study. All study patients were followed up to 5 years. Kaplan-Meier was applied to study the time to first event, death or rehospitalization due to stroke recurrence. Cox proportional hazard model was applied to study the time to death with adjustment for stroke type, age, sex, ethnic group, and admission year. Cumulative incidence model with competing risk was applied for comparing the risks of rehospitalization due to stroke recurrence with death as the competing risk.

Results

Totally 12,559 stroke patients were included in the study. Among them, 59.3% survived for 5 years; 18.4% were rehospitalized due to stroke recurrence in 5 years. The risk of stroke recurrence and mortality increased with age in all stroke types. Gender, ethnic group and admitting year were not significantly associated with the risk of mortality or stroke recurrence in hemorrhagic stroke. Male or Malay patient had higher risk of stroke recurrence and mortality in ischemic stroke. Hemorrhagic stroke had higher early mortality while ischemic stroke had higher recurrence and late mortality. The top cause of death among died stroke patients was cerebrovascular diseases, followed by pneumonia and ischemic heart diseases. The recurrent stroke was most likely to be the same type as the initial stroke among rehospitalized stroke patients.

Conclusions

Five year post-stroke survival and rehospitalization due to stroke recurrence as well as their associations with patient demographics were studied for different stroke types in Singapore. Specific preventive strategies are needed to target the high risk groups to improve their long-term outcomes after acute stroke.

Sex differences in revascularization interventions after acute ischemic stroke

BACKGROUND

Studies suggest that women are less likely than men to receive intravenous (IV) tissue plasminogen activator (tPA) for acute ischemic stroke (AIS). Relatively little is known about whether this sex disparity in AIS management extends beyond IV tPA use, reflects national practice patterns, or is changing.

METHODS

Data from the Nationwide Inpatient Sample from 1997 to 2006 were used to identify adults (≥18 years of age) who were discharged with a primary diagnosis of AIS (n = 4,453,207) in the United States. Of 605,960 individuals admitted to 1056 hospitals that performed reperfusion/revascularization procedures, sex-specific rates of cerebrovascular reperfusion (e.g., IV tPA, intra-arterial therapy, angioplasty, stent, or carotid endarterectomy [CEA]), and cardiac reperfusion (e.g., catheterization, angioplasty, stent, or bypass graft) were determined before and after adjustment for sociodemographic, clinical, and hospital factors.

RESULTS

Men were more likely than women to receive IV tPA (prevalence ratio [PR] 1.37, 95% confidence interval [CI] 1.32-1.42), catheter angiography (PR 1.36, 95% CI 1.33-1.38), intracranial or extracranial angioplasty/stent (PR 1.73, 95% CI 1.49-2.01), CEA (PR 1.79, 95% CI 1.72-1.86), or any cardiac reperfusion therapy (PR 1.62, 95% CI 1.53-1.71). Multivariable adjustment slightly attenuated the sex disparity. Use of all procedures except CEA rose from 1997 to 2006 in both sexes, but IV tPA use increased at a higher rate for women (compared to men); by 2006, there was no sex difference.

CONCLUSIONS

Over the last decade, women hospitalized for AIS in the United States were less likely than men to receive cerebrovascular and cardiac reperfusion therapies. However, the IV tPA treatment sex disparity may have been eliminated.

Evaluating Random Forests for Survival Analysis using Prediction Error Curves

Prediction error curves are increasingly used to assess and compare predictions in survival analysis. This article surveys the R package pec which provides a set of functions for efficient computation of prediction error curves. The software implements inverse probability of censoring weights to deal with right censored data and several variants of cross-validation to deal with the apparent error problem. In principle, all kinds of prediction models can be assessed, and the package readily supports most traditional regression modeling strategies, like Cox regression or additive hazard regression, as well as state of the art machine learning methods such as random forests, a nonparametric method which provides promising alternatives to traditional strategies in low and high-dimensional settings. We show how the functionality of pec can be extended to yet unsupported prediction models. As an example, we implement support for random forest prediction models based on the R-packages randomSurvivalForest and party. Using data of the Copenhagen Stroke Study we use pec to compare random forests to a Cox regression model derived from stepwise variable selection. Reproducible results on the user level are given for publicly available data from the German breast cancer study group.

