Clinical Pathways and Outcomes of Andexanet Alfa Administration for the Reversal of Critical Bleeding in Patients on Oral Direct Factor Xa Inhibitors.

Background Andexanet is U.S. Food and Drug Administration (FDA) approved for the reversal of critical bleeding from factor Xa inhibitors and off-label for surgical reversal. Data are lacking on andexanet administration processes. Methods We retrospectively studied patients at a 23-hospital system who received andexanet from November 2019 to March 2023. Abstractors coded demographics, comorbidities, anticoagulant use, andexanet indication, and process times. The primary outcome was presentation-to-andexanet time; diagnosis, ordering, and administration times were calculated. Secondary outcomes included in-hospital postandexanet major thromboembolism/bleeding and mortality. Results In total, 141 patients were analyzed. Andexanet indications were predominantly neurologic bleeding (85.8%). Twenty-four patients (17.0%) were transferred from nontertiary/academic centers to tertiary/academic centers. The median presentation-to-administration time was 192.5 minutes (interquartile range [IQR]: 108.0-337.0 minutes). Components were as follows: 72.5 minutes (IQR: 39.0-137.5 minutes) for bleeding diagnosis; 35.5 minutes (IQR: 0-96.5 minutes) for andexanet ordering; and 53.0 minutes (IQR: 38.5-78.5 minutes) for administration, which was longer at tertiary/academic hospitals (ratio 1.5, 95% confidence interval [CI]: 1.2-2.0, p = 0.002). Gastrointestinal or other critical bleeding (ratio 2.59, 95% CI: 1.67-4.02, p < 0.001), and tertiary/academic center treatment (ratio 1.58, 95% CI: 1.15-2.18, p = 0.005), were associated with increased time. Major thromboembolism, bleeding, and mortality occurred in 10.6, 12.0, and 22.9% of patients, respectively. Conclusions In our cohort, the median presentation-to-administration time was over 3 hours. Cumulative times were longer at tertiary/academic hospitals and for gastrointestinal/other bleeding. Postandexanet major thromboembolism/bleeding occurred more at tertiary/academic hospitals, possibly related to transfers. Prospective studies may elucidate clinical decision-making bottlenecks.

System-Wide Thromboprophylaxis Interventions for Hospitalized Patients at Risk of Venous Thromboembolism: Focus on Cross-Platform Clinical Decision Support.

Thromboprophylaxis of hospitalized patients at risk of venous thromboembolism (VTE) presents challenges owing to patient heterogeneity and lack of adoption of evidence-based methods. Intuitive practices for thromboprophylaxis have resulted in many patients being inappropriately prophylaxed. We conducted a narrative review summarizing system-wide thromboprophylaxis interventions in hospitalized patients. Multiple interventions for thromboprophylaxis have been tested, including multifaceted approaches such as national VTE prevention programs with audits, pre-printed order entry, passive alerts (either human or electronic), and more recently, the use of active clinical decision support (CDS) tools incorporated into electronic health records (EHRs). Multifaceted health-system and order entry interventions have shown mixed results in their ability to increase appropriate thromboprophylaxis and reduce VTE unless mandated through a national VTE prevention program, though the latter approach is potentially costly and effort- and time-dependent. Studies utilizing passive human or electronic alerts have also shown mixed results in increasing appropriate thromboprophylaxis and reducing VTE. Recently, a universal cloud-based and EHR-agnostic CDS VTE tool incorporating a validated VTE risk score revealed high adoption and effectiveness in increasing appropriate thromboprophylaxis and reducing major thromboembolism. Active CDS tools hold promise in improving appropriate thromboprophylaxis, especially with further refinement and widespread implementation within various EHRs and clinical workflows.

