Definition of factor Xa inhibitor-related, life-threatening gastrointestinal bleeding and guidance on when to use reversal therapy: A Delphi panel.

Objective: To define and contextualize life-threatening gastrointestinal (GI) bleeding in the setting of factor Xa (FXa) inhibitor therapy and to derive a consensus-based, clinically oriented approach to the administration of FXa inhibitor reversal therapy. Methods: We convened an expert panel of clinicians representing specialties in emergency medicine, gastroenterology, vascular medicine, and trauma surgery. Consensus was reached among the clinician panelists using the Delphi technique, which consisted of 2 survey questionnaires followed by virtual, real-time consensus-building exercises. Results: Hypovolemia and hemodynamic instability were considered the most important clinical signs of FXa inhibitor-related, life-threatening GI bleeds. Clinician panelists agreed that potentially life-threatening GI bleeding should be determined on the basis of hemodynamic instability, signs of shock, individual patient characteristics, and clinical judgment. Last, the panel agreed that all patients with life-threatening, FXa inhibitor-associated GI bleeding should be considered for FXa inhibitor reversal therapy; the decision to reverse FXa inhibition should be individualized, weighing the risks and benefits of reversal; and when reversal is elected, therapy should be administered within 1 h after initial emergency department evaluation, when possible. Conclusions: Consensus-based definitions of life-threatening GI bleeding and approaches to FXa inhibitor reversal centered on hemodynamic instability, signs of shock, individual patient characteristics, and clinical judgment. The results from this Delphi panel may inform clinical decision-making for the treatment of patients experiencing GI bleeding associated with FXa inhibitor use in the emergency department setting.

Retrospective Analysis of the Real-World Utilization of 4-Factor Prothrombin Complex Concentrate and Plasma in Oral Anticoagulant-Associated Bleeding in US Hospitals.

Real-world utilization of 4-factor prothrombin complex concentrate (4F-PCC) and plasma for the management of oral anticoagulant (OAC)-associated bleeding in US trauma hospitals was described.This is amulticenter, retrospective chart review evaluating the use of 4F-PCC and plasma in OAC reversal across medical specialties. Physicians completed a survey and extracted data from 3 to 5 patient charts. Variables of interest included medical specialty, urgency, and bleed type. Two hundred and thirty-five physicians completed the survey, and 861 patient charts were included in the study. 4F-PCC was commonly used in life-threatening or emergent indications, whereas plasma was used in emergent and urgent indications. Plasma was used mostly for patients on warfarin (53% vs 47% 4F-PCC) and 4F-PCC for those on apixaban (82% vs 18% plasma) and rivaroxaban (77% vs 23% plasma). This retrospective analysis showed that 4F-PCC was predominantly used for OAC reversal despite available specific reversal agents for some of the OAC. Although it is not recommended by any reversal guidelines, plasma is still used for OAC reversal. Plasma should be avoided in the management of OAC-associated bleeding.

Final Study Report of Andexanet Alfa for Major Bleeding With Factor Xa Inhibitors.

