Trends in acute ischemic stroke treatments and mortality in the United States from 2012 to 2018

The role of stroke care infrastructure on the effectiveness of a hub-and-spoke telestroke model in South Carolina

OBJECTIVE

To examine the relationship between stroke care infrastructure and stroke quality-of-care outcomes at 29 spoke hospitals participating in the Medical University of South Carolina (MUSC) hub-and-spoke telestroke network.

MATERIALS AND METHODS

Encounter-level data from MUSC's telestroke patient registry were filtered to include encounters during 2015-2022 for patients aged 18 and above with a clinical diagnosis of acute ischemic stroke, and who received intravenous tissue plasminogen activator. Unadjusted and adjusted generalized estimating equations assessed associations between time-related stroke quality-of-care metrics captured during the encounter and the existence of the two components of stroke care infrastructure-stroke coordinators and stroke center certifications-across all hospitals and within hospital subgroups defined by size and rurality.

RESULTS

Telestroke encounters at spoke hospitals with stroke coordinators and stroke center certifications were associated with shorter door-to-needle (DTN) times (60.9 min for hospitals with both components and 57.3 min for hospitals with one, vs. 81.2 min for hospitals with neither component, p <.001). Similar patterns were observed for the percentage of encounters with DTN time of ≤60 min (63.8% and 68.9% vs. 32.0%, p <.001) and ≤45 min (34.0% and 38.4% vs. 8.42%, p <.001). Associations were similar for other metrics (e.g., door-to-registration time), and were stronger for smaller (vs. larger) hospitals and rural (vs. urban) hospitals.

CONCLUSIONS

Stroke coordinators or stroke center certifications may be important for stroke quality of care, especially at spoke hospitals with limited resources or in rural areas.

The choroid plexus maintains ventricle volume and adult subventricular zone neuroblast pool, which facilitates post-stroke neurogenesis

The brain's neuroreparative capacity after injuries such as ischemic stroke is contained in the brain's neurogenic niches, primarily the subventricular zone (SVZ), which lies in close contact with the cerebrospinal fluid (CSF) produced by the choroid plexus (ChP). Despite the wide range of their proposed functions, the ChP/CSF remain among the most understudied compartments of the central nervous system (CNS). Here we report a mouse genetic tool (the ROSA26iDTR mouse line) for non-invasive, specific, and temporally controllable ablation of CSF-producing ChP epithelial cells to assess the roles of the ChP and CSF in brain homeostasis and injury. Using this model, we demonstrate that ChP ablation causes rapid and permanent CSF volume loss accompanied by disruption of ependymal cilia bundles. Surprisingly, ChP ablation did not result in overt neurological deficits at one-month post-ablation. However, we observed a pronounced decrease in the pool of SVZ neuroblasts following ChP ablation, which occurs due to their enhanced migration into the olfactory bulb. In the MCAo model of ischemic stroke, neuroblast migration into the lesion site was also reduced in the CSF-depleted mice. Thus, our study establishes an important and novel role of ChP/CSF in regulating the regenerative capacity of the adult brain under normal conditions and after ischemic stroke.

Identification of Key Genes Mediated by N6-Methyladenosine Methyltransferase METTL3 in Ischemic Stroke via Bioinformatics Analysis and Experiments

The N6-methyladenosine (m6A) methyltransferase METTL3 has been demonstrated to function in mediating m6A modification, but its role in ischemic stroke (IS) has not been fully elucidated. This study aimed to explore the downstream mechanism of METTL3-mediated m6A modification in IS. GSE16561 and GSE22255 were downloaded from the Gene Expression Omnibus database for analysis of differentially expressed genes (DEGs), and it was found that METTL3 mRNA was downregulated in IS. Then quantitative real-time polymerase chain reaction was used to verify the downregulation of METTL3 mRNA in the peripheral blood of IS patients and the cortexes of transient middle cerebral artery occlusion mice. By combining DEGs with the m6A-downregulated genes in GSE142386 which performed methylated RNA immunoprecipitation sequencing (MeRIP-seq) on METTL3-deficient and control endothelial cells, a total of 131 genes were identified as the METTL3-mediated m6A-modified genes in IS. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis showed that the genes were mainly involved in cytokine-cytokine receptor interaction, MAPK signaling pathway and NF-kappa B signaling pathway. CTSS and SBK1 were further screened as the key METTL3-mediated m6A-modified genes by random forest model and PCR validation. The ROC curve analysis showed that the combination with CTSS and SBK1 was of good diagnostic value for IS, with the AUC of 0.810, sensitivity of 0.780, and specificity of 0.773. Overall, we found that METTL3-mediated m6A modification may influence the occurrence and development of IS by participating in inflammation-related biological processes, and two key m6A-modified genes mediated by METTL3 (CTSS and SBK1) can be used as diagnostic biomarkers for IS.

