The impact of the COVID-19 pandemic on the provision of endovascular thrombectomy for stroke: an Irish perspective

BACKGROUND

The COVID-19 pandemic produced unprecedented challenges to healthcare systems. These challenges were amplified in the setting of endovascular thrombectomy (EVT) for large vessel occlusion strokes given the time-sensitive nature of the procedure.

AIMS

To assess the impact of the COVID-19 pandemic on service provision at the primary endovascular stroke centre in Ireland.

METHODS

A retrospective review of the National Thrombectomy Service database was performed. All patients undergoing EVT from 1 January to 31 December inclusive of 2019 to 2021 were included. Patient demographics, functional outcomes and endovascular treatment time metrics were recorded.

RESULTS

Data from 2019, 2020 and 2021 were extracted. Three hundred seven thrombectomies were performed in 2019 and 2020; this number increased to 327 in 2021. Median time from arrival to groin puncture for thrombectomy was 64 min in 2019, increasing to 65 min in 2020. In 2021, this decreased to 52 min. Median time taken from groin puncture to first perfusion remained stable from 2019 to 2021 years at 20 min. Total duration of emergency thrombectomies reduced from 32 min in 2019 to 27 min in 2020. This increased to 29 min in 2021.

CONCLUSIONS

Despite the myriad of challenges presented by the pandemic, service provision at the primary Irish ESC, and the referring hospitals, has proven to be robust. Procedural time metrics were maintained whilst the expected reduction in number of EVTs performed did not materialise, there actually being a significant increase in number of EVTs performed in the pandemic's second year.

Seizures at stroke onset: A case-control study

PURPOSE

Seizures occurring at the immediate onset of a stroke, abbreviated "seizures at onset" (SaO), pose a diagnostic and therapeutic challenge for physicians. In this study, we report on the current clinical practice in managing stroke patients with SaO from a large tertiary stroke center in Germany.

METHODS

We selected all patients with SaO and acute ischemic or hemorrhagic stroke admitted to the Department of Neurology at the University Hospital of Cologne between 2019 and 01-01 and 2020-12-31. SaO patients were then compared to patients with acute ischemic or hemorrhagic stroke without SaO from the local stroke registry. Further, we compared SaO patients who received intravenous recombinant tissue-type plasminogen activator (rt-PA) and/or mechanical thrombectomy with matched controls.

RESULTS

Overall, 54 out of 2312 stroke patients (2.3 %) in the examined period presented with SaO. The most prevalent SaO semiology was focal to bilateral tonic-clonic (42.6 %). SaO was associated with hemorrhagic strokes and higher in-hospital mortality in all stroke patients. The rate of acute stroke therapy was not influenced by the occurrence of SaO. In patients that received acute stroke therapy, patients with SaO had higher scores on the National Institutes of Health Stroke Scale (NIHSS) and the modified Rankin Scale (mRS) at admission, and longer door-to-needle times for the administration of rt-PA, while none of the examined outcome parameters revealed a difference between patients with and without SaO after adjusting for potential confounders.

CONCLUSION

Data show that SaO is rare in stroke patients but associated with more extensive strokes.

Outcomes of mechanical thrombectomy in orally anticoagulated patients with anterior circulation large vessel occlusion: a propensity-matched analysis of the Imperial College Thrombectomy Registry

BACKGROUND

Mechanical thrombectomy (MT) remains an effective treatment for patients with acute ischemic stroke receiving oral anticoagulation (OAC) and large vessel occlusion (LVO). However, to date, it remains unclear whether MT is safe in patients on treatment with OAC.

AIMS

In our study, we performed a propensity-matched analysis to investigate the safety and efficacy of MT in patients with acute ischemic stroke receiving anticoagulants. A propensity score method was used to target the causal inference of the observational study design.

METHODS

This observational, prospective, single-centre study included consecutive patients with acute LVO ischemic stroke of the anterior circulation. Demographic, neuro-imaging and clinical data were collected and compared according to the anticoagulation status at baseline, patients on OAC vs those not on OAC. The primary study outcomes were the occurrence of any intracerebral haemorrhage (ICH) and symptomatic ICH. The secondary study outcomes were functional independence at 90 days after stroke (defined as modified Rankin Scale (mRS) scores of 0 through 2), mortality at 3 months and successful reperfusion rate according to the modified treatment in cerebral infarction (mTICI) score.

RESULTS

Overall, our cohort included 573 patients with acute ischemic stroke and LVO treated with MT. After propensity score matching, 495 patients were matched (99 OAC group vs 396 no OAC group). There were no differences in terms of clinical characteristics between the two groups, except for the rate of intravenous thrombolysis less frequently given in the OAC group. There was no significant difference in terms of the rate of any ICH and symptomatic ICH between the two groups. With regards to the secondary study outcome, there was no significant difference in terms of the rate of successful recanalization post-procedure and functional independence at 3 months between the two groups. Patients in the OAC group showed a reduced mortality rate at 90 days compared to the patients with no previous use of anticoagulation (20.2% vs 21.2%, p = 0.031). Logistic regression analysis did not reveal a statistically significant influence of the anticoagulation status on the likelihood of any ICH (OR = 0.95, 95% CI = 0.46-1.97, p = 0.900) and symptomatic ICH (OR = 4.87, 95% CI = 0.64-37.1, p = 0.127). Our analysis showed also that pre-admission anticoagulant use was not associated with functional independence at 90 days after stroke (OR = 0.76, 95% CI = 0.39-1.48, p = 0.422) and rate of successful reperfusion (OR = 0.81, 95% CI = 0.38-1.72, p = 0.582).

CONCLUSION

According to our findings anticoagulation status at baseline did not raise any suggestion of safety and efficacy concerns when MT treatment is provided according to the standard guidelines. Confirmation of these results in larger controlled prospective cohorts is necessary.

