Predictors of Radiographic and Symptomatic Hemorrhagic Conversion Following Endovascular Thrombectomy for Acute Ischemic Stroke Due to Large Vessel Occlusion.

Background Endovascular therapy is known to achieve a high rate of recanalization in patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO) and is currently the standard of care. Hemorrhagic conversion is a severe complication that may occur following AIS in patients undergoing endovascular thrombectomy (EVT). There is a scarcity of data on the risk factors related to HV in post-EVT patients, especially those who develop symptomatic hemorrhagic conversion. The main objective of our study is to identify independent predictors of radiographic and symptomatic hemorrhagic conversion in our diverse patient population with multiple baseline comorbidities that presented with AIS and were treated with EVT as per the most updated guidelines and practices. Methodology This is a retrospective chart review in which we enrolled adult patients treated with EVT for AIS at a comprehensive stroke center in the Bronx, NY, over a four-year period. Bivariate analyses followed by multiple logistic regression modeling were performed to determine the independent predictors of all and symptomatic hemorrhagic conversion. Results A total of 326 patients who underwent EVT for AIS were enrolled. Of these, 74 (22.7%) had an HC, while 252 (77.3%) did not. In total, 25 out of the 74 (33.7%) patients were symptomatic. In the logistic regression model, a history of prior ischemic stroke (odds ratio (OR) = 2.197; 95% confidence interval (CI) = 1.062-4.545; p-value = 0.034), Alberta Stroke Program Early CT Score (ASPECTS) of <6 (OR = 2.207; 95% CI = 1.477-7.194; p-value = 0.019), and Thrombolysis in Cerebral Infarction (TICI) 2B-3 recanalization (OR = 2.551; 95% CI = 1.998-6.520; p-value=0.045) were found to be independent predictors of all types of hemorrhagic conversion. The only independent predictor of symptomatic hemorrhagic conversion on multiple logistic regression modeling was an elevated international normalized ratio (INR) (OR = 11.051; 95% CI = 1.866-65.440; p-value = 0.008). Conclusions History of prior ischemic stroke, low ASPECTS score, and TICI 2B-3 recanalization are independent predictors of hemorrhagic conversion while an elevated INR is the only independent predictor of symptomatic hemorrhagic conversion in post-thrombectomy patients.

Predicting 90-day Functional Dependency and Death after Endovascular Thrombectomy for Stroke: The BET Score.

OBJECTIVES: Despite being the current standard of care, outcomes after endovascular thrombectomy (EVT) for acute ischemic stroke (AIS) remain highly variable. Though several scoring systems exist to predict outcomes in AIS, they were mainly developed to direct patient selection for treatment. Recognizing the integral role peri-procedural metrics play on outcome, our study aimed to develop a post-EVT prognostic score to predict 90-day functional dependency and death. MATERIALS AND METHODS: We included all eligible adult AIS patients treated with EVT at our institution from June 2016 to January 2020. Data was systematically collected via chart review including pre-, intra- and post-procedural variables. The outcome was modified Rankin score (mRS) at 90 days post-EVT where a poor outcome was defined as mRS 3-6: 3-5 for functional dependency and 6 for death. Model selection methods including stepwise and Lasso were evaluated via cross-validation where the final multivariable logistic regression model was chosen by optimizing the Area Under the Receiver Operating Characteristic Curve (ROC AUC). RESULTS: We included 224 patients (mean age: 65 years old, male: 55%, 90-day poor outcome: 60%). The final model achieved a median AUC of 0.84, IQR: (0.80, 0.87). A 7-point score, called Bronx Endovascular Thrombectomy (BET) score, was developed with more points indicating higher likelihood of 90-day poor outcome (0 point: ≤21% risk; 1-2: 24%; 3: 61%; 4: 86%; 5: 96%; 6-7: ≥99%). One point was awarded for the following variables: current smoker, diabetic, general anesthesia received, puncture to perfusion time ≥45 minutes, and Thrombolysis in Cerebral Infarction (TICI) score <3. Two points were awarded for a post-EVT National Institute of Health Stroke scale (NIHSS) of ≥10. CONCLUSION: Incorporating peri-procedural data we developed the competitive BET score predicting 90-day functional dependency and death, which may help providers, patients and caregivers manage expectations and organize early rehabilitative services.

