Impact of Intensive Blood Pressure Lowering After Multiple-Attempt Endovascular Thrombectomy : a secondary analysis of the OPTIMAL-BP trial.

BACKGROUND: Multiple attempts of thrombectomy have been linked to a higher risk of intracerebral hemorrhage and worsened functional outcomes, potentially influenced by blood pressure (BP) management strategies. Nonetheless, the impact of intensive BP management following successful recanalization through multiple attempts remains uncertain. AIMS: This study aimed to investigate whether conventional and intensive BP management differentially affect outcomes according to multiple-attempt recanalization (MAR) and first-attempt recanalization (FAR) groups. METHODS: In this secondary analysis of the OPTIMAL-BP trial, which was a comparison of intensive (systolic BP target <140 mm Hg) and conventional (systolic BP target 140-180 mm Hg) BP managements during the 24 hours after successful recanalization, we included intention-to-treat population of the trial. Patients were divided into the MAR and the FAR groups. We examined a potential interaction between the number of thrombectomy attempts (MAR and FAR groups) and the effect of BP managements on clinical and safety outcomes. The primary outcome was functional independence at 3 months. Safety outcomes were symptomatic intracerebral hemorrhage within 36 hours and mortality within 3 months. RESULTS: Of the 305 patients (median 75 years), 102 (33.4%) were in the MAR group and 203 (66.6%) were in the FAR group. The intensive BP management was significantly associated with a lower rate of functional independence in the MAR group (intensive, 32.7% vs. conventional, 54.9%, adjusted OR 0.33, 95% CI 0.12-0.90, p = 0.03). In the FAR group, the proportion of patients with functional independence was not significantly different between the BP managements (intensive, 42.5% vs. conventional, 54.2%, adjusted OR 0.73, 95% CI 0.38-1.40). Incidences of symptomatic intracerebral hemorrhage and mortality rates were not significantly different according to the BP managements in both MAR and FAR groups. CONCLUSIONS: Among stroke patients who received multiple attempts of thrombectomy, intensive BP management for 24 hours resulted in a reduced chance of functional independence at 3 months and did not reduce symptomatic intracerebral hemorrhage following successful reperfusion.

Functional Outcomes Associated With Blood Pressure Decrease After Endovascular Thrombectomy.

Importance: The associations between blood pressure (BP) decreases induced by medication and functional outcomes in patients with successful endovascular thrombectomy remain uncertain. Objective: To evaluate whether BP reductions induced by intravenous BP medications are associated with poor functional outcomes at 3 months. Design, Setting, and Participants: This cohort study was a post hoc analysis of the Outcome in Patients Treated With Intra-Arterial Thrombectomy-Optimal Blood Pressure Control trial, a comparison of intensive and conventional BP management during the 24 hours after successful recanalization from June 18, 2020, to November 28, 2022. This study included 302 patients who underwent endovascular thrombectomy, achieved successful recanalization, and exhibited elevated BP within 2 hours of successful recanalization at 19 stroke centers in South Korea. Exposure: A BP decrease was defined as at least 1 event of systolic BP less than 100 mm Hg. Patients were divided into medication-induced BP decrease (MIBD), spontaneous BP decrease (SpBD), and no BP decrease (NoBD) groups. Main Outcomes and Measures: The primary outcome was a modified Rankin scale score of 0 to 2 at 3 months, indicating functional independence. Primary safety outcomes were symptomatic intracerebral hemorrhage within 36 hours and mortality due to index stroke within 3 months. Results: Of the 302 patients (median [IQR] age, 75 [66-82] years; 180 [59.6%] men), 47 (15.6%)were in the MIBD group, 39 (12.9%) were in the SpBD group, and 216 (71.5%) were in the NoBD group. After adjustment for confounders, the MIBD group exhibited a significantly smaller proportion of patients with functional independence at 3 months compared with the NoBD group (adjusted odds ratio [AOR], 0.45; 95% CI, 0.20-0.98). There was no significant difference in functional independence between the SpBD and NoBD groups (AOR, 1.41; 95% CI, 0.58-3.49). Compared with the NoBD group, the MIBD group demonstrated higher odds of mortality within 3 months (AOR, 5.15; 95% CI, 1.42-19.4). The incidence of symptomatic intracerebral hemorrhage was not significantly different among the groups (MIBD vs NoBD: AOR, 1.89; 95% CI, 0.54-5.88; SpBD vs NoBD: AOR, 2.75; 95% CI, 0.76-9.46). Conclusions and Relevance: In this cohort study of patients with successful endovascular thrombectomy after stroke, MIBD within 24 hours after successful recanalization was associated with poor outcomes at 3 months. These findings suggested lowering systolic BP to below 100 mm Hg using BP medication might be harmful.

