Value of risk scores in the decision to palliate patients withruptured abdominal aortic aneurysm

Background: The aim of this study was to develop a 48‐h mortality risk score, which included morphology data, for patients with ruptured abdominal aortic aneurysm presenting to an emergency department, and to assess its predictive accuracy and clinical effectiveness in triaging patients to immediate aneurysm repair, transfer or palliative care. Methods: Data from patients in the IMPROVE (Immediate Management of the Patient With Ruptured Aneurysm: Open Versus Endovascular Repair) randomized trial were used to develop the risk score. Variables considered included age, sex, haemodynamic markers and aortic morphology. Backwards selection was used to identify relevant predictors. Predictive performance was assessed using calibration plots and the C‐statistic. Validation of the newly developed and other previously published scores was conducted in four external populations. The net benefit of treating patients based on a risk threshold compared with treating none was quantified. Results: Data from 536 patients in the IMPROVE trial were included. The final variables retained were age, sex, haemoglobin level, serum creatinine level, systolic BP, aortic neck length and angle, and acute myocardial ischaemia. The discrimination of the score for 48‐h mortality in the IMPROVE data was reasonable (C‐statistic 0·710, 95 per cent c.i. 0·659 to 0·760), but varied in external populations (from 0·652 to 0·761). The new score outperformed other published risk scores in some, but not all, populations. An 8 (95 per cent c.i. 5 to 11) per cent improvement in the C‐statistic was estimated compared with using age alone. Conclusion: The assessed risk scores did not have sufficient accuracy to enable potentially life‐saving decisions to be made regarding intervention. Focus should therefore shift to offering repair to more patients and reducing non‐intervention rates, while respecting the wishes of the patient and family

Outcomes of Mechanical Thrombectomy for Patients With Stroke Presenting With Low Alberta Stroke Program Early Computed Tomography Score in the Early and Extended Window

Importance: Limited data are available about the outcomes of mechanical thrombectomy (MT) for real-world patients with stroke presenting with a large core infarct. Objective: To investigate the safety and effectiveness of MT for patients with large vessel occlusion and an Alberta Stroke Program Early Computed Tomography Score (ASPECTS) of 2 to 5. Design, setting, and participants: This retrospective cohort study used data from the Stroke Thrombectomy and Aneurysm Registry (STAR), which combines the prospectively maintained databases of 28 thrombectomy-capable stroke centers in the US, Europe, and Asia. The study included 2345 patients presenting with an occlusion in the internal carotid artery or M1 segment of the middle cerebral artery from January 1, 2016, to December 31, 2020. Patients were followed up for 90 days after intervention. The ASPECTS is a 10-point scoring system based on the extent of early ischemic changes on the baseline noncontrasted computed tomography scan, with a score of 10 indicating normal and a score of 0 indicating ischemic changes in all of the regions included in the score. Exposure: All patients underwent MT in one of the included centers. Main outcomes and measures: A multivariable regression model was used to assess factors associated with a favorable 90-day outcome (modified Rankin Scale score of 0-2), including interaction terms between an ASPECTS of 2 to 5 and receiving MT in the extended window (6-24 hours from symptom onset). Results: A total of 2345 patients who underwent MT were included (1175 women [50.1%]; median age, 72 years [IQR, 60-80 years]; 2132 patients [90.9%] had an ASPECTS of ≥6, and 213 patients [9.1%] had an ASPECTS of 2-5). At 90 days, 47 of the 213 patients (22.1%) with an ASPECTS of 2 to 5 had a modified Rankin Scale score of 0 to 2 (25.6% [45 of 176] of patients who underwent successful recanalization [modified Thrombolysis in Cerebral Ischemia score ≥2B] vs 5.4% [2 of 37] of patients who underwent unsuccessful recanalization; P = .007). Having a low ASPECTS (odds ratio, 0.60; 95% CI, 0.38-0.85; P = .002) and presenting in the extended window (odds ratio, 0.69; 95% CI, 0.55-0.88; P = .001) were associated with worse 90-day outcome after controlling for potential confounders, without significant interaction between these 2 factors (P = .64). Conclusions and relevance: In this cohort study, more than 1 in 5 patients presenting with an ASPECTS of 2 to 5 achieved 90-day functional independence after MT. A favorable outcome was nearly 5 times more likely for patients with low ASPECTS who had successful recanalization. The association of a low ASPECTS with 90-day outcomes did not differ for patients presenting in the early vs extended MT window