IV thrombolysis plus thrombectomy versus IV thrombolysis alone for minor stroke with anterior circulation large vessel occlusion from the IRETAS and Italian SITS-ISTR cohorts

INTRODUCTION

The aim of this study was to compare the outcomes of patients treated with intravenous thrombolysis (IVT) <4.5 h after symptom onset plus mechanical thrombectomy (MT) <6 h with those treated with IVT alone <4.5 h for minor stroke (NIHSS ≤5) with large vessel occlusion (LVO) in the anterior circulation.

PATIENTS AND METHODS

Patients enrolled in the Italian Registry of Endovascular Treatment in Acute Stroke (IRETAS) and in the Italian centers included in the SITS-ISTR were analyzed.

RESULTS

Among the patients with complete data on 24-h ICH type, 236 received IVT plus MT and 382 received IVT alone. IVT plus MT was significantly associated with unfavorable shift on 24-h ICH types (from no ICH to PH-2) (OR, 2.130; 95% CI, 1.173-3.868; p=0.013) and higher rate of PH (OR, 4.363; 95% CI, 1.579-12.055; p=0.005), sICH per ECASS II definition (OR, 5.527; 95% CI, 1.378-22.167; p=0.016), and sICH per NINDS definition (OR, 3.805; 95% CI, 1.310-11.046; p=0.014). Among the patients with complete data on 3-month mRS score, 226 received IVT plus MT and 262 received IVT alone. No significant difference was reported between IVT plus MT and IVT alone on mRS score 0-1 (72.1% versus 69.1%), mRS score 0-2 (79.6% versus 79%), and death (6.2% versus 6.1%).

CONCLUSIONS

Compared with IVT alone, IVT plus MT was associated with unfavorable shift on 24-h ICH types and higher rate of 24-h PH and sICH in patients with minor stroke and LVO in the anterior circulation. However, no difference was reported between the groups on 3-month functional outcome measures.

CTP-based estimated ischemic core: A comparative multicenter study between Olea and RAPID software

BACKGROUND AND PURPOSE

CTP is increasingly used to assess eligibility for endovascular therapy (EVT) in patients with large vessel occlusions (LVO). There remain variability and inconsistencies between software packages for estimation of ischemic core. We aimed to use heterogenous data from four stroke centers to perform a comparative analysis for CTP-estimated ischemic core between RAPID (iSchemaView) and Olea (Olea Medical).

METHODS

In this retrospective multicenter study, patients with anterior circulation LVO who underwent pretreatment CTP, successful EVT (defined TICI ≥ 2b), and follow-up MRI included. Automated CTP analysis was performed using Olea platform [rCBF < 25% and differential time-to-peak (dTTP)>5s] and RAPID (rCBF < 30%). The CTP estimated core volumes were compared against the final infarct volume (FIV) on post treatment MRI-DWI.

RESULTS

A total of 151 patients included. The CTP-estimated ischemic core volumes (mean ± SD) were 18.7 ± 18.9 mL on Olea and 10.5 ± 17.9 mL on RAPID significantly different (p < 0.01). The correlation between CTP estimated core and MRI final infarct volume was r = 0.38, p < 0.01 for RAPID and r = 0.39, p < 0.01 for Olea. Both software platforms demonstrated a strong correlation with each other (r = 0.864, p < 0.001). Both software overestimated the ischemic core volume above 70 mL in 4 patients (2.6%).

CONCLUSIONS

Substantial variation between Olea and RAPID CTP-estimated core volumes exists, though rates of overcalling of large core were low and identical. Both showed comparable core volume correlation to MRI infarct volume.

Effect of mechanical thrombectomy with and without intravenous thrombolysis on the functional outcome of patients with different degrees of thrombus perviousness

PURPOSE

This study aimed to investigate the long-term functional outcome of patients with different degrees of thrombus perviousness (TP) undergoing mechanical thrombectomy alone and those undergoing combined intravenous thrombolysis (IVT) plus mechanical thrombectomy.

METHODS

We conducted a retrospective analysis of consecutive patients with acute ischemic stroke due to large vessel occlusion who underwent mechanical thrombectomy alone or bridging therapy between January 2016 and October 2020. TP was quantified by thrombus attenuation increase (TAI) on admission computed tomography angiography compared with non-contrast computed tomography. After dichotomization of TAI as higher or lower perviousness, Fisher exact tests were performed to estimate the associations of different therapies with favorable functional outcomes [Modified Ranking Scale score at 90 days (90-day mRS) of 0 to 2].

RESULTS

A total of 73 patients were included in our study. 35 (47.9%) thrombi were classified as higher-perviousness clots with TAI of ≥ 24 HU, and the other 38 thrombi were lower-perviousness clots. A favorable outcome with a 90-day mRS of 0 to 2 was observed in 32 patients. In patients with thrombi of lower perviousness, favorable outcome was more common in the bridging therapy group than in the thrombectomy-alone group (p = 0.013), whereas in patients with thrombi of higher perviousness, the long-term neurological outcome did not significantly differ between two therapy groups (p = 0.094).

CONCLUSION

Patients with thrombi of lower perviousness were recommended to undergo intravenous alteplase followed by endovascular thrombectomy, and those with thrombi of higher perviousness could undergo thrombectomy alone.

Association between left atrial enlargement and poor cerebral collaterals in large vessel occlusion

OBJECTIVES

Left atrial enlargement (LAE) is a known risk factor for atrial fibrillation, a common cause of large vessel occlusion (LVO) leading to ischemic stroke. While robust cerebral collaterals protect penumbral tissue from infarction, the effect of structural heart disease on cerebral collaterals remains uncertain. This study aims to investigate the association between LAE and cerebral collaterals in patients with acute LVO stroke.

MATERIALS AND METHODS

We conducted a retrospective study of consecutive patients with middle cerebral and/or internal carotid LVO who underwent endovascular thrombectomy (EVT) between 2012 to 2020. Consecutive patients with echocardiography and computed tomography angiography (CTA) of the head were included. Multivariate logistic regression analysis was performed to evaluate the relationship between LAE and poor cerebral collaterals, adjusting for demographics (age, sex, race) and vascular risk factors (hypertension, diabetes and smoking).