BACKGROUND: Andexanet alfa is a modified recombinant inactive factor Xa (FXa) designed to reverse FXa inhibitors. ANNEXA-4 (Andexanet Alfa, a Novel Antidote to the Anticoagulation Effects of Factor Xa Inhibitors) was a multicenter, prospective, phase-3b/4, single-group cohort study that evaluated andexanet alfa in patients with acute major bleeding. The results of the final analyses are presented. METHODS: Patients with acute major bleeding within 18 hours of FXa inhibitor administration were enrolled. Co-primary end points were anti-FXa activity change from baseline during andexanet alfa treatment and excellent or good hemostatic efficacy, defined by a scale used in previous reversal studies, at 12 hours. The efficacy population included patients with baseline anti-FXa activity levels above predefined thresholds (≥75 ng/mL for apixaban and rivaroxaban, ≥40 ng/mL for edoxaban, and ≥0.25 IU/mL for enoxaparin; reported in the same units used for calibrators) who were adjudicated as meeting major bleeding criteria (modified International Society on Thrombosis and Haemostasis definition). The safety population included all patients. Major bleeding criteria, hemostatic efficacy, thrombotic events (stratified by occurring before or after restart of either prophylactic [ie, a lower dose, for prevention rather than treatment] or full-dose oral anticoagulation), and deaths were assessed by an independent adjudication committee. Median endogenous thrombin potential at baseline and across the follow-up period was a secondary outcome. RESULTS: There were 479 patients enrolled (mean age, 78 years; 54% male; 86% White); 81% were anticoagulated for atrial fibrillation, and the median time was 11.4 hours since last dose, with 245 (51%) on apixaban, 176 (37%) on rivaroxaban, 36 (8%) on edoxaban, and 22 (5%) on enoxaparin. Bleeding was predominantly intracranial (n=331 [69%]) or gastrointestinal (n=109 [23%]). In evaluable apixaban patients (n=172), median anti-FXa activity decreased from 146.9 ng/mL to 10.0 ng/mL (reduction, 93% [95% CI, 94-93]); in rivaroxaban patients (n=132), it decreased from 214.6 ng/mL to 10.8 ng/mL (94% [95% CI, 95-93]); in edoxaban patients (n=28), it decreased from 121.1 ng/mL to 24.4 ng/mL (71% [95% CI, 82-65); and in enoxaparin patients (n=17), it decreased from 0.48 IU/mL to 0.11 IU/mL (75% [95% CI, 79-67]). Excellent or good hemostasis occurred in 274 of 342 evaluable patients (80% [95% CI, 75-84]). In the safety population, thrombotic events occurred in 50 (10%) patients; in 16 patients, these occurred during treatment with prophylactic anticoagulation that began after the bleeding event. No thrombotic episodes occurred after oral anticoagulation restart. Specific to certain populations, reduction of anti-FXa activity from baseline to nadir significantly predicted hemostatic efficacy in patients with intracranial hemorrhage (area under the receiver operating characteristic curve, 0.62 [95% CI, 0.54-0.70]) and correlated with lower mortality in patients <75 years of age (adjusted P=0.022; unadjusted P=0.003). Median endogenous thrombin potential was within the normal range by the end of andexanet alfa bolus through 24 hours for all FXa inhibitors. CONCLUSIONS: In patients with major bleeding associated with the use of FXa inhibitors, treatment with andexanet alfa reduced anti-FXa activity and was associated with good or excellent hemostatic efficacy in 80% of patients. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT02329327.

Smartphone imaging repository: a novel method for creating a CT image bank.

BACKGROUND: Imaging repositories are commonly attached to ongoing clinical trials, but capturing, transmitting, and storing images can be complicated and labor-intensive. Typical methods include outdated technologies such as compact discs. Electronic file transfer is becoming more common, but even this requires hours of staff time on dedicated computers in the radiology department. METHODS: We describe and test an image capture method using smartphone camera video-derived images of brain computed tomography (CT) scans of traumatic intracranial hemorrhage. The deidentified videos are emailed or uploaded from the emergency department for central adjudication. We selected eight scans, mild moderate, and severe subdural and multicompartmental hematomas and mild and moderate intraparenchymal hematomas. Ten users acquired data using seven different smartphones. We measured the time in seconds it took to capture and send the files. The primary outcomes were hematoma volume measured by ABC/2, Marshall scale, midline shift measurement, image quality by a contrast-to-noise ratio (CNR), and time to capture. A radiologist and an imaging scientist applied the ABC/2 method and calculated the Marshall scale and midline shift on the data acquired on different smartphones and the PACS in a randomized order. We calculate the intraclass correlation coefficient (ICC). We measured image quality by calculating the contrast-to-noise ratio (CNR). We report summary statistics on time to capture in the smartphone group without a comparator. RESULTS: ICC for lesion volume, midline shift, and Marshall score were 0.973 (95% CI 0.931, 0.994), 0.998 (95% CI: 0.996, 0.999), and 0.973 (0.931, 0.994), respectively. Lesion conspicuity was not different among the image types via assessment of CNR using the Friedman test, [Formula: see text] of 24.8, P = < .001, with a small Kendall's W effect size (0.591). Mean (standard deviation) time to capture and email the video was 60.1 (24.3) s. CONCLUSIONS: Typical smartphones may produce video image quality high enough for use in a clinical trial imaging repository. Video capture and transfer takes only seconds, and hematoma volumes, Marshall scales, and image quality measured on the videos did not differ significantly from those calculated on the PACS.

