Impact of Time to Treatment on Endovascular Thrombectomy Outcomes in the Early Versus Late Treatment Time Windows

BACKGROUND: The impact of time to treatment on outcomes of endovascular thrombectomy (EVT) especially in patients presenting after 6 hours from symptom onset is not well characterized. We studied the differences in characteristics and treatment timelines of EVT-treated patients participating in the Florida Stroke Registry and aimed to characterize the extent to which time impacts EVT outcomes in the early and late time windows. METHODS: Prospectively collected data from Get With the Guidelines-Stroke hospitals participating in the Florida Stroke Registry from January 2010 to April 2020 were reviewed. Participants were EVT patients with onset-to-puncture time (OTP) of ≤24 hours and categorized into early window treated (OTP ≤6 hours) and late window treated (OTP \u3e6 and ≤24 hours). Association between OTP and favorable discharge outcomes (independent ambulation, discharge home and to acute rehabilitation facility) as well as symptomatic intracerebral hemorrhage and in-hospital mortality were examined using multilevel-multivariable analysis with generalized estimating equations. RESULTS: Among 8002 EVT patients (50.9% women; median age [±SD], 71.5 [±14.5] years; 61.7% White, 17.5% Black, and 21% Hispanic), 34.2% were treated in the late time window. Among all EVT patients, 32.4% were discharged home, 23.5% to rehabilitation facility, 33.7% ambulated independently at discharge, 5.1% had symptomatic intracerebral hemorrhage, and 9.2% died. As compared with the early window, treatment in the late window was associated with lower odds of independent ambulation (odds ratio [OR], 0.78 [0.67-0.90]) and discharge home (OR, 0.71 [0.63-0.80]). For every 60-minute increase in OTP, the odds of independent ambulation reduced by 8% (OR, 0.92 [0.87-0.97]; CONCLUSIONS: In routine practice, just over one-third of EVT-treated patients independently ambulate at discharge and only half are discharged to home/rehabilitation facility. Increased time from symptom onset to treatment is significantly associated with lower chance of independent ambulation and ability to be discharged home after EVT in the early time window

Abstract WP153: Abnormal Cerebral Blood Flow Determined By Transcranial Doppler In Patients With Anterior Circulation Large-vessel Occlusion Stroke And Successful Endovascular Recanalization

Background: Almost half of large-vessel occlusion (LVO) stroke patients have unfavorable outcomes despite successful endovascular revascularization. We aim to characterize post-revascularization cerebral blood flow (CBF) determined by transcranial Doppler (TCD) and explore whether abnormal CBF associates with in-hospital outcomes in this population. Methods: We analyzed 105 stroke patients with anterior circulation LVO who had successful endovascular revascularization (Thrombolysis in Cerebral Infarction 2b-3) and CBF assessment by TCD within 48 hours of recanalization. TCD parameters recorded at the ipsilateral middle cerebral artery included mean flow velocity, peak systolic velocity, pulsatility index (PI), and resistance index (RI). CBF was classified according to the Thrombolysis in Brain Ischemia (TIBI) score into dampened flow (score of 3), stenotic flow (score of 4), and normal flow (score of 5). We explored unadjusted associations between post-revascularization CBF and hospitalization outcomes including reduced disability at discharge (modified Rankin Score [mRS] 0-2), home disposition, and in-hospital mortality. Results: Table 1 summarizes study population characteristics. Overall, 62 (59.1%) individuals had normal CBF, 29 (27.6%) had stenotic flow, and 14 (13.3%) had dampened flow. Patients with abnormal CBF showed a trend towards lower likelihood of mRS 0-2 at discharge (32.1% vs. 44.2%; p=0.20) and home disposition (28.1% vs. 46.6%; p=0.08). TCD parameters were not associated with disability at discharge or home disposition. However, in-hospital mortality was significantly associated with elevated PI (1.3 ± 0.4 vs. 1.1 ± 0.5; p<0.01) and RI (0.7 ± 0.1 vs. 0.6 ± 0.1; p<0.01). Conclusion: A noteworthy fraction of anterior circulation LVO stroke patients had TCD-defined abnormal CBF despite successful revascularization. Abnormal CBF and increased vascular resistance may relate to unfavorable outcomes in this population

Sickle Cell Disease and Stroke: Data from the Florida Stroke Registry (S35.002)

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Abstract TP206: Transcranial Doppler Markers of Increased Microvascular Resistance After Successful Endovascular Revascularization Are Associated With Larger Infarct Volumes

