Safety Outcomes of Antiplatelet Therapy During Endovascular Treatment of Tandem Lesions in Acute Ischemic Stroke Patients

Risk of hemorrhage remains with antiplatelet medications required with carotid stenting during endovascular therapy (EVT) for tandem lesion (TLs). We evaluated the safety of antiplatelet regimens in EVT of TLs. This multicenter study included anterior circulation TL patients from 2015 to 2020, stratified by periprocedural EVT antiplatelet strategy: (1) no antiplatelets, (2) single oral, (3) dual oral, and (4) intravenous IV (in combination with single or dual oral). Primary outcome was symptomatic intracranial hemorrhage (sICH). Secondary outcomes were any hemorrhage, favorable functional status (mRS 0-2) at 90 days, successful reperfusion (mTICI score ≥ 2b), in-stent thrombosis, and mortality at 90 days. Of the total 691 patients, 595 were included in the final analysis. One hundred and nineteen (20%) received no antiplatelets, 134 (22.5%) received single oral, 152 (25.5%) dual oral, and 196 (31.9%) IV combination. No significant association was found for sICH (ref: no antiplatelet: 5.7%; single:4.2%; aOR 0.64, CI 0.20-2.06, p = 0.45, dual:1.9%; aOR 0.35, CI 0.09-1.43, p = 0.15, IV combination: 6.1%; aOR 1.05, CI 0.39-2.85, p = 0.92). No association was found for parenchymal or petechial hemorrhage. Odds of successful reperfusion were significantly higher with dual oral (aOR 5.85, CI 2.12-16.14, p = 0.001) and IV combination (aOR 2.35, CI 1.07-5.18, p = 0.035) compared with no antiplatelets. Odds of excellent reperfusion (mTICI 2c/3) were significantly higher for cangrelor (aOR 4.41; CI 1.2-16.28; p = 0.026). No differences were noted for mRS 0-2 at 90 days, in-stent thrombosis, and mortality rates. Administration of dual oral and IV (in combination with single or dual oral) antiplatelets during EVT was associated with significantly increased odds of successful reperfusion without an increased rate of symptomatic hemorrhage or mortality in patients with anterior circulation TLs.

Clinical and Safety Outcomes of Endovascular Therapy 6 to 24 Hours After Large Vessel Occlusion Ischemic Stroke With Tandem Lesions

BACKGROUND AND PURPOSE

Effect of endovascular therapy (EVT) in acute large vessel occlusion (LVO) patients with tandem lesions (TLs) within 6-24 hours after last known well (LKW) remains unclear. We evaluated the clinical and safety outcomes among TL-LVO patients treated within 6-24 hours.

METHODS

This multicenter cohort was divided into two groups, based on LKW to puncture time: early window (<6 hours), and late window (6-24 hours). Primary clinical and safety outcomes were 90-day functional independence measured by the modified Rankin Scale (mRS: 0-2) and symptomatic intracranial hemorrhage (sICH). Secondary outcomes were successful reperfusion (modified Thrombolysis in Cerebral Infarction score ≥2b), first-pass effect, early neurological improvement, ordinal mRS, and in-hospital and 90-day mortality.

RESULTS

Of 579 patients (median age 68, 32.1% females), 268 (46.3%) were treated in the late window and 311 (53.7%) in the early window. Late window group had lower median National Institutes of Health Stroke Scale score at admission, Alberta Stroke Program Early Computed Tomography Score, rates of intravenous thrombolysis, and higher rates for perfusion imaging. After adjusting for confounders, the odds of 90-day mRS 0-2 (47.7% vs. 45.0%, adjusted odds ratio [aOR] 0.71, 95% confidence interval [CI] 0.49-1.02), favorable shift in mRS (aOR 0.88, 95% CI 0.44-1.76), and sICH (3.7% vs. 5.2%, aOR 0.56, 95% CI 0.20-1.56) were similar in both groups. There was no difference in secondary outcomes. Increased time from LKW to puncture did not predicted the probability of 90-day mRS 0-2 (aOR 0.99, 95% CI 0.96-1.01, for each hour delay) among patients presenting <24 hours.

CONCLUSION

EVT for acute TL-LVO treated within 6-24 hours after LKW was associated with similar rates of clinical and safety outcomes, compared to patients treated within 6 hours.

Abstract TP116: Procoagulant Reversal Of Warfarin After Intracranial Hemorrhage Is Not Associated With Improved Functional Outcome When Coagulation Is Abnormal Without Full Anticoagulation

Introduction: Although the current guidelines recommend procoagulant reversal of elevated INR >= 2.0 (International Normalized Ratio) in patients with intracranial hemorrhage using warfarin, the benefit of procoagulant reversal is uncertain when patients have abnormal coagulation but are not fully anticoagulated.