Effectiveness of endovascular treatment for in-hospital stroke vs. community-onset stroke: a propensity score-matched analysis.

BACKGROUND: The effectiveness of endovascular treatment for in-hospital stroke remains debatable. We aimed to compare the outcomes between patients with in-hospital stroke and community-onset stroke who received endovascular treatment. METHODS: This prospective registry-based cohort study included consecutive patients who underwent endovascular treatment from January 2013 to December 2022 and were registered in the Selection Criteria in Endovascular Thrombectomy and Thrombolytic Therapy study and Yonsei Stroke Cohort. Functional outcomes at day 90, radiological outcomes, and safety outcomes were compared between the in-hospital and community-onset groups using logistic regression and propensity score-matched analysis. RESULTS: Of 1,219 patients who underwent endovascular treatment, 117 (9.6%) had in-hospital stroke. Patients with in-hospital onset were more likely to have a pre-stroke disability and active cancer than those with community-onset. The interval from the last known well to puncture was shorter in the in-hospital group than in the community-onset group (155 vs. 355 min, p<0.001). No significant differences in successful recanalization or safety outcomes were observed between the groups; however, the in-hospital group exhibited worse functional outcomes and higher mortality at day 90 than the community-onset group (all p<0.05). After propensity score matching including baseline characteristics, functional outcomes after endovascular treatment did not differ between the groups (OR: 1.19, 95% CI 0.78-1.83, p=0.4). Safety outcomes did not significantly differ between the groups. CONCLUSION: Endovascular treatment is a safe and effective treatment for eligible patients with in-hospital stroke. Our results will help physicians in making decisions when planning treatment and counseling caregivers or patients.

Intensive vs Conventional Blood Pressure Lowering After Endovascular Thrombectomy in Acute Ischemic Stroke: The OPTIMAL-BP Randomized Clinical Trial.

Importance: Optimal blood pressure (BP) control after successful reperfusion with endovascular thrombectomy (EVT) for patients with acute ischemic stroke is unclear. Objective: To determine whether intensive BP management during the first 24 hours after successful reperfusion leads to better clinical outcomes than conventional BP management in patients who underwent EVT. Design, Setting, and Participants: Multicenter, randomized, open-label trial with a blinded end-point evaluation, conducted across 19 stroke centers in South Korea from June 2020 to November 2022 (final follow-up, March 8, 2023). It included 306 patients with large vessel occlusion acute ischemic stroke treated with EVT and with a modified Thrombolysis in Cerebral Infarction score of 2b or greater (partial or complete reperfusion). Interventions: Participants were randomly assigned to receive intensive BP management (systolic BP target <140 mm Hg; n = 155) or conventional management (systolic BP target 140-180 mm Hg; n = 150) for 24 hours after enrollment. Main Outcomes and Measures: The primary outcome was functional independence at 3 months (modified Rankin Scale score of 0-2). The primary safety outcomes were symptomatic intracerebral hemorrhage within 36 hours and death related to the index stroke within 3 months. Results: The trial was terminated early based on the recommendation of the data and safety monitoring board, which noted safety concerns. Among 306 randomized patients, 305 were confirmed eligible and 302 (99.0%) completed the trial (mean age, 73.0 years; 122 women [40.4%]). The intensive management group had a lower proportion achieving functional independence (39.4%) than the conventional management group (54.4%), with a significant risk difference (-15.1% [95% CI, -26.2% to -3.9%]) and adjusted odds ratio (0.56 [95% CI, 0.33-0.96]; P = .03). Rates of symptomatic intracerebral hemorrhage were 9.0% in the intensive group and 8.1% in the conventional group (risk difference, 1.0% [95% CI, -5.3% to 7.3%]; adjusted odds ratio, 1.10 [95% CI, 0.48-2.53]; P = .82). Death related to the index stroke within 3 months occurred in 7.7% of the intensive group and 5.4% of the conventional group (risk difference, 2.3% [95% CI, -3.3% to 7.9%]; adjusted odds ratio, 1.73 [95% CI, 0.61-4.92]; P = .31). Conclusions and Relevance: Among patients who achieved successful reperfusion with EVT for acute ischemic stroke with large vessel occlusion, intensive BP management for 24 hours led to a lower likelihood of functional independence at 3 months compared with conventional BP management. These results suggest that intensive BP management should be avoided after successful EVT in acute ischemic stroke. Trial Registration: ClinicalTrials.gov Identifier: NCT04205305.

