Stroke Systems of Care: Current State of Affairs and Future Directions

Evaluation of a prehospital endovascular therapy stroke bypass program

INTRODUCTION

Prehospital stroke endovascular therapy bypass transports patients with suspected large vessel occlusion directly to an endovascular therapy capable center. Our objective was to determine if an endovascular therapy bypass protocol improved access to stroke treatments. Secondary objectives were to determine safety, effectiveness, and rate of subsequent interfacility transfers.

METHODS

Endovascular therapy bypass in 2018 was implemented in Eastern Ontario, for patients with a Los-Angeles-Motor-Scale ≥ 4 (positive large vessel occlusion screen) with a 90-min transport time if < 6 h from last seen well. A before-after health record review was conducted from Dec 1, 2017 to Nov 30, 2019. A piloted data form was used to extract demographics, times, primary outcomes (endovascular therapy and intravenous (IV) tissue plasminogen activator (tPA) rate), and secondary outcomes (redirect to closer hospital, airway intervention, and subsequent interfacility transfer). We present descriptive statistics and odds ratios (OR) with 95% confidence intervals (CI) from multivariable logistic regression.

RESULTS

We included 379 stroke patients (165 pre and 214 post-implementation). The endovascular therapy rate between groups was similar (14.1% vs 15.1%). The bypass had an OR of 0.98 (95% CI 0.54-1.78) for receiving endovascular therapy. IV tPA was given to 25.4% of patients pre vs 27.4% post-implementation (OR 1.06, 95% CI 0.65-1.74). No patients became unstable during transport, only one patient had an intubation attempt. The inappropriate bypass (false positive) rate was 12.7% pre vs 12.8% post-implementation (positive predictive value 87%). The bypass protocol had an OR of 1.06 (95% CI 0.58-1.95) for subsequent interfacility transfer with a mean of 2.7 h at the community site before transfer.

CONCLUSIONS

Endovascular therapy stroke bypass with 90-min transport radius and Los-Angeles-Motor-Scale ≥ 4 was safe and well executed by paramedics. Our study did not show any difference in endovascular therapy rate from its implementation. The IV tPA rate was similar between groups despite potentially bypassing thrombolysis capable centers.

CT after interhospital transfer in acute ischemic stroke: Imaging findings and impact of prior intravenous contrast administration

Objectives

Large vessel occlusion (LVO) stroke patients routinely undergo interhospital transfer to endovascular thrombectomy capable centers. Imaging is often repeated with residual intravenous (IV) iodine contrast at post-transfer assessment. We determined imaging findings and the impact of residual contrast on secondary imaging. Anterior circulation LVO stroke patients were selected out of a consecutive cohort. Directly admitted patients were contrast naïve, and transferred patients had previously received IV iodine contrast for stroke assessment at the referring hospital. Two independent readers rated the visibility of residual contrast on non-contrast computed tomography (CT) after transfer and assessed the hyperdense vessel sign. Multivariate linear regression analysis was used to investigate the association of the Alberta Stroke Program Early CT score (ASPECTS) with prior contrast administration, time from symptom onset (TFSO), and CTP ischemic core volume in both directly admitted and transferred patients.

Results

We included 161 patients, with 62 (39%) transferred and 99 (62%) directly admitted patients. Compared between these groups, transferred patients had a longer TFSO-to-imaging at our institution (median: 212 vs. 75 min, p < 0.001) and lower ASPECTS (median: 8 vs. 9, p < 0.001). Regression analysis presented an independent association of ASPECTS with prior contrast administration (β = -0.25, p = 0.004) but not with TFSO (β = -0.03, p = 0.65). Intergroup comparison between transferred and directly admitted patients pointed toward a stronger association between ASPECTS and CTP ischemic core volume in transferred patients (β = -0.39 vs. β = -0.58, p = 0.06). Detectability of the hyperdense vessel sign was substantially lower after transfer (66 vs. 10%, p < 0.001).

Conclusion

Imaging alterations due to residual IV contrast are frequent in clinical practice and render the hyperdense vessel sign largely indetectable. Larger studies are needed to clarify the influence on the association between ASPECTS and ischemic core.