2023 ISTH update of the 2022 ISTH guidelines for antithrombotic treatment in COVID-19.

Based on emerging evidence from the COVID-19 pandemic, the International Society on Thrombosis and Haemostasis (ISTH) guidelines for antithrombotic treatment in COVID-19 were published in 2022. Since then, at least 16 new randomized controlled trials have contributed additional evidence, which necessitated a modification of most of the previous recommendations. We used again the American College of Cardiology Foundation/American Heart Association methodology for assessment of level of evidence (LOE) and class of recommendation (COR). Five recommendations had the LOE upgraded to A and 2 new recommendations on antithrombotic treatment for patients with COVID-19 were added. Furthermore, a section was added to answer questions about COVID-19 vaccination and vaccine-induced immune thrombotic thrombocytopenia (VITT), for which studies have provided some evidence. We only included recommendations with LOE A or B. Panelists agreed on 19 recommendations, 4 for nonhospitalized, 5 for noncritically ill hospitalized, 3 for critically ill hospitalized, and 2 for postdischarge patients, as well as 5 for vaccination and VITT. A strong recommendation (COR 1) was given for (a) use of prophylactic dose of low-molecular-weight heparin or unfractionated heparin in noncritically ill patients hospitalized for COVID-19, (b) for select patients in this group, use of therapeutic-dose low-molecular-weight heparin/unfractionated heparin in preference to prophylactic dose, and (c) for use of antiplatelet factor 4 enzyme immunoassays for diagnosing VITT. A strong recommendation was given against (COR 3) the addition of an antiplatelet agent in hospitalized, noncritically ill patients. These international guidelines provide recommendations for countries with diverse healthcare resources and COVID-19 vaccine availability.

Periprocedural management of direct oral anticoagulants in patients with atrial fibrillation and active cancer.

BACKGROUND: Cancer and atrial fibrillation (AF) are common concurrent disorders. Direct oral anticoagulants (DOACs) are prescribed to prevent stroke in patients with AF. Patients with cancer often undergo invasive procedures for diagnostic or therapeutic purposes, necessitating interruption of anticoagulation. There are limited data to guide best periprocedural anticoagulation management practices in the setting of active cancer. OBJECTIVES: To describe patient characteristics, periprocedural management, and clinical outcomes in DOAC-treated patients with AF according to active cancer status. METHODS: We conducted descriptive and comparative analyses using data from the PAUSE study. Multivariable logistic regression was used to determine whether active cancer status was an independent risk factor for bleeding outcomes. Covariates were selected a priori based on biological rationale and preexisting knowledge. RESULTS: Patients with active cancer were older (P < .001), more likely to be thrombocytopenic (P = .026), have moderate renal dysfunction (P = .005), and more likely to receive low-dose DOAC therapy (P < .001). A greater proportion of patients with active cancer underwent a high-bleed-risk procedure (P < .001), with longer periprocedural DOAC-interruption intervals (P <.001) and lower preprocedural residual DOAC levels (P = .002). Active cancer was an independent predictor for surgical major bleeding (OR = 2.45; 95% CI, 1.08-5.14) after adjusting for study center, procedure category and bleed risk, thrombocytopenia, hypertension, and the use of a P2Y12 inhibitor. CONCLUSIONS: Active cancer status is associated with an increased risk of surgical major bleeding among DOAC-treated patients with AF undergoing interruption of anticoagulation for elective invasive procedures.

Longitudinal dynamic clinical phenotypes of in-hospital COVID-19 patients across three dominant virus variants in New York.

