United States trends in thrombolysis for older adults with acute ischemic stroke

Association Between Insulin Resistance Markers and Poor Prognosis in Patients With Acute Ischemic Stroke After Intravenous Thrombolysis

OBJECTIVES

This study aims to investigate the significance of insulin resistance markers in predicting poor prognosis in acute ischemic stroke (AIS) patients after intravenous thrombolysis and to establish the corresponding nomogram.

METHODS

From January 2019 to March 2023, the data of 412 patients with AIS who received intravenous alteplase thrombolytic therapy in the Affiliated Taizhou People's Hospital of Nanjing Medical University were selected. Patients were randomly divided into training groups (70%, 288 cases) and validation groups (30%, 124 cases). In the training group, multivariate logistic regression analysis was used to establish the best nomogram prediction model. The predictive ability of the nomogram was further evaluated by the area under the receiver operating characteristic curve, calibration curve, decision curve analysis, and reclassification analysis. Furthermore, the model was further validated in the validation set.

RESULTS

Multivariate logistic regression analysis showed that systolic blood pressure, diabetes, National Institutes of Health Stroke Scale score, triglyceride-glucose index, triglyceride-glucose-body mass index, ratio of low-density lipoprotein cholesterol to high-density lipoprotein cholesterol were associated with poor prognosis in AIS patients after intravenous thrombolysis ( P <0.05). Compared with conventional factors, the nomogram showed stronger prognostic ability, area under receiver operating characteristic curves were 0.948 (95% CI: 0.920-0.976, P <0.001) and 0.798 (95% CI: 0.747-0.849, P <0.001), respectively.

CONCLUSIONS

Triglyceride-glucose index, triglyceride-glucose-body mass index, and low-density lipoprotein cholesterol to high-density lipoprotein cholesterol levels upon admission can serve as markers for poor prognosis in AIS patients after intravenous thrombolysis. The nomogram enables a more accurate prediction of poor prognosis in AIS patients after intravenous thrombolysis.

Persistent Inequities in Intravenous Thrombolysis for Acute Ischemic Stroke in the United States: Results From the Nationwide Inpatient Sample

BACKGROUND

Despite its approval for acute ischemic stroke >25 years ago, intravenous thrombolysis (IVT) remains underused, with inequities by age, sex, race, ethnicity, and geography. Little is known about IVT rates by insurance status.

METHODS AND RESULTS

We assessed temporal trends from 2002 to 2015 in IVT for acute ischemic stroke in the Nationwide Inpatient Sample using adjusted, survey-weighted logistic regression. We calculated odds ratios for IVT for each category in 2002 to 2008 (period 1) and 2009 to 2015 (period 2). IVT use for acute ischemic stroke increased from 1.0% in 2002 to 6.8% in 2015 (adjusted annual relative ratio, 1.15). Individuals aged ≥85 years had the most pronounced increase during 2002 to 2015 (adjusted annual relative ratio, 1.18) but were less likely to receive IVT compared with 18- to 44-year-olds in period 1 (adjusted odds ratio [aOR], 0.23) and period 2 (aOR, 0.36). Women were less likely than men to receive IVT, but the disparity narrowed over time (period 1: aOR, 0.81; period 2: aOR, 0.94). Inequities in IVT resolved for Hispanic individuals in period 2 (aOR, 0.96) but not for Black individuals (period 2: aOR, 0.81). The disparity in IVT for Medicare patients, compared with privately insured patients, lessened over time (period 1: aOR, 0.59; period 2: aOR, 0.75). Patients treated in rural hospitals remained less likely to receive IVT than in urban hospitals; a more dramatic increase in urbanity widened the inequity (period 2, urban nonteaching versus rural: aOR, 2.58, period 2, urban teaching versus rural: aOR, 3.90).

CONCLUSIONS

IVT for acute ischemic stroke increased among adults. Despite some encouraging trends, the remaining disparities highlight the need for intensified efforts at addressing inequities.

Effects of System-Level Factors on Race/Ethnic Differences in In-Hospital Mortality after Acute Ischemic Stroke

Introduction

Stroke mortality has declined, with differential changes by race; stroke is now the 5th leading cause of death overall, but 2nd leading cause of death in Black individuals. Little is known about recent race/ethnic and sex trends in in-hospital mortality after acute ischemic stroke (AIS) and whether system-level factors contribute to possible differences.

Methods

Using the National Inpatient Sample, adults (≥18 years) with a primary diagnosis of AIS from 2006 to 2017 (n=643,912) were identified. We assessed in-hospital mortality by race/ethnicity (White, Black, Hispanic, Asian/Pacific Islander [API], other), sex, and age. Hospitals were categorized by proportion of non-White patients served: <25% ("predominantly White patients"), 25-50% ("mixed race/ethnicity profile"), and ≥50% ("predominantly non-White patients"). Using survey adjusted logistic regression, the association between race/ethnicity and odds of mortality was assessed, adjusting for key sociodemographic, clinical, and hospital characteristics (e.g., age, comorbidities, stroke severity, do not resuscitate orders, and palliative care).