Cancer Prediction With Machine Learning of Thrombi From Thrombectomy in Stroke: Multicenter Development and Validation.

BACKGROUND: We aimed to develop and validate machine learning models to diagnose patients with ischemic stroke with cancer through the analysis of histopathologic images of thrombi obtained during endovascular thrombectomy. METHODS: This was a retrospective study using a prospective multicenter registry which enrolled consecutive patients with acute ischemic stroke from South Korea who underwent endovascular thrombectomy. This study included patients admitted between July 1, 2017 and December 31, 2021 from 6 academic university hospitals. Whole-slide scanning was performed for immunohistochemically stained thrombi. Machine learning models were developed using transfer learning with image slices as input to classify patients into 2 groups: cancer group or other determined cause group. The models were developed and internally validated using thrombi from patients of the primary center, and external validation was conducted in 5 centers. The model was also applied to patients with hidden cancer who were diagnosed with cancer within 1 month of their index stroke. RESULTS: The study included 70 561 images from 182 patients in both internal and external datasets (119 patients in internal and 63 in external). Machine learning models were developed for each immunohistochemical staining using antibodies against platelets, fibrin, and erythrocytes. The platelet model demonstrated consistently high accuracy in classifying patients with cancer, with area under the receiver operating characteristic curve of 0.986 (95% CI, 0.983-0.989) during training, 0.954 (95% CI, 0.937-0.972) during internal validation, and 0.949 (95% CI, 0.891-1.000) during external validation. When applied to patients with occult cancer, the model accurately predicted the presence of cancer with high probabilities ranging from 88.5% to 99.2%. CONCLUSIONS: Machine learning models may be used for prediction of cancer as the underlying cause or detection of occult cancer, using platelet-stained immunohistochemical slide images of thrombi obtained during endovascular thrombectomy.

Improving the Prognosis of Patients With Acute Ischemic Stroke Treated in the Late Time Window After the Introduction of Advanced Imaging Software: Benefits From Thrombectomy in the Extended Time Window.

BACKGROUND: Mechanical thrombectomy (MT) of ischemic stroke was recommended as a clinical guideline in 2015, and the indication for time was expanded in 2018 based on two clinical studies. We aimed to compare and analyze the prognosis of patients treated under the extended time indication before and after the introduction of advanced software. METHODS: We obtained data from medical records between 2016 to 2020. From 2016 to 2017, patients who did not receive MT who visited the hospital within 24 hours from the last normal time (LNT) were classified as standard medical treatment (SMT) group. Among patients who underwent MT between 2019 and 2020, patients who visited the hospital between 6-24 hours from the LNT were classified into the extended MT (EMT) group. Good outcome was defined as 3-months modified rankin scale (mRS) ≤ 2, and a poor outcome as mRS ≥ 4. RESULTS: From 2016 to 2017, 1,058 patients were hospitalized for ischemic stroke, of which 60 (5.7%) received MT, and 27 patients were classified into the SMT group. Among 1,019 patients between 2019 and 2020, 85 (8.3%) received MT, and 24 patients were in the EMT group. Among the SMT group, only 3 had a good prognosis, and 24 (88.9%) had a poor prognosis. However, in the EMT group, 10 (41.7%) had a good prognosis, and 9 (37.5%) had a poor prognosis. The SMT group had a 49.1 times higher risk of poor prognosis compared to the EMT group (P = 0.008). CONCLUSION: The number of patients with ischemic stroke who receive MT has increased by using advanced imaging software. It was confirmed that patients treated based on the extended time indication also had a good prognosis.

