Endovascular treatment for basilar artery occlusion: whether the "weekend effect" affects time metrics and clinical outcomes at a comprehensive stroke center.

Objectives: This study aimed to evaluate whether the "weekend effect" would affect the time metrics and the prognosis of acute ischemic stroke (AIS) patients who underwent endovascular treatment (EVT) due to basilar artery occlusion (BAO). Methods: Clinical data of AIS patients who underwent EVT due to BAO between December 2019 and July 2023 were retrospectively analyzed. At the time when the patients were admitted, the study population was divided into the weekdays daytime group and weekends nighttime group. In the subgroup analysis, the study cohort was divided into four groups: the weekdays daytime group, weekdays nighttime group, weekend daytime group, and weekend nighttime group. A good outcome was defined as a modified Rankin Scale score of ≤3 at 90 days after EVT. Time metrics [e.g. onset-to-door time (ODT) and door-to-puncture time (DPT)] and clinical outcomes were compared using appropriate statistical methods. Results: A total of 111 patients (88 male patients, mean age, 67.7 ± 11.7 years) were included. Of these, 37 patients were treated during weekdays daytime, while 74 patients were treated during nights or weekends. There were no statistically significant differences in ODT (P = 0.136), DPT (P = 0.931), and also clinical outcomes (P = 0.826) between the two groups. Similarly, we found no significant differences in the time metrics and clinical outcomes among the four sub-groups (all P > 0.05). Conclusion: This study did not reveal any influence of the "weekend effect" on the time metrics and clinical outcomes in AIS patients who underwent EVT due to BAO at a comprehensive stroke center.

Potential Approach to Quantifying the Volume of the Ischemic Core in Truncated Computed Tomography Perfusion Scans: A Preliminary Study.

OBJECTIVE: This study aimed to provide an alternative approach for quantifying the volume of the ischemic core (IC) if truncation of computed tomography perfusion (CTP) occurs in clinical practice. METHODS: Baseline CTP and follow-up diffusion-weighted imaging (DWI) data from 88 patients with stroke were retrospectively collected. CTP source images (CTPSI) from the unenhanced phase to the peak arterial phase (CTPSI-A) or the peak venous phase (CTPSI-V) were collected to simulate the truncation of CTP in the arterial or venous phases, respectively. The volume of IC on CTPSI-A (V CTPSI-A ) or CTPSI-V (V CTPSI-V ) was defined as the volume of the brain tissue with >65% reduction in attenuation compared with that of the normal tissue. The volume of IC on the baseline CTP (V CTP ) was defined as a relative cerebral blood flow of <30% of that in the normal tissue. The volume of the posttreatment infarct on the follow-up DWI (V DWI ) image was manually delineated and calculated. One-way analysis of variance, Bland-Altman plots, and Spearman correlation analyses were used for the statistical analysis. RESULTS: V CTPSI-A was significantly higher than V DWI ( P < 0.001); however, no significant difference was observed between V CTP and V DWI ( P = 0.073) or between V CTPSI-V and V DWI ( P > 0.999). The mean differences between V DWI and V CTPSI-V , V DWI and V CTP , and V DWI and V CTPSI-A were 1.70 mL (limits of agreement [LoA], -56.40 to 59.70), 8.30 mL (LoA, -40.70 to 57.30), and -68.10 mL (LoA, -180.90 to 44.70), respectively. Significant correlations were observed between V DWI and V CTP ( r = 0.68, P < 0.001) and between V DWI and V CTPSI-V ( r = 0.39, P < 0.001); however, no significant correlation was observed between V DWI and V CTPSI-A ( r = 0.20, P = 0.068). CONCLUSIONS: V CTPSI-V may be a promising method for quantifying the volume of the IC if truncation of CTP occurs.

Spatial accuracy of computed tomography perfusion to estimate the follow-up infarct on diffusion-weighted imaging after successful mechanical thrombectomy.