Hypothesis: For patients using warfarin (INR 1.5 to 1.9) who have intracranial hemorrhage the use of procoagulant reversal will improve functional outcome based upon dichotomized discharge mRS (modified Rankin scale) 0-3 vs 4-6.

Methods: The Get With The Guidelines - Stroke registry was used to identify 239,681 patients with intracranial hemorrhage from hospitals using the comprehensive stroke center form between January 1, 2015 and January 4, 2022. Patients were excluded if they received thrombolytics, were using direct oral anticoagulants, if INR was not between 1.5 and 1.9, or if they were not using warfarin. To evaluate the association between procoagulant reversal and mRS at discharge, 1868 patients with non-missing mRS were analyzed for the primary outcome (mRS 0-3 vs. 4-6). Secondary outcomes that did not require mRS were analyzed among a possible 2569 patients. Propensity scores were estimated and overlap weighting was used to account for confounding. Logistic and negative binomial regression models were fit for binary and count variables, respectively.

Results: There was an even distribution of patients into treatment and nontreatment (N=974 no reversal, N=894 reversal), and the groups were strikingly similar. Key outcomes are shown in the Table.

Conclusions: Procoagulant reversal of warfarin for patients with acute intracranial hemorrhage and INR 1.5 - 1.9 was not associated with an improvement in functional outcome based upon mRS 0-3 vs 4-6. Patients that received a reversal agent had 25% lower odds of dying in the hospital or being discharged to hospice, but had a longer hospital stay and were less likely to be fully ambulatory at discharge.

Demographics in Children Presenting With Acute Neurologic Deficits Concerning for Stroke: An Evaluation of the Stroke Alert Process

Objective: To assess the demographics and clinical characteristics of children presenting with acute neurologic symptoms concerning for stroke. Background: Stroke leads to significant morbidity in the pediatric population. Stroke protocols were created as a means to help identify and triage these children. Despite implementation of these protocols, there have been few population-based studies evaluating the demographics and clinical features of children presenting with acute strokelike symptoms. Methods: A retrospective chart review of patients for whom the stroke alert process was activated from September 2016 through August 2018 at Children's Mercy Hospital. Results: There were a total of 61 activations. Acute ischemic stroke or transient ischemic attack comprised 18% and was the second leading diagnoses after seizure with postictal (Todd) paralysis (20%). Two activations were candidates for mechanical thrombectomy, and none received tissue plasminogen activator (tPA). Children with acute ischemic stroke / transient ischemic attack were likely to be younger in age (median 4 years, interquartile range [IQR] 3-9) compared to those with nonischemic stroke diagnoses (median 12.5 years, IQR 7-15.3) (P = .010). The anatomical location of acute ischemic stroke was widespread, including both anterior and posterior circulations. Past medical history, family history, racial demographics, sex, and initial presenting symptoms were not predictive of the diagnosis of acute ischemic stroke / transient ischemic attack. 38% of activations with diagnoses other than transient ischemic attack / acute ischemic stroke required urgent treatment, with 16% requiring intensive care unit admission. Conclusion: Acute ischemic stroke / transient ischemic attack comprised nearly one-fifth of all pediatric stroke activations, highlighting the importance of developing protocols for early recognition and evaluation of children who present with symptoms concerning for stroke.

The design, construction and calibration of a carefully controlled source for exposure of mammalian cells to extremely low-frequency electromagnetic fields

Despite some epidemiological evidence for an association between increased risk of cancer and exposure to electromagnetic fields (EMFs), cancer causation by such exposure remains unproven. Furthermore, for reasons such as biological unresponsiveness of the chosen system, poor equipment design and experimental confounders, no reproducible effects on animals or mammalian cells in culture have been demonstrated following exposure to power frequency EMFs at levels normally encountered in residential settings (<10 to 1000 microT). The apparatus described here, designed specifically to perform large, well-controlled cell biology experiments, reduces extraneous variables to the absolute minimum, so that small effects cannot be ascribed to some cause unrelated to the experimental protocol. Our novel apparatus consists of two identical solenoids which, in use, only differ by whether the field-producing current is flowing or not; they do not influence one another in any way. They are supplied with conditioned air from a common tissue culture incubator, are completely screened from environmental a.c. fields with Mumetal shielding and can be operated under normal laboratory conditions. Furthermore, the arrangement is such that the investigator is unaware whether cells have, or have not, been exposed until after the results have been evaluated. We report the design, construction, calibration and potential uses of this source.

