Abstract WMP5: CT Perfusion Profiles of Infarct Growth in Large Vessel Occlusion Acute Stroke Patients Sensitive to Decreases in Blood Pressure

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Santiago Ortega-Gutierrez ◽  
Biyue Dai ◽  
Sudeepta Dandapat ◽  
Andrea Holcombe ◽  
Cynthia Zevallos ◽  
...  

The growth of a final infarct volume largely depends on cerebral perfusion after a large vessel occlusion (LVO) stroke. Decreases of blood pressure (BP) before recanalization are associated with larger infarct and worse functional outcome. It is uncertain whether an intervention to elevate BP improves outcome, particularly if susceptibility to the BP beneficial effect varies by individual factors such as the collateral vessel status. We aim to define the association of BP, infarct growth and perfusion patterns of potential vulnerable patients. We retrospectively studied patients with anterior LVOs who underwent mechanical thrombectomy (MT) at two comprehensive stroke centers. Only patients with TICI score ≥2b and admission CTP and 24 hours MRI were included. Infarct growth was calculated as 620 ADC volume subtracted from CBF <30% in the ischemic hemisphere using the Automatic Rapid Software. Hypoperfusion intensity ratio (HIR) was calculated as the ratio of the Tmax >10s volume to the Tmax >6s volume with a lower value indicating a more favorable ratio. Intra-procedural BP was continuously monitored using a non-invasive cuff or intraarterial catheter. Systolic BP (SBP) and mean arterial pressure (MAP) were averaged at various time points throughout MT. We analyzed 199 patients from 317 MT. A quantile regression with quantile τ = 0.25, 0.5 and 0.75 was fitted to study how Infarct Growth Rate (IGR) is affected by BP change. At 0.25 and 0.5 quantiles, one unit change in MAP did not lead to a significant change for IGR. At the 0.75 quantile (quartile 3), one unit change in MAP resulted in 0.79 unit change in IGR (95% CI: -0.11, 1.69; p= 0.09). Hence, we identified patients whose IGR is above the 0.75 quantile as the vulnerable subgroup. The vulnerable subgroup had significant larger median volumes of Tmax in all sequences when compared to the non-vulnerable subgroup: Tmax10 (67.8cc vs 40.0cc, p= 0.004), Tmax8 (92.9cc vs 62.0cc, p= 0.003), Tmax6 (134cc vs 98.7cc, p =0.003), Tmax4 (228.6cc vs 184.3cc, p= 0.016). The median HIR was also significantly higher (0.4 vs 0.3, p= 0.026) in the BP vulnerable population. Admission perfusion patterns of collaterals evaluated may help to identify the most vulnerable population to increase their infarct growth when facing decrease in BP.

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
David Baker ◽  
Dinesh Jillella ◽  
Takashi Shimoyama ◽  
Ken Uchino

Introduction: In patients with large vessel occlusion presenting with acute ischemic stroke, cerebral perfusion is a major determinant of stroke severity. However, limited data exists to guide hemodynamic management of these patients early after presentation. In this study, we aim to evaluate the effect of blood pressure reductions during the hyper-acute period on infarct size. Methods: From a clinical stroke registry at a single comprehensive stroke center, we reviewed patients with middle cerebral artery (M1) or internal carotid artery occlusion who underwent hyperacute magnetic resonance imaging (MRI) for endovascular treatment decision in 2018. Infarct volume was determined by area of reduced apparent diffusion coefficient using RAPID software. Collateral circulation was scored based on baseline CT angiogram (good collaterals constituted >50% filling, poor collaterals ≤50% filling). Average mean arterial pressure (MAP) readings from the first hour of presentation were compared to average MAP readings from the hour prior to magnetic resonance imaging. For the purposes of our study, a drop of > 20% in the average MAP was regarded as a significant decrease. We hypothesized that both significant drop in MAP and the presence of good collateral circulation were independent predictors of infarct volume expressed as a logarithmic value in multivariable regression model. Results: Of the 35 patients (mean age 67, mean NIHSS 16) meeting inclusion criteria, 11% of patients experienced an early significant drop in MAP prior to time of MRI. Among patients with a significant drop in MAP, the average decrease was 35 mm Hg ±3.3 among those with significant drop from a baseline mean MAP of 125 mm Hg. In the multivariable analysis adjusting for collateral status, a significant drop in average MAP was independently associated with an increase in infarct volume (β = -0.727, p=0.0306). Collateral status also independently predicted infarct size (β=0.775, p=0.0007). Conclusion: Among ischemic stroke patients with large vessel occlusion, a >20% drop in MAP during the hyper-acute period is associated with larger infarct volumes. Further studies are needed to optimize early blood pressure management in these patients.