Association of Noncontrast Computed Tomography and Perfusion Modalities With Outcomes in Patients Undergoing Late-Window Stroke Thrombectomy

Importance: There is substantial controversy with regards to the adequacy and use of noncontrast head computed tomography (NCCT) for late-window acute ischemic stroke in selecting candidates for mechanical thrombectomy. Objective: To assess clinical outcomes of patients with acute ischemic stroke presenting in the late window who underwent mechanical thrombectomy stratified by NCCT admission in comparison with selection by CT perfusion (CTP) and diffusion-weighted imaging (DWI). Design, setting, and participants: In this multicenter retrospective cohort study, prospectively maintained Stroke Thrombectomy and Aneurysm (STAR) database was used by selecting patients within the late window of acute ischemic stroke and emergent large vessel occlusion from 2013 to 2021. Patients were selected by NCCT, CTP, and DWI. Admission Alberta Stroke Program Early CT Score (ASPECTS) as well as confounding variables were adjusted. Follow-up duration was 90 days. Data were analyzed from November 2021 to March 2022. Exposures: Selection by NCCT, CTP, or DWI. Main outcomes and measures: Primary outcome was functional independence (modified Rankin scale 0-2) at 90 days. Results: Among 3356 patients, 733 underwent late-window mechanical thrombectomy. The median (IQR) age was 69 (58-80) years, 392 (53.5%) were female, and 449 (65.1%) were White. A total of 419 were selected with NCCT, 280 with CTP, and 34 with DWI. Mean (IQR) admission ASPECTS were comparable among groups (NCCT, 8 [7-9]; CTP, 8 [7-9]; DWI 8, [7-9]; P = .37). There was no difference in the 90-day rate of functional independence (aOR, 1.00; 95% CI, 0.59-1.71; P = .99) after adjusting for confounders. Symptomatic intracerebral hemorrhage (NCCT, 34 [8.6%]; CTP, 37 [13.5%]; DWI, 3 [9.1%]; P = .12) and mortality (NCCT, 78 [27.4%]; CTP, 38 [21.1%]; DWI, 7 [29.2%]; P = .29) were similar among groups. Conclusions and relevance: In this cohort study, comparable outcomes were observed in patients in the late window irrespective of neuroimaging selection criteria. Admission NCCT scan may triage emergent large vessel occlusion in the late window

Abstract TP12: The Trend of Successful First Pass in M2 Segment Stroke Thrombectomy- Insights From the STAR Collaboration

Introduction: Stroke thrombectomy devices and the experience of neurointerventionists have improved significantly over the last few years making targeting distal occlusions such as of the M2 segment of the middle cerebral artery more feasible. We aimed to study the trend in the successful first pass (SFP) of M2 occlusions over time using the data from a contemporary multicenter registry. Methods: We reviewed the data from the Stroke Thrombectomy and Aneurysm Registry (STAR), which included data from 11 thrombectomy-capable stroke centers to identify stroke patients who underwent mechanical thrombectomy of M2 segment occlusion. SFP was defined by achieving modified Thrombolysis in Cerebral Infarction (mTICI) score≥2b with a single thrombectomy device pass. We analyzed the linear trendline of the rate of SFP over time. Then, we used a logistic regression model to assess predictors of SFP of M2 segment occlusion. Results: We included 401 patients who underwent stroke thrombectomy of M2 occlusion; median age was 71 (IQR 60-80), 212 (52.9%) were females, 174 (43.4%) were white, National Institute of Health stroke scale (NIHSS) was 14 (IQR 8-19), Alberta Stroke Program Early CT (ASPECT) score on presentation was 9 (IQR 7-10) and onset wot groin time was 287 (IQR 181-454). SFP was achieved in 118 (29.4%) patients (linear trendline over time is in Figure 1). Presenting after 2014 was an independent predictor of SFP (OR 1.9, 95% CI 1.1-3.2, P=0.019) after controlling for age, sex, NIHSS on presentation, intravenous alteplase (IV-tPA), and onset to groin time. Conclusion: SFP rate of M2 segment occlusion has increased after 2014 likely secondary the improvement in stroke thrombectomy devices and neurointerventionists experience