INR and vitamin K-dependent factor levels after vitamin K antagonist reversal with 4F-PCC or plasma.

Restoration of the international normalized ratio (INR) to values <1.5 is commonly targeted to achieve hemostasis in patients with major bleeding or undergoing urgent surgery who are treated using vitamin K antagonists (VKAs). However, the relationship between corrected INR and vitamin K-dependent factor (VKDF) levels for hemostasis is uncertain. We aim to examine the impact of 4-factor prothrombin complex concentrate (4F-PCC) or plasma on INR correction and VKDF restoration and evaluate the relationship between INR values and VKDF levels in patients with acute major bleeding or patients requiring an urgent surgical procedure. Adult patients treated with VKA with an elevated INR (≥2.0 within 3 hours before study treatment) who received 4F-PCC or plasma after major bleeding or before an urgent surgery or invasive procedure were included in this retrospective analysis of data from 2 prospective phase 3b randomized controlled trials. Of the 370 patients included in this analysis, 185 received 4F-PCC, and 185 received plasma. In the 4F-PCC group, 159 of 185 (85.9%) had an INR ≤1.5 at 30 minutes after the end of infusion compared with only 72 of 184 (39.1%) in the plasma group. After 4F-PCC treatment, all VKDF levels exceeded 50% activity regardless of the postinfusion INR value. However, after plasma administration, mean activity levels for factors II and X were <50% at all time points assessed within 3 hours after starting the infusion, regardless of the postinfusion INR value. This retrospective analysis demonstrated that treatment with 4F-PCC among patients treated with VKA rapidly restores VKDFs to hemostatic levels irrespective of the postinfusion INR value, whereas treatment with plasma does not.

Prospective Observational Cohort Study of Tenecteplase Versus Alteplase in Routine Clinical Practice.

BACKGROUND: A 10-hospital regional network transitioned to tenecteplase as the standard of care stroke thrombolytic in September 2019 because of potential workflow advantages and reported noninferior clinical outcomes relative to alteplase in meta-analyses of randomized trials. We assessed whether tenecteplase use in routine clinical practice reduced thrombolytic workflow times with noninferior clinical outcomes. METHODS: We designed a prospective registry-based observational, sequential cohort comparison of tenecteplase- (n=234) to alteplase-treated (n=354) stroke patients. We hypothesized: (1) an increase in the proportion of patients meeting target times for target door-to-needle time and transfer door-in-door-out time, and (2) noninferior favorable (discharge to home with independent ambulation) and unfavorable (symptomatic intracranial hemorrhage, in-hospital mortality or discharge to hospice) in the tenecteplase group. Total hospital cost associated with each treatment was also compared. RESULTS: Target door-to-needle time within 45 minutes for all patients was superior for tenecteplase, 41% versus 29%; adjusted odds ratio, 1.85 (95% CI, 1.27-2.71); P=0.001; 58% versus 41% by Get With The Guidelines criteria. Target door-in-door-out time within 90 minutes was superior for tenecteplase 37% (15/43) versus 14% (9/65); adjusted odds ratio, 3.62 (95% CI, 1.30-10.74); P=0.02. Favorable outcome for tenecteplase fell within the 6.5% noninferiority margin; adjusted odds ratio, 1.26 (95% CI, 0.89-1.80). Unfavorable outcome was less for tenecteplase, 7.3% versus 11.9%, adjusted odds ratio, 0.77 (95% CI, 0.42-1.37) but did not fall within the prespecified 1% noninferior boundary. Net benefit (%favorable-%unfavorable) was greater for the tenecteplase sample: 37% versus 27%. P=0.02. Median cost per hospital encounter was less for tenecteplase cases ($13 382 versus $15 841; P<0.001). CONCLUSIONS: Switching to tenecteplase in routine clinical practice in a 10-hospital network was associated with shorter door-to-needle time and door-in-door-out times, noninferior favorable clinical outcomes at discharge, and reduced hospital costs. Evaluation in larger, multicenter cohorts is recommended to determine if these observations generalize.