2016 ◽  
Vol 9 (5) ◽  
pp. 451-454 ◽  
Author(s):  
Nitin Goyal ◽  
Georgios Tsivgoulis ◽  
Sulaiman Iftikhar ◽  
Yasser Khorchid ◽  
Muhammad Fawad Ishfaq ◽  
...  

Background and purposeHigh admission blood pressure (BP) levels have been associated with lower recanalization rates after endovascular treatment (EVT) for patients with acute ischemic stroke (AIS) with emergent large vessel occlusion (ELVO). We sought to evaluate the association of admission BP with early outcomes in patients with ELVO treated with EVT.MethodsConsecutive patients with AIS presenting with ELVO in a tertiary stroke center during a 4-year period were prospectively evaluated. Admission systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured using automated cuff recordings. A blinded neuroradiologist calculated the final infarct volume (FIV) using standardized ABC/2 methodology. A favorable functional outcome (FFO) at 3 months was defined as modified Rankin Scale score of 0–2.ResultsOur study population consisted of 116 patients with AIS (mean age 63±13 years, median NIH Stroke Scale score 17 points (IQR 14–21), median FIV 30 cm3 (IQR 8–94)). Higher admission SBP correlated with higher FIV (r +0.225; p=0.020). Patients with FFO had lower admission SBP (151±24 mm Hg vs 165±28 mm Hg; p=0.010), while admission SBP levels were higher in patients who died during hospitalization (169±34 mm Hg vs 156±24 mm Hg; p=0.043). A 10 mm Hg increment in admission SBP was independently (p=0.010) associated with an increase of 12 cm3 in FIV (95% CI 3 to 21) in multiple linear regression models adjusting for potential confounders. A 10 mm Hg increment in admission SBP was independently (p=0.012) associated with a lower likelihood of FFO at 3 months (OR 0.64; 95% CI 0.45 to 0.91) in multiple logistic regression models adjusting for potential confounders.ConclusionsHigher admission SBP is an independent predictor of increased FIV and lower likelihood of 3-month FFO in patients with ELVO treated with EVT.


Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Victor Lopez-Rivera ◽  
James Fan ◽  
Songmi Lee ◽  
Aditya Kumar ◽  
Mehmet Enes Inam ◽  
...  

Introduction: Estimation of infarct core (IC) is a critical component in the evaluation of patients with large vessel occlusion (LVO) for endovascular stroke therapy (EST), but the optimal method to determine IC is uncertain. Methods: From our prospectively maintained institutional registry, we identified acute ischemic stroke (AIS) patients with LVO between 1/2018 and 2/2019. Patients were included if they underwent consecutively and technically adequate non-contrast CT, CT angiography (CTA), and CT Perfusion (CTP). ASPECTS was assessed by an experienced neuroradiologist. CTP IC was determined using RAPID. Final infarct volume (FIV) was determined by manual volume segmentation on DWI sequences from 24h MRI, but this analysis was limited to patients who underwent EST with TICI 2b/3 reperfusion within 120 minutes of presentation CT imaging, to minimize IC growth affecting the results. Correlation between IC measurements was calculated using Spearman p. Results are provided as median [IQR]. Results: Among 772 patients with LVO, 199 patients met inclusion criteria. Median age was 69 [59-79], 47% were female and 57% were white. Median NIHSS was 15 [9-21], the most common occlusion site was M1 MCA (55%). Median CT ASPECTS was 7 [6-9], median CTA ASPECTS was 6 [5-7], and median CTP-RAPID IC volume was 11 [0-47]. Presentation CT ASPECTS correlated with CTP-RAPID IC (Fig. 1A, r=-0.57; p<0.0001), as did CTA ASPECTS (Fig. 1B, r=-0.61; p<0.0001). Presentation CTA ASPECTS correlated with CTP-RAPID IC in patients presenting 0-6 hrs (CTA r=-0.69; p<0.0001) and 6-24 hrs (r=-0.58; p<0.0001). Among 90 patients with EST and TICI 2b/3, presentation CTA ASPECTS correlated better with FIV (r=-0.65; p<0.0001) compared to presentation CTP-RAPID (r=0.61; p<0.0001). Conclusions: In patients with LVO in the anterior circulation, CTA ASPECTS correlated well with CTP-RAPID IC in the early and late time windows, and was more reflective of 24h MRI findings in patients who received EST.