Value of risk scores in the decision to palliate patients with ruptured abdominal aortic aneurysm.

BACKGROUND: The aim of this study was to develop a 48-h mortality risk score, which included morphology data, for patients with ruptured abdominal aortic aneurysm presenting to an emergency department, and to assess its predictive accuracy and clinical effectiveness in triaging patients to immediate aneurysm repair, transfer or palliative care. METHODS: Data from patients in the IMPROVE (Immediate Management of the Patient With Ruptured Aneurysm: Open Versus Endovascular Repair) randomized trial were used to develop the risk score. Variables considered included age, sex, haemodynamic markers and aortic morphology. Backwards selection was used to identify relevant predictors. Predictive performance was assessed using calibration plots and the C-statistic. Validation of the newly developed and other previously published scores was conducted in four external populations. The net benefit of treating patients based on a risk threshold compared with treating none was quantified. RESULTS: Data from 536 patients in the IMPROVE trial were included. The final variables retained were age, sex, haemoglobin level, serum creatinine level, systolic BP, aortic neck length and angle, and acute myocardial ischaemia. The discrimination of the score for 48-h mortality in the IMPROVE data was reasonable (C-statistic 0·710, 95 per cent c.i. 0·659 to 0·760), but varied in external populations (from 0·652 to 0·761). The new score outperformed other published risk scores in some, but not all, populations. An 8 (95 per cent c.i. 5 to 11) per cent improvement in the C-statistic was estimated compared with using age alone. CONCLUSION: The assessed risk scores did not have sufficient accuracy to enable potentially life-saving decisions to be made regarding intervention. Focus should therefore shift to offering repair to more patients and reducing non-intervention rates, while respecting the wishes of the patient and family.This project was funded by the UK National Institute for Health Research (NIHR) Health Technology Assessment (HTA) programme (project number 07/37/64). The views and opinions expressed herein are those of the authors and do not necessarily reflect those of the HTA programme, NIHR, National Health Service or the Department of Health

Abstract WP3: Predictors and Outcomes of Successful First Pass in Neurothrombectomy- Insights From the STAR Collaboration

Introduction: Shorter procedure time during neurothrombectomy is a strong predictor for good outcomes in stroke patients with large vessel occlusion. We sought to assess the predictors and outcomes of successful first pass (SFP) using multi-center investigator-initiated database. Methods: Prospectively collected neurothrombectomy data from 11 thrombectomy-capable stroke centers was combined in the Stroke Thrombectomy and Aneurysm Registry (STAR). SFP was defined by achieving modified Thrombolysis in Cerebral Infarction (mTICI) score≥2b with a single thrombectomy device pass. We compared the baseline characteristics, procedural metrics, rate of symptomatic intracranial hemorrhage (sICH), and long-term functional outcomes between SFP and non-SFP patients. A multivariate logistic regression analysis was used to assess the predictors of SFP and evaluate whether SFP was an independent predictor for good long-term functional outcomes (90-day mRS≤2). Results: A total of 733 SFP patients and 1134 non-SFP patients were included in this analysis. SFP patients were older (73 vs. 70, P=0.001), had higher Alberta Stroke Program Early CT (ASPECT) score on presentation (9 vs. 8, P=0.002). The use of Solumbra technique was an independent predictor of SFP (OR 1.2, 95% CI 1.1-1.4, P=0.004) after controlling for age, sex, location of occlusion, National Institute of Health stroke scale (NIHSS) on presentation, intravenous alteplase (IV-tPA), and onset to groin (OTG) time. SFP was an independent predictor for good long-term functional outcomes (OR1.6, 95% CI 1.1-2.3, P=0.008) after controlling for age, sex, location of occlusion, NIHSS on presentation, OTG time, IV-tPA, procedure technique, and procedure duration. Conclusion: SFP lead to higher rates of functional independence in stroke patients with large vessel occlusion. These records reiterate the importance of SFP as a benchmark measure for stroke thrombectomy devices