BACKGROUND: COVID-19 is a challenging disease to characterize given its wide-ranging heterogeneous symptomatology. Several studies have attempted to extract clinical phenotypes but often relied on data from small patient cohorts, usually limited to only one viral variant and utilizing a static snapshot of patient data. OBJECTIVE: This study aimed to identify clinical phenotypes of hospitalized COVID-19 patients and investigate their longitudinal dynamics throughout the pandemic, with the goal to relate these phenotypes to clinical outcomes and treatment strategies. METHODS: We utilized routinely collected demographic and clinical data throughout the hospitalization of 38,077 patients admitted between 3/2020 to 5/2022, in 12 New York hospitals. Uniform Manifold Approximation and Projection and agglomerative hierarchical clustering were used to derive the clusters, followed by exploratory data analysis to compare the prevalence of comorbidities and treatments per cluster. RESULTS: 4 distinct clinical phenotypes remained robust in multi-site validation and were associated with different mortality rates. The temporal progression of these phenotypes throughout the COVID-19 pandemic demonstrated increased variability across the waves of the three dominant viral variants (alpha, delta, omicron). Longitudinal analysis evaluating changes in clinical phenotypes of each patient throughout the course of a 4-week hospital stay exemplified the dynamic nature of the disease progression. Factors such as sex, race/ethnicity and specific treatment modalities revealed significant and clinically relevant differences between the observed phenotypes. CONCLUSIONS: Our proposed methodology has the potential of enabling clinicians and policy makers to draw evidence-based conclusions for guiding treatment modalities in a dynamic fashion.

Antithrombotic Prophylaxis with Rivaroxaban in Patients with Prehospital COVID-19: A Meta-analysis of Two Placebo-Controlled Trials.

BACKGROUND: We conducted a prespecified meta-analysis of two randomized, placebo-controlled trials of rivaroxaban 10 mg daily in prehospital patients with acute coronavirus disease 2019 (COVID-19). Individually, the trials had limited power to detect a treatment effect due to recruitment stopping ahead of plan. MATERIAL AND METHODS: The statistical analysis plan for the meta-analysis was finalized before unblinding of PREVENT-HD, the larger of the two trials. Pooled risk ratios and pooled risk differences along with the two-sided 95% confidence intervals were calculated using random-effect models. RESULTS: Rivaroxaban did not reduce the occurrence of either the primary prespecified endpoint, a composite of symptomatic arterial and venous thromboembolism, myocardial infarction, ischemic stroke, acute limb ischemia, all-cause hospitalization, and all-cause mortality (risk difference: 0.0044; 95% confidence interval: -0.0263, 0.0175; p = 0.69 for pooled risk difference) or the secondary endpoint of all-cause hospitalization (p = 0.76). Although thrombotic events were infrequent, pooled analysis did reveal that rivaroxaban reduced arterial and venous thrombotic events (placebo 6 events, rivaroxaban 0 events; pooled risk difference: -0.0068; 95% confidence interval: -0.0132, -0.0006; p = 0.03). In the pooled studies, only one major bleeding event was observed in a rivaroxaban-allocated patient with no critical site or fatal bleeding events. CONCLUSION: Although this meta-analysis does not support antithrombotic prophylaxis with rivaroxaban in a broad prehospital population with acute COVID-19, the prevention of arterial and venous thrombotic events among rivaroxaban-allocated patients is consistent with the known thromboprophylactic effect of the drug in medically ill patients.

Integrating Clinical Decision Support Into Electronic Health Record Systems Using a Novel Platform (EvidencePoint): Developmental Study.