RESULTS

The study included 235 patients with mean age of 69±15 years and an initial mean National Institutes of Health Stroke Scale score of 18. Of these, 89 (37.9 %) had LAE, and 105 (44.7 %) had poor collaterals. Patients with LAE were more likely to have poor collaterals compared to those without LAE (58.4 % vs 36.3 %, P = 0.001). LAE was independently associated with higher odds of poor collaterals (odds ratio, 2.47; P = 0.001), even after adjusting for covariables (odds ratio 1.84, P = 0.048).

CONCLUSIONS

Our study demonstrated a significant association between LAE and poor cerebral collaterals in patients with LVO stroke undergoing EVT. Further research is warranted to explore potential shared mechanisms, such as endothelial dysfunction, underlying this heart-brain association.

The risk and outcome of malignant brain edema in post-mechanical thrombectomy: acute ischemic stroke by anterior circulation occlusion

BACKGROUND AND PURPOSE

Malignant brain edema (MBE) occurring after mechanical thrombectomy (MT) in acute ischemic stroke (AIS) could lead to severe disability and mortality. We aimed to investigate the incidence, predictors, and clinical outcomes of MBE in patients with AIS after MT.

METHODS

The clinical and imaging data of 155 patients with AIS of anterior circulation after MT were studied. Standard non-contrast CT was used to evaluate baseline imaging characteristics at admission. Clinical outcomes were measured using the 90-day modified Rankin Scale (mRS) score. Based on the follow-up CT scans performed within 72 h after MT, the patients were classified into MBE and non-MBE group. MBE was defined as a midline shift of ≥ 5 mm with signs of local brain swelling. Univariate and multivariate regression analyses were used to analyze the relationship between MBE and clinical outcomes and identify the predictors that correlate with MBE.

RESULTS

MBE was observed in 19.4% of the patients who underwent MT and was associated with a lower rate of favorable 90-day clinical outcomes. Significant differences were observed in both MBE and non-MBE groups: baseline Alberta Stroke Program Early CT (ASPECT) score, hyperdense middle cerebral artery sign (HMCAS), baseline signs of early infarct, angiographic favorable collaterals, number of retrieval attempts, and revascularization rate. Multivariate analysis indicated that low baseline ASPECT score, absent HMCAS, angiographic poor collaterals, more retrieval attempt count, and poor revascularization independently influenced the occurrence of MBE in AIS patients with anterior circulation after MT.

CONCLUSION

MBE was associated with a lower rate of favorable 90-day clinical outcomes. Low baseline ASPECT score, absent HMCAS, angiographic poor collaterals, more retrieval attempt count and poor revascularization were independently associated with MBE after MT.

Efficacy and Safety of Mechanical Thrombectomy in Elderly and Non-Elderly Patients with Large Vessel Occlusion Stroke: Systematic Review and Meta-Analysis

INTRODUCTION

Mechanical thrombectomy (MT) is recommended for large vessel occlusion (LVO) stroke. However, most of the studies that investigated the superiority of MT over best medical management (BMM) alone included preponderantly non-elderly patients. Thus, there is uncertainty in relation to the efficacy of MT in the elderly. We aim to compare the effect of BMM to BMM plus MT among elderly and non-elderly patients with LVO.

METHODS

We performed a systematic search of medical databases from inception to April 2023 to identify randomized studies that reported the functional outcome at 90 days by age for patients with LVO treated with MT versus BMM. Patients were divided into elderly (>70 or >80 years, depending on the cutoff used in each study) and non-elderly. Outcomes were defined as excellent (modified Rankin Scale [mRS] ≤1), good (mRS ≤3), poor (mRS ≥5), or death. Effect sizes were calculated by using random effects meta-analyses. Results were represented by odds ratio (OR) and their 95% confidence intervals (95% CIs).

RESULTS

A total of 2,195 patients were included in the analysis (≥70 years, 7 trials, n = 696; ≥80 years, 2 trials, n = 139). Non-elderly patients treated with MT had higher odds of excellent outcome (OR: 3.05; 95% CI: 2.23-4.18) and good outcome (OR: 2.70; 95% CI: 1.94-3.74), and lower odds of poor outcome (OR: 0.54; 95% CI: 0.40-0.72) and death (OR: 0.63; 95% CI: 0.41-0.96). Similarly, elderly patients treated with MT had higher odds of excellent (OR: 2.39; 95% CI: 1.05-5.45) and good outcomes (OR: 2.18; 95% CI: 1.43-3.33) and lower odds of poor outcome (OR: 0.48; 95% CI: 0.33-0.70) and mortality (OR: 0.50; 0.26-0.95). When outcomes were analyzed by age subgroups, MT was associated with higher odds of good outcome in patients ≥70 years (OR: 1.95, 95% CI: 1.26-3.03) and ≥80 years (OR: 4.43, 95% CI: 1.02-19.23).

CONCLUSION

MT increases the likelihood of achieving a good outcome in elderly and non-elderly patients without increasing the risk of severe disability or death. MT, when otherwise clinically indicated, should be considered over BMM alone in both age groups.