Association between CHADS2, CHA2DS2-VASc, ATRIA, and Essen Stroke Risk Scores and Functional Outcomes in Acute Ischemic Stroke Patients Who Received Endovascular Thrombectomy.

Background: CHADS2, CHA2DS2-VASc, ATRIA, and Essen stroke risk scores are used to estimate thromboembolism risk. We aimed to investigate the association between unfavorable outcomes and stroke risk scores in patients who received endovascular thrombectomy (EVT). Methods: This study was performed using data from a nationwide, multicenter registry to explore the selection criteria for patients who would benefit from reperfusion therapies. We calculated pre-admission CHADS2, CHA2DS2-VASc, ATRIA, and Essen scores for each patient who received EVT and compared the relationship between these scores and 3-month modified Rankin Scale (mRS) records. Results: Among the 404 patients who received EVT, 213 (52.7%) patients had unfavorable outcomes (mRS 3−6). All scores were significantly higher in patients with unfavorable outcomes than in those with favorable outcomes. Multivariable logistic regression analysis indicated that CHADS2 and the ATRIA score were positively correlated with unfavorable outcomes after adjusting for body mass index and variables with p < 0.1 in the univariable analysis (CHADS2 score: odds ratio [OR], 1.484; 95% confidence interval [CI], 1.290−1.950; p = 0.005, ATRIA score, OR, 1.128; 95% CI, 1.041−1.223; p = 0.004). Conclusions: The CHADS2 and ATRIA scores were positively correlated with unfavorable outcomes and could be used to predict unfavorable outcomes in patients who receive EVT.

Impact of Renal Function on Short-Term Outcome After Reperfusion Therapy in Patients With Ischemic Stroke.

BACKGROUND: A high and low estimated glomerular filtration rate (eGFR) could affect outcomes after reperfusion therapy for ischemic stroke. This study aimed to determine whether renal function based on eGFR affects mortality risk in patients with ischemic stroke within 6 months following reperfusion therapy. METHODS: This prospective registry-based cohort study included 2266 patients who received reperfusion therapy between January 2000 and September 2019 and were registered in the SECRET (Selection Criteria in Endovascular Thrombectomy and Thrombolytic Therapy) study or the Yonsei Stroke Cohort. A high and low eGFR were based on the Chronic Kidney Disease Epidemiology Collaboration equation and defined, respectively, as the 5th and 95th percentiles of age- and sex-specific eGFR. Occurrence of death within 6 months was compared among the groups according to their eGFR such as low, normal, or high eGFR. RESULTS: Of the 2266 patients, 2051 (90.5%) had a normal eGFR, 110 (4.9%) a low eGFR, and 105 (4.6%) a high eGFR. Patients with high eGFR were younger or less likely to have hypertension, diabetes, or atrial fibrillation than the other groups. Active cancer was more prevalent in the high-eGFR group. During the 6-month follow-up, there were 24 deaths (22.9%) in the high-eGFR group, 37 (33.6%) in the low-eGFR group, and 237 (11.6%) in the normal-eGFR group. After adjusting for variables with P<0.10 in the univariable analysis, 6-month mortality was independently associated with high eGFR (hazard ratio, 2.22 [95% CI, 1.36-3.62]; P=0.001) and low eGFR (HR, 2.29 [95% CI, 1.41-3.72]; P=0.001). These associations persisted regardless of treatment modality or various baseline characteristics. CONCLUSIONS: High eGFR as well as low eGFR were independently associated with 6-month mortality after reperfusion therapy. Kidney function could be considered a prognostic factor in patients with ischemic stroke after reperfusion therapy.