BACKGROUND: Through our work, we have demonstrated how clinical decision support (CDS) tools integrated into the electronic health record (EHR) assist providers in adopting evidence-based practices. This requires confronting technical challenges that result from relying on the EHR as the foundation for tool development; for example, the individual CDS tools need to be built independently for each different EHR. OBJECTIVE: The objective of our research was to build and implement an EHR-agnostic platform for integrating CDS tools, which would remove the technical constraints inherent in relying on the EHR as the foundation and enable a single set of CDS tools that can work with any EHR. METHODS: We developed EvidencePoint, a novel, cloud-based, EHR-agnostic CDS platform, and we will describe the development of EvidencePoint and the deployment of its initial CDS tools, which include EHR-integrated applications for clinical use cases such as prediction of hospitalization survival for patients with COVID-19, venous thromboembolism prophylaxis, and pulmonary embolism diagnosis. RESULTS: The results below highlight the adoption of the CDS tools, the International Medical Prevention Registry on Venous Thromboembolism-D-Dimer, the Wells' criteria, and the Northwell COVID-19 Survival (NOCOS), following development, usability testing, and implementation. The International Medical Prevention Registry on Venous Thromboembolism-D-Dimer CDS was used in 5249 patients at the 2 clinical intervention sites. The intervention group tool adoption was 77.8% (4083/5249 possible uses). For the NOCOS tool, which was designed to assist with triaging patients with COVID-19 for hospital admission in the event of constrained hospital resources, the worst-case resourcing scenario never materialized and triaging was never required. As a result, the NOCOS tool was not frequently used, though the EvidencePoint platform's flexibility and customizability enabled the tool to be developed and deployed rapidly under the emergency conditions of the pandemic. Adoption rates for the Wells' criteria tool will be reported in a future publication. CONCLUSIONS: The EvidencePoint system successfully demonstrated that a flexible, user-friendly platform for hosting CDS tools outside of a specific EHR is feasible. The forthcoming results of our outcomes analyses will demonstrate the adoption rate of EvidencePoint tools as well as the impact of behavioral economics "nudges" on the adoption rate. Due to the EHR-agnostic nature of EvidencePoint, the development process for additional forms of CDS will be simpler than traditional and cumbersome IT integration approaches and will benefit from the capabilities provided by the core system of EvidencePoint.

Defining heparin resistance: communication from the ISTH SSC Subcommittee of Perioperative and Critical Care Thrombosis and Hemostasis.

The term heparin resistance (HR) is used by clinicians without specific criteria. We performed a literature search and surveyed our SSC membership to better define the term when applied to medical and intensive care unit patients. The most common heparin dosing strategy reported in the literature (53%) and by survey respondents (80.4%) was the use of weight-based dosing. Heparin monitoring results were similar based on the proportion of publications and respondents that reported the use of anti-Xa and activated partial thromboplastin time. The most common literature definition of HR was >35 000 U/d, but no consensus was reported among survey respondents regarding weight-based and the total dose of heparin when determining resistance. Respondent consensus on treating HR included antithrombin supplementation, direct thrombin inhibitors, or administering more heparin as the strategies available for treating HR. A range of definitions for HR exist. Given the common use of heparin weight-based dosing, future publications employing the term HR should include weight-based definitions, monitoring assay, and target level used. Further work is needed to develop a consensus for defining HR.

Cost-effectiveness analysis of extended thromboprophylaxis with rivaroxaban versus no prophylaxis in high-risk patients after hospitalisation for COVID-19: an economic modelling study.

Background: In patients at high risk of thromboembolism who were discharged after hospitalisation due to COVID-19, thromboprophylaxis with rivaroxaban 10 mg/day for 35 days significantly improved clinical outcomes, reducing thrombotic events compared with no post-discharge anticoagulation. The present study aimed to estimate the cost-effectiveness of this anticoagulation strategy. Methods: Using the database of the MICHELLE trial, we developed a decision tree to estimate the cost-effectiveness of thromboprophylaxis with rivaroxaban 10 mg/day for 35 days versus no thromboprophylaxis in high-risk post-discharge patients for COVID-19 through an incremental cost-effectiveness analysis. Findings: 318 patients in 14 centres in Brazil were enrolled in the primary MICHELLE trial. The mean age was 57.1 years (SD 15.2), 127 (40%) were women, 191 (60%) were men, and the mean body-mass index was 29.7 kg/m2 (SD 5.6). Rivaroxaban 10 mg per day orally for 35 days after discharge decreased the risk of events defined by the primary efficacy outcome by 67% (relative risk 0.33, 95% CI 0.12-0.90; p = 0.03). The mean cost for thromboprophylaxis with rivaroxaban was $53.37/patient, and no prophylaxis was $34.22/patient, with an incremental cost difference of $19.15. The effectiveness means obtained in the intervention group was 0.1457, while in the control group was 0.1421, determining an incremental QALY difference of 0.0036. The estimated incremental cost-effectiveness ratio (ICER) was $5385.52/QALY. Interpretation: Extended treatment with Rivaroxaban as thromboprophylaxis after hospital discharge for high-risk patients with COVID-19 is a cost-effective treatment option. Funding: Modest funding was provided by Science Valley Research Institute, São Paulo, Brazil.