BACKGROUND: Volumetric accuracy of using computed tomography perfusion (CTP) to estimate the post-treatment infarct in stroke patients with successful recanalization after mechanical thrombectomy (MT) has been studied a lot, however the spatial accuracy and its influence factors has not been fully investigated. METHODS: This retrospective study reviewed the data from consecutive anterior large vessel occlusion (LVO) patients who had baseline CTP, successful recanalization after MT, and post-treatment diffusion-weighed imaging (DWI). Ischemic core on baseline CTP was estimated using relative cerebral blood flood (CBF) of < 30%. The infarct area was outlined manually on post-treatment DWI, and registered to CTP. Spatial agreement was assessed using the Dice similarity coefficient (DSC) and average Hausdorff distance. According to the median DSC, the study population was dichotomized into high and low Dice groups. Univariable and multivariable regression analyses were used to determine the factors independently associated with the spatial agreement. RESULTS: In 72 included patients, the median DSC was 0.26, and the median average Hausdorff distance was 1.77 mm. High Dice group showed significantly higher median ischemic core volume on baseline CTP (33.90 mL vs 3.40 mL, P < 0.001), lower proportion of moderate or severe leukoaraiosis [27.78% vs 52.78%, P = 0.031], and higher median infarct volume on follow-up DWI (51.17 mL vs 9.42 mL, P < 0.001) than low Dice group. Ischemic core volume on baseline CTP was found to be independently associated with the spatial agreement (OR, 1.092; P < 0.001). CONCLUSIONS: CTP could help to spatially locate the post-treatment infarct in anterior LVO patients who achieving successful recanalization after MT. Ischemic core volume on baseline CTP was independently associated with the spatial agreement.

Use of ABC/2 method for rapidly estimating the target mismatch on computed tomography perfusion imaging in patients with acute ischemic stroke.

BACKGROUND: Target mismatch (ischemic core, mismatch volume and mismatch ratio) in patients with acute ischemic stroke (AIS) highly relies on the automated perfusion analysis software. PURPOSE: To evaluate the feasibility and accuracy of using the ABC/2 method to rapidly estimate the target mismatch on computed tomography perfusion (CTP) imaging in patients with AIS, using RAPID results as a reference. MATERIAL AND METHODS: In total, 243 patients with anterior circulation AIS who underwent CTP imaging were retrospectively reviewed. Target mismatch associated perfusion parameters were derived from RAPID results and calculated using the ABC/2 method. Paired t-test was used to assess the difference of volumetric parameters between the two methods. The ability of using the ABC/2 method to predict the important cutoff volumetric metrics was also evaluated. RESULT: There was no significant difference in the volumes of ischemic core (P = 0.068), ischemic area (P = 0.209), and mismatch volume (P = 0.518) between ABC/2 and RAPID. Using RAPID results as reference, the ABC/2 method showed high accuracy for predicting perfusion parameters (70 mL and 90 mL: sensitivity=98.5% and 98.5%, specificity=100% and 100%, positive predictive value [PPV]=100% and 100%, negative predictive value [NPV]=93.8% and 92.9%; 10 mL and 15mL: sensitivity=99.6% and 99.5%, specificity=55.6% and 50.0%, PPV=96.6% and 94.8%, NPV=90.9% and 92.3%; 1.2 and 1.8: sensitivity=99.6% and 94.8%, specificity=75.0% and 96.9%, PPV=98.7% and 99.5%, NPV=90.0% and 73.8%). CONCLUSION: The ABC/2 method may be a feasible alternative to RAPID for estimation of target mismatch parameters on CTP in patients with AIS.

Predictors of ghost infarct core on baseline computed tomography perfusion in stroke patients with successful recanalization after mechanical thrombectomy.