Use of deep artificial neural networks to identify stroke during triage via subtle changes in circulating cell counts.

BACKGROUND: The development of tools that could help emergency department clinicians recognize stroke during triage could reduce treatment delays and improve patient outcomes. Growing evidence suggests that stroke is associated with several changes in circulating cell counts. The aim of this study was to determine whether machine-learning can be used to identify stroke in the emergency department using data available from a routine complete blood count with differential. METHODS: Red blood cell, platelet, neutrophil, lymphocyte, monocyte, eosinophil, and basophil counts were assessed in admission blood samples collected from 160 stroke patients and 116 stroke mimics recruited from three geographically distinct clinical sites, and an ensemble artificial neural network model was developed and tested for its ability to discriminate between groups. RESULTS: Several modest but statistically significant differences were observed in cell counts between stroke patients and stroke mimics. The counts of no single cell population alone were adequate to discriminate between groups with high levels of accuracy; however, combined classification using the neural network model resulted in a dramatic and statistically significant improvement in diagnostic performance according to receiver-operating characteristic analysis. Furthermore, the neural network model displayed superior performance as a triage decision making tool compared to symptom-based tools such as the Cincinnati Prehospital Stroke Scale (CPSS) and the National Institutes of Health Stroke Scale (NIHSS) when assessed using decision curve analysis. CONCLUSIONS: Our results suggest that algorithmic analysis of commonly collected hematology data using machine-learning could potentially be used to help emergency department clinicians make better-informed triage decisions in situations where advanced imaging techniques or neurological expertise are not immediately available, or even to electronically flag patients in which stroke should be considered as a diagnosis as part of an automated stroke alert system.

Andexanet Alfa for Specific Anticoagulation Reversal in Patients with Acute Bleeding during Treatment with Edoxaban.

BACKGROUND: Andexanet alfa (andexanet) is approved for specific anticoagulation reversal in patients with life-threatening or uncontrolled bleeding during treatment with rivaroxaban or apixaban. There is limited experience with andexanet in patients with acute bleeding on edoxaban. METHODS: Patients with acute major bleeding within 18 hours of edoxaban intake were prospectively enrolled. Patients received a bolus and 2-hour follow-on infusion of andexanet. The co-primary efficacy outcomes were change in antifactor Xa activity and the percentage of patients achieving excellent or good hemostasis, 12 hours after andexanet treatment. Efficacy was analyzed in patients with confirmed major bleeding and baseline antifactor Xa activity ≥40 ng/mL. Safety was analyzed in all patients. RESULTS: Thirty-six patients (mean age: 82 years, 61.1% male and 91.7% with atrial fibrillation) with acute major bleeding on edoxaban received andexanet. The primary site of bleeding was intracranial in 29 patients (80.6%). In the efficacy population (n = 28), median antifactor Xa activity decreased from 121.1 (interquartile range [IQR]: 70.3-202.4) ng/mL at baseline to 24.0 (IQR: 77.7-83.7) ng/mL at the end of andexanet bolus (median decrease: 68.9%, 95% confidence interval [CI]: 56.1-77.7%). Excellent or good hemostasis at 12 hours was achieved in 78.6% (95% CI: 59.0-91.7%) of patients. Within 30 days, four patients (11.1%) experienced a thrombotic event and four others (11.1%) died. CONCLUSION: In patients with acute major bleeding on edoxaban, andexanet significantly decreased antifactor Xa activity. Hemostatic efficacy was similar to that observed in patients with bleeding on rivaroxaban or apixaban. Thrombotic events occurred at a rate expected in such patients.

