Current status of aspiration thrombectomy for acute stroke patients in China: data from ANGEL-ACT Registry.

BACKGROUND AND AIMS: Although noninferior to stent retriever (SR) as first-line approach for endovascular treatment (EVT) of acute large vessel occlusion (LVO) stroke, little is known about the current status of direct aspiration (DA) as first-line thrombectomy in China. This analysis of a prospective, nationwide registry (ANGEL-ACT) aimed to investigate the prevalence and comparative effectiveness of DA-first thrombectomy in a real-world practice in China. METHODS: All patients receiving thrombectomy were screened from a prospective cohort of LVO patients undergoing EVT at 111 hospitals in China between November 2017 and March 2019, and divided into two groups based upon which type of thrombectomy was attempted first ("DA-first" and "SR-first"). The following outcome measures were compared using logistic regression models with adjustment: successful recanalization after first-device alone and all procedures, use of rescue treatment, intracranial hemorrhage (ICH) within 24 h, and modified Rankin Scale (mRS) score at 90 days. RESULTS: A total of 1225 patients, 102 (8.3%) in DA-first group and 1123 (91.7%) in SR-first group, were included. Patients receiving DA-first had less often successful recanalization after first-device alone [30.4 versus 66.4%; odds ratio (OR) = 0.23, 95% confidence interval (CI) = 0.15-0.37], more frequent rescue treatment (62.8 versus 27.0%; OR = 4.55, 95% CI = 2.92-7.08) and ICH (35.4 versus 22.1%; OR = 1.78, 95% CI = 1.12-2.83) than those receiving SR-first; however, no significant difference was found in successful recanalization after all procedures (84.3 versus 90.3%; p = 0.18) and 90-day mRS (median: 3 versus 3 points; p = 0.90) between both groups. CONCLUSION: This real-world registry suggested that DA-first thrombectomy for acute stroke patients lagged behind in China during the study period. Far fewer DA-first than SR-first thrombectomies were performed, and DA-first was associated with lower first-device recanalization, more frequently requiring rescue treatment, and increased ICH risk. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT03370939.

Thrombectomy Versus Combined Thrombolysis and Thrombectomy in Patients With Acute Stroke: A Matched-Control Study.

A recent randomized controlled trial DIRECT-MT (Direct Intra-Arterial Thrombectomy to Revascularize AIS Patients With Large Vessel Occlusion Efficiently in Chinese Tertiary Hospitals) compared the safety and efficacy of mechanical thrombectomy (MT) versus combined intravenous thrombolysis (IVT) and MT for acute large vessel occlusion. The current study utilized a prospective, nationwide registry to validate the results of the DIRECT-MT trial in a real-world practice setting. Subjects were selected from a prospective cohort of acute large vessel occlusion patients undergoing endovascular treatment at 111 hospitals from 26 provinces in China (ANGEL-ACT registry [Endovascular Treatment Key Technique and Emergency Work Flow Improvement of Acute Ischemic Stroke]) between November 2017 and March 2019. All patients eligible for IVT and receiving MT were reviewed and then grouped according to whether prior IVT or not (MT and combined IVT+MT). After a 1:1 propensity score matching, the outcome measures including the 90-day modified Rankin Scale, successful recanalization, door-to-puncture time, symptomatic intracranial hemorrhage, and intraprocedural embolization were compared. A total of 1026 patients, 600 in the MT group and 426 in the combined group, were included. Among 788 patients identified after matching, there were no significant differences in the 90-day modified Rankin Scale (median, 3 versus 3 points; P=0.82) and successful recanalization (86.6% versus 89.3%; P=0.23) between the two groups; however, patients of the MT group had a shorter door-to-puncture time (median, 112 versus 136 minutes; ß=−45.02 [95% CI, −68.31 to −21.74]), lower rates of symptomatic intracranial hemorrhage (5.5% versus 10.1%; odds ratio, 0.52 [95% CI, 0.30­0.91]), and embolization (4.6% versus 8.1%; odds ratio, 0.54 [95% CI, 0.30­0.98]) than those of the combined group. This matched-control study largely confirmed the findings of the DIRECT-MT trial in a real-world practice setting, suggesting that MT may carry similar effectiveness to combined IVT+MT for acute large vessel occlusion patients, despite MT alone seems to be associated with a shorter in-hospital delay until procedure, lower risks of symptomatic intracranial hemorrhage, and embolization. URL: https://www.clinicaltrials.gov; Unique identifier: NCT03370939

Current Status of Endovascular Treatment for Acute Large Vessel Occlusion in China: A Real-World Nationwide Registry.