Association between CHADS2, CHA2DS2-VASc, ATRIA, and Essen Stroke Risk Scores and Unsuccessful Recanalization after Endovascular Thrombectomy in Acute Ischemic Stroke Patients.

BACKGROUND: The CHADS2, CHA2DS2-VASc, ATRIA, and Essen scores have been developed for predicting vascular outcomes in stroke patients. We investigated the association between these stroke risk scores and unsuccessful recanalization after endovascular thrombectomy (EVT). METHODS: From the nationwide multicenter registry (Selection Criteria in Endovascular Thrombectomy and Thrombolytic therapy (SECRET)) (Clinicaltrials.gov NCT02964052), we consecutively included 501 patients who underwent EVT. We identified pre-admission stroke risk scores in each included patient. RESULTS: Among 501 patients who underwent EVT, 410 (81.8%) patients achieved successful recanalization (mTICI ≥ 2b). Adjusting for body mass index and p < 0.1 in univariable analysis revealed the association between all stroke risk scores and unsuccessful recanalization (CHADS2 score: odds ratio (OR) 1.551, 95% confidence interval (CI) 1.198-2.009, p = 0.001; CHA2DS2VASc score: OR 1.269, 95% CI 1.080-1.492, p = 0.004; ATRIA score: OR 1.089, 95% CI 1.011-1.174, p = 0.024; and Essen score: OR 1.469, 95% CI 1.167-1.849, p = 0.001). The CHADS2 score had the highest AUC value and differed significantly only from the Essen score (AUC of CHADS2 score; 0.618, 95% CI 0.554-0.681). CONCLUSION: All stroke risk scores were associated with unsuccessful recanalization after EVT. Our study suggests that these stroke risk scores could be used to predict recanalization in stroke patients undergoing EVT.

BTT-105 ameliorates hepatic fibrosis in non-alcoholic fatty liver animal model.

BTT-105 (1-O-hexyl-2,3,5-trimethylhydroquinone), a hydroquinone derivative, is a potent anti-oxidant that was safe and tolerable in phase I clinical trial. This study examined the anti-fibrotic effect of BTT-105 in a mouse model of non-alcoholic fatty liver disease (NAFLD) along with the underlying mechanisms. In vivo, efficacy of BTT-105 evaluated from three kinds of NAFLD models (methionine/choline deficient diet (MCD), high fat diet (HF) and western diet (WD)). Metabolomics and transcriptomics profiling analysis in liver tissues were conducted. In vitro, anti-fibrotic effect of BTT-105 assessed in human hepatic stellated cells (HSCs) and primary mouse HSCs. BTT-105 improved NAFLD activity score in three kinds of NAFLD animal models (MCD, HF, and WD). BTT-105 also decreased levels of hepatic pro-collagen and collagen fibers deposition in liver tissue. Metabolome and transcriptome analysis revealed that BTT-105 decreased lipid metabolites and increased antioxidants in NAFLD mice. In HepG2 cells, BTT-105 enhanced Nrf2-ARE reporter activity in a dose-dependent manner and increased the levels of antioxidant gene expression. BTT-105 showed inhibition of HSCs activation and migration. Gene expression profiling and protein expression showed that BTT-105 increased Nrf2 activation as well as decreased PI3K-Akt pathway in activated HSCs. BTT-105 attenuated ameliorates steatohepatitis and hepatic fibrosis.

Outcome in Patients Treated with Intra-arterial thrombectomy: The optiMAL Blood Pressure control (OPTIMAL-BP) Trial.