Pharmacological Inhibition of NHE1 Protein Increases White Matter Resilience and Neurofunctional Recovery after Ischemic Stroke

To date, recanalization interventions are the only available treatments for ischemic stroke patients; however, there are no effective therapies for reducing stroke-induced neuroinflammation. We recently reported that H+ extrusion protein Na+/H+ exchanger-1 (NHE1) plays an important role in stroke-induced inflammation and white matter injury. In this study, we tested the efficacy of two potent NHE1 inhibitors, HOE642 and Rimeporide, with a delayed administration regimen starting at 24 h post-stroke in adult C57BL/6J mice. Post-stroke HOE642 and Rimeporide treatments accelerated motor and cognitive function recovery without affecting the initial ischemic infarct, neuronal damage, or reactive astrogliosis. However, the delayed administration of NHE1 blockers after ischemic stroke significantly reduced microglial inflammatory activation while enhanced oligodendrogenesis and white matter myelination, with an increased proliferation and decreased apoptosis of the oligodendrocytes. Our findings suggest that NHE1 protein plays an important role in microglia-mediated inflammation and white matter damage. The pharmacological blockade of NHE1 protein activity reduced microglia inflammatory responses and enhanced oligodendrogenesis and white matter repair, leading to motor and cognitive function recovery after stroke. Our study reveals the potential of targeting NHE1 protein as a therapeutic strategy for ischemic stroke therapy.

Twenty-Year Disparity Trends in United States Stroke Death Rate by Age, Race/Ethnicity, Geography, and Socioeconomic Status

BACKGROUND AND OBJECTIVES

In 2017, the Centers for Disease Control and Prevention (CDC) issued an alert that, after decades of consistent decline, the stroke death rate levelled off in 2013, particularly in younger individuals and without clear origin. The objective of this analysis was to understand whether social determinants of health have influenced trends in stroke mortality.

METHODS

We performed a longitudinal analysis of county-level ischemic and hemorrhagic stroke death rate per 100,000 adults from 1999 to 2018 using a Bayesian spatiotemporally smoothed CDC dataset stratified by age (35-64 years [younger] and 65 years or older [older]) and then by county-level social determinants of health. We reported stroke death rate by county and the percentage change in stroke death rate during 2014-2018 compared with that during 2009-2013.

RESULTS

We included data from 3,082 counties for younger individuals and 3,019 counties for older individuals. The stroke death rate began to increase for younger individuals in 2013 (p < 0.001), and the slope of the decrease in stroke death rate tapered for older individuals (p < 0.001). During the 20-year period of our study, counties with a high social deprivation index and ≥10% Black residents consistently had the highest rates of stroke death in both age groups. Comparing stroke death rate during 2014-2018 with that during 2009-2013, larger increases in younger individuals' stroke death rate were seen in counties with ≥90% (vs <90%) non-Hispanic White individuals (3.2% mean death rate change vs 1.7%, p < 0.001), rural (vs urban) populations (2.6% vs 2.0%, p = 0.019), low (vs high) proportion of medical insurance coverage (2.9% vs 1.9%, p = 0.002), and high (vs low) substance abuse and suicide mortality (2.8 vs 1.9%, p = 0.008; 3.3% vs 1.5%, p < 0.001). In contrast to the younger individuals, in older individuals, the associations with increased death rates were with more traditional social determinants of health such as the social deprivation index, urban location, unemployment rate, and proportion of Black race and Hispanic ethnicity residents.

DISCUSSION

Improvements in the stroke death rate in the United States are slowing and even reversing in younger individuals and many US counties. County-level increases in stroke death rate were associated with distinct social determinants of health for younger vs older individuals. These findings may inform targeted public health strategies.