Gender difference in stroke case fatality: an integrated study of hospitalization and mortality

BACKGROUND

Providing regional and state-specific prognosis factors for stroke patients has both clinical and public health importance. Results from previous studies of sex difference in stroke case fatality have been mixed. The current study links stroke hospitalizations to community-based mortality records to examine sex difference in stroke case fatality and associated prognosis factors.

METHODS

Hospital discharge data and death certificate data from January 2005 to December 2009 in Nebraska were linked. Multivariable logistic regression was used to estimate sex differences in 30-day mortality, and the Cox proportional hazard model was used to predict overall survival.

RESULTS

A total of 15,806 patients were included. Females were more likely to die during the 30 days after stroke hospitalization. However, there was no significant difference in overall survival in the multivariate analysis that controlled for age, comorbidity, and rehabilitation factors. Females were more likely to have comorbidities, such as atrial fibrillation, anemia, and heart failure, while males were more likely to have chronic kidney disease. In addition, males were more likely to receive rehabilitation services after stroke.

CONCLUSIONS

Among persons hospitalized with a stroke in Nebraska between 2005 and 2009, the crude case fatality rate was 50% higher in women. However, after accounting for age and other variables, adjusted mortality rates were essentially the same for men and women.

Risk equations to predict life expectancy of people with Type 2 diabetes mellitus following major complications: a study from Western Australia

AIMS

  To develop a model for predicting life expectancy following major diabetes-related complications and to summarize these results by age and gender in the form of a simple table.

METHODS

  Equations for forecasting mortality were derived using an observational cohort of 12,792 patients who had one of the following complications of diabetes: myocardial infarction, stroke, heart failure, amputation or renal failure, recorded in administrative health and mortality data from the state of Western Australia between 1990 and 1999. Logistic regression was used to estimate mortality within the first month post-event and a Gompertz proportional hazards model was used to estimate survival over the patients' remaining lifetime. After examining the internal validity over a 5-year period, these equations were used to estimate remaining life expectancy by age and sex following specific complications.

RESULTS

  Of the complications examined, renal failure had most impact on life expectancy at all ages, followed by heart failure; the best prognosis was following stroke, myocardial infarction and amputation. For a 60-year-old male, life expectancy immediately post-event ranged from 10.1 years (95% CI 9.4-10.8 years) for stroke to 4.3 years (95% CI 3.1-6.1 years) for renal failure. Life expectancies for women at 60 and 70 years of age were significantly lower than men following myocardial infarction and significantly higher than men following heart failure and amputation at 70 and 80 years of age.

CONCLUSION

  The model allows estimation of both survival probability and life expectancy post-event for men and women of any age. The summary table may provide a useful and simple reference for clinicians and diabetes specialists.

Female survival advantage relates to male inferiority rather than female superiority: A hypothesis based on the impact of age and stroke severity on 1-week to 1-year case fatality in 40,155 men and women

BACKGROUND

It is generally believed that differences in age, stroke characteristics, and cardiovascular risk factors account for observed sex-specific differences in stroke survival.

OBJECTIVES

We aimed to study female stroke survival advantage before and after the average age of menopause, and whether female survival advantage applies only to patients for whom stroke is the most likely cause of death.

METHODS

The Danish National Indicator Project, a registry designed to list all hospitalized stroke patients in Denmark beginning in March 2001, had 40,155 registered patients as of February 2007. All registered patients had undergone evaluation including stroke severity (as measured by the Scandinavian Stroke Scale [SSS], using a total score of 0-58, in which lower scores indicate more severe strokes), computed tomography, and cardiovascular risk factors. Patients were followed from admission until death or censoring. Case fatality (stratified by 1 week, 1 month, 3 months, and 1 year) in men and women was correlated with age and stroke severity. Adjustment for cardiovascular risk factors was performed by means of multivariate regression analysis.

RESULTS

A total of 20,854 (51.9%) men and 19,301 (48.1%) women were registered. Women were significantly older than men at the time of stroke (74.5 vs 69.7 years, respectively; P < 0.001) and had signficantly more severe strokes, as expressed by the mean SSS score (39.6 vs 43.3; P < 0.001). Stratification of 1-week to 1-year case fatality according to age and stroke severity indicated that women survived significantly better than men from the mid-fifties onward, when controlling for age, stroke severity, and cardiovascular risk factor profile. The observed female survival advantage increased with age. The female survival advantage was seen in patients with severe as well as mild strokes, but not in those younger than age 50 years.