Abstract only Background: Markers of increased microvascular resistance on Transcranial Doppler (TCD) obtained shortly after successful endovascular therapy (EVT) in patients with large-vessel occlusion (LVO) stroke have been associated with unfavorable outcomes. We aim to investigate whether post-EVT pulsatility index (PI) correlates with final infarct volume in this population. Methods: We analyzed consecutive anterior circulation LVO patients who underwent successful EVT (mTICI 2c-3) from 2012 to 2022. Patients with available TCD within 48 hours of EVT and brain MRI during admission were included. The TCD-derived PI was obtained from the ipsilateral middle cerebral artery. The ABC/2 method was used to estimate the final infarct volume in mL on MRI diffusion-weighted imaging. Pearson correlation and adjusted linear regression analysis were used to investigate the relationship between post-EVT PI and final infarct volume. Linear regression analysis was adjusted for age, NIHSS, and ASPECTS. Results: Out of 155 LVO patients with successful EVT during the study period, 40 were included in the analysis (mean age, 69 ± 16.7 years; 57% female; median NIHSS 15 (IQR 10); and median ASPECTS 9 (IQR, 2)). The median time from EVT to TCD and EVT to MRI was 21 hours (IQR, 17 hours) and 41 hours (IQR, 33 hours), respectively. Post EVT PI displayed a positive moderate correlation with final infarct volume (r=0.39, p<0.01; Figure 1). Larger PI values were independently associated with larger infarct volumes (β = 42.2 mL, 95% CI 37.0 - 47.5 mL). Conclusion: TCD-derived PI shortly after EVT correlated with final infarct volume in successfully revascularized LVO patients. TCD may serve as a valuable tool to identify those at risk for infarct progression and reveal potential therapeutic targets to maximize EVT benefit in this population

Abstract TP441: Poor Atrial Fibrillation Management Leads to Unnecessary Thrombectomies in Elderly Patients

Background: A significant proportion of mechanical thrombectomies for large vessel occlusion (LVO) stroke are avoidable with improved oral anticoagulant (OAC) use in patients with atrial fibrillation (AF). We sought to identify the proportion of avoidable thrombectomies in elderly patients (age ≥70) with stroke due to AF. Methods: This study included 348 consecutive MT cases at a high-volume stroke center from Feb 2015 to Sept 2018. A retrospective chart review was conducted to identify patient sociodemographics, presence of AF, use of anticoagulation, stroke severity, CHA 2 DS 2 -VASc scores, and functional outcome Results: A total of 191 (55%) patients were ≥70 years (median age 81±7, 61% female), of which 116 (61%) had AF (median age 82±6, 67% female). Elderly patients with AF were more likely to have hypertension and heart failure and be on antiplatelets and OACs. Pre-existing AF was present in 75 (39%) patients, of which 38 (49%) were not on OACs prior to stroke. Of the 39 (51%) patients with known AF on OACs, 10 (68%) had subtherapeutic INR levels and 5 (21%) were not adherent to direct OACs. Overall, 53/191 (28%) patients with known AF were not adequately anticoagulated prior to the index stroke. There was no significant difference in modified Rankin Scale score at discharge or rate of symptomatic intracerebral hemorrhage between the two groups. Conclusion: In our study, about 1 in 4 elderly patients with known AF were not adequately anticoagulated prior to stroke and underwent potentially avoidable thrombectomy. Better practice strategies are needed to increase OAC utilization and adherence to reduce the burden of stroke in patients with AF, especially in elderly women

Accuracy of transcranial Doppler in detecting intracranial stenosis in patients with sickle cell anemia when compared to magnetic resonance angiography

Stroke, the most devastating consequence of sickle cell anemia (SCA), is associated with endothelial damage and intracranial artery stenosis. We aimed to assess transcranial Doppler (TCD) ultrasound accuracy in detecting intracranial stenosis when compared to magnetic resonance angiography (MRA). Children with SCA and at least one TCD and MRA within 1 month were identified from a retrospectively collected database. Sensitivity and specificity were obtained to assess the overall accuracy of TCD mean flow velocity (mFV) ≥200 cm/s in detecting vessel stenosis of ≥50%. Multivariate analysis identified independent factors associated with MRA stenosis. Among 157 patients in the database, 64 had a TCD and MRA within 1 month (age 11.8 ± 5.3 years, 56% female, 20% with cerebral infarcts on MRI, 8 or 13% had mFV ≥200 cm/s and 20% or 21%, had intracranial stenosis ≥50% on MRA). TCD mFV ≥200 cm/s had a high specificity (95%) but low sensitivity (29%) to detecting intracranial stenosis. As a continuous variable, TCD mFV of 137.5 cm/s had maximal specificity (77%) and sensitivity (72%). After adjustment for age, hemoglobin level, transfusion status, hydroxyurea treatment, and vessel, for every increase in cm/sec on TCD, there was a 2% increase in the odds of ≥50% stenosis on MRA (p < 0.001). Our study reports TCD mFV is a positive predictor of MRA stenosis in SCA, independent of patient characteristics, including hemoglobin. A mFV ≥200 cm/s is highly specific but less sensitive in detecting stenosis ≥50%. Lower mFV cut points may be needed for the early detection of intracranial stenosis