Rivaroxaban for Prevention of Thrombotic Events, Hospitalization, and Death in Outpatients With COVID-19: A Randomized Clinical Trial.

BACKGROUND: COVID-19 (coronavirus disease 2019) is associated with heightened risks of venous and arterial thrombosis and hospitalization due to respiratory failure. To assess whether prophylactic anticoagulation can safely reduce the frequency of venous and arterial thrombosis, hospitalization, and death in nonhospitalized patients with symptomatic COVID-19 and at least one thrombosis risk factor, we conducted the PREVENT-HD double-blind, placebo-controlled randomized trial (A Study of Rivaroxaban to Reduce the Risk of Major Venous and Arterial Thrombotic Events, Hospitalization and Death in Medically Ill Outpatients With Acute, Symptomatic COVID-19] Infection). METHODS: PREVENT-HD was conducted between August 2020 and April 2022 at 14 US integrated health care delivery networks. A virtual trial design used remote informed consent and clinical monitoring and facilitated data collection through electronic health record integration with a cloud-based research platform. Nonhospitalized patients with symptomatic COVID-19 and at least one thrombosis risk factor were enrolled and randomly assigned to either 10 mg of oral rivaroxaban or placebo daily for 35 days. The primary efficacy outcome was time to first occurrence of a composite of symptomatic venous thromboembolism, myocardial infarction, ischemic stroke, acute limb ischemia, non-central nervous system systemic arterial embolism, hospitalization, or death through day 35. The principal safety end point was International Society on Thrombosis and Hemostasis critical-site or fatal bleeding. The last study visit was on day 49. RESULTS: The study was terminated prematurely because of enrollment challenges and a lower-than-expected blinded pooled event rate. A total of 1284 patients underwent randomization with complete accrual of primary events through May 2022. No patients were lost to follow-up. The primary efficacy outcome occurred in 22 of 641 in the rivaroxaban group and 19 of 643 in the placebo group (3.4% versus 3.0%; hazard ratio, 1.16 [95% CI, 0.63-2.15]; P=0.63). No patient in either group experienced critical-site or fatal bleeding. One patient receiving rivaroxaban had a major bleed. CONCLUSIONS: The study was terminated prematurely after enrollment of 32% of planned accrual because of recruitment challenges and lower-than-expected event rate. Rivaroxaban prescribed for 35 days in nonhospitalized patients with symptomatic COVID-19 at risk for thrombosis did not appear to reduce a composite end point of venous and arterial thrombotic events, hospitalization, and death. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT04508023.