CONCLUSIONS

Our findings dispute the effects of female sex hormones as the underlying cause of female survival superiority over men. Instead, we propose the hypothesis that the progressive deficiency of male sex hormones (testosterone), beginning in men in middle age, is the underlying cause of the gap in survival rates between men and women. Accordingly, the female survival advantage is rooted in male inferiority rather than innate female superiority.

The difference between acute coronary heart disease and ischaemic stroke risk with regard to gender and age in Finnish and Swedish populations

BACKGROUND

We studied the age and gender difference between acute coronary heart disease and ischaemic stroke risk and examined the extent to which such a difference may be explained by known risk factors.

METHODS

Data from Finnish and Swedish population-based cohorts including 9278 individuals were collaboratively analysed. Hazards ratios (95% confidence intervals) for coronary heart disease and stroke incidence were estimated using the Cox-proportional hazards model.

RESULTS

The incidence of coronary heart disease and stroke was higher in all age groups in men than in women, and the gender difference was more marked for coronary heart disease than for ischaemic stroke. There was a 10-year lag in the development of coronary heart disease and stroke in women compared with men. The multivariable adjusted hazard ratios for the incidence of coronary heart disease in men and women were 3.87 (2.49-6.02) and 1.71 (1.07-2.74) at age 50-59 years, and 7.22 (4.59-11.36) and 3.49 (2.18-5.57) at age 60-69 years compared with women aged 40-49 years. For ischaemic stroke, they were 2.64 (1.45-4.82) and 2.17 (1.18-3.97) at age 50-59 years, and 5.19 (2.81-9.58) and 4.89 (2.67-8.97) at age 60-69 years, respectively.

CONCLUSIONS

Acute coronary heart disease and ischaemic stroke events appeared approximately 10 years earlier in men than in women, and these rates remained higher in men than in women in all age groups. The gender difference was more marked for coronary heart disease than for ischaemic stroke. This may be taken into account when developing interventions and treatment strategies.

A review on sex differences in stroke treatment and outcome

BACKGROUND

Beyond epidemiological differences, it has been controversial whether any important sex differences exist in the treatment of stroke. In this review paper, the following areas are covered: thrombolysis, stroke unit care, secondary prevention, surgical treatment, and rehabilitation. Additionally, symptoms at stroke onset, as well as outcome measures, such as death, dependency, stroke recurrence, quality of life, and depression are reviewed.

METHODS

Search in PubMed, tables-of-contents, review articles, and reference lists after studies that include information about sex differences in stroke care.

RESULTS

Ninety papers are included in this review. Women suffer more from cortical and non-traditional symptoms. Men and women benefit equally from thrombolysis and stroke unit care. Women with cardioembolic strokes may benefit more from anticoagulant therapy. Most studies have not found any tendency towards sexism in the choice of treatment. Post-stroke depression and low quality-of-life seem to be more common among women. Mortality rates are higher among men in some studies, while long-term ADL-dependency seems to be more common among women.

CONCLUSIONS

Sex differences in stroke treatment and outcome are small, with no unequivocal proof of sex discrimination. Women have less favourable functional outcome because of higher age at stroke onset and more severe strokes.

Predictors of in-Hospital Mortality after Acute Stroke: Impact of Gender

The purpose of this study was to identify predictors of in-hospital mortality after acute stroke and investigate the impact of gender on stroke mortality. All patients admitted to Al-watani governmental hospital in Palestine from September 2006 to August 2007 and diagnosed with acute stroke were included in the study. Diagnosis of stroke was confirmed by computerized tomography scan. Demographics and clinical data pertaining to the patients were obtained from their medical files. The main outcome measure in this study was vital status at hospital discharge. Multiple logistic regression analysis was used to identify the independent predictors of in-hospital mortality. Statistical analysis was carried out using SPSS 15. A total of 186 acute stroke cases (95 females and 91 males) were included in the study. Hypertension (69.9%) and diabetes mellitus (45.2%) were the most common risk factors among the patients. Thirty nine (21%) of the stroke patients died in hospital. Multiple logistic regression analysis indicated that chronic kidney disease (P = 0.004), number of post-stroke complications (P = 0.037), and stroke subtype (P = 0.015) were independent predictors of in-hospital mortality among the total stroke patients. Knowledge of in-hospital mortality predictors is required to improve survival rate after acute stroke. The study showed that gender was not an independent predictor of mortality after acute stroke. More research is required to understand gender differences in stroke mortality.