SUMOtherapeutics for Ischemic Stroke

The small, ubiquitin-like modifier (SUMO) is a post-translational modifier with a profound influence on several key biological processes, including the mammalian stress response. Of particular interest are its neuroprotective effects, first recognized in the 13-lined ground squirrel (Ictidomys tridecemlineatus), in the context of hibernation torpor. Although the full scope of the SUMO pathway is yet to be elucidated, observations of its importance in managing neuronal responses to ischemia, maintaining ion gradients, and the preconditioning of neural stem cells make it a promising therapeutic target for acute cerebral ischemia. Recent advances in high-throughput screening have enabled the identification of small molecules that can upregulate SUMOylation, some of which have been validated in pertinent preclinical models of cerebral ischemia. Accordingly, the present review aims to summarize current knowledge and highlight the translational potential of the SUMOylation pathway in brain ischemia.

In-hospital outcomes and recurrence of stroke during pregnancy and puerperium

BACKGROUND

There are limited data regarding the best management and outcomes of acute stroke during pregnancy and the puerperium.

METHODS

Pregnancy-related hospitalizations with age > 18 years were identified from the Nationwide Readmissions Database 2016-2018. The study cohort consisted of all patients with acute stroke and a 5% random sample of the remaining non-stroke hospitalizations. Logistic regression and survival analyses were used to compare the in-hospital outcomes and readmissions in patients with and without acute stroke.

RESULTS

There were 11,829,044 pregnancy-related hospitalizations, of which 4057 had acute stroke. The mean ± SD age of the study cohort was 29.0 ± 5.7 years. Among patients with acute ischemic stroke, 60 (3.7%) patients received intravenous thrombolysis and 112 (6.8%) patients underwent endovascular thrombectomy. Among patients with intracranial hemorrhage, 205 (10.5%) patients underwent ventriculostomy and 18 (0.9%) patients underwent decompressive craniotomy. Patients with stroke had longer length of stay (mean: 10.7 vs 2.7 days), higher in-hospital mortality (4.6% vs 0.0001%) and were less likely to discharge home (73.0% vs 98.6%). Non-elective readmission within 90 days of discharge occurred in 14.8% of patients with stroke versus in 3.9% of patients without stroke. Readmissions due to cerebrovascular events occurred in 2.3% of patients with stroke versus in 0.007% of patients without stroke within 1 year of discharge, with mean ± SD time to readmission 66.2 ± 78.0 days.

CONCLUSION

Stroke is a serious complication of pregnancy, associated with high morbidity and mortality. Recurrence of stroke occurs in a small proportion of patients, and the risk is highest during the initial 3 months.

Age- and Sex-Specific Trends in Medical Complications After Acute Ischemic Stroke in the United States

BACKGROUND AND OBJECTIVES

To test the hypothesis that the age and sex-specific prevalence of infectious (pneumonia, sepsis, and urinary tract infection [UTI]) and noninfectious (deep venous thrombosis [DVT], pulmonary embolism [PE], acute renal failure [ARF], acute myocardial infarction [AMI], and gastrointestinal bleeding [GIB]) complications increased after acute ischemic stroke (AIS) hospitalization in the United States from 2007 to 2019.

METHODS

We conducted a serial cross-sectional study using the 2007-2019 National Inpatient Sample. Primary AIS admissions in adults (aged 18 years or older) with and without complications were identified using International Classification of Diseases codes. We quantified the age/sex-specific prevalence of complications and used negative binomial regression models to evaluate trends over time.

RESULTS

Of 5,751,601 weighted admissions, 51.4% were women. 25.1% had at least 1 complication. UTI (11.8%), ARF (10.1%), pneumonia (3.2%), and AMI (2.5%) were the most common complications, while sepsis (1.7%), GIB (1.1%), DVT (1.2%), and PE (0.5%) were the least prevalent. Marked disparity in complication risk existed by age/sex (UTI: men 18-39 years 2.1%; women 80 years or older 22.5%). Prevalence of UTI (12.9%-9.7%) and pneumonia (3.8%-2.7%) declined, but that of ARF increased by ≈3-fold (4.8%-14%) over the period 2007-2019 (all p < 0.001). AMI (1.9%-3.1%), DVT (1.0%-1.4%), and PE (0.3%-0.8%) prevalence also increased (p < 0.001), but that of sepsis and GIB remained unchanged over time. After multivariable adjustment, risk of all complications increased with increasing NIH Stroke Scale (pneumonia: prevalence rate ratio [PRR] 1.03, 95% CI 1.03-1.04, for each unit increase), but IV thrombolysis was associated with a reduced risk of all complications (pneumonia: PRR 0.80, 85% CI 0.73-0.88; AMI: PRR 0.85, 95% CI 0.78-0.92; and DVT PRR 0.87, 95% CI 0.78-0.98). Mechanical thrombectomy was associated with a reduced risk of UTI, sepsis, and ARF, but DVT and PE were more prevalent in MT hospitalizations compared with those without. All complications except UTI were associated with an increased risk of in-hospital mortality (sepsis: PRR 1.97, 95% CI 1.78-2.19).