Hemostatic Efficacy and Anti-FXa (Factor Xa) Reversal With Andexanet Alfa in Intracranial Hemorrhage: ANNEXA-4 Substudy.

Background and Purpose: Andexanet alfa is a recombinant modified human FXa (factor Xa) developed to reverse FXa inhibition from anticoagulants. Hemostatic efficacy and reversal of anti-FXa activity with andexanet were assessed in patients from the ANNEXA-4 study (Andexanet Alfa, a Novel Antidote to the Anticoagulation Effects of FXa Inhibitors) with intracranial hemorrhage (ICrH). Methods: ANNEXA-4 was a single-arm study evaluating andexanet in patients presenting with major bleeding ≤18 hours after taking an FXa inhibitor. Patients received a bolus plus 2-hour infusion of andexanet. Brain imaging in patients with ICrH was performed at baseline and at 1 and 12 hours postandexanet infusion. Coprimary efficacy outcomes were change in anti-FXa activity and hemostatic efficacy at 12 hours (excellent/good efficacy defined as ≤35% increase in hemorrhage volume/thickness). Safety outcomes included occurrence of thrombotic events and death at 30 days. Results: A total of 227 patients with ICrH were included in the safety population (51.5% male; mean age 79.3 years) and 171 in the efficacy population (99 spontaneous and 72 traumatic bleeds). In efficacy evaluable patients, excellent/good hemostasis 12 hours postandexanet occurred in 77 out of 98 (78.6%) and in 58 out of 70 (82.9%) patients with spontaneous and traumatic bleeding, respectively. In the subanalysis by FXa inhibitor treatment group in the efficacy population, median of percent change in anti-FXa from baseline to nadir showed a decrease of 93.8% for apixaban-treated patients (n=99) and by 92.6% for rivaroxaban-treated patients (n=59). Within 30 days, death occurred in 34 out of 227 (15.0%) patients and thrombotic events occurred in 21 out of 227 (9.3%) patients (safety population). Conclusions: Andexanet reduced anti-FXa activity in FXa inhibitor-treated patients with ICrH, with a high rate of hemostatic efficacy. Andexanet may substantially benefit patients with ICrH, the most serious complication of anticoagulation. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02329327.

Low-dose versus standard-dose four-factor prothrombin complex concentrate for factor-Xa inhibitor reversal in spontaneous and traumatic intracranial hemorrhage.

STUDY OBJECTIVES: Current neurocritical care guidelines recommend 50 IU/kg four-factor prothrombin complex concentrate (4PCC) for factor Xa inhibitor (FXaI) reversal in intracranial hemorrhage (ICH) based on few clinical studies conducted among non-ICH subjects. Two recent studies suggest that low-dose (25 IU/kg) 4PCC may be similar to 50 IU/kg in reversal of FXaI in ICH, and both 25 and 50 IU/kg doses are used in clinical practice for this indication. To our knowledge, no studies have directly compared 25 IU/kg versus 50 IU/kg 4PCC for FXaI reversal in ICH. The purpose of this study is to determine whether there is a difference in hemostatic efficacy between 25 IU/kg versus 50 IU/kg 4PCC for FXaI reversal in ICH. DESIGN: This multicenter, retrospective cohort study was performed in five hospitals in central Texas from November 2013 to December 2019. DATA SOURCE: Patients were identified with a medication use report of 4PCC and were classified in the low- or standard-dose group based on whether the 25 IU/kg or 50 IU/kg dose was received, respectively. PATIENTS: A total of 93 patients were included (25 IU/kg, n = 62; 50 IU/kg, n = 31). MEASUREMENTS AND MAIN RESULTS: There was no difference in hemostatic efficacy between groups (82.3% low dose vs. 83.9% standard dose, p = 0.846). No differences were identified in-hospital mortality, length of stay, thrombotic events, or the need for surgery or additional blood products between groups. CONCLUSION: For the reversal of FXaI in ICH, a 25 IU/kg dose may be an effective alternative to 50 IU/kg 4PCC dosing.