Abstract 148: Mechanical Thrombectomy for Distal Occlusions: Efficacy, Functional and Safety Outcomes. Insights From the STAR Collaboration

Background: Mechanical thrombectomy (MT) is the standard of care for acute ischemic stroke due to large vessel occlusions. There is strong evidence supporting the benefit of MT in proximal anterior circulation vessel occlusions and basilar occlusions. However, data regarding the efficacy and safety of MT in distal occlusions is scarce. In this study, we aim to report the efficacy, functional and safety outcomes of MT for distal occlusions. Methods: This a retrospective study from 14 comprehensive stroke centers across 4 countries. For the purpose of this study, distal occlusion was defined as MCA occlusion distal to M2 (M3-4 segments), any segments of ACA and any segments of PCA. Patients with concomitant proximal occlusions were excluded from this study. Results: Of 2826 patients, 111 patients were included in this study (mean (SD) age: 69 (13), 51% of patients were female, and 52% received tPA). Median onset to groin time was 241 (IQR, 136 minutes), median NIHSS on admission was 11 (IQR, 8), and median ASPECTS was 10 (IQR, 1). The procedure was done using ADAPT, stent retriever, and Solumbra techniques in 58%, 17% and 15% of patients respectively. Successful revascularization (mTICI 2b-3) and complete revascularization (mTICI 3) were achieved in 78% and 35% of our cohort, respectively. Median procedure time (puncture to revascularization or end of the procedure) was 29 minutes (IQR 42 minutes) and the median number of attempts was 1 (IQR=2). Five percent of patients suffered procedural complications Hemorrhagic complications occurred in 11% of patients of whom only 4% were PH2 hemorrhage. At the last follow up, mRS 0-2 was achieved in 53% of patients. Conclusion: Up to our knowledge, this represents the largest study to the date investigating the safety and efficacy of MT in distal occlusions treatment. MT was safe and achieved a high rate of successful revascularization with an acceptable safety profile

Abstract 168: Outcomes of Intra-Arterial Tissue Plasminogen Activator Rescue Therapy During Stroke Thrombectomy-Insights From the STAR Collaboration

Introduction: Intra-arterial tissue plasminogen activator (IA-tPA) can be used as rescue therapy during mechanical thrombectomy for stroke patients, mostly in the setting of distal occlusion. The outcomes of IA-tPA has not been assessed in large-scale multi-center studies yet. Methods: We used data from the Stroke Thrombectomy and Aneurysm Registry (STAR), which included prospectively maintained databases of 11 thrombectomy-capable stroke centers in the US, Europe, and Asia. We compared the baseline characteristics, procedural metrics, rate of symptomatic intracranial hemorrhage (sICH), and long-term functional outcomes between thrombectomy patients who received rescue IA-tPA and a control group of thrombectomy patients with matched age, National Institute of Health stroke scale (NIHSS) on presentation, location of occlusion and IV-tPA receipt. Results: A total of 2827 thrombectomy patients were included in the STAR registry. Out of those, 205 patients received IA-tPA. We matched 191 patients from the IA-tPA group with a control group of 191 patients (table 1). No difference was seen in age, sex, race, vascular risk factors, or Alberta Stroke Program Early CT (ASPECT) score between both groups. In addition, procedural metrics, including onset to groin time, the procedure duration, and rate of successful recanalization (modified Thrombolysis in Cerebral Infarction score≥2b) were similar. Finally, similar outcomes were noted in both groups, including the rate of sICH and good 90-day functional outcome (modified Rankin scale≤2). Conclusion: The use of IA-tPA as an adjunctive treatment to mechanical thrombectomy was safe but did not result in a higher rate of successful recanalization or good long-term functional outcomes