Stroke ◽  
2021 ◽  
Author(s):  
Shadi Yaghi ◽  
Eytan Raz ◽  
Seena Dehkharghani ◽  
Howard Riina ◽  
Ryan McTaggart ◽  
...  

Background and Purpose: In patients with acute large vessel occlusion, the natural history of penumbral tissue based on perfusion time-to-maximum (T max ) delay is not well established in relation to late-window endovascular thrombectomy. In this study, we sought to evaluate penumbra consumption rates for T max delays in patients with large vessel occlusion evaluated between 6 and 16 hours from last known normal. Methods: This is a post hoc analysis of the DEFUSE 3 trial (The Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke), which included patients with an acute ischemic stroke due to anterior circulation occlusion within 6 to 16 hours of last known normal. The primary outcome is percentage penumbra consumption, defined as (24-hour magnetic resonance imaging infarct volume–baseline core infarct volume)/(T max 6 or 10 s volume–baseline core volume). We stratified the cohort into 4 categories based on treatment modality and Thrombolysis in Cerebral Infarction (TICI score; untreated, TICI 0-2a, TICI 2b, and TICI3) and calculated penumbral consumption rates in each category. Results: We included 141 patients, among whom 68 were untreated. In the untreated versus TICI 3 patients, a median (interquartile range) of 53.7% (21.2%–87.7%) versus 5.3% (1.1%–14.6%) of penumbral tissue was consumed based on T max >6 s ( P <0.001). In the same comparison for T max >10 s, we saw a difference of 165.4% (interquartile range, 56.1%–479.8%) versus 25.7% (interquartile range, 3.2%–72.1%; P <0.001). Significant differences were not demonstrated between untreated and TICI 0-2a patients for penumbral consumption based on T max >6 s ( P =0.52) or T max >10 s ( P =0.92). Conclusions: Among extended window endovascular thrombectomy patients, T max >10-s mismatch volume may comprise large volumes of salvageable tissue, whereas nearly half the T max >6-s mismatch volume may remain viable in untreated patients at 24 hours.


Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Shadi Yaghi ◽  
Eytan Raz ◽  
Seena Dehkharghani ◽  
Howard Riina ◽  
Ryan McTaggart ◽  
...  