DISCUSSION

Infectious complications declined, but noninfectious complications increased after AIS admissions in the United States in the last decade. Utilization of IV thrombolysis is associated with a reduced risk of all complications.

CircFOXP1 alleviates brain injury after acute ischemic stroke by regulating STAT3/apoptotic signaling

According to previous studies, circular RNAs (circRNAs) are involved in multiple pathological processes of acute ischemic stroke (AIS). However, the relationship between circFOXP1 and IS has not yet been reported. Here, we found that circFOXP1 expression was significantly decreased in the peripheral blood of AIS patients compared to controls and was associated with the severity and prognosis of AIS. Functionally, knockdown and overexpression of circFOXP1 promoted and inhibited apoptotic signaling, respectively, following oxygen-glucose deprivation/reperfusion (OGD/R) treatment in vitro. Adeno-associated virus (AAV)-mediated circFOXP1 overexpression attenuated neurological deficits and improved functional recovery after transient middle cerebral artery occlusion (tMCAO) treatment in vivo. Mechanistically, decreased QKI expression inhibited circFOXP1 biogenesis under hypoxic conditions. Decreased circFOXP1 expression accelerated signal transducer and activator of transcription 3 (STAT3) protein degradation by binding to and increasing STAT3 protein ubiquitination, ultimately aggravating brain injury after cerebral ischemia by activating apoptotic signaling. In summary, our study is the first to reveal that circFOXP1 alleviates brain injury after cerebral ischemia by regulating STAT3/apoptotic signaling, which provides a potentially novel therapeutic target for AIS.

Glial roles in sterile inflammation after ischemic stroke

Stroke is a leading cause of death and disability worldwide, but there are a limited number of therapies that improve patients' functional recovery. The complicated mechanisms of post-stroke neuroinflammation, which is responsible for secondary ischemic neuronal damage, have been clarified by extensive research. Activation of microglia and astrocytes due to ischemic insults is implicated in the production of pro-inflammatory factors, formation of the glial scar, and breakdown of the blood-brain barrier. This leads to the infiltration of leukocytes, which are activated by damage-associated molecular patterns (DAMPs) to produce pro-inflammatory factors and induce additional neuronal damage. In this review, we focus on the glial mechanisms underlying sterile post-ischemic inflammation after stroke.

Demographic and Regional Trends in Stroke-Related Mortality in Young Adults in the United States, 1999 to 2019

Background Despite improvements in the management and prevention of stroke, increasing hospitalizations for stroke and stagnant mortality rates have been described in young adults. However, there is a paucity of contemporary national mortality estimates in young adults. Methods and Results Trends in mortality related to stroke in young adults (aged 25-64 years) were assessed using the Centers for Disease Control and Prevention Wide-Ranging Online Data for Epidemiologic Research database. Age-adjusted mortality rates per 100 000 people with associated annual percentage change were calculated. Joinpoint regression was used to assess the trends in the overall sample and different demographic (sex, race and ethnicity, and age) and geographical (state, urban-rural, and regional) subgroups. Between 1999 and 2019, a total of 566 916 stroke-related deaths occurred among young adults. After the initial decline in mortality in the overall population, age-adjusted mortality rate increased from 2013 to 2019 with an associated annual percentage change of 1.5 (95% CI, 1.1-2.0). Mortality rates were higher in men versus women and in non-Hispanic Black people versus individuals of other races and ethnicities. Non-Hispanic American Indian or Alaskan Native people had a marked increase in stroke-related mortality (annual percentage change 2010-2019: 3.3). Furthermore, rural (nonmetropolitan) counties experienced the greatest increase in mortality (annual percentage change 2012-2019: 3.1) compared with urban (metropolitan) counties. Conclusions Following the initial decline in stroke-related mortality, young adults have experienced increasing mortality rates from 2013 to 2019, with considerable differences across demographic groups and regions.