Exploring the Essential Stroke Care Structures in Tertiary Healthcare Facilities in Rivers State, Nigeria

This study evaluated the essential stroke care structure available in the two Tertiary Health Facilities in Rives State, Nigeria. This was a descriptive survey involving the Stroke Care Survey and Assessment Tool (checklist/questionnaire) developed by the World Stroke Organisation to obtain information about the available essential stroke care structure (facilities, equipment, personnel and management protocol) at the two tertiary health facilities (RSUTH & UPTH). The study gathered relevant information, which was summarised into tables and graphs using Microsoft Excel 2016. From the results, although facilities had A and E departments, dedicated stroke units (fixed or mobile) were unavailable, and there was no locally developed protocol to support rapid triage of stroke patients. The facilities and equipment were either unavailable or insufficient. Only one health facility (RSUTH) provided 24 hrs/7 days laboratory services. The workforces were a mix between regular clinical staff and some specialists. Tissue plasminogen activator (tPA) use was non-existent, though specialists were trained on its administration. There was no locally developed or adopted stroke-specific clinical guidelines. In conclusion, the structural services available for stroke care within the studied tertiary health facilities were poor, unavailable or grossly insufficient. The state facility (RSUTH) suffered the most in terms of unavailable national support and staff development.

Acute Ischemic Stroke Interventions in the United States and Racial, Socioeconomic, and Geographic Disparities

BACKGROUND AND OBJECTIVES

In patients with ischemic stroke (IS), IV alteplase (tissue plasminogen activator [tPA]) and endovascular thrombectomy (EVT) reduce long-term disability, but their utilization has not been fully optimized. Prior research has also demonstrated disparities in the use of tPA and EVT specific to sex, race/ethnicity, socioeconomic status, and geographic location. We sought to determine the utilization of tPA and EVT in the United States from 2016-2018 and if disparities in utilization persist.

METHODS

This is a retrospective, longitudinal analysis of the 2016-2018 National Inpatient Sample. We included adult patients who had a primary discharge diagnosis of IS. The primary study outcomes were the proportions who received tPA or EVT. We fit a multivariate logistic regression model to our outcomes in the full cohort and also in the subset of patients who had an available baseline National Institutes of Health Stroke Scale (NIHSS) score.

RESULTS

The full cohort after weighting included 1,439,295 patients with IS. The proportion who received tPA increased from 8.8% in 2016 to 10.2% in 2018 (p < 0.001) and who had EVT from 2.8% in 2016 to 4.9% in 2018 (p < 0.001). Comparing Black to White patients, the odds ratio (OR) of receiving tPA was 0.82 (95% confidence interval [CI] 0.79-0.86) and for having EVT was 0.75 (95% CI 0.70-0.81). Comparing patients with a median income in their zip code of ≤$37,999 to >$64,000, the OR of receiving tPA was 0.81 (95% CI 0.78-0.85) and for having EVT was 0.84 (95% CI 0.77-0.91). Comparing patients living in a rural area to a large metro area, the OR of receiving tPA was 0.48 (95% CI 0.44-0.52) and for having EVT was 0.92 (95% CI 0.81-1.05). These associations were largely maintained after adjustment for NIHSS, although the effect size changed for many of them. Contrary to prior reports with older datasets, sex was not consistently associated with tPA or EVT.

DISCUSSION

Utilization of tPA and EVT for IS in the United States increased from 2016 to 2018. There are racial, socioeconomic, and geographic disparities in the accessibility of tPA and EVT for patients with IS, with important public health implications that require further study.

Cost-effectiveness of a quality improvement project, including simulation-based training, on reducing door-to-needle times in stroke thrombolysis

BACKGROUND

Rapid revascularisation in acute ischaemic stroke is crucial to reduce its total burden including societal costs. A quality improvement (QI) project that included streamlining the stroke care pathway and simulation-based training was followed by a significant reduction in median door-to-needle time (27 to 13 min) and improved patient outcomes after stroke thrombolysis at our centre. Here, we present a retrospective cost-effectiveness analysis of the QI project.

METHODS

Costs for implementing and sustaining QI were assessed using recognised frameworks for economic evaluations. Effectiveness was calculated from previously published outcome measures. Cost-effectiveness was presented as incremental cost-effectiveness ratios including costs per minute door-to-needle time reduction per patient, and costs per averted death in the 13-month post-intervention period. We also estimated incremental cost-effectiveness ratios for a projected 5-year post-intervention period and for varying numbers of patients treated with thrombolysis. Furthermore, we performed a sensitivity analysis including and excluding costs of unpaid time.

RESULTS

All costs including fixed costs for implementing the QI project totalled US$44 802, while monthly costs were US$2141. We calculated a mean reduction in door-to-needle time of 13.1 min per patient and 6.36 annual averted deaths. Across different scenarios, the estimated costs per minute reduction in door-to-needle time per patient ranged from US$13 to US$29, and the estimated costs per averted death ranged from US$4679 to US$10 543.

CONCLUSIONS

We have shown that a QI project aiming to improve stroke thrombolysis treatment at our centre can be implemented and sustained at a relatively low cost with increasing cost-effectiveness over time. Our work builds on the emerging theory and practice for economic evaluations in QI projects and simulation-based training. The presented cost-effectiveness data might help guide healthcare leaders planning similar interventions.