BACKGROUND AND PURPOSE: The benefit of endovascular treatment (EVT) for large vessel occlusion in clinical practice in developing countries like China needs to be confirmed. The aim of the study was to determine whether the benefit of EVT for acute ischemic stroke in randomized trials could be generalized to clinical practice in Chinese population. METHODS: We conducted a prospective registry of EVT at 111 centers in China. Patients with acute ischemic stroke caused by imaging-confirmed intracranial large vessel occlusion and receiving EVT were included. The primary outcome was functional independence at 90 days defined as a modified Rankin Scale score of 0 to 2. Outcomes of specific subgroups in the anterior circulation were reported and logistic regression was performed to predict the primary outcome. RESULTS: Among the 1793 enrolled patients, 1396 (77.9%) had anterior circulation large vessel occlusion (median age, 66 [56-73] years) and 397 (22.1%) had posterior circulation large vessel occlusion (median age, 64 [55-72] years). Functional independence at 90 days was reached in 45% and 44% in anterior and posterior circulation groups, respectively. For anterior circulation population, underlying intracranial atherosclerotic disease was identified in 29% of patients, with higher functional independence at 90 days (52% versus 44%; P=0.0122) than patients without intracranial atherosclerotic disease. In the anterior circulation population, after adjusting for baseline characteristics, procedure details, and early outcomes, the independent predictors for functional independence at 90 days were age <66 years (odds ratio [OR], 1.733 [95% CI, 1.213-2.476]), time from onset to puncture >6 hours (OR, 1.536 [95% CI, 1.065-2.216]), local anesthesia (OR, 2.194 [95% CI, 1.325-3.633]), final modified Thrombolysis in Cerebral Infarction 2b/3 (OR, 2.052 [95% CI, 1.085-3.878]), puncture-to-reperfusion time ≤1.5 hours (OR, 1.628 [95% CI, 1.098-2.413]), and National Institutes of Health Stroke Scale score 24 hours after the procedure <11 (OR, 9.126 [95% CI, 6.222-13.385]). CONCLUSIONS: Despite distinct characteristics in the Chinese population, favorable outcome of EVT can be achieved in clinical practice in China. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03370939.

Indications for Mechanical Thrombectomy-Too Wide or Too Narrow?

The indications for mechanical thrombectomy (MT) have expanded since the American Heart Association/American Stroke Association reported its first guidelines for MT in 2013. Multiple subsequent randomized clinical trials of MT have proved its efficacy, including the DAWN (DWI [diffusion weighted imaging] or CTP [computed tomography perfusion] Assessment with Clinical Mismatch in the Triage of Wake-up and Late Presenting Strokes Undergoing Neurointervention with Trevo) and DEFUSE-3 (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke-3) trials. The current guidelines from the American Heart Association/American Stroke Association provide class I support for the use of MT for the following indications: 1) internal carotid artery (ICA)/M1 middle cerebral artery (MCA) occlusion, symptom onset <6 hours, National Institutes of Health Stroke Scale score of ≥6, Alberta Stroke Program Early Computed Tomography Score of ≥6; and 2) large vessel occlusions in the anterior circulation, symptom onset 6-16 hours, and meeting the DAWN or DEFUSE-3 eligibility criteria. Class IIa evidence is also available for the use of MT for large vessel occlusions in the anterior circulation, symptom onset 16-24 hours, and meeting other DAWN eligibility criteria. In clinical practice, these class I and IIa indications for MT have been well followed. However, many other potential indications are available, including 1) M2 or M3 MCA occlusion, symptom onset <6 hours; 2) Alberta Stroke Program Early Computed Tomography Score <6, ICA or M1 MCA occlusion, symptom onset <6 hours; 3) National Institutes of Health Stroke Scale score <6, ICA or M1 occlusion, symptom onset <6 hours; 4) tandem occlusions; and 5) posterior circulation occlusion <6 hours. The present review analyzed the available data to provide support for further prospective clinical trials regarding these potential indications.

Cocaine-like discriminative stimulus effects of phendimetrazine and phenmetrazine in rats.