Restart of Anticoagulant Therapy and Risk of Thrombosis, Rebleeding, and Death after Factor Xa Inhibitor Reversal in Major Bleeding Patients.

BACKGROUND: Lack of data on balancing bleeding and thrombosis risk causes uncertainty about restarting anticoagulants after major bleeding. Anticoagulant reversal trials offer prospectively gathered data after major bleeding with well-documented safety events and restarting behavior. OBJECTIVES: To examine the relationship of restarting anticoagulation with thrombosis, rebleeding, and death. METHODS: This is a posthoc analysis of a prospective factor Xa inhibitor reversal study at 63 centers in North America and Europe. We compared outcomes of restarted patients with those not restarted using landmark and time-dependent Cox proportional hazards models. Outcomes included thrombotic and bleeding events and death and a composite of all three. RESULTS: Of 352 patients enrolled, oral anticoagulation was restarted in 100 (28%) during 30-day follow-up. Thirty-four (9.7%) had thrombotic events, 15 (4.3%) had bleeding events (after day 3), and 49 (14%) died. In the landmark analysis comparing patients restarted within 14 days to those not, restarting was associated with decreased thrombotic events (hazard ratio [HR] = 0.112; 95% confidence interval [CI]: 0.001-0.944; p = 0.043) and increased rebleeding (HR = 8.39; 95% CI: 1.13-62.29; p = 0.037). The time-dependent Cox model showed evidence for a reduction in a composite (thrombotic events, bleeding, and death) attempting to capture net benefit (HR = 0.384; 95% CI: 0.161-0.915; p = 0.031). CONCLUSION: This analysis provides modest evidence that restarting anticoagulation in factor Xa inhibitor-associated major bleeding patients is correlated with reduced risk of thrombotic events and increased risk of rebleeding. There is low-level evidence of net benefit for restarting. A randomized trial of restarting would be appropriate.

Restart TICrH: An Adaptive Randomized Trial of Time Intervals to Restart Direct Oral Anticoagulants after Traumatic Intracranial Hemorrhage.

Anticoagulants prevent thrombosis and death in patients with atrial fibrillation and venous thromboembolism (VTE) but also increase bleeding risk. The benefit/risk ratio favors anticoagulation in most of these patients. However, some will have a bleeding complication, such as the common trip-and-fall brain injury in elderly patients that results in traumatic intracranial hemorrhage. Clinicians must then make the difficult decision about when to restart the anticoagulant. Restarting too early risks making the bleeding worse. Restarting too late risks thrombotic events such as ischemic stroke and VTE, the indications for anticoagulation in the first place. There are more data on restarting patients with spontaneous intracranial hemorrhage, which is very different than traumatic intracranial hemorrhage. Spontaneous intracranial hemorrhage increases the risk of rebleeding because intrinsic vascular changes are widespread and irreversible. In contrast, traumatic cases are caused by a blow to the head, usually an isolated event portending less future risk. Clinicians generally agree that anticoagulation should be restarted but disagree about when. This uncertainty leads to long restart delays causing a large, potentially preventable burden of strokes and VTE, which has been unaddressed because of the absence of high quality evidence. Restart Traumatic Intracranial Hemorrhage (the "r" distinguished intracranial from intracerebral) (TICrH) is a prospective randomized open label blinded end-point response-adaptive clinical trial that will evaluate the impact of delays to restarting direct oral anticoagulation (1, 2, or 4 weeks) on the composite of thrombotic events and bleeding in patients presenting after traumatic intracranial hemorrhage.

Anticoagulant Reversal in Gastrointestinal Bleeding: Review of Treatment Guidelines.