Abstract WP2: Long-Term Functional Outcomes Following Mechanical Thrombectomy Stratified by Race- Insights From the STAR Collaboration

Introduction: Previous research reported higher prevalence of vascular risk factors and worse outcomes after stroke in non-white patients compared to whites. Whether similar results still apply in the post mechanical thrombectomy era remains unknown. Methods: The STAR registry combined the prospectively maintained databases of 11 thrombectomy-capable stroke centers in the US, Europe, and Asia. Consecutive patients who underwent MT were included in these analyses. Baseline features, risk factors, location of occlusion, time from symptom onset, tPA receipt, procedural complication rates, symptomatic hemorrhage, and long-term functional outcome were compared between white and non-white patients. Multivariate logistic regression analysis was performed to evaluate the impact of race on long-term outcome. Results: Total of 2,284 patients were included in this analysis. Of those, 1,436 (62.9%) were white. Baseline features and outcomes are summarized in table 1. Non-white patients were older ( 71 Vs 66, p=<0.001), more likely to be female ( 53.1% Vs 48.5%, p=0.034), had lower NIHSS on admission ( 15 Vs 16, p=<0.001), higher prevalence of hypertension, hyperlipidemia, diabetes, lower incidence of atrial fibrillation, higher rate of tPA receipt, shorter onset to groin access times, and longer procedural times. White patients had higher rates of successful revascularization (77.4% Vs 72.3%, p=0.006) and longer hospital stay. On multivariate logistic regression analysis, white race was an independent predictor of good 90-day outcome (OR 1.35, 95% CI 1.03-1.76, P=0.031) after controlling for age, sex, location of occlusion, IV-tPA, ASPECT score, procedure duration and final TICI score. Conclusion: In this study, white race was independent predictor of good 90-day outcome. This finding could be due to higher prevalence of vascular risk factors in non-white patients

Outcomes of Rescue Endovascular Treatment of Emergent Large Vessel Occlusion in Patients With Underlying Intracranial Atherosclerosis: Insights From STAR.

Background: Some emergent large vessel occlusions (ELVOs) are refractory to reperfusion because of underlying intracranial atherosclerosis (ICAS), often requiring rescue therapy (RT) with balloon angioplasty, stenting, or both. In this study, we investigate the safety, efficacy, and long-term outcomes of RT in the setting of mechanical thrombectomy for ICAS-related ELVO. Methods and Results: We queried the databases of 10 thrombectomy‐capable centers in North America and Europe included in STAR (Stroke Thrombectomy and Aneurysm Registry). Patients with ELVO who underwent ICAS‐related RT were included. A matched sample was produced for variables of age, admission National Institute of Health Stroke Scale, Alberta Stroke Program Early CT Score, onset to groin puncture time, occlusion site, and final recanalization. Out of 3025 patients with MT, 182 (6%) patients required RT because of underlying ICAS. Balloon angioplasty was performed on 122 patients, and 117 patients had intracranial stenting. In the matched analysis, 141 patients who received RT matched to a similar number of controls. The number of thrombectomy passes was higher (3 versus 1, P\u3c0.001), and procedural time was longer in the RT group (52 minutes versus 36 minutes, P=0.004). There was a higher rate of symptomatic hemorrhagic transformation in the RT group (7.8% versus 4.3%, P=0.211), however, the difference was not significant. There was no difference in 90‐day modified Rankin scale of 0 to 2 (44% versus 47.5%, P=0.543) between patients in the RT and control groups. Conclusions: In patients with ELVO with underlying ICAS requiring RT, despite longer procedure time and a more thrombectomy passes, the 90 days favorable outcomes were comparable with patients with embolic ELVO