Phendimetrazine is a clinically available anorectic and candidate medication for the treatment of cocaine addiction. Phendimetrazine can be metabolized to the amphetamine-like monoamine releaser phenmetrazine, but it is unclear if phendimetrazine functions as an inactive prodrug or might have activity on its own. As one method to address this issue, the present study compared the potency and time course of phendimetrazine and phenmetrazine to produce cocaine-like discriminative stimulus effects in adult, male rats (N=5) trained to discriminate cocaine (5.6 mg/kg, intraperitoneally) from saline in a two-key food-reinforced discrimination procedure. We hypothesized that, if metabolism to phenmetrazine was required for phendimetrazine effects, then phendimetrazine would be less potent and have a slower onset and offset of effects than phenmetrazine. Both phendimetrazine and phenmetrazine produced dose-dependent cocaine-like discriminative stimulus effects, and phendimetrazine was 7.8-fold less potent than phenmetrazine. However, the time courses of discriminative stimulus effects produced by phendimetrazine and phenmetrazine were similar, with peak effects at 10 min and offset by 100 min. These results show the effectiveness of phendimetrazine to rapidly produce cocaine-like behavioral effects in rats and support other nonhuman primate evidence to suggest that metabolism to phenmetrazine may not be required for phendimetrazine effects.

Role of 5-HT2C receptors in effects of monoamine releasers on intracranial self-stimulation in rats.

RATIONALE: Many monoamine releasers are abused by humans and produce abuse-related facilitation of intracranial self-stimulation (ICSS) in rats. Facilitation of ICSS in rats can be limited by monoamine releaser-induced serotonin (5-HT) release, but receptors that mediate 5-HT effects of monoamine releasers are unknown. OBJECTIVES: The aim of this study is to investigate whether 5-HT2C receptor activation is necessary for rate-decreasing effects produced in an ICSS procedure in rats by the 5-HT-selective monoamine releaser fenfluramine and the non-selective releasers napthylisopropylamine (PAL-287) and (+)-3,4-methylenedioxymethamphetamine ((+)-MDMA). METHODS: Adult male Sprague-Dawley rats with electrodes implanted in the medial forebrain bundle were trained to lever press for brain stimulation under a "frequency-rate" ICSS procedure. Effectiveness of the 5-HT2C antagonist SB 242,084 was evaluated to block rate-decreasing effects produced by (1) the 5-HT2C agonist Ro 60-0175, (2) the 5-HT-selective releaser fenfluramine, and (3) the mixed-action dopamine (DA)/norepinephrine (NE)/5-HT releasers PAL-287 (1.0-5.6 mg/kg) and (+)-MDMA (1.0-3.2 mg/kg). For comparison, effectiveness of SB 242,084 to alter rate-decreasing effects of the kappa-opioid receptor agonist U69,593 and rate-increasing effects of the DA>5-HT releaser amphetamine was also examined. RESULTS: SB 242,084 pretreatment blocked rate-decreasing effects of Ro 60-0175 and fenfluramine, but not the rate-decreasing effects of U69,593 or the rate-increasing effects of amphetamine. SB 242,084 blunted the rate-decreasing effects and enhanced expression of rate-increasing effects of PAL-287 and (+)-MDMA. CONCLUSIONS: These data suggest that 5-HT2C receptor activation contributes to rate-decreasing effects that are produced by selective and mixed-action 5-HT releasers in rats and that may oppose and limit the expression of abuse-related ICSS facilitation by these compounds.

Abuse-related effects of dual dopamine/serotonin releasers with varying potency to release norepinephrine in male rats and rhesus monkeys.

d-Amphetamine selectively promotes release of both dopamine (DA) and norepinephrine (NE) versus serotonin (5HT), and chronic d-amphetamine treatment decreases cocaine-taking behavior in rats, nonhuman primates, and humans. However, abuse liability limits the clinical utility of amphetamine maintenance for treating cocaine abuse. One strategy to improve safety and efficacy of monoamine releasers as candidate anticocaine medications has been to develop dual DA/5HT releasers like 1-napthyl-2-aminopropane (PAL-287), but the pharmacology of this class of compounds has not been extensively examined. In particular, PAL-287 has similar potencies to release DA, 5HT, and NE, and the role of manipulating NE release potency on abuse-related or anticocaine effects of dual DA/5HT releasers is not known. To address this issue, the present study compared effects of four novel DA/5HT releasers that varied >800-fold in their selectivities to release DA/5HT versus NE: [1-(5-chloro-1H-indol-3-yl)propan-2-amine (PAL-542), 1-(5-fluoro-1H-indol-3-yl)propan-2-amine (PAL-544), 1-(1H-indol-5-yl)propan-2-amine (PAL-571), and (R)-1-(1H-indol-1-yl)propain-2-amine (PAL-569). Abuse-related effects of all four compounds were evaluated in assays of intracranial self-stimulation (ICSS) in rats and cocaine discrimination in rats and monkeys, and none of the compounds reliably facilitated ICSS or substituted for cocaine. Anticocaine effects of the compound with highest selectivity to release DA/5HT versus NE (PAL-542) were tested in an assay of cocaine versus food choice in rhesus monkeys, and PAL-542 failed to reduce cocaine choice. These results suggests that potency to release NE has minimal influence on abuse liability of dual DA/5HT releasers, and reducing relative potency to release NE versus DA/5HT does not improve anticocaine efficacy.