Stroke with large vessel occlusion in the posterior circulation: IV thrombolysis plus thrombectomy versus IV thrombolysis alone

Efficacy and safety of mechanical thrombectomy (MT) for stroke with posterior circulation large vessel occlusion (LVO) is still under debate. We aimed to compare the outcomes of stroke patients with posterior circulation LVO treated with intravenous thrombolysis (IVT) (< 4.5 h after symptom onset) plus MT < 6 h after symptom onset with those treated with IVT alone (< 4.5 h after symptom onset). Patients enrolled in the Italian Registry of Endovascular Treatment in Acute Stroke (IRETAS) and in the Italian centers included in the SITS-ISTR were analysed. We identified 409 IRETAS patients treated with IVT plus MT and 384 SITS-ISTR patients treated with IVT alone. IVT plus MT was significantly associated with higher rate of sICH (ECASS II) compared with IVT alone (3.1 vs 1.9%; OR 3.984, 95% CI 1.014-15.815), while the two treatments did not differ significantly in 3-month mRS score ≤ 3 (64.3 vs 74.1%; OR 0.829, 95% CI 0.524-1.311). In 389 patients with isolated basilar artery (BA) occlusion, IVT plus MT was significantly associated with higher rate of any ICH compared with IVT alone (9.4 vs 7.4%; OR 4.131, 95% CI 1.215-14.040), while two treatments did not differ significantly in 3-month mRS score ≤ 3 and sICH per ECASS II definition. IVT plus MT was significantly associated with higher rate mRS score ≤ 2 (69.1 vs 52.1%; OR 2.692, 95% CI 1.064-6.811) and lower rate of death (13.8 vs 27.1%; OR 0.299, 95% CI 0.095-0.942) in patients with distal-segment BA occlusion, while two treatments did not differ significantly in 3-month mRS score ≤ 3 and sICH per ECASS II definition. IVT plus MT was significantly associated with lower rate of mRS score ≤ 3 (37.1 vs 53.3%; OR 0.137, 0.009-0.987), mRS score ≤ 1 (22.9 vs 53.3%; OR 0.066, 95% CI 0.006-0.764), mRS score ≤ 2 (34.3 vs 53.3%; OR 0.102, 95% CI 0.011-0.935), and higher rate of death (51.4 vs 40%; OR 16.244, 1.395-89.209) in patients with proximal-segment BA occlusion. Compared with IVT alone, IVT plus MT was significantly associated with higher rate of sICH per ECASS II definition in patients with stroke and posterior circulation LVO, while two treatment groups did not differ significantly in 3-month mRS score ≤ 3. IVT plus MT was associated with lower rate of mRS score ≤ 3 compared with IVT alone in patients with proximal-segment BA occlusion, whereas no significant difference was found between the two treatments in primary endpoints in patients isolated BA occlusion and in the other subgroups based on site occlusion.

Arterial Glyceryl Trinitrate in Acute Ischemic Stroke After Thrombectomy for Neuroprotection (AGAIN): A Pilot Randomized Controlled Trial

Although endovascular therapy demonstrates robust clinical efficacy in acute ischemic stroke (AIS), not all stroke patients benefit from successful reperfusion. This study aimed to evaluate the safety, feasibility, and preliminary efficacy of intra-arterial administration of glyceryl trinitrate (GTN) after endovascular recanalization for neuroprotection. This is a prospective randomized controlled study. Eligible patients were randomized to receive 800 μg GTN or the same volume of normal saline through the catheter after recanalization. The primary outcome was symptomatic intracranial hemorrhage (ICH), while secondary outcomes included mortality, functional outcome, infarction volume, complications, and blood nitrate index (NOx). A total of 40 patients were enrolled and randomized with no participants being lost to follow-up. There was no significant difference in the proportion of sICH between GTN and control groups. Additionally, no significant difference was observed in mortality or rates of neurological deterioration and other complications. Favorable trends, while non-significant, were noted in both outcome and imaging for functional independence at 90 days and reduction in final infarct volume (75.0% vs 65.0%; 33.2 vs 38.9 ml) for the GTN group. Moreover, the concentration of blood NOx in the GTN group was significantly higher than in the control group at 2 h after GTN administration (26.2 vs 18.0 μmol/l, p < 0.05). The AGAIN study suggests intra-arterial administration of GTN post-endovascular therapy is safe and feasible and GTN successfully raised NOx levels over controls at 2 h. A multi-center randomized controlled trial with a larger sample size is warranted to determine GTN neoadjuvant efficacy.

Effect of using G-FAST to recognize emergent large vessel occlusion: A city-wide community experience

BACKGROUND/PURPOSE

A prehospital bypass strategy was suggested for large vessel occlusion. This study aimed to evaluate the effect of a bypass strategy using the gaze-face-arm-speech-time test (G-FAST) implemented in a metropolitan community.

METHODS

Pre-notified patients with positive Cincinnati Prehospital Stroke Scale and symptom onset <3 h from July 2016 to December 2017 (pre-intervention period) and those with positive G-FAST and symptom onset <6 h from July 2019 to December 2020 (intervention period) were included. Patients aged <20 years and those with missing in-hospital data were excluded. The primary outcomes were the rates of receiving endovascular thrombectomy (EVT) and intravenous thrombolysis (IVT). The secondary outcomes were total prehospital time, door-to-computed tomography (CT) time, door-to-needle (DTN) time, and door-to-puncture (DTP) time.

RESULTS

We included 802 and 695 pre-notified patients from the pre-intervention and intervention periods, respectively. The characteristics of the patients in the two periods were similar. In the primary outcomes, pre-notified patients during the intervention period showed higher rates of receiving EVT (4.49% vs. 15.25%, p < 0.001) and IVT (15.34% vs. 21.58%, p = 0.002). In the secondary outcomes, pre-notified patients during intervention period had longer total prehospital time (mean 23.38 vs 25.23 min, p < 0.001), longer door-to-CT time (median 10 vs 11 min, p < 0.001), longer DTN time (median 53 vs 54.5 min, p < 0.001) but shorter DTP time (median 141 vs 139.5 min, p < 0.001).

CONCLUSION

The prehospital bypass strategy with G-FAST showed benefits for stroke patients.

Efficacy, safety, and predictors for functional outcomes of mechanical thrombectomy in patients aged over 90 years with acute ischemic stroke and literature review

BACKGROUND

No evidence supports the efficacy and safety of mechanical thrombectomy (MT) in patients aged ≥ 90 years with acute ischemic stroke (AIS). This study clarifies the efficacy, safety, and predictors of MTs in patients aged ≥ 90 years by investigating our results and reviewing previous studies.