Results

Overall, mortality decreased from 5.0% in 2006 to 2.9% in 2017 (p<0.001). Comparing 2012-2017 to 2006-2011, there was a 68% reduction in mortality odds overall after adjusting for covariates, most prominent in White individuals (69%) and smallest in Black individuals (57%). Compared to White patients, Black and Hispanic patients had lower odds of mortality (adjusted odds ratio (aOR) 0.82, 95% CI 0.78-0.87 and aOR 0.93, 95% CI 0.87-1.00), primarily driven by those >65 years (age x ethnicity interaction p < 0.0001). Compared to White men, Black, Hispanic, and API men, and Black women had lower aOR of mortality. The differences in mortality between White and non-White patients were most pronounced in hospitals predominantly serving White patients (aOR 0.80, 0.74-0.87) compared to mixed hospitals (aOR 0.85, 0.79-0.91) and predominantly non-White hospitals (aOR 0.88, 0.81-0.95; interaction effect: p=0.005).

Discussion

AIS mortality decreased dramatically in recent years in all race/ethnic subgroups. Overall, non-White AIS patients had lower mortality than their White counterparts, a difference that was most striking in hospitals predominantly serving White patients. Further study is needed to understand these differences and to what extent biological, sociocultural, and system-level factors play a role.

Persistent Inequities in Intravenous Thrombolysis for Acute Ischemic Stroke in the United States: Results from the Nationwide Inpatient Sample

Background

Despite its approval for use in acute ischemic stroke (AIS) >25 years ago, intravenous thrombolysis (IVT) remains underutilized, with inequities by age, sex, race/ethnicity, and geography. Little is known about IVT rates by insurance status. We aimed to assess temporal trends in the inequities in IVT use.

Methods

We assessed trends from 2002 to 2015 in IVT for AIS in the Nationwide Inpatient Sample by sex, age, race/ethnicity, hospital location/teaching status, and insurance, using survey-weighted logistic regression, adjusting for sociodemographics, comorbidities, and hospital characteristics. We calculated odds ratios for IVT for each category in 2002-2008 (Period 1) and 2009-2015 (Period 2).

Results

Among AIS patients (weighted N=6,694,081), IVT increased from 1.0% in 2002 to 6.8% in 2015 (adjusted annual relative ratio (AARR) 1.15, 95% CI 1.14-1.16). Individuals ≥85 years had the most pronounced increase from 2002 to 2015 (AARR 1.18, 1.17-1.19), but were less likely to receive IVT compared to those aged 18-44 years in both Period 1 (adjusted odds ratio (aOR) 0.23, 0.21-0.26) and Period 2 (aOR 0.36, 0.34-0.38). Women were less likely than men to receive IVT, but the disparity narrowed over time (Period 1 aOR 0.81, 0.78-0.84, Period 2 aOR 0.94, 0.92-0.97). Inequities in IVT by race/ethnicity resolved for Hispanic individuals in Period 2 but not for Black individuals (Period 2 aOR 0.81, 0.78-0.85). The disparity in IVT for Medicare patients, compared to privately insured patients, lessened over time (Period 1 aOR 0.59, 0.56-0.52, Period 2 aOR 0.75, 0.72-0.77). Patients treated in rural hospitals were less likely to receive IVT than those treated in urban hospitals; a more dramatic increase in urban areas widened the inequity (Period 2 urban non-teaching vs. rural aOR 2.58, 2.33-2.85, urban teaching vs. rural aOR 3.90, 3.55-4.28).

Conclusion

From 2002 through 2015, IVT for AIS increased among adults. Despite encouraging trends, only 1 in 15 AIS patients received IVT and persistent inequities remained for Black individuals, women, government-insured, and those treated in rural areas, highlighting the need for intensified efforts at addressing inequities.

Association of triglyceride-glucose index with clinical outcomes in patients with acute ischemic stroke receiving intravenous thrombolysis

Intravenous tissue plasminogen activator (tPA) remains the cornerstone of recanalization therapy for acute ischemic stroke (AIS), albeit with varying degrees of response. The triglyceride-glucose (TyG) index is a novel marker of insulin resistance, but association with outcomes among AIS patients who have received tPA has not been well elucidated. We studied 698 patients with AIS who received tPA from 2006 to 2018 in a comprehensive stroke centre. TyG index was calculated using the formula: ln[fasting triglycerides (mg/dL) × fasting glucose (mg/dL)/2]. TyG index was significantly lower in patients that survived at 90-days than those who died (8.61 [Interquartile Range: 8.27–8.99] vs 8.76 [interquartile range: 8.39–9.40], p = 0.007). In multivariate analysis, TyG index was significantly associated with 90-day mortality (OR: 2.12, 95% CI: 1.39–3.23, p = 0.001), poor functional outcome (OR: 1.41 95% CI: 1.05–1.90, p = 0.022), and negatively associated with early neurological improvement (ENI) (OR: 0.68, 95% CI: 0.52–0.89, p = 0.004). There was no association between TyG index and symptomatic intracranial hemorrhage. ‘High TyG’ (defined by TyG index ≥ 9.15) was associated with mortality, poor functional outcomes and no ENI. In conclusion, the TyG index, a measure of insulin resistance, was significantly associated with poorer clinical outcomes in AIS patients who received tPA.