RATIONALE: Very early stage blood pressure (BP) levels may affect outcome in stroke patients who have successfully undergone recanalization following intra-arterial treatment, but the optimal target of BP management remains uncertain. AIM: We hypothesized that the clinical outcome after intensive BP-lowering is superior to conventional BP control after successful recanalization by intra-arterial treatment. SAMPLE-SIZE ESTIMATES: We aim to randomize 668 patients (334 per arm), 1:1. METHODS AND DESIGN: We initiated a multicenter, prospective, randomized, open-label trial with a blinded end-point assessment (PROBE) design. After successful recanalization (thrombolysis in cerebral infarction score ≥ 2 b), patients with elevated systolic BP level, defined as the mean of two readings ≥ 140 mmHg, will be randomly assigned to the intensive BP-lowering (systolic BP < 140 mm Hg) group or the conventional BP-lowering (systolic BP, 140-180 mm Hg) group. STUDY OUTCOMES: The primary efficacy outcomes are from dichotomized analysis of modified Rankin Scale (mRS) scores at three months (mRS scores: 0-2 vs. 3-6). The primary safety outcomes are symptomatic intracerebral hemorrhage and death within three months. DISCUSSION: The OPTIMAL-BP trial will provide evidence for the effectiveness of active BP control to achieve systolic BP < 140 mmHg during 24 h in patients with successful recanalization after intra-arterial treatment. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04205305.

Prediction of Early Recanalization after Intravenous Thrombolysis in Patients with Large-Vessel Occlusion.

BACKGROUND AND PURPOSE: We aimed to develop a model predicting early recanalization after intravenous tissue plasminogen activator (t-PA) treatment in large-vessel occlusion. METHODS: Using data from two different multicenter prospective cohorts, we determined the factors associated with early recanalization immediately after t-PA in stroke patients with large-vessel occlusion, and developed and validated a prediction model for early recanalization. Clot volume was semiautomatically measured on thin-section computed tomography using software, and the degree of collaterals was determined using the Tan score. Follow-up angiographic studies were performed immediately after t-PA treatment to assess early recanalization. RESULTS: Early recanalization, assessed 61.0±44.7 minutes after t-PA bolus, was achieved in 15.5% (15/97) in the derivation cohort and in 10.5% (8/76) in the validation cohort. Clot volume (odds ratio [OR], 0.979; 95% confidence interval [CI], 0.961 to 0.997; P=0.020) and good collaterals (OR, 6.129; 95% CI, 1.592 to 23.594; P=0.008) were significant factors associated with early recanalization. The area under the curve (AUC) of the model including clot volume was 0.819 (95% CI, 0.720 to 0.917) and 0.842 (95% CI, 0.746 to 0.938) in the derivation and validation cohorts, respectively. The AUC improved when good collaterals were added (derivation cohort: AUC, 0.876; 95% CI, 0.802 to 0.950; P=0.164; validation cohort: AUC, 0.949; 95% CI, 0.886 to 1.000; P=0.036). The integrated discrimination improvement also showed significantly improved prediction (0.097; 95% CI, 0.009 to 0.185; P=0.032). CONCLUSIONS: The model using clot volume and collaterals predicted early recanalization after intravenous t-PA and had a high performance. This model may aid in determining the recanalization treatment strategy in stroke patients with large-vessel occlusion.

Immediate and Long-Term Outcomes of Reperfusion Therapy in Patients With Cancer.

Background and Purpose: Patients with acute stroke are often accompanied by comorbidities, such as active cancer. However, adequate treatment guidelines are not available for these patients. The purpose of this study was to evaluate the association between cancer and the outcomes of reperfusion therapy in patients with stroke. Methods: We compared treatment outcomes in patients who underwent reperfusion therapy, using a nationwide reperfusion therapy registry. We divided the patients into 3 groups according to cancer activity: active cancer, nonactive cancer, and without a history of cancer. We investigated reperfusion processes, 24-hour neurological improvement, adverse events, 3-month functional outcome, and 6-month survival and related factors after reperfusion therapy. Results: Among 1338 patients who underwent reperfusion therapy, 62 patients (4.6%) had active cancer, 78 patients (5.8%) had nonactive cancer, and 1198 patients (89.5%) had no history of cancer. Of the enrolled patients, 969 patients received intravenous thrombolysis and 685 patients underwent endovascular treatment (316 patients received combined therapy). Patients with active cancer had more comorbidities and experienced more severe strokes; however, they showed similar 24-hour neurological improvement and adverse events, including cerebral hemorrhage, compared with the other groups. Although the functional outcome at 3 months was poorer than the other groups, 36.4% of patients with active cancer showed functional independence. Additionally, 52.9% of the patients with determined stroke etiology showed functional independence despite active cancer. During the 6-month follow-up, 46.6% of patients with active cancer died, and active cancer was independently associated with poor survival (hazard ratio, 3.973 [95% CI, 2.528­6.245]). Conclusions: In patients with active cancer, reperfusion therapy showed similar adverse events and short-term outcomes to that of other groups. While long-term prognosis was worse in the active cancer group than the nonactive cancer groups, not negligible number of patients had good functional outcomes, especially those with determined stroke mechanisms.