A Predictive Model for Functional Outcome in Patients with Acute Ischemic Stroke Undergoing Endovascular Thrombectomy.

INTRODUCTION: Endovascular thrombectomy (EVT) is a well-established treatment of acute ischemic stroke. Variability in outcomes among thrombectomy patients results in a need for patient centered approaches to recovery. Identifying key factors that are associated with outcomes can help prognosticate and direct resources for continued improvement post-treatment. Thus, we developed a comprehensive predictive model of short-term outcomes post-thrombectomy. METHODS: This is a retrospective chart review of adult patients who underwent EVT at our institution over the last four years. Primary outcome was dichotomized 90-day mRS (mRS 0-2 v mRS 3-6). Bivariate analyses were conducted, followed by logistic regression modelling via a backward-elimination approach to identify the best fit predictive model. RESULTS: 326 thrombectomies were performed; 230 cases were included in the model. In the final predictive model, adjusting for age, gender, race, diabetes, and presenting NIHSS, pre-admission mRS = 0-2 (OR 18.1; 95% 3.44-95.48; p < 0.001) was the strongest predictor of a good outcome at 90-days. Other independent predictors of good outcomes included being a non-smoker (OR 5.4; 95% CI 1.53-19.00; p = 0.01) and having a post-thrombectomy NIHSS<10 (OR 9.7; 95% CI 3.90-24.27; p < 0.001). A decompressive hemicraniectomy (DHC) was predictive of a poor outcome at 90-days (OR 0.07; 95% CI 0.01-0.72; p = 0.03). This model had a Sensitivity of 79%, a Specificity of 89% and an AUC=0.89. CONCLUSION: Our model identified low pre-admission mRS score, low post-thrombectomy NIHSS, non-smoker status and not requiring a DHC as predictors of good functional outcomes at 90-days. Future works include developing a prognostic scoring system.

Re-Evaluating Stroke Systems of Care: Association of Transfer Status With Thrombectomy Outcomes at an Urban Comprehensive Stroke Center.

Introduction Given the efficacy of mechanical thrombectomies (MT) for large vessel occlusions (LVO), there is concern that the Hub and Spoke model of stroke care, which prioritizes initial assessment of the acute ischemic stroke (AIS) patient at a primary stroke center, would cause a delay in arterial reperfusion, thus leading to worse outcomes. In this study that occurred at our comprehensive stroke center in New York, we compared the clinical outcomes of patients that were either directly admitted for thrombectomy versus those who were transferred from another institution. Methods Retrospective review of the electronic medical record (EMR) was performed on all adult patients treated with endovascular therapy for ischemic stroke between January 2016 and February 2020. A bivariate analysis was performed to compare patients in the direct admit versus transfer group. A multivariable logistic regression model was developed to determine which factors affect 90-day modified Rankin score (mRS) and to evaluate if transfer status was an independent predictor in this model. Results Three hundred and twenty-five patients were included in this study; 127 patients belonged to the direct admit group while 198 were in the transfer group. Thirteen patients (20%) in the direct admit group had a 90-day mRS score of 0-2 and so did 29 patients (25.2%) in the transfer group; thus, no statistically significant difference found in clinical outcomes between both groups (p-value = 0.427). In a multivariable logistic regression model that accounts for age, gender, smoking status, baseline mRS, presenting National Institute of Health Stroke Scale (NIHSS), procedure duration, thrombolysis in cerebral infarction (TICI) score, post-NIHSS and decompressive hemicraniectomy, transfer status was not found to be predictive of clinical outcomes (OR 0.727 95% CI 0.349-1.516; p-value = 0.396).  Conclusion Transfer status is not significantly associated with 90-day outcome. Since Hub and Spoke is not associated with worse outcomes compared to direct admit, it remains a viable model for providing effective care to stroke patients in an urban setting.