How Much of the Thrombectomy Related Improvement in Functional Outcome Is Already Apparent at 24 Hours and at Hospital Discharge?

Validation of a model for outcome prediction after endovascular treatment for ischemic stroke

INTRODUCTION

The recently developed MR-PREDICTS@24 h model showed excellent performance in the MR-CLEAN Registry cohort in patients presenting within 12 h from onset. However, its applicability to an U.S. population and to patients presenting beyond 12 h from last known normal are still undetermined. We aim to externally validate the MR-PREDICTS@24 h model in a new geographic setting and in the late window.

METHODS

In this retrospective analysis of a prospectively collected database from a comprehensive stroke center in the United States, we included patients with intracranial carotid artery or middle cerebral artery M1 or M2 segment occlusions who underwent endovascular therapy and applied the MR-PREDICTS@24 h formula to estimate the probabilities of functional outcome at day 90. The primary endpoint was the modified Rankin Scale (mRS) at 90 days.

RESULTS

We included 1246 patients, 879 in the early (<12 h) and 367 in the late (≥12 h) cohort. For both cohorts, calibration and discrimination of the model were accurate throughout mRS levels, with absolute differences between estimated and predicted proportions ranging from 1% to 5%. Calibration metrics and curve inspections showed good performance for estimating the probabilities of mRS ≤ 1 to mRS ≤ 5 for the early cohort. For the late cohort, predictions were reliable for the probabilities of mRS ≤ 1 to mRS ≤ 4.

CONCLUSION

The MR-PREDICTS@24 h was transferrable to a real-world U.S.-based cohort in the early window and showed consistently accurate predictions for patients presenting in the late window without need for updating.

Thrombectomy patients with minor stroke: factors of early neurological deterioration

BACKGROUND

A sizeable proportion of stroke patients with large vessel occlusion present with minor neurological deficits. Whether mechanical thrombectomy (MT) is beneficial in these patients is controversial. We aimed to investigate factors of early neurological deterioration (END) in thrombectomy patients with minor stroke and hypothesized that END is linked to unfavorable functional outcomes.

METHODS

Multicenter cohort study screening all patients prospectively enrolled in the German Stroke Registry-Endovascular Treatment (n=13 082) between 2015 and 2021. Patients who underwent MT for anterior circulation vessel occlusion with baseline National Institutes of Health Stroke Scale (NIHSS) score of <6 were included. END was defined as an increase in NIHSS score of ≥4 within the first 24 hours after MT. Multivariable regression analyses were performed to investigate factors associated with END and its association with unfavorable functional outcomes 90 days after treatment (modified Rankin Scale (mRS) score ≥2).

RESULTS

Among 817 patients included, 24% exhibited END and 48% had unfavorable functional outcomes. Prestroke mRS (adjusted odds ratio (aOR) [95% CI] 1.42 [1.13 to 1.78]), baseline NIHSS (aOR [95% CI] 0.83 [0.73 to 0.94]), time from admission to groin puncture (aOR [95% CI] 1.04 [1.02 to 1.07]), general anesthesia (aOR [95% CI] 1.68 [1.08 to 2.63]), number of passes (aOR [95% CI] 1.15 [1.03 to 1.29]), adverse events during treatment (aOR [95% CI] 1.89 [1.19 to 3.01]), successful recanalization (aOR [95% CI] 0.29 [0.17 to 0.50]), and intracranial hemorrhage on follow-up imaging (aOR [95% CI] 3.40 [1.90 to 6.07]) were independently associated with END. END was independently linked to unfavorable functional outcomes (aOR [95% CI] 7.51 [4.57 to 12.34]).

CONCLUSIONS

Almost a quarter of thrombectomy patients with minor stroke developed END. These patients had twice the odds of experiencing unfavorable functional outcomes.

Hypoperfusion Intensity Ratio Is Associated with Early Neurologic Deficit Severity and Deterioration after Mechanical Thrombectomy in Large-Vessel Occlusion Ischemic Stroke

BACKGROUND AND PURPOSE

The hypoperfusion intensity ratio is a surrogate marker for collateral status and a predictor of infarct growth, malignant cerebral edema, and hemorrhagic transformation. Its utility to predict a poor NIHSS score and early neurologic deterioration after mechanical thrombectomy for large vessel (LVO) versus distal and medium vessel occlusions (DMVO) has not been investigated. The objective of this study was to determine whether the higher hypoperfusion intensity ratio is associated with a worse NIHSS score at 24 hours post-mechanical thrombectomy and early neurologic deterioration in LVO versus DMVO acute ischemic stroke.

MATERIALS AND METHODS

This was a retrospective study of 231 patients with acute ischemic stroke with LVO or DMVO amenable for mechanical thrombectomy and available CTP for hypoperfusion intensity ratio assessment pre-mechanical thrombectomy. Clinical and imaging characteristics were abstracted from the medical records. The primary outcome was the NIHSS score at 24 hours post-mechanical thrombectomy. The secondary outcome was early neurologic deterioration, defined as a >4-point increase in the NIHSS score between the initial assessment and 24 hours post-mechanical thrombectomy. All analyses were first conducted in the entire cohort and then separately for the LVO versus DMVO groups.