METHODS

We retrospectively investigated data from 80 consecutive patients who underwent MT at our hospital between 2018 and 2021. We analyzed outcomes using the modified Thrombolysis in the Cerebral Infarction (mTICI) scale and modified Rankin Scale (mRS). Functional outcomes were investigated at 90 days or discharge.

RESULTS

We obtained functional outcomes mRS ≤ 3 patients in 41.6%. The mortality rate was 16.6%. The rate of successful recanalization was 75%. Comparison mRS ≤ 3 and mRS ≥ 4 at 90 days or discharge showed statistical significance in the National Institute of Health Stroke Scale, the location of occluded vessels, and mTICI ≥ 2b at the first pass. Univariable logistic regression analysis indicated that the Alberta Stroke Program Early Computed Tomography Score was a predictor of mRS ≤ 3.

CONCLUSIONS

The efficacy is lower than that of patients aged < 90; however, MT is effective even in patients aged ≥ 90 years. The safety of MT in patients aged ≥ 90 years was similar to that in those aged < 90 years. Neuro-interventionalists should consider predictors and take the best strategies to achieve successful recanalization in patients aged ≥ 90 years with AIS.

Impact of age on mechanical thrombectomy and clinical outcome in patients with acute ischemic stroke

BACKGROUND AND PURPOSE

Mechanical thrombectomy is less effective in patients aged 80 years or older. Our goal was to better understand the impact of age in general on recanalization rates and clinical outcome.

METHODS

We performed a retrospective analysis of our prospective database of adult patients with acute ischemic stroke due to large vessel occlusions, who had undergone mechanical thrombectomy between 2019 and mid-2021. The cohort was categorized into five age groups: 18 - 49, 50 - 59, 60 - 69, 70 - 79 and ≥ 80 years. Our primary outcome measure was clinical outcome at three months after mechanical thrombectomy, measured by the mRS score. Secondary outcomes were procedure times and rates of successful recanalization, defined by mTICI ≥ 2b.

RESULTS

Data of 264 patients were analyzed. There were no significant differences in procedure times (p = 0.46) or in rates of successful recanalization (p = 0.49) between age groups. There was a significant association of age and mRS score at three months (p < 0.0001): From youngest to oldest group, odds of functional independence (mRS ≤ 2) decreased (80.0% vs. 21.3%) and odds of death (mRS 6) increased (13.3% vs. 57.3%). Increasing age was significantly associated with lower rates of functional independence (OR 0.93; [95% CI 0.90 - 0.95]), higher rates of care dependency (OR 1.04; [95% CI 1.01 - 1.07]) and higher mortality rates (OR 1.06; [95% CI 1.04 - 1.09]).

CONCLUSION

Higher age had no significant impact on recanalization times or recanalization rates but was strongly associated with worse clinical outcome after mechanical thrombectomy.

Stent reconstruction in intracranial atherosclerotic disease related acute ischemic stroke results in high revascularization rates

OBJECTIVES

Intracranial atherosclerotic disease (ICAD) is a major cause of large vessel occlusion (LVO) in acute ischemic stroke (AIS). Our study aimed to analyze the effect of percutaneous transluminal angioplasty and stenting (PTAS) in patients with ICAD undergoing rescue treatment in terms of functional outcome and mortality rate at 90 days and compare the results to LVO with thromboembolic origins.

MATERIALS AND METHODS

A retrospective review of a mechanical thrombectomy (MT) single center database from 01/2019 to 09/2021 was carried out using chart review and angiogram analysis. From 469 acute stroke patients, 361 patients were enroled in the study, of whom twenty-four (6.6%) were diagnosed with underlying ICAD and treated with angioplasty and stent reconstruction (PTAS) with a standardized medication protocol. Successful reperfusion, peri-procedural complications, and functional independence at 90 days were collected as outcomes.

RESULTS

There was no difference in age or admission National Institutes of Health Stroke Scale (NIHSS). Onset to groin puncture (median 460 vs 277 min, P = 0.019) was significantly longer in the ICAD group. The procedure time (median 73 vs 60 min, P = 0.137) did not differ. Successful reperfusion was achieved in 95.8% of ICAD and 91.1% of the remaining patients (P = 0.445). Functional independence (mRS ≤ 2) at 90 days was achieved in 45.8% (11/24) and 42.7% (144/337, (P = 0.767)). The mortality rates (mRS 6) at 90 days were similar (29.2% vs 29.4% (P = 0.983)).

CONCLUSION

Despite significantly longer treatment delays, the outcome and revascularization rates of ICAD patients were similar to the thromboembolic cohort. Our proposed protocol of PTAS and medication protocol in ICAD was effective with a similar safety profile as MT in general.

Pupillometry in the follow-up of patients undergoing EVT - prediction of space-occupying hemispheric infarction

BACKGROUND

Despite benefits of endovascular treatment (EVT) for large vessel occlusion (LVO) ischemic stroke, space-occupying brain edema (BE) represents a detrimental complication. In critical-care settings, CT-imaging is needed for monitoring these patients. Yet, bed-side techniques with the potential to predict whether patients develop BE or not would facilitate a time- and cost-efficient patient care. We assessed clinical significance of automated pupillometry in the follow-up of patients undergoing EVT.

METHODS

From 10/2018 to 10/2021, neurocritical-care-unit patients were retrospectively enrolled after EVT of anterior circulation LVO. We monitored parameters of pupillary reactivity [light-reflex-latency (Lat), constriction- and redilation-velocities (CV, DV), percentage-change-of-apertures (per-change); NeurOptics-pupilometer®] up to every hour on day 1-3 of ICU stay. BE was defined as midline shift ≥ 5 mm on follow-up imaging 3-5 days after EVT. We calculated mean values of intra-individual differences between successive pairs of parameters (mean-deltas), determined best discriminative cut-off values for BE development (ROC-analyses), and evaluated prognostic performance of pupillometry for BE development (sensitivity/specificity/positive-/negative-predictive-values).