BACKGROUND: Patients receiving anticoagulant therapies, such as vitamin K antagonists (VKAs) or direct oral anticoagulants (DOACs), commonly experience gastrointestinal (GI) bleeding as a complication and may require anticoagulant reversal prior to endoscopic treatment. Anticoagulant reversal agents include prothrombin complex concentrates (PCCs; including 3 or 4 coagulation factors), plasma, vitamin K, and target-specific DOAC reversal agents (e.g., idarucizumab and andexanet alfa). AIM: To review current US, as well as international, guidelines for anticoagulant reversal agents in patients on VKAs or DOACs presenting with GI bleeding prior to endoscopy, guideline-based management of coagulation defects, timing of endoscopy, and recommendations for resumption of anticoagulant therapy following hemostasis. Supporting clinical data were also reviewed. METHODS: This is a narrative review, based on PubMed and Internet searches reporting GI guidelines and supporting clinical data. RESULTS: GI-specific guidelines state that use of reversal agents should be considered in patients with life-threatening GI bleeding. For VKA patients presenting with an international normalized ratio > 2.5, guidelines recommend PCCs (specifically 4F-PCC), as they may exhibit greater efficacy/safety compared with fresh frozen plasma in reversal of VKA-associated GI bleeding. For DOAC patients, most guidelines recommend targeted specific reversal agents in the setting of GI bleeding; however, PCCs (primarily 4F-PCC) are often listed as another option. Resumption of anticoagulant therapy following cessation of GI bleeding is also recommended to reduce risks of future thromboembolic complications. CONCLUSIONS: The utility of anticoagulant reversal agents in GI bleeding is recognized in guidelines; however, such agents should be reserved for use in truly life-threatening scenarios.

Tenecteplase Thrombolysis for Acute Ischemic Stroke.

Tenecteplase is a fibrinolytic drug with higher fibrin specificity and longer half-life than the standard stroke thrombolytic, alteplase, permitting the convenience of single bolus administration. Tenecteplase, at 0.5 mg/kg, has regulatory approval to treat ST-segment-elevation myocardial infarction, for which it has equivalent 30-day mortality and fewer systemic hemorrhages. Investigated as a thrombolytic for ischemic stroke over the past 15 years, tenecteplase is currently being studied in several phase 3 trials. Based on a systematic literature search, we provide a qualitative synthesis of published stroke clinical trials of tenecteplase that (1) performed randomized comparisons with alteplase, (2) compared different doses of tenecteplase, or (3) provided unique quantitative meta-analyses. Four phase 2 and one phase 3 study performed randomized comparisons with alteplase. These and other phase 2 studies compared different tenecteplase doses and effects on early outcomes of recanalization, reperfusion, and substantial neurological improvement, as well as symptomatic intracranial hemorrhage and 3-month disability on the modified Rankin Scale. Although no single trial prospectively demonstrated superiority or noninferiority of tenecteplase on clinical outcome, meta-analyses of these trials (1585 patients randomized) point to tenecteplase superiority in recanalization of large vessel occlusions and noninferiority in disability-free 3-month outcome, without increases in symptomatic intracranial hemorrhage or mortality. Doses of 0.25 and 0.4 mg/kg have been tested, but no advantage of the higher dose has been suggested by the results. Current clinical practice guidelines for stroke include intravenous tenecteplase at either dose as a second-tier option, with the 0.25 mg/kg dose recommended for large vessel occlusions, based on a phase 2 trial that demonstrated superior recanalization and improved 3-month outcome relative to alteplase. Ongoing randomized phase 3 trials may better define the comparative risks and benefits of tenecteplase and alteplase for stroke thrombolysis and answer questions of tenecteplase efficacy in the >4.5-hour time window, in wake-up stroke, and in combination with endovascular thrombectomy.

A review of guidelines on anticoagulation reversal across different clinical scenarios - Is there a general consensus?