Abstract P582: Accuracy of Transcranial Doppler in Detection of Intracranial Stenosis in Patients With Sickle Cell Disease

Background: Stroke is among the most devastating consequences of sickle cell disease (SCD). Most SCD strokes occur due to intracranial stenosis, that can be detected by increased flow velocities on Transcranial Doppler (TCD). However, increased velocities may also reflect anemia rather than arteriopathy and vessel stenosis. We aimed to assess the accuracy of TCD in detection of intracranial stenosis in SCD. Methods: Pediatric SCD patients with at least one TCD and MRA within one month apart were identified from a retrospectively collected database maintained at our institution from January 2000 to December 2016. Patient demographics, hemoglobin level, transfusion and hydroxyurea status were collected, along with mean flow velocities (mFV) and degree of stenosis from bilateral middle and anterior cerebral, and internal carotid arteries. A mFV of > 200 cm/s and vessel stenosis > 50% were considered abnormal. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were obtained to assess overall accuracy of TCD velocities in relation to vessel stenosis. Multivariate analysis was performed to identify independent factors associated with MRA stenosis. Results: A total of 164 patients were included in the database (median age 12 [IQR 8.9] years, 56% had ischemic strokes) and 64 of them had at least one TCD and MRA one month apart. Of these, 20% had ischemic strokes, 17% had MRA stenosis > 50% and 10% had TCD velocity > 200 cm/s. TCD mFV > 200 cm/s had a high specificity (95%) and NPV (87%) but low sensitivity (29%) and PPV (55%) when compared to MRA stenosis > 50%. As a continuous variable, TCD mFV 137.5 cm/s had the best balance between maximal specificity (77%) and sensitivity (72%). After adjustment for age, hemoglobin level, transfusion status, hydroxyurea, and vessel, for every increase in cm/sec on TCD, there was a 2% increase in the odds of > 50% stenosis on MRA (OR=1.02, 95% CI 1.01-1.03, p 200 cm/s is highly specific but less sensitive to detect stenosis > 50%. Lower mFV cut points may need to be considered for early detection of intracranial stenosis and risk of stroke

Transcranial Doppler After Successful Endovascular Revascularization and Hospitalization Outcomes

Background Almost half of large‐vessel occlusion strokes have unfavorable outcomes despite successful endovascular therapy. We aim to investigate whether postrevascularization cerebral hemodynamics, determined by transcranial Doppler (TCD), associate with hospitalization outcomes in this population. Methods The current observational cohort study analyzed 155 patients with successfully revascularized anterior circulation large‐vessel occlusion stroke (mean age, 68.3±15.4 years; 55% women) who had TCD within 48 hours from endovascular therapy. TCD parameters (mean flow velocity, peak systolic velocity, and pulsatility index) were recorded at the ipsilateral middle cerebral artery, and blood flow signals were categorized using the Thrombolysis in Brain Ischemia grades into normal (grade 5), stenotic (grade 4), or dampened (grade ≤3). Hospitalization outcomes comprised favorable discharge modified Rankin Scale score (0–2), favorable discharge destination (home or acute inpatient rehabilitation), and in‐hospital mortality. Logistic regression models adjusted for age, initial National Institutes of Health Stroke Scale score, and Alberta Stroke Program Early CT [Computed Tomography] Score were fit to determine TCD findings in association with study outcomes. Results Abnormal TCD‐derived blood flow was found in 54 (35%) cases, including 35 (23%) with Thrombolysis in Brain Ischemia grade 4 and 19 (12%) with Thrombolysis in Brain Ischemia grade ≤3. Overall, 31% had favorable discharge modified Rankin Scale score, 65% had favorable destination, and 14% died. Thrombolysis in Brain Ischemia grade ≤3 was associated with lower likelihood of both favorable discharge modified Rankin Scale score (adjusted odds ratio [OR], 0.09 [95% CI, 0.01–0.81]) and favorable destination (adjusted OR, 0.22 [95% CI, 0.07–0.71]). Mean flow velocity and peak systolic velocity were not associated with study outcomes. Conversely, increased pulsatility index was inversely associated with favorable destination (adjusted OR, 0.34 [95% CI, 0.13–0.87]). Conclusions TCD after successful endovascular therapy identified abnormal blood flow in one‐third of cases. Dampened flow and markers of increased microvascular resistance were associated with unfavorable hospitalization outcomes. TCD could provide valuable prognostic information in this population and identify potential therapeutic targets