Implications of the WAKE-UP Trial

FLAIR vascular hyperintensity-DWI mismatch and DWI-FLAIR mismatch ASPECTS for prediction of good outcome after recanalization in anterior circulation stroke; multicenter observational study

INTRODUCTION

Acute ischemic stroke is a medical emergency caused by decreased blood flow to the brain, leading cause of long-term disability. Recanalization, one of the most concerning difficulties linked with intracranial arterial occlusion, has been used to reduce mortality in ischemic stroke treatment. The mismatch concepts MR PWI-DWI or DWI-FLAIR can help identify patients for thrombolysis.

PURPOSE

This paper introduces a novel method of predicting revascularization using the value of fluid-attenuated inversion recovery vascular hyperintensity FVH-DWI mismatch and DWI-FLAIR mismatch, which releases anterior circulation large vessel occlusion (LVO) after endovascular thrombectomy (EVT). Moreover, we present a new scoring system following anatomical region distributed for MCA territory called a DWI-FLAIR MISMATCH ASPECTS.

RESULT

Statistical analysis was performed to predict revascularization and functional outcome with 110 patients with anterior circulation LVO treated with EVT. We found that FVH-DWI mismatch was present in 71 patients (89.9 %) with complete revascularization and present in 8 patients (10.1 %) with no/partial revascularization, which had no significant difference (p = 0.12), and there was no significant difference between good functional outcome and poor functional outcome. Moreover, in 76 patients with DWI-FLAIR mismatch ASPECTS of > 6 point-group, present FVH-DWI mismatch in 57 patients (83.8 %) with complete revascularization had a significant difference as compared to 11 patients (16.2 %) with absent FVH-DWI mismatch (p < 0.05). The clinical outcome in complete revascularization is better than no/partial revascularization, and complete revascularization is independently associated with good functional outcomes (p < 0.05).

CONCLUSION

FVH-DWI mismatch paired with DWI-FLAIR mismatch ASPECTS > 6 points may be possible to predict revascularization in patients with anterior circulation LVO.

Identifying Best Practices to Improve Evaluation and Management of In-Hospital Stroke: A Scientific Statement From the American Heart Association

This scientific statement describes a path to optimizing care for patients who experience an in-hospital stroke. Although these patients are in a monitored environment, their evaluation and treatment are often delayed compared with patients presenting to the emergency department, contributing to higher rates of morbidity and mortality. Reducing delays and optimizing treatment for patients with in-hospital stroke could improve outcomes. This scientific statement calls for the development of hospital systems of care and targeted quality improvement for in-hospital stroke. We propose 5 core elements to optimize in-hospital stroke care: 1. Deliver stroke training to all hospital staff, including how to activate in-hospital stroke alerts. 2. Create rapid response teams with dedicated stroke training and immediate access to neurological expertise. 3. Standardize the evaluation of patients with potential in-hospital stroke with physical assessment and imaging. 4. Address barriers to treatment potentially, including interfacility transfer to advanced stroke treatment. 5. Establish an in-hospital stroke quality oversight program delivering data-driven performance feedback and driving targeted quality improvement efforts. Additional research is needed to better understand how to reduce the incidence, morbidity, and mortality of in-hospital stroke.

Time to Wake-Up: Extending the Window for Management of Unknown-Onset Strokes

The term "Wake-Up Stroke" is applied to a patient who displays no symptoms before sleep, but wakes with neurologic deficits suggestive of stroke. The current guidelines for acute ischemic stroke limit intravenous tissue plasminogen activator use to stroke patients in whom symptom onset or last known well is less than 4.5 hours. Approximately one-third of acute ischemic stroke patients present with unknown time of symptom onset and are often not eligible for intravenous reperfusion therapy in clinical practice. This review provides an overview of several earlier trials that used advanced neuroimaging to determine eligibility for reperfusion therapy in patients with unknown stroke onset. The reassuring results of these earlier trials that led to recent thrombolysis trials specifically targeted at "wake-up stroke" patients are discussed in this review. Ongoing studies aim to expand our knowledge regarding the safety and efficacy of thrombolysis in these patients.

Routine use of FLAIR-negative MRI in the treatment of unknown onset stroke

BACKGROUND

Treatment of FLAIR-negative stroke in patients presenting in an unknown time window has been shown to be safe and effective. However, implementation can be challenging due to the need for hyper-acute MRI screening. The purpose of this study was to review the routine application of this practice outside of a clinical trial.

METHODS

Patients presenting from 3/1/16 to 8/22/18 in a time window <4.5 h from symptom discovery but >4.5 h from last known normal were included if they had a hyper-acute MRI performed. Quantitative assessment based on the MR WITNESS trial and qualitative assessment based on the WAKE-UP trial were used to grade the FLAIR images. The MR WITNESS trial used a quantitative assessment of FLAIR change where the fractional increase in signal change had to be <1.15, whereas the WAKE-UP trial used a visual assessment requiring the absence of marked FLAIR signal changes.

RESULTS

During the study period, 136 stroke patients presented and were imaged in the specified time window. Of these, 17 (12.5%) received IV tPA. Three patients had hemorrhage on 24-h MRI follow up; none had an increase in NIHSS ≥4. Of the 119 patients who were screened but not treated, 18 (15%) were eligible based on FLAIR quantitative assessment and 55 (46%) were eligible based on qualitative assessment. In all cases where patients were not treated, there was an identifiable exclusion based on trial criteria. During the study period, IV tPA utilization was increased by 5.6% due to screening and treating patients with unknown onset stroke.

CONCLUSIONS

Screening stroke patients in an unknown time window with MRI is practical in a real-world setting and increases IV tPA utilization.