Can clinical audits be enhanced by pathway simulation and machine learning? An example from the acute stroke pathway

OBJECTIVE

To evaluate the application of clinical pathway simulation in machine learning, using clinical audit data, in order to identify key drivers for improving use and speed of thrombolysis at individual hospitals.

DESIGN

Computer simulation modelling and machine learning.

SETTING

Seven acute stroke units.

PARTICIPANTS

Anonymised clinical audit data for 7864 patients.

RESULTS

Three factors were pivotal in governing thrombolysis use: (1) the proportion of patients with a known stroke onset time (range 44%-73%), (2) pathway speed (for patients arriving within 4 hours of onset: per-hospital median arrival-to-scan ranged from 11 to 56 min; median scan-to-thrombolysis ranged from 21 to 44 min) and (3) predisposition to use thrombolysis (thrombolysis use ranged from 31% to 52% for patients with stroke scanned with 30 min left to administer thrombolysis). A pathway simulation model could predict the potential benefit of improving individual stages of the clinical pathway speed, whereas a machine learning model could predict the benefit of 'exporting' clinical decision making from one hospital to another, while allowing for differences in patient population between hospitals. By applying pathway simulation and machine learning together, we found a realistic ceiling of 15%-25% use of thrombolysis across different hospitals and, in the seven hospitals studied, a realistic opportunity to double the number of patients with no significant disability that may be attributed to thrombolysis.

CONCLUSIONS

National clinical audit may be enhanced by a combination of pathway simulation and machine learning, which best allows for an understanding of key levers for improvement in hyperacute stroke pathways, allowing for differences between local patient populations. These models, based on standard clinical audit data, may be applied at scale while providing results at individual hospital level. The models facilitate understanding of variation and levers for improvement in stroke pathways, and help set realistic targets tailored to local populations.

Intravenous thrombolysis for acute ischemic stroke: a bridge between two centuries

INTRODUCTION

Intravenous tissue-plasminogen activator (tPA) remains the only approved systemic reperfusion therapy suitable for most patients presenting timely with acute ischemic stroke. Accumulating real-word experience for over 20 years regarding tPA safety and effectiveness led to re-appraisal of original contraindications for intravenous thrombolysis (IVT). Areas covered: This narrative review focuses on fast yet appropriate selection of patients for safe administration of tPA per recently expanded indications. Novel strategies for rapid patient assessment will be discussed. The potential for mobile stroke units (MSU) that shorten onset-to-needle time and increase tPA treatment rates is addressed. The use of IVT in the era of non-vitamin K antagonist oral anticoagulants (NOACs) is highlighted. The continuing role of IVT in large vessel occlusion (LVO) patients eligible for mechanical thrombectomy (MT) is discussed with regards to 'drip and ship' vs. 'mothership' treatment paradigms. Promising studies of penumbral imaging to extend IVT beyond the 4.5-hour window and in wake-up strokes are summarized. Expert commentary: This review provides an update on the role of IVT in specific conditions originally considered tPA contraindications. Novel practice challenges including NOAC's, MSU proliferation and bridging therapy (IVT&MT) for LVO patients, and the potential extension of IVT time-window using penumbral imaging are emerging as safe and potentially effective IVT applications.

Interfacility transfers for US ischemic stroke and TIA, 2006-2014

OBJECTIVE

To investigate changes in emergency department (ED) transfers for ischemic stroke (IS) and TIA.

METHODS

We performed a retrospective observational study using the US Nationwide Emergency Department Sample to identify changes in interfacility ED transfers for IS and TIA from the perspective of the transferring ED (2006-2014). We calculated nationwide transfer rates and individual ED transfer rates for IS/TIA by diagnosis and hospital characteristics. Hospital-level fractional logistic regression examined changes in transfer rates over time.

RESULTS

The population-estimated number of transfers for IS/TIA increased from 22,576 patient visits in 2006 to 54,485 patient visits in 2014 (p trend < 0.001). The rate of IS/TIA transfer increased from 3.4 (95% confidence interval [CI] 3.0-3.8) in 2006 to 7.6 (95% CI 7.2-7.9) in 2014 per 100 ED visits. Among individual EDs, mean transfer rates for IS/TIA increased from 8.2 per 100 ED visits (median 2.0, interquartile range [IQR] 0-10.2) to 19.4 per 100 ED visits (median 8.1, IQR 1.1-33.3) (2006-2014) (p trend < 0.001). Transfers were more common among IS. Transfer rates were greatest among rural (adjusted odds ratio [AOR] 3.05, 95% CI 2.56-3.64) vs urban/teaching and low-volume EDs (AOR 7.49, 95% CI 6.58-8.53, 1st vs 4th quartile). The adjusted odds of transfer for IS/TIA increased threefold (2006-2014).

CONCLUSIONS

Interfacility ED transfers for IS/TIA more than doubled from 2006 to 2014. Further work should determine the necessity of IS/TIA transfers and seek to optimize the US stroke care system.