Comorbidity index for predicting mortality at 6 months after reperfusion therapy.

The eligibility of reperfusion therapy has been expanded to increase the number of patients. However, it remains unclear the reperfusion therapy will be beneficial in stroke patients with various comorbidities. We developed a reperfusion comorbidity index for predicting 6-month mortality in patients with acute stroke receiving reperfusion therapy. The 19 comorbidities included in the Charlson comorbidity index were adopted and modified. We developed a statistical model and it was validated using data from a prospective cohort. Among 1026 patients in the retrospective nationwide reperfusion therapy registry, 845 (82.3%) had at least one comorbidity. As the number of comorbidities increased, the likelihood of mortality within 6 months also increased (p < 0.001). Six out of the 19 comorbidities were included for developing the reperfusion comorbidity index on the basis of the odds ratios in the multivariate logistic regression analysis. This index showed good prediction of 6-month mortality in the retrospective cohort (area under the curve [AUC], 0.747; 95% CI, 0.704-0.790) and in 333 patients in the prospective cohort (AUC, 0.784; 95% CI, 0.709-0.859). Consideration of comorbidities might be helpful for the prediction of the 6-month mortality in patients with acute ischemic stroke who receive reperfusion therapy.

Care Process of Recanalization Therapy for Acute Stroke during the COVID-19 Outbreak in South Korea.

BACKGROUND AND PURPOSE: We aimed to determine whether the care process and outcomes in patients with acute stroke who received recanalization therapy changed during the outbreak of coronavirus disease 2019 (COVID-19) in South Korea. METHODS: We used data from a prospective multicenter reperfusion therapy registry to compare the care process-including the time from symptom onset to treatment, number of treated patients, and discharge disposition-and treatment outcomes between before and during the COVID-19 outbreak in South Korea. RESULTS: Upon the COVID-19 outbreak in South Korea, the number of patients receiving endovascular treatment to decrease temporarily but considerably. The use of emergency medical services by stroke patients increased from 91.5% before to 100.0% during the COVID-19 outbreak (p=0.025), as did the median time from symptom onset to hospital visit [median (interquartile range), 91.0 minutes (39.8-277.0) vs. 176.0 minutes (56.0-391.5), p=0.029]. Furthermore, more functionally dependent patients with disabilities were discharged home (59.5% vs. 26.1%, p=0.020) rather than staying in a regional or rehabilitation hospital. In contrast, there were no COVID-19-related changes in the times from the hospital visit to brain imaging and treatment or in the functional outcome, successful recanalization rate, or rate of symptomatic intracerebral hemorrhage. CONCLUSIONS: These findings suggest that a prehospital delay occurred during the COVID-19 outbreak, and that patients with acute stroke might have been reluctant to visit and stay in hospitals. Our findings indicate that attention should be paid to prehospital care and the behavior of patients with acute stroke during the COVID-19 outbreak.

Inhibitory effect of therapeutic genes, cytosine deaminase and interferon­ß, delivered by genetically engineered stem cells against renal cell carcinoma.