Final report on phase I trial of WR-2721 before protracted fractionated radiation therapy

This is the final report of the Phase I Protocol for the initial clinical study of Multiple Dose WR-2721 with radiotherapy (RTOG 80-02). The essential object of the study was to determine the highest dose of WR-2721 that could be given daily for the greatest number of weeks 15 to 30 minutes before conventional radiation treatment schedules. Eighty-four patients were entered into various dose levels. The major and dose-limiting toxicities were emesis, hypotension and malaise. The latter symptom was characterized by increasing weakness, fatigability, and ill-feeling. The maximum tolerated dose (MTD) established by this study is 340 mg/m2 given 4 days a week (excepting Wednesday) for 5 weeks. The drug is delivered intravenously in 7 minutes. There were no long-term blood chemistry changes. There were no deaths due to the administration of the radioprotector.

Prostaglandin production by murine tumors as a predictor for therapeutic response to indomethacin

We investigated whether there is a relationship between the production of eicosanoids by murine solid tumors and their response to the prostaglandin H (PGH) synthase inhibitor indomethacin. Three sarcomas, designated FSA, NFSA, and SA-NH, and two carcinomas, designated MCA-K and HCA-I, syngeneic to C3Hf/Kam mice were used. In general, FSA and NFSA produced more PGH synthase products than lipoxygenase products, whereas HCA-I produced both types of metabolites in large quantities. All three tumors responded well to indomethacin treatment by slowing their growth. In contrast, MCA-K and SA-NH tumors produced insignificant quantities of PGH synthase products, but substantial amounts of lipoxygenase products. Their growth was not affected by treatment with indomethacin. Indomethacin did not influence tumor cell survival either in vitro or in vivo, but it reduced the proportion of S-phase cells in the tumors. The antitumor effect of indomethacin was not reduced by immunosuppression of the tumor host and was independent of tumor immunogenicity, implying that indomethacin acted through nonimmunological mechanisms. Thus, the effectiveness of indomethacin was directly related to the ability of tumors to produce PGs. Consequently, the eicosanoid profile of tumors could serve as a valuable way to select patients likely to respond to indomethacin and other PGH synthase inhibiting agents.

Increase in radioresponse of murine tumors by treatment with indomethacin

Indomethacin, an inhibitor of prostaglandin (PG) synthesis, was investigated for its ability to increase radioresponse of two fibrosarcomas, FSA and NFSA, in C3Hf/Kam mice. In addition, the effect of indomethacin on radioresponse of hematopoietic tissue, jejunum, hair follicles, and tissues involved in the development of radiation-induced leg contractures was determined. Indomethacin greatly increased radioresponse of 8-mm tumors, as assessed by both tumor growth delay and TCD50 assays. Enhancement factors for tumor growth delay and tumor radiocurability (TCD50) were 1.55 and 1.39, respectively, for FSA, and 1.4 and 1.26, respectively, for NFSA tumors. Of four normal tissues assessed, two (hair follicles and tissues responsible for development of leg contractures) showed no change in radioresponse after treatment with indomethacin, one (hematopoietic tissue) exhibited radioprotection, and one (jejunum) exhibited slight radiosensitization (enhancement factor, 1.12). Therefore, indomethacin significantly augmented tumor radiocurability but had minimal effect on radioresponse of some normal tissues.

Modification of tumor response to cyclophosphamide and irradiation by preirradiation of the tumor bed: prolonged growth delay but reduced curability

The effect of tumor bed irradiation (TBX) on subsequent tumor response to treatment with cyclophosphamide (CY) or further irradiation was studied in mice. Using the growth delay assay, the therapeutic response was enhanced by prior TBX: for example, in mice receiving 3000 rad TBX 1 day before fibrosarcoma cell inoculation, the growth delay from 8 to 12 mm produced by CY (150 mg/kg) was 18.8 days compared with 9.4 days without prior TBX. This effect was independent of time between TBX and tumor cell inoculation over the range 1-56 days. When tumor cure experiments were performed, however, the effect of prior TBX was to decrease significantly the proportion of tumors controlled by either CY or irradiation and to make the dose-response curve for radiocurability less steep. These data are best interpreted by postulating that TBX increases the environmental heterogeneity of tumors growing in preirradiated sites, with an overall net decrease in the cell kill achieved by a given dose of CY or radiation. This results in increased resistance to cure and a lack of dose response. However, the TBX also causes slower regrowth of surviving cells, so that an increase in tumor growth delay is realized. Thus, although eradication of postirradiation recurrences by chemotherapy is compromised, their palliation may actually be enhanced.

Radiotherapy of regional epidermoid carcinoma of the lung: a study in fractionation

This paper reports a prospective randomized multicenter trial of two fractionation schemes in the supervoltage radiotherapy of locally inoperable epidermoid lung cancer. This study was stimulated by the need to provide improved and more acceptable treatment methods for patients with this condition, the most common cell type of lung cancer. The majority of such patients are not suitable for resection because of metastasis or because of extensive local disease, even though exploratory thoracotomy may be performed. It was therefore considered important to identify preferred methods of irradiation in this situation which is found in a large proportion of patients with lung cancer.