RESULTS

3241 pupillary assessments of 122 patients [67 women, 73 years (61.0-85.0)] were included. 13/122 patients developed BE. Patients with BE had significantly lower CVs, DVs, and smaller per-changes than patients without BE. On day 1 after EVT mean-deltas of CV, DV, and per-changes were significantly lower in patients with than without BE. Positive-predictive-values of calculated thresholds to discriminate both groups were considerably low, yet, we found high negative-predictive-values for CV, DV, per-changes, and mean-deltas (max.: 98.4%).

CONCLUSION

Our data suggest associations between noninvasively detected changes in pupillary reactivity and BE early after LVO-EVT. Pupillometry may identify patients who are unlikely to develop BE and may not need repetitive follow-up-imaging or rescue-therapy.

Mode of Imaging Study and Endovascular Therapy for a Large Ischemic Core: Insights From the RESCUE-Japan LIMIT

BACKGROUND AND PURPOSE

Differences in measurement of the extent of acute ischemic stroke using the Alberta Stroke Program Early Computed Tomographic Score (ASPECTS) by non-contrast computed tomography (CT-ASPECTS stratum) and diffusion-weighted imaging (DWI-ASPECTS stratum) may impact the efficacy of endovascular therapy (EVT) in patients with a large ischemic core.

METHODS

The RESCUE-Japan LIMIT (Recovery by Endovascular Salvage for Cerebral Ultra-acute Embolism Japan-Large IscheMIc core Trial) was a multicenter, open-label, randomized clinical trial that evaluated the efficacy and safety of EVT in patients with ASPECTS of 3-5. CT-ASPECTS was prioritized when both CT-ASPECTS and DWI-ASPECTS were measured. The effects of EVT on the modified Rankin Scale (mRS) score at 90 days were assessed separately for each stratum.

RESULTS

Among 183 patients, 112 (EVT group, 53; No-EVT group, 59) were in the CT-ASPECTS stratum and 71 (EVT group, 40; No-EVT group, 31) in the DWI-ASPECTS stratum. The common odds ratio (OR) (95% confidence interval) of the EVT group for one scale shift of the mRS score toward 0 was 1.29 (0.65-2.54) compared to the No-EVT group in CT-ASPECTS stratum, and 6.15 (2.46-16.3) in DWI-ASPECTS stratum with significant interaction between treatment assignment and mode of imaging study (P=0.002). There were significant interactions in the improvement of the National Institutes of Health Stroke Scale score at 48 hours (CT-ASPECTS stratum: OR, 1.95; DWIASPECTS stratum: OR, 14.5; interaction P=0.035) and mortality at 90 days (CT-ASPECTS stratum: OR, 2.07; DWI-ASPECTS stratum: OR, 0.23; interaction P=0.008).

CONCLUSION

Patients with ASPECTS of 3-5 on MRI benefitted more from EVT than those with ASPECTS of 3-5 on CT.

Specialist Perspectives on the Imaging Selection of Large Vessel Occlusion in the Late Window

BACKGROUND

The proper imaging modality for use in the selection of patients for endovascular thrombectomy (EVT) presenting in the late window remains controversial, despite current guidelines advocating the use of advanced imaging in this population. We sought to understand if clinicians with different specialty training differ in their approach to patient selection for EVT in the late time window.

METHODS

We conducted an international survey of stroke and neurointerventional clinicians between January and May 2022 with questions focusing on imaging and treatment decisions of large vessel occlusion (LVO) patients presenting in the late window. Interventional neurologists, interventional neuroradiologists, and endovascular neurosurgeons were defined as interventionists whereas all other specialties were defined as non-interventionists. The non-interventionist group was defined by all other specialties of the respondents: stroke neurologist, neuroradiologist, emergency medicine physician, trainee (fellows and residents) and others.

RESULTS

Of 3000 invited to participate, 1506 (1027 non-interventionists, 478 interventionists, 1 declined to specify) physicians completed the study. Interventionist respondents were more likely to proceed directly to EVT (39.5% vs. 19.5%; p < 0.0001) compared to non-interventionist respondents in patients with favorable ASPECTS (Alberta Stroke Program Early CT Score). Despite no difference in access to advanced imaging, interventionists were more likely to prefer CT/CTA alone (34.8% vs. 21.0%) and less likely to prefer CT/CTA/CTP (39.1% vs. 52.4%) for patient selection (p < 0.0001). When faced with uncertainty, non-interventionists were more likely to follow clinical guidelines (45.1% vs. 30.2%) while interventionists were more likely to follow their assessment of evidence (38.7% vs. 27.0%) (p < 0.0001).

CONCLUSION

Interventionists were less likely to use advanced imaging techniques in selecting LVO patients presenting in the late window and more likely to base their decisions on their assessment of evidence rather than published guidelines. These results reflect gaps between interventionists and non-interventionists reliance on clinical guidelines, the limits of available evidence, and clinician belief in the utility of advanced imaging.

Significant Slowed Cortical Venous Blood Flow in Patients with Acute Ischemic Stroke with Large Vessel Occlusion Suggests Poor Collateral Circulation and Prognosis

RATIONALE AND OBJECTIVES

To investigate the change of cortical venous flow in acute ischemic stroke patients with large vessel occlusion (LVO-AIS) and its clinical value.

MATERIALS AND METHODS

Baseline whole-brain 4D-CTA/CTP and clinical data of LVO-AIS and a control group were collected from June 2020 to October 2021. Venous inflow time (VIT), venous peak time (VPT), and venous outflow time (VOT) were analyzed on both sides of patients and normal controls. The VIT/VPT/VOT were statistically described and compared between the patient group and normal controls, then, in patients with different collateral circulation and prognoses. Next, the correlation between cortical venous drainage time and collateral circulation grading was analyzed. Finally, logistic regression analysis was used to explore the relationship between the three venous times and prognosis, and receiver operating characteristic (ROC) curves were plotted to assess the value of delayed cortical venous imaging in predicting prognosis.