Although the effects of stem cells expressing anticancer genes on tumor growth have been demonstrated by many researchers in various types of cancer, relatively few studies have investigated their inhibitory effects on cancer metastasis. In the present study, we examined the inhibitory effects of cytosine deaminase (CD)/5­fluorocytosine (5­FC) and interferon­ß (IFN­ß) using genetically engineered neural stem cells (hNSCs) in a cellular and metastasis model of renal cell carcinoma (RCC). The CD/5­FC method has the advantage of minimizing damage to normal tissues since it selectively targets cancer cells by the CD gene, which converts prodrug 5­FC to the drug 5­fluorouracil. Moreover, we used hNSCs as a tool to effectively deliver the anticancer genes to the tumor site. These stem cells are known to possess tumor­tropism because of chemoattractant factors expressed in cancer cells. Therefore, we ascertained the expression of these factors in A498 cells, a cell line of RCC, and identified the A498­specific migration ability of hNSCs. We also confirmed that the proliferation of A498 cells was significantly reduced by therapeutic hNSCs in the presence of 5­FC. Furthermore, we established an A498 metastasis model. In the animal experiment, the weight of the lungs increased in response to cancer metastasis, but was normalized by hNSCs expressing CD and/or IFN­ß genes, while the incidence of liver metastasis was suppressed by the hNSCs. Overall, the results of this study demonstrate that stem cells expressing anticancer genes have the potential for use as an alternative to conventional therapy for metastatic cancer.

Improving the Clinical Outcome in Stroke Patients Receiving Thrombolytic or Endovascular Treatment in Korea: from the SECRET Study.

We investigated whether there was an annual change in outcomes in patients who received the thrombolytic therapy or endovascular treatment (EVT) in Korea. This analysis was performed using data from a nationwide multicenter registry for exploring the selection criteria of patients who would benefit from reperfusion therapies in Korea. We compared the annual changes in the modified Rankin scale (mRS) at discharge and after 90 days and the achievement of successful recanalization from 2012 to 2017. We also investigated the determinants of favorable functional outcomes. Among 1230 included patients, the improvement of functional outcome at discharge after reperfusion therapy was noted as the calendar year increased (p < 0.001). The proportion of patients who were discharged to home significantly increased (from 45.6% in 2012 to 58.5% in 2017) (p < 0.001). The successful recanalization rate increased over time from 78.6% in 2012 to 85.1% in 2017 (p = 0.006). Time from door to initiation of reperfusion therapy decreased over the years (p < 0.05). These secular trends of improvements were also observed in 1203 patients with available mRS data at 90 days (p < 0.05). Functional outcome was associated with the calendar year, age, initial stroke severity, diabetes, preadmission disability, intervals from door to reperfusion therapy, and achievement of successful recanalization. This study demonstrated the secular trends of improvement in functional outcome and successful recanalization rate in patients who received reperfusion therapy in Korea.

A promising therapeutic strategy for metastatic gestational trophoblastic disease: Engineered anticancer gene-expressing stem cells to selectively target choriocarcinoma.

Gestational trophoblastic disease (GTD) is an unusual disease occurring in pregnancy that originates from abnormal trophoblastic cells and comprises a group of diseases with different properties of invasion, metastasis and recurrence. The GTD group includes hydatidiform moles and gestational trophoblastic neoplasms (GTNs), with GTNs being divided into invasive moles, choriocarcinoma, placental site trophoblastic tumors and epithelioid trophoblastic tumors. The present review focuses on current effective treatments for GTD, including conventional and novel promising direct enzyme prodrug therapies (DEPTs). Conventional therapies, such as chemotherapy and hysterectomy, are currently used in a clinical setting; however, the use of diverse DEPTs, including antibody-DEPT and gene-DEPT is also being attempted to cure GTNs. In addition, gene delivery tools using genetically engineered neural stem cells (NSCs) are presently being examined for the treatment of GTNs. The tumor-tropism of NSCs by chemoattractant factors is a unique characteristic of these cells and can serve as a vehicle to deliver anticancer agents. Previous studies have demonstrated that injection with NSC-expressing suicide genes into xenograft animal models has a significant inhibitory effect on tumor growth. Stem cells can be genetically engineered to express anticancer genes, which migrate to the metastatic sites and selectively target cancer cells, and are considered to effectively target metastatic GTNs. However, the safety issue of stem cell therapy, such as tumorigenesis, remains a challenge. Novel therapies comprising a combination of conventional and novel promising treatments are anticipated to be definitive treatments for metastasized and/or recurrent patients with GTNs.