OBJECTIVES: To assess the predictors of ghost infarct core (GIC) in stroke patients achieving successful recanalization after mechanical thrombectomy (MT), based on final infarct volume (FIV) calculated from follow-up diffusion-weighted imaging (DWI). METHODS: A total of 115 consecutive stroke patients who had undergone baseline computed tomography perfusion (CTP) scan, achieved successful recanalization after MT, and finished follow-up DWI evaluation were retrospectively enrolled. Ischemic core volume was automatically generated from baseline CTP, and FIV was determined manually based on follow-up DWI. Stroke-related risk factors and demographic, clinical, imaging, and procedural data were collected and assessed. Univariate and multivariate analyses were applied to identify the predictors of GIC. RESULTS: Of the 115 included patients (31 women and 84 men; median age, 66 years), 18 patients (15.7%) showed a GIC. The GIC group showed significantly shorter time interval from stroke onset to CTP scan and that from stroke onset to recanalization (both p < 0.001), but higher ischemic core volume (p < 0.001), hypoperfused area volume (p < 0.001), mismatch area volume (p = 0.006), and hypoperfusion ratio (p = 0.001) than the no-GIC group. In multivariate analysis, time interval from stroke onset to CTP scan (odds ratio [OR], 0.983; p = 0.005) and ischemic core volume (OR, 1.073; p < 0.001) were independently associated with the occurrence of GIC. CONCLUSIONS: In stroke patients achieving successful recanalization after MT, time interval from stroke onset to CTP and ischemic core volume are associated with the occurrence of GIC. Patients cannot be excluded from MT solely based on baseline CTP-derived ischemic core volume, especially for patients with a shorter onset time. KEY POINTS: • Ghost infarct core (GIC) was found in 15.7% of patients with acute ischemic stroke (AIS) in our study cohort. • GIC was associated with stroke onset time, volumetric parameters derived from CTP, and collateral status indicated by HIR. • Time interval from stroke onset to CTP scan and ischemic core volume were independent predictors of GIC.

CT perfusion with increased temporal sampling interval to predict target mismatch status in patients with acute ischemic stroke.

PURPOSE: To evaluate the feasibility of using CT perfusion (CTP) with increased temporal sampling interval to predict the target mismatch status in acute ischemic stroke (AIS) patients with anterior circular large-vessel occlusion (LVO). METHODS: CTP with a sampling interval of 1.7 s (CTP1.7 s) was scanned in 77 AIS patients for pre-treatment evaluation. Simulated CTP data with sampling interval of 3.4 s (CTP3.4 s) or 5.1 s (CTP5.1 s) were reconstructed, respectively. Target mismatch was defined according to the EXTEND-IA (Extending the Time for Thrombolysis in Emergency Neurological Deficits-Intra-Arterial) and DEFUSE 3 (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke) trial criteria, respectively. Pearson correlation analysis, Mann-Whitney U test, Bland-Altman analysis, and chi-square test were used for statistical analysis as appropriate. RESULTS: Significant correlations were found on the volume of ischemic core, hypo-perfused area, mismatch area, and ratio between CTP1.7 s and CTP3.4 s or CTP5.1 s (all p < 0.001). There was no significant difference on the volume of ischemic core, hypo-perfused area, mismatch area, and mismatch ratio between CTP1.7 s and CTP3.4 s or CTP5.1 s (all p > 0.05). Compared with CTP1.7 s, CTP3.4 s or CTP5.1 s showed comparable performance in predicting the target mismatch status in the AIS patients with LVO (both p > 0.05). CONCLUSIONS: CTPs with increased temporal sampling intervals that lead to reduced radiation doses are feasible and may provide comparable performance in predicting target mismatch status in AIS patients with LVO.

Prognostic value of post-treatment fluid-attenuated inversion recovery vascular hyperintensity in ischemic stroke after endovascular thrombectomy.