Introduction: In patients with acute large vessel occlusion, the definition of penumbral tissue based on T max delay perfusion imaging is not well established in relation to late-window endovascular thrombectomy (EVT). In this study, we sought to evaluate penumbra consumption rates for T max delays in patients treated between 6 and 16 hours from last known normal. Methods: This is a secondary analysis of the DEFUSE-3 trial, which included patients with an acute ischemic stroke due to anterior circulation occlusion within 6-16 hours of last known normal. The primary outcome is percentage penumbra consumption defined as (24 hour infarct volume-core infarct volume)/(Tmax volume-baseline core volume). We stratified the cohort into 4 categories (untreated, TICI 0-2a, TICI 2b, and TICI3) and calculated penumbral consumption rates. Results: We included 143 patients, of which 66 were untreated, 16 had TICI 0-2a, 46 had TICI 2b, and 15 had TICI 3. In untreated patients, a median (IQR) of 48% (21% - 85%) of penumbral tissue was consumed based on Tmax6 as opposed to 160.6% (51% - 455.2%) of penumbral tissue based on Tmax10. On the contrary, in patients achieving TICI 3 reperfusion, a median (IQR) of 5.3% (1.1% - 14.6%) of penumbral tissue was consumed based on Tmax6 and 25.7% (3.2% - 72.1%) of penumbral tissue based on Tmax10. Conclusion: Contrary to prior studies, we show that at least 75% of penumbral tissue with Tmax > 10 sec delay can be salvaged with successful reperfusion and new generation devices. In untreated patients, since infarct expansion can occur beyond 24 hours, future studies with delayed brain imaging are needed to determine the optimal T max delay threshold that defines penumbral tissue in patients with proximal anterior circulation large vessel occlusion.


Stroke ◽  
2021 ◽  
Author(s):  
Raul G. Nogueira ◽  
Jason M. Davies ◽  
Rishi Gupta ◽  
Ameer E. Hassan ◽  
Thomas Devlin ◽  
...  

Background and Purpose: The degree to which the coronavirus disease 2019 (COVID-19) pandemic has affected systems of care, in particular, those for time-sensitive conditions such as stroke, remains poorly quantified. We sought to evaluate the impact of COVID-19 in the overall screening for acute stroke utilizing a commercial clinical artificial intelligence platform. Methods: Data were derived from the Viz Platform, an artificial intelligence application designed to optimize the workflow of patients with acute stroke. Neuroimaging data on suspected patients with stroke across 97 hospitals in 20 US states were collected in real time and retrospectively analyzed with the number of patients undergoing imaging screening serving as a surrogate for the amount of stroke care. The main outcome measures were the number of computed tomography (CT) angiography, CT perfusion, large vessel occlusions (defined according to the automated software detection), and severe strokes on CT perfusion (defined as those with hypoperfusion volumes >70 mL) normalized as number of patients per day per hospital. Data from the prepandemic (November 4, 2019 to February 29, 2020) and pandemic (March 1 to May 10, 2020) periods were compared at national and state levels. Correlations were made between the inter-period changes in imaging screening, stroke hospitalizations, and thrombectomy procedures using state-specific sampling. Results: A total of 23 223 patients were included. The incidence of large vessel occlusion on CT angiography and severe strokes on CT perfusion were 11.2% (n=2602) and 14.7% (n=1229/8328), respectively. There were significant declines in the overall number of CT angiographies (−22.8%; 1.39–1.07 patients/day per hospital, P <0.001) and CT perfusion (−26.1%; 0.50–0.37 patients/day per hospital, P <0.001) as well as in the incidence of large vessel occlusion (−17.1%; 0.15–0.13 patients/day per hospital, P <0.001) and severe strokes on CT perfusion (−16.7%; 0.12–0.10 patients/day per hospital, P <0.005). The sampled cohort showed similar declines in the rates of large vessel occlusions versus thrombectomy (18.8% versus 19.5%, P =0.9) and comprehensive stroke center hospitalizations (18.8% versus 11.0%, P =0.4). Conclusions: A significant decline in stroke imaging screening has occurred during the COVID-19 pandemic. This analysis underscores the broader application of artificial intelligence neuroimaging platforms for the real-time monitoring of stroke systems of care.


Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Joseph F Carrera ◽  
Joseph H Donahue ◽  
Prem P Batchala ◽  
Andrew M Southerland ◽  
Bradford B Worrall