RESULTS

149 LVO-AIS and 73 normal controls were collected. VIT, VPT, and VOT were significantly delayed on the affected side in the patient group compared with the healthy side (p<0.05) and the controls (p<0.05); VIT and VPT were also significantly delayed on the healthy side of patients compared with the controls (p<0.05). Delayed VIT and VPT on the affected side in the patient group were more significant in patients with poor collateral circulation (p<0.05), and VIT and VPT on the affected side in the patient group were negatively correlated with arterial collateral scores. VIT and VPT were significantly delayed in both sides of patients in the poor prognosis group compared with the good prognosis group (p<0.05). logistic regression showed that patients' affected VPT, arterial collateral scores, and NIHSS were independent predictors of poor prognosis, with an accuracy of 79.6% in predicting poor prognosis. The affected VPT and NIHSS were independent predictors of poor prognosis for patients presenting within 24 hours, with an accuracy of 79.6% in predicting poor prognosis.

CONCLUSION

Cortical venous flow was significantly slowed in both sides of LVO-AIS patients. delayed ipsilateral VPT in LVO-AIS patients can be used as an imaging indicator to determine poor collateral circulation and predict poor prognosis.

Point-of-Care Ultrasound to Detect Acute Large Vessel Occlusions in Stroke Patients: A Proof-of-Concept Study

BACKGROUND AND PURPOSE

A primary admission of patients with suspected acute ischemic stroke and large vessel occlusion (LVO) to centers capable of providing endovascular stroke therapy (EVT) may induce shorter time to treatment and better functional outcomes. One of the limitations in this strategy is the need for accurately identifying LVO patients in the prehospital setting. We aimed to study the feasibility and diagnostic performance of point-of-care ultrasound (POCUS) for the detection of LVO in patients with acute stroke.

METHODS

We conducted a proof-of-concept study and selected 15 acute ischemic stroke patients with angiographically confirmed LVO and 15 patients without LVO. Duplex ultrasonography (DUS) of the common carotid arteries was performed, and flow profiles compatible with LVO were scored independently by one experienced and one junior neurologist.

RESULTS

Among the 15 patients with LVO, 6 patients presented with an occlusion of the carotid-T and 9 patients presented with an M1 occlusion. Interobserver agreement between the junior and the experienced neurologist was excellent (kappa = 0.813, p < 0.001). Flow profiles of the CAA allowed the detection of LVO with a sensitivity of 73%, a positive predictive value of 92 and 100%, and a c-statistics of 0.83 (95%CI = 0.65-0.94) and 0.87 (95%CI = 0.69-0.94) (experienced neurologist and junior neurologist, respectively). In comparison with clinical stroke scales, DUS was associated with better trade-off between sensitivity and specificity.

CONCLUSION

POCUS in acute stroke setting is feasible, it may serve as a complementary tool for the detection of LVO and is potentially applicable in the prehospital phase.

Resolving the Smoking Paradox: No Evidence for Smoking-Induced Preconditioning in Large Vessel Occlusion Stroke

INTRODUCTION

Smoking is an established risk factor for stroke. However, several studies have reported a better outcome after stroke for patients who smoke. According to this "smoking paradox" hypothesis, smoking might promote less severe strokes, higher collateral scores, and smaller infarct cores.

METHODS

In this retrospective study, we screened data of 2,980 acute ischemic stroke patients with MCA-M1 occlusion treated with mechanical thrombectomy. Patients were categorized according to smoking status (current, former, or never). We assessed univariate associations between clinical characteristics and smoking status. Subsequently, we used adjusted regression analysis to evaluate associations of smoking with stroke severity on admission (National Institutes of Health Stroke Scale [NIHSS]; primary endpoint), infarct core volume, and collateral status (secondary endpoints).

RESULTS

Out of 320 patients, 19.7% (n = 63) were current smokers and 18.8% (n = 60) were former smokers. Admission NIHSS, reperfusion success, and modified Rankin Scale (mRS) after 3-6 months were similar in all groups. Current smokers were younger, more often male and less likely to have atrial fibrillation compared to former and never smokers. In regression analyses, smoking status was neither associated with admission NIHSS (estimate 0.54, 95% confidence interval [CI]: -1.27-2.35, p = 0.557) nor with collateral status (estimate 0.79, 95% CI: 0.44-1.44, p = 0.447) or infarct core volume (estimate -0.69, 95% CI: -15.15-13.77, p = 0.925 for current vs. never smokers).

CONCLUSION

We could not confirm the smoking paradox. Our results support the fact that smoking causes stroke at a younger age, highlighting the role of smoking as a modifiable vascular risk factor.

Underlying intracranial atherosclerotic disease is associated with worse outcomes in acute large vessel occlusion undergoing endovascular thrombectomy

BACKGROUND

Data on large vessel occlusion (LVO) management due to intracranial atherosclerotic disease (ICAD) are scarce.

OBJECTIVE

To compare clinical outcomes between patients with ICAD and those without ICAD following mechanical thrombectomy (MT).

METHODS

We performed a retrospective analysis of consecutive patients who underwent MT for LVO in a large academic comprehensive stroke center, and compared in-hospital mortality, 90-day mortality, favorable functional outcome at 90 days, and symptomatic intracranial hemorrhage (ICH) using chi-squared tests and multivariate logistic regression analyses. We defined ICAD as observable plaque at occlusion site post-thrombectomy.