RESULTS

The optimal hypoperfusion intensity ratio threshold to detect early neurologic deterioration was 0.54. A hypoperfusion intensity ratio ≥ 0.54 was more frequently present in LVO versus DMVO (n = 37 [77.1%] versus n = 11 [22.9%]; P < .001). On multivariable linear regression, the hypoperfusion intensity ratio ≥ 0.54 was independently associated with a worse NIHSS score at 24 hours post-mechanical thrombectomy in the entire cohort (β = 0.163; P = .002) and the LVO group (β = 0.210; P = .005), but not in the DMVO group. The early neurologic deterioration occurred in 26 (11.3%) subjects. On multivariable logistic regression, there was no association of the hypoperfusion intensity ratio ≥ 0.54 with early neurologic deterioration in the entire cohort. However, when analyzed separately, a hypoperfusion intensity ratio ≥ 0.54 significantly increased the odds of early neurologic deterioration in subjects with LVO (OR = 5.263; 95% CI, 1.170-23.674; P = .030) but not in the DMVO group.

CONCLUSIONS

The hypoperfusion intensity ratio ≥ 0.54 was independently associated with a worse 24-hour post-mechanical thrombectomy NIHSS score and early neurologic deterioration in LVO, but not in DMVO acute ischemic stroke. Pending confirmation in future, prospective studies assessing the hypoperfusion intensity ratio may help identify patients at risk of secondary decline to improve peri-thrombectomy care and clinical decision-making.

Predictors of failure of early neurological improvement in early time window following endovascular thrombectomy: a multi-center study

Background and objective

Endovascular thrombectomy (EVT) has become the gold standard in the treatment of acute stroke patients. However, not all patients respond well to this treatment despite successful attempts. In this study, we aimed to identify variables associated with the failure of improvements following EVT.

Methods

We retrospectively analyzed prospectively collected data of 292 ischemic stroke patients with large vessel occlusion who underwent EVT at three academic stroke centers in China from January 2019 to February 2022. All patients were above 18 years old and had symptoms onset ≤6 h. A decrease of more than 4 points on the National Institute of Health Stroke Scale (NIHSS) after 24 h compared with admission or an NIHSS of 0 or 1 after 24 h was defined as early neurological improvement (ENI), whereas a lack of such improvement in the NIHSS was defined as a failure of early neurological improvement (FENI). A favorable outcome was defined as a modified Rankin scale (mRS) score of 0-2 after 90 days.

Results

A total of 183 patients were included in the final analyses, 126 of whom had FENI, while 57 had ENI. Favorable outcomes occurred in 80.7% of patients in the ENI group, in contrast to only 22.2% in the FENI group (p < 0.001). Mortality was 7.0% in the ENI group in comparison to 42.1% in the FENI group (p < 0.001). The multiple logistic regression model showed that diabetes mellitus [OR (95% CI), 2.985 (1.070-8.324), p = 0.037], pre-stroke mRS [OR (95% CI), 6.221 (1.421-27.248), p = 0.015], last known well to puncture time [OR (95% CI), 1.010 (1.003-1.016), p = 0.002], modified thrombolysis in cerebral infarction = 3 [OR (95% CI), 0.291 (0.122-0.692), p = 0.005], and number of mechanical thrombectomy passes [OR (95% CI), 1.582 (1.087-2.302), p = 0.017] were the predictors of FENI.

Conclusion

Diabetes mellitus history, pre-stroke mRS, longer last known well-to-puncture time, lack of modified thrombolysis in cerebral infarction = 3, and the number of mechanical thrombectomy passes are the predictors of FENI. Future large-scale studies are required to validate these findings.

Patient characteristics associated with delayed neurological improvement following acute ischemic stroke: A systematic review and meta-analysis

BACKGROUND

Delayed neurological improvement (DNI) is a phenomenon that involves patient improvement in the absence of early neurological change following treatment for acute ischemic stroke. The patient characteristics associated with this condition are largely unexplored.

METHODS

Following the PRISMA guidelines, a systematic review of the English language literature was conducted using PubMed, Embase, Web of science, and Scopus. We calculated pooled odds ratios (ORs), mean differences (MDs), and their corresponding 95% confidence intervals (CIs) to test the association between patient characteristics and achievement of DNI.

RESULTS

Seven studies, with 3266 patients, were included in our analysis. All studies reported a different definition of DNI, with five studies focusing on rates of good functional outcome at 90 days post-treatment in the absence of early neurological improvement. Use of intravenous thrombolytics was associated with increased rates of DNI (OR 1.96, 95% CI 1.28 to 3.00; p = 0.002). Atrial fibrillation was associated with decreased rates of DNI (OR 0.69, 95% CI 0.57 to 0.82; p < 0.001), as was hypertension (OR 0.66, 95% CI 0.53 to 0.83, p < 0.001), and diabetes mellitus (OR 0.71, 95% CI 0.56 to 0.90; p = 0.005). On average, patients who achieved DNI were 6.30 years younger than their non-DNI counterparts (MD -6.30, 95% CI -9.19 to -3.41; p < 0.001). There were modest associations between male sex and DNI (OR 1.36, 95% CI 1.01 to 1.74, p = 0.042), and smoking and DNI (OR 1.28, 95% CI 1.03 to 1.59, p = 0.027).

CONCLUSIONS

DNI is a phenomenon that is not presently well understood. Lack of uniformity among definitions of DNI hinders efforts to explore DNI and the factors associated with its occurrence. Future studies should work to establish a consensus definition of DNI to determine its causes and significance more accurately.