Introduction: CTP and MRI are increasingly used to assess endovascular thrombectomy (EVT) candidacy in large vessel occlusion stroke. Unfortunately, availability of these advanced neuroimaging techniques is not widespread and this can lead to over-triage to EVT-capable centers. Hypothesis: ASPECTS scoring applied to computed tomography angiography source images (CTA-SI) will be predictive of final infarct volume (FIV) and functional outcome. Methods: We reviewed data from consecutive patients undergoing EVT at our institution for anterior circulation occlusion between 01/14 - 01/19. We recorded demographics, comorbidities, NIHSS, treatment time parameters, and outcomes as defined by mRS (0-2 = good outcome). Cerebrovascular images were assessed by outcome-blinded raters and collateral score, TICI score, FIV, and both CT and CTA-SI ASPECTS scores were noted. Patients were grouped by ASPECTS score into low (0-4), intermediate (5-7), and high (8-10) for some analyses. FIV was predicted using a linear regression with NIHSS, good reperfusion (TICI 2b/3), collateral score, CT to groin puncture, CT and CTA-SI ASPECTS as independent variables. After excluding those with baseline mRS≥2, a binary logistic regression was performed including covariates of age, NIHSS, good reperfusion, and diabetes (factors significant at p<0.05 on univariate analysis) to assess the impact of CTA-SI ASPECTS group on outcome. Results: Analysis included 137 patients for FIV and 102 for outcome analysis (35 excluded for baseline mRS≥ 2). Linear regression found CTA-SI ASPECTS (Beta -10.8, p=0.002), collateral score (Beta -42.9, p=0.001) and good reperfusion (Beta 72.605, p=0.000) were independent predictors of FIV. Relative to the low CTA-SI ASPECTS group, the high CTA-SI ASPECTS group was more likely to have good outcome (OR 3.75 [95% CI 1.05-13.3]; p=0.41). CT ASPECTS was not predictive of FIV or good outcome. Outcomes: In those undergoing EVT for anterior circulation occlusion, CTA-SI ASPECTS is predictive of both FIV and functional outcome, while CT ASPECTS predicts neither. CTA-SI ASPECTS holds promise as a lower-cost, more widely available option for triage of patients with large vessel occlusion. Further study is needed comparing CTA-SI ASPECTS to CTP parameters.


Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Shashvat Desai ◽  
Bradley J Molyneaux ◽  
Marcelo Rocha ◽  
Matthew Starr ◽  
Tudor G Jovin ◽  
...  

Introduction: Patient selection for endovascular thrombectomy (EVT) for anterior circulation large vessel occlusion (LVO) strokes in the 6-24-hour time window is dependent on delineating clinical core mismatch (CCM) as defined by DAWN trial criteria. In contrast, patient selection in the early window (0-6 hours) can be performed using ASPECTS on CT head. We aim to determine the prevalence of DAWN-CCM in LVO strokes and the impact of time and ASPECTS. Methods: Retrospective analysis of large vessel occlusion [internal carotid and middle cerebral artery-M1] strokes at a CSC. Consecutive patients who underwent CT perfusion or MRI within 120 minutes of CT head were included in the study (treated and untreated). Ischemic core volume was assessed using RAPID [IschemaView] and ASPECTS using automated ASPECTS [Brainomix]. CCM was defined using DAWN trial criteria [DAWN-CCM: NIHSS ≥10 and core <31 ml, NIHSS ≥20 and core <51 ml]. Results: A total of 116 patients were included. Mean age was 71 ±14 and 62% were females. Mean ischemic core volume and median ASPECTS were 46 ±65 ml and 8 (6-9), respectively. In patients with NIHSS score ≥10 (98), 57% had DAWN-CCM in the 0-24-hour window. Proportion of patients with DAWN-CCM in 6-24-hour window was 70% (6-12 hours), 50% (12-18 hours), and 50% (18-24 hours) [p=0.35]. Proportion of patients with DAWN-CCM by ASPECTS group was 88% (ASPECTS 9-10), 64% (ASPECTS 6-8) and 13% (ASPECTS 0-5) [p=<0.01] (Figure 1). Probability of DAWN-CCM declines by 7% for every 2 hours increase in TLKW to imaging, and by 13% for every 1-point decrease in ASPECTS. Conclusion: Approximately 57% of LVO strokes have clinical core mismatch. LVO strokes with DAWN-CCM decline with increasing time and decreasing ASPECTS. ASPECTS alone may be sufficient to identify patients with DAWN-CCM in a resource limited setting and avoid time consuming advanced imaging.


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