Sex differences in stroke epidemiology: a systematic review

BACKGROUND AND PURPOSE

Epidemiological studies, mainly based on Western European surveys, have shown that stroke is more common in men than in women. In recent years, sex-specific data on stroke incidence, prevalence, subtypes, severity and case-fatality have become available from other parts of the world. The purpose of this article is to give a worldwide review on sex differences in stroke epidemiology.

METHODS

We searched PubMed, tables-of-contents, review articles, and reference lists for community-based studies including information on sex differences. In some areas, such as secular trends, ischemic subtypes and stroke severity, noncommunity-based studies were also reviewed. Male/female ratios were calculated.

RESULTS

We found 98 articles that contained relevant sex-specific information, including 59 incidence studies from 19 countries and 5 continents. The mean age at first-ever stroke was 68.6 years among men, and 72.9 years among women. Male stroke incidence rate was 33% higher and stroke prevalence was 41% higher than the female, with large variations between age bands and between populations. The incidence rates of brain infarction and intracerebral hemorrhage were higher among men, whereas the rate of subarachnoidal hemorrhage was higher among women, although this difference was not statistically significant. Stroke tended to be more severe in women, with a 1-month case fatality of 24.7% compared with 19.7% for men.

CONCLUSIONS

Worldwide, stroke is more common among men, but women are more severely ill. The mismatch between the sexes is larger than previously described.

Gender differences in long-term functional outcome after first-ever ischemic stroke

OBJECTIVE

Recent studies have demonstrated gender differences in functional outcome after stroke. However, the underlying reasons for differences have been inconsistent. The present study examined whether gender differences in long-term functional outcomes exist among surviving patients with first-ever ischemic stroke and with individual subtypes of stroke.

METHODS

A total of 997 patients (654 men, 343 women) were followed for 5 years after discharge. Patients were assigned to 4 subtypes of ischemic stroke (atherothrombotic, lacunar, cardioembolic and unclassified infarction). Functional outcomes were expressed as locomotor activity, assessed using a questionnaire delivered by mail 1 and 5 years after stroke. Locomotor function was classified into 5 categories according to the grade of disability.

RESULTS

Women showed significantly worse locomotor function than men at both 1 and 5 years (p < 0.001 and p < 0.01, respectively). Furthermore, significant gender differences in functional outcome were observed in all subtypes of ischemic stroke at 1 and 5 years after stroke. Logistic regression analysis revealed that gender was a significant determinant for functional outcome at 1 and 5 years after stroke (p < 0.01 and p < 0.001, respectively). No significant gender difference was seen in the rate of stroke recurrence. Women also showed a worse survival ratio after stroke than men (p < 0.01).

CONCLUSION

The present study demonstrated significantly worse functional outcomes for women than for men at 1 and 5 years after stroke. Gender differences in long-term functional outcomes by subtypes of ischemic stroke were also significant.

Sex-related time-dependent variations in post-stroke survival--evidence of a female stroke survival advantage

BACKGROUND

Women live longer than men, yet most studies show that gender has no influence on survival after stroke.

METHODS

A registry was started in 2001, with the aim of registering all hospitalized stroke patients in Denmark, and it now holds 39,484 patients of which 48% are female. We studied the influence of gender on post-stroke mortality, from the time of admission through the subsequent years until death or censoring (mean follow-up time: 538 days). All patients underwent an evaluation including stroke severity, computed tomography and cardiovascular risk factors. Independent predictors of death were identified by means of a survival model based on 22,222 individuals with a complete data set.

RESULTS

Females were older and had severer stroke. Interestingly, the risk of death between genders was time dependent. The female/male stroke mortality rate favoured women from the first day of stroke and remained so during the first month suggesting a female survival advantage. Throughout the second month the rate reversed in favour of men suggesting that women in that period are paying a 'toll' for their initial survival advantage. Hereafter, the rate steadily decreased, and after 4 months women continued to have the same low risk as in the first week.

CONCLUSIONS

Our study suggests a female superiority in stroke survival competence.