The effect of chronic amphetamine treatment on cocaine-induced facilitation of intracranial self-stimulation in rats.

RATIONALE: Chronic amphetamine treatment reduces cocaine self-administration in pre-clinical and clinical settings, and amphetamine has been proposed as a candidate medication for treatment of cocaine abuse. OBJECTIVE: The objective of the present study was to investigate whether chronic amphetamine treatment can decrease abuse-related cocaine effects in an assay of intracranial self-stimulation (ICSS). METHODS: Thirteen adult male Sprague-Dawley rats were equipped with intracranial electrodes targeting the medial forebrain bundle and trained to lever press for pulses of brain stimulation in a "frequency-rate" ICSS procedure. Cocaine (10 mg/kg) was administered before (day 0), during (days 7 and 14), and after (posttreatment days 1 and 3) 2 weeks of continuous treatment with either amphetamine (0.32 mg/kg/h, n = 7) or saline (n = 6) via osmotic pump. RESULTS: Prior to treatment, cocaine facilitated ICSS in all rats. Saline treatment had no effect on baseline ICSS or cocaine-induced facilitation of ICSS at any time. Conversely, amphetamine produced a sustained though submaximal facilitation of baseline ICSS, and cocaine produced little additional facilitation of ICSS during amphetamine treatment. Termination of amphetamine treatment produced a depression of baseline ICSS and recovery of cocaine-induced facilitation of ICSS. CONCLUSIONS: These data suggest that chronic amphetamine treatment blunts expression of abuse-related cocaine effects on ICSS in rats.

Rate-dependent effects of monoamine releasers on intracranial self-stimulation in rats: implications for abuse liability assessment.

'Rate dependency' in the discipline of behavioral pharmacology describes a phenomenon wherein the effect of a drug on the rate of a behavior varies systematically as a function of the baseline, predrug rate of that behavior. Historically, rate-dependency studies have compared drug effects on different baseline rates of behavior maintained either by different schedules of reinforcement or during sequential segments of a fixed-interval schedule. The current experiment generated different baseline rates of behavior by altering frequency of electrical stimulation in an intracranial self-stimulation assay. Amphetamine and 10 other monoamine releasers were analyzed for their ability to produce rate-dependent effects in this assay. There were three main findings. First, all compounds produced rate-dependent effects at some dose. Second, one parameter of rate-dependency plots (peak Y-intercept of the regression line) correlated with in-vitro neurochemical data on selectivity of these compounds to release dopamine versus serotonin (P<0.025, R=0.50). Lastly, a correlation between peak Y-intercept and breakpoints under a progressive-ratio procedure in nonhuman primates was also significant (P<0.05, R=0.64). Overall, these results extend the rate-dependent effects of monoamine releasers to behavior maintained under intracranial self-stimulation and suggest that, at least for monoamine releasers, the Y-intercept parameter of rate-dependency plots might be a useful metric of drug reward and predictor of drug self-administration measures of drug reinforcement.

Intraneuronal vesicular organelle transport changes with cell population density in vitro.

Primary neuron cultures are widely used in research due to the ease and usefulness of observing individual cells. Therefore, it is vital to understand how variations in culture conditions may affect neuron physiology. One potential variation for cultured neurons is a change in intracellular transport. As transport is necessary for the normal delivery of organelles, proteins, nucleic acids, and lipids, it is a logical indicator of a cell's physiology. We test the hypothesis that organelle transport may change with varying in vitro population densities, thus indicating a change in cellular physiology. Using a novel background subtraction imaging method we show that, at 5 days in vitro (DIV), transport of vesicular organelles in embryonic rat spinal cord neurons is positively correlated with cell density. When density increased 6.5-fold, the number of transported organelles increased 2.2+/-0.3-fold. Intriguingly, this effect was not observable at 3-4 DIV. These results show a significant change in cellular physiology with a relatively small change in plating procedure; this indicates that cells appearing to be morphologically similar, and at the same DIV, may still suffer from a great degree of variability.