Anticoagulation is key to the treatment/prevention of thromboembolic events. The primary complication of anticoagulation is serious or life-threatening hemorrhage, which may necessitate prompt anticoagulation reversal; this could also be required for nonbleeding patients requiring urgent/emergent invasive procedures. The decision to reverse anticoagulation should weigh the benefit-risk ratio of supporting hemostasis versus post-reversal thrombosis. We appraise the available guidelines/recommendations for vitamin K antagonist (VKA) and direct oral anticoagulant (DOAC) reversal in the management of major bleeding, and also assess recent clinical data that may not yet be reflected in official guidance. In general, available guidelines are consistent in their recommendations, advocating administration of vitamin K and 4-factor prothrombin complex concentrates (4F-PCCs) rather than fresh frozen plasma to patients with VKA-associated intracranial hemorrhage and life-threatening bleeding, and specific reversal agents as essential therapy for DOAC reversal in those same severe conditions. However, guidelines also recommend off-label use of PCCs for DOAC reversal when specific reversal agents are unavailable. Limited recent evidence generally support the latter recommendation, but guidelines are likely to evolve as more data become available.

A review of oral anticoagulants, old and new, in major bleeding and the need for urgent surgery.

Oral anticoagulants, old and new, are effective therapies for prevention and treatment of venous thromboembolism and reduction of stroke risk in patients with atrial fibrillation. However, blocking elements of the clotting cascade carries an inherent risk of bleeding. Also, anticoagulated patients sometimes require urgent surgery or invasive procedures. This has led to the emergence of a body of scientific literature on the reversal of anticoagulation in these two settings. Traditionally, vitamin K antagonists (VKAs), which indirectly inactivate clotting factors II, VII, IX and X (and natural anticoagulant proteins C and S), had been the mainstay of oral anticoagulation for half a century. Only a few years ago, the US Food and Drug Administration (FDA) approved a specific VKA reversal agent, 4-Factor Prothrombin Complex Concentrate (4F-PCC). The last decade has seen the rise of non-Vitamin K oral anticoagulants (NOACs), which target specific factors, i.e. Factors IIa and Xa. Investigators have rapidly developed reversal agents for these agents as well, idarucizumab for the Factor IIa inhibitor dabigatran (Pradaxa) and andexanet alfa for the entire class of Factor Xa inhibitors (FXaIs), currently four drugs: rivaroxaban (Xarelto), apixaban (Eliquis), edoxaban (Savaysa) and betrixaban (Bevyxxa). Clinicians still use off-label PCC for reversing FXaIs in some settings, and a universal reversal agent, ciraparantag, remains in development. This review summarizes the safety and efficacy of these reversal agents in the setting of anticoagulant-associated major bleeding and the need for urgent surgery.

Intravenous Thrombolysis at 3.5 Hours From Onset of Pediatric Acute Ischemic Stroke.

Acute thrombolysis has a proven benefit for adults presenting with acute ischemic stroke, but data within the pediatric population are extremely limited. We report the case of a 14-year-old girl who presented with right-sided weakness and ataxia, loss of sensation, and altered mental status. Magnetic resonance imaging with diffusion-weighted imaging showed an acute lesion in the distribution of the left posterior cerebral artery, and magnetic resonance angiogram demonstrated occlusion of the third branch of the left posterior cerebral artery. With parental consent, clinicians decided to infuse an adult dose of weight-adjusted intravenous alteplase at 3.5 hours from onset of symptoms, with subsequent improvement in National Institutes of Health Stroke Scale score from 11 to 3. Computed tomography angiogram at 24 hours showed recanalization of the occluded vessel with no evidence of intracranial hemorrhage. Stroke Scale score at discharge was 3, with modified Rankin Scale scores at discharge of 1 and at 90 days of 0. This case highlights the importance of magnetic resonance imaging in diagnosing pediatric acute ischemic stroke and suggests consideration of thrombolysis in select confirmed pediatric stroke cases. However, a rigorous evidence base is lacking, and clinical trials have not been successful in recruiting patients.