RESULTS

Among 215 patients (mean age 67.1 ± 16.0 years; 60.5% female; 83.6% Black, median NIHSS score 16), ICAD was present in 38 patients (17.7%). Diabetes and dyslipidemia were more common in those with ICAD (57.9% vs. 38.4%, p = 0.027 and 29.0% vs. 14.7%, p = 0.035, respectively). Substantial reperfusion (TICI ≥2b) was achieved less often (84.2% vs. 94.4%, p = 0.031) but symptomatic ICH was also less common in ICAD patients (0% vs. 9.0%, p = 0.081). In-hospital and 90-day mortality were more common (36.8% vs. 15.8%, p = 0.003 and 52.6% vs. 26.6%, p = 0.002, respectively) and favorable functional outcome (mRS 0-2) at 90 days was less common (7.9% vs. 33.9%, p = 0.001) in ICAD patients. After adjusting for prognostic variables, ICAD was independently associated with in-hospital mortality (OR=4.1, 95% CI 1.7-9.7), 90-day mortality (OR=3.7, 95% CI 1.6-8.6), and poor functional outcome at 90 days (OR=5.5, 95% CI 1.6-19.4).

CONCLUSION

Symptomatic ICAD in a predominantly African American cohort is associated with increased odds of mortality and poor functional outcome at 90 days in patients with LVO undergoing MT.

Effect of intra-arterial thrombolysis following successful endovascular thrombectomy on functional outcomes in patients with large vessel occlusion acute ischemic stroke: A post-CHOICE meta-analysis

INTRODUCTION

Endovascular thrombectomy (EVT) is the standard treatment of acute ischemic stroke (AIS) due to large vessel occlusion (LVO). Although > 70% of patients in the trials assessing EVT for AIS-LVO had successful recanalization, only a third ultimately achieved favorable outcomes. A "no-reflow" phenomenon due to distal microcirculation disruption might contribute to such suboptimal outcomes. Combining intra-arterial (IA) tissue plasminogen activator (tPA) and EVT to reduce the distal microthrombi burden was investigated in a few studies. We present a pooled-data meta-analysis of the existing evidence of this combinatorial treatment.

METHODS

We followed the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA) recommendations. We aimed to include all original studies investigating EVT plus IA tPA in AIS-LVO patients. Using R software, we calculated pooled odds ratios (ORs) with corresponding 95% confidence intervals (CI). A fixed-effects model was adopted to evaluate pooled data.

RESULTS

Five studies satisfied the inclusion criteria. Successful recanalization was comparable between the IA tPA and control groups at 82.9% and 82.32% respectively. The 90-day functional independence was similar between both groups (OR= 1.25; 95% CI= 0.92-1.70; P= 0.154). Symptomatic intracranial hemorrhage (sICH) was also comparable between both groups (OR= 0.66; 95% CI= 0.34-1.26; P= 0.304).

CONCLUSION

Our current meta-analysis does not show significant differences between EVT alone and EVT plus IA tPA in terms of functional independence or sICH. However, with the limited number of studies and included patients, more randomized controlled trials (RCTs) are needed to further investigate the benefits and safety of combined EVT and IA tPA.

Elevated Hypoperfusion Intensity Ratio (HIR) observed in patients with a large vessel occlusion (LVO) presenting in the evening

BACKGROUND

Circadian variability has been implicated in timing of stroke onset, yet the full impact of underlying biological rhythms on acute stroke perfusion patterns is not known. We aimed to describe the relationship between time of stroke onset and perfusion profiles in patients with large vessel occlusion (LVO).

METHODS

A retrospective observational study was conducted using prospective registries of four stroke centers across North America and Europe with systematic use of perfusion imaging in clinical care. Included patients had stroke due to ICA, M1 or M2 occlusion and baseline perfusion imaging performed within 24h from last-seen-well (LSW). Stroke onset was divided into eight hour intervals: (1) Night: 23:00-6:59, (2) Day: 7:00-14:59, (3) Evening: 15:00-22:59. Core volume was estimated on CT perfusion (rCBF <30%) or DWI-MRI (ADC <620) and the collateral circulation was estimated with the Hypoperfusion Intensity Ratio (HIR = [Tmax>10s]/[Tmax>6s]). Non-parametric testing was conducted using SPSS to account for the non-normalized dependent variables.

RESULTS

A total of 1506 cases were included (median age 74.9 years, IQR 63.0-84.0). Median NIHSS, core volumes, and HIR were 14.0 (IQR 8.0-20.0), 13.0mL (IQR 0.0-42.0), and 0.4 (IQR 0.2-0.6) respectively. Most strokes occurred during the Day (n = 666, 44.2%), compared to Night (n = 360, 23.9%), and Evening (n = 480, 31.9%). HIR was highest, indicating worse collaterals, in the Evening compared to the other timepoints (p = 0.006). Controlling for age and time to imaging, Evening strokes had significantly higher HIR compared to Day (p = 0.013).

CONCLUSION

Our retrospective analysis suggests that HIR is significantly higher in the evening, indicating poorer collateral activation which may lead to larger core volumes in these patients.

Association between population changes and the number of endovascular thrombectomies

Background

Randomized controlled trials have demonstrated the efficacy of mechanical thrombectomy (MT) for acute ischemic stroke. However, few studies indicate an association between the number of mechanical thrombectomies and population changes. We aimed to clarify the association between population changes and the number of mechanical thrombectomies for proper allocation of limited medical resources.

Methods

We retrospectively analyzed data from 162 patients who underwent MT for large vessel occlusion at our hospitals and compared the number of mechanical thrombectomies per 100,000 person/year to population changes in five regions covered by our hospitals within 2015-2016 and 2017-2019. We performed a simple linear regression analysis to determine the association between population changes and the number of mechanical thrombectomies.

Results

Overall, the number of mechanical thrombectomies increased from 15.1 to 19. However, a significant decrease was noted in Toya Lake and Sobetsu/Toyoura. Furthermore, there was a significant negative linear correlation between the overall population reduction rate and the number of mechanical thrombectomies and a positive linear correlation between the increased proportion of the population aged >65 years and the number of mechanical thrombectomies.

Conclusion

The number of mechanical thrombectomies may decrease in areas where the overall population reduction rate exceeds 8% or the increased rate of the population aged >65 years is <4%. However, it is necessary to continue establishing a system for MT in areas that have yet to reach these levels.