OBJECTIVES: To explore the value of post-treatment fluid-attenuated inversion recovery vascular hyperintensity (FVH) in predicting clinical outcome in patients with acute ischemic stroke (AIS) after endovascular thrombectomy (EVT). METHODS: This retrospective study reviewed data from consecutive patients with large vessel occlusion of anterior circulation between July 2017 and February 2021. Together with other variables, status of post-treatment FVH was assessed for each patient. Good outcome was defined as a 3-month modified Rankin Scale score of 0-2. Chi-square test, Fisher's exact test, independent-samples t test, multivariate logistic regression analysis, and receiver operating characteristic analysis were used as appropriate. RESULTS: Among 84 included patients, 48 (57.1%) patients showed post-treatment FVH. Post-treatment FVH significantly correlated with incomplete recanalization (p < 0.05) and low Alberta Stroke Project Early CT Changes Score on post-treatment diffusion-weighted imaging (p < 0.05). Higher incidence of hemorrhage transformation was observed in patients with post-treatment FVH than those without (27.1% vs. 16.7%); however, the difference did not reach significance (p = 0.259). Successful recanalization (odds ratio [OR], 0.024; 95% confidence interval [CI] 0.003-0.194; p < 0.05), lower National Institutes of Health Stroke Scale scores at admission (NIHSSpre) (OR, 1.196; 95% CI, 1.017-1.406; p < 0.05), and no post-treatment FVH (OR, 74.690; 95% CI, 4.624-1206.421; p < 0.05) were found to be independent predictors of good outcomes. Combined models integrating all three independent predictors (recanalization+NIHSSpre+post-treatment FVH) significantly outperformed the combined model without post-treatment FVH (recanalization+NIHSSpre) in predicting clinical outcome (p = 0.004). CONCLUSIONS: Post-treatment FVH may be an effective prognostic marker associated with clinical outcome in patients with AIS after EVT. KEY POINTS: • Post-treatment FVH correlates with incomplete recanalization and higher infarct volume. • Post-treatment FVH is independently associated with an unfavorable outcome. • Post-treatment FVH may provide prognostic information in patients with AIS after EVT.

Prognostic value of ASPECTS on post-treatment diffusion-weighted imaging for acute ischemic stroke patients after endovascular thrombectomy: comparison with infarction volume.

OBJECTIVES: To assess the prognostic value of Alberta Stroke Program Early Computed Tomography Score (ASPECTS) on post-treatment diffusion-weighted imaging (DWI) for acute ischemic stroke (AIS) patients after endovascular thrombectomy (EVT) and compare it with that of infarction volume. METHODS: Ninety-eight consecutive AIS patients who underwent EVT and post-treatment DWI were retrospectively enrolled. ASPECTS and infarction volume were evaluated based on post-treatment DWI, respectively. Good clinical outcome was defined as modified Rankin Scale score of 0-2 at 90 days. Predictors of good clinical outcome were evaluated using univariate and multivariate logistic regression analysis. Prognostic value of post-treatment DWI ASPECTS and infarction volume were assessed and compared using receiver-operating-characteristic curves and the DeLong method. RESULTS: Favorable outcome was achieved in 62 (63.3%) patients. A strong correlation was found between post-treatment DWI ASPECTS and infarction volume (ρ = -0.847). Due to strong correlation and potential collinearity, two multivariate logistic regression models were respectively developed which included post-treatment DWI ASPECTS or infarction volume. As a result, post-treatment DWI ASPECTS (OR, 2.401; 95%CI, 1.567-3.678; p < 0.001) and infarction volume (OR, 0.982; 95%CI, 0.846-0.998; p = 0.002) were both independent predictors of good clinical outcome. Setting post-treatment DWI ASPECTS ≥ 6 as a cut-off value, optimal performance (AUC = 0.836; sensitivity, 87.1%; specificity, 66.7%) could be obtained in predicting good clinical outcome, which was comparable with that of infarction volume (cut-off volume, ≤ 94.87 ml; AUC = 0.821; sensitivity, 90.3%; specificity, 55.6%). CONCLUSIONS: Post-treatment DWI ASPECTS might be a potential surrogate of infarction volume and be effective in predicting the clinical outcome of AIS patients after EVT. KEY POINTS: • Post-treatment DWI ASPECTS correlated significantly with infarction volume. • A post-treatment DWI ASPECTS ≥ 6 best predicts good outcomes for AIS patients after EVT. • Post-treatment DWI ASPECTS has the potential in substituting infarction volume in predicting the clinical outcome of AIS patients.