Use of Clinical Pathway Simulation and Machine Learning to Identify Key Levers for Maximizing the Benefit of Intravenous Thrombolysis in Acute Stroke

Expert opinion is that about 20% of emergency stroke patients should receive thrombolysis. Currently, 11% to 12% of patients in England and Wales receive thrombolysis, ranging from 2% to 24% between hospitals. The aim of this study was to assess how much variation is due to differences in local patient populations, and how much is due to differences in clinical decision-making and stroke pathway performance, while estimating a realistic target thrombolysis use.

The impact of a comprehensive national policy on improving acute stroke patient care in Lithuania

Introduction:

Reperfusion therapy (RT) is a mainstay treatment for acute ischemic stroke (AIS). We aimed to evaluate the impact of a comprehensive national policy (CNP) to improve access to RT for AIS patients across Lithuania.

Patients and methods:

Aggregated anonymized data on AIS cases treated in Lithuanian hospitals between 2006 and 2019 were retrospectively obtained from the Institute of Hygiene and the Stroke Integrated Care Management Committee. Through an interrupted time series analysis, we examined the trends in AIS hospital admissions, RT, and in-hospital case fatality rates prior to the enactment of CNP in 2014, changes immediately after the intervention, and differences in trends between the pre- and post-intervention periods. Mean yearly door-to-needle times were calculated post-intervention.

Results:

114,436 cases were treated for AIS in Lithuanian hospitals before, and 65,084 after the government intervention. We observed a significant decreasing post-intervention trend change in AIS hospital admission rate per 100,000 population (regression coefficient ± standard error: β = –16.47 ± 3.95, p = 0.002) and an increasing trend change in the proportion of AIS patients who received reperfusion treatment: intravenous thrombolysis (β = 1.42 ± 0.96, p < 0.001) and endovascular therapy (β = 0.85 ± 0.05, p < 0.001). The proportion of patients treated in stroke centers increased immediately after the intervention (β = 4.95 ± 1.14, p = 0.001), but the long-term post-intervention trend did not change. In addition, there was a significant decreasing trend in all cause in-hospital case fatality rate within primary and comprehensive stroke centers after the intervention (β = –0.60 ± 0.18, p = 0.008) despite its prompt initial immediate increase (β = 1.68 ± 0.73, p = 0.043). The mean countrywide door-to-needle time decreased from 68 min in 2014 to 43 min in 2019.

Conclusion:

The comprehensive national stroke patient care policy could be associated with an immediate increase in stroke center treatment rate, increased access to RT, and improved stroke care performance measures.

Renewing the Call for Reforms to Medical Device Safety-The Case of Penumbra

IMPORTANCE

Strengthening premarket and postmarket surveillance of medical devices has long been an area of focus for health policy makers. The recent class I recall (the most serious of the US Food and Drug Administration [FDA] recalls) of reperfusion catheters manufactured by Penumbra, a US-based medical device company, illustrates issues of device safety and oversight that mandate attention.

OBJECTIVES

To review the regulatory history and clinical evidence of the Penumbra JET 7 Reperfusion Catheter with Xtra Flex Technology (JET 7) and use the device recall as a case study of the challenges associated with clinical evaluation, transparency, and oversight of medical devices in the US.

EVIDENCE

Regulatory history and clinical evidence for the Penumbra medical devices were analyzed through a qualitative review of decision letters in the Access FDA database for medical devices and medical device reports in the Manufacturer and User Facility Device Experience database and a review of market data (eg, earnings calls, company communications) and clinical literature.

FINDINGS

The JET 7 device was subjected to a class I recall following more than 200 adverse event reports, 14 of which involved patient deaths. Regulatory analysis indicated that each of the Penumbra reperfusion catheters was cleared under the 510(k) pathway (which allows devices to be authorized with limited to no clinical evidence), with limited submission of either new clinical or animal data. Clinical evidence for Penumbra devices was generated from nonrandomized, single-arm trials with small sample sizes. The regulatory issues raised by JET 7 are reflective of broader challenges for medical device regulation. Opportunities for reform include strengthening premarket evidence requirements, requiring safety reporting with unique device identifiers, and mandating active methods of postmarket surveillance.

CONCLUSIONS AND RELEVANCE

The case study of JET 7 highlights the long-standing gaps in medical device oversight and renews the impetus to build on the Institute of Medicine recommendations and reform FDA medical device regulation to protect public health.