The safety and efficacy of a low dose of tirofiban for early complications during and after stent-assisted coiling of ruptured intracranial aneurysms: A propensity matching study.

PURPOSE: During stent-assisted coiling of ruptured intracranial aneurysms (RIA), appropriate antiplatelet administration is an important element of management. We aimed to evaluate the safety and efficacy of intravenous tirofiban administration versus dual antiplatelet therapy (DAPT) for stent-assisted coiling of RIAs within 24 h after procedure. METHODS: From January 2015 to March 2019, two groups of patients with RIAs treated with stent-coiling were compared: the DAPT group (a loading dose of 300 mg clopidogrel and 300 mg aspirin) and the tirofiban group (intravenous administration of tirofiban 5 µg/kg over 1 min, followed by a maintenance dose of 0.1 µg/kg/min). The main outcome measures were rates of ischemic events and intracranial hemorrhage. Propensity score-matching (PSM) analysis was performed to correct imbalances in patient characteristics between the two groups. RESULTS: A total of 200 patients with RIAs were identified, with 36 patients in DAPT group and 164 in tirofiban group. After PSM, 36 patients in DAPT group and 72 patients in tirofiban group were matched. Ischemic events were noted for 8.33% (3/36) of patients in DAPT group, and 4.17% (3/72) in tirofiban group within 24 h after procedure(P = 0.398). Intracranial hemorrhage was noted for 0.00% (0/36) of patients in DAPT group, and 1.39% (1/72) in tirofiban group (P = 1.000) within 24 h. And no significant difference in the rate of ischemic or hemorrhagic events after 24 h was detected. CONCLUSIONS: Intravenous administration of a low dose of tirofiban may represent a safe and effective alternative to DAPT during stent-assisted coiling of RIAs.

Diagnostic accuracy of using Alberta Stroke Program Early Computed Tomography Score on CT perfusion map to predict a target mismatch in patients with acute ischemic stroke.

PURPOSE: To assess the diagnostic accuracy of using Alberta Stroke Program Early Computed Tomography Score (ASPECTS) on CT perfusion (CTP) map to predict a volumetric target mismatch in patients with acute ischemic stroke (AIS). METHODS: Three-hundred and seven AIS patients with an onset time within 24h or unclear onset time who underwent CTP evaluation for large vessel occlusion of anterior circulation were enrolled. CTP ASPECTS was evaluated on cerebral blood flow (CBF) and time-to-maximum (Tmax) colored maps, respectively. Automated perfusion analysis software was used to calculate the volumes of ischemic core (volumeCBF<30%) and tissue at risk (volumeTmax>6s). Target mismatch was defined as volumeCBF< 30%<70ml, volumemismatch≥15ml, and volumeTmax >6s/volume CBF< 30%≥1.8. Spearman correlation and receiver operating characteristic curves were used for statistical analyses. RESULTS: Strong correlations were found between CBF ASPECTS and volumeCBF<30%, and between Tmax ASPECTS and volumeTmax>6s for overall population (ρ=-0.872, -0.757) and late-arriving patients (ρ=-0.900, -0.789). Mismatch ASPECTS moderately correlated with mismatch volume for overall population (ρ=0.498) and late-arriving patients (ρ=0.407). A CBF ASPECTS≥5 optimally predicted an ischemic core volume<70ml in overall population (sensitivity, 94.4%; specificity, 80.4%) and late-arriving patients (sensitivity, 89.5%; specificity, 90.5%). A CBF ASPECTS≥6 combined with a Mismatch ASPECTS≥1 optimally identified a target mismatch in overall population (sensitivity, 84.5%; specificity, 77.0%) and late-arriving patients (sensitivity, 83.7%; specificity, 90.0%). CONCLUSION: CTP ASPECTS might be useful in predicting target mismatch derived from automated perfusion analysis software, and assisting in patient selection for endovascular therapy.