Risk Factors for Postdischarge Major Thromboembolism and Mortality in Hospitalized Patients with COVID-19 with Cardiovascular Comorbidities: Insights from the CORE-19 Registry.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is associated with venous and arterial thromboembolism (VTE and ATE) and all-cause mortality (ACM) in hospitalized patients. High-quality data are needed on postdischarge outcomes in patients with cardiovascular disease. OBJECTIVES: To analyze outcomes and identify risk factors for ATE, VTE, and ACM in a high-risk subgroup of hospitalized COVID-19 patients with baseline cardiovascular disease. METHODS: We investigated postdischarge rates and associated risk factors of ATE, VTE, and ACM in 608 hospitalized COVID-19 patients with coronary artery disease, carotid artery stenosis (CAS), peripheral arterial disease (PAD), or ischemic stroke. RESULTS: Through 90 days postdischarge, outcome rates were: ATE 27.3% (10.2% myocardial infarction, 10.1% ischemic stroke, 13.2% systemic embolism, 12.7% major adverse limb event); VTE 6.9% (4.1% deep vein thrombosis, 3.6% pulmonary embolism); composite of ATE, VTE, or ACM 35.2% (214/608). Multivariate analysis showed significant association between this composite endpoint and age >75 years (odds ratio [OR]: 1.90, 95% confidence interval [CI]: 1.22-2.94, p = 0.004), PAD (OR: 3.23, 95% CI: 1.80-5.81, p ≤ 0.0001), CAS (OR: 1.74, 95% CI: 1.11-2.75, p = 0.017), congestive heart failure (CHF) (OR: 1.84, 95% CI: 1.02-3.35, p = 0.044), previous VTE (OR: 3.08, 95% CI: 1.75-5.42, p < 0.0001), and intensive care unit (ICU) admission (OR: 2.93, 95% CI: 1.81-4.75, p < 0.0001). CONCLUSION: COVID-19 inpatients with cardiovascular disease experience high rates of ATE, VTE, or ACM through 90 days postdischarge. Age >75 years, PAD, CAS, CHF, previous VTE, and ICU admission are independent risk factors.

Antithrombotic therapy in the management of hospitalised patients with COVID-19.

Hospitalised patients with coronavirus disease 2019 (COVID-19) are at a significantly higher risk of having thromboembolic events while in hospital and in the immediate post-hospital discharge period. Based on early data from observational studies, multiple high quality randomised controlled trials have been conducted worldwide to evaluate optimal thromboprophylaxis regimens to reduce thromboembolism and other COVID-19-related adverse outcomes in hospitalised patients. The International Society on Thrombosis and Haemostasis has published evidence-based guideline recommendations using established methodology for the management of antithrombotic therapy of COVID-19 patients, both in-hospital and in the immediate post-hospital discharge period. A good clinical practice statement supplemented these guidelines based on topics for which there was no or limited high-quality evidence. This review summarises the main recommendations of these documents to serve as a quick access tool for hospital doctors to use in their everyday practice when treating COVID-19 patients.

Implementation of the Management of Anticoagulation in the Periprocedural Period App into an Electronic Health Record: A Cost-Effectiveness Analysis.

The Management of Anticoagulation in the Periprocedural Period (MAPPP) app is a free tool providing up-to-date guidelines on the periprocedural management of patients on long-term anticoagulants. After validating its effectiveness in the post-procedural period, we aimed to study its overall cost-effectiveness. SF-12 surveys were sent to eligible patients, converted into SF-6D forms, and subsequently into quality-adjusted life years (QALYs) to calculate the incremental cost-effectiveness ratio (ICER). The number of 30-day readmissions was used to calculate hospitalization costs, utilizing publicly available data. From 1/1/2018 to 1/31/2019, 642 patients were screened for enrollment, with an overall response rate of 94% (164/175) among the consented and 49% (164/336) among all eligible patients. The average QALY score was 0.7134 (95% CI [0.6836, 0.7431]) for the patients whose treatment plan followed the MAPPP app recommendations (acceptance group) and 0.7104 (95% CI [0.6760, 0.7448]) for those who did not (rejection group), without statistically significant differences. The difference in ICER scores was -$429 866.67, with the negative sign demonstrating that acceptance was the dominant strategy. By utilizing QALYs and ICER scores we have shown that the acceptance of MAPPP app recommendations is the dominant strategy for the periprocedural management of patients on long-term anticoagulation.

Management of Anticoagulation/Antiplatelet Medication and Venous Thromboembolism Prophylaxis in Elective Spine Surgery: Concise Clinical Recommendations Based on a Modified Delphi Process.

STUDY DESIGN: Delphi method. OBJECTIVE: To gain consensus on the following questions: (1) When should anticoagulation/antiplatelet (AC/AP) medication be stopped before elective spine surgery?; (2) When should AC/AP medication be restarted after elective spine surgery?; (3) When, how, and in whom should venous thromboembolism (VTE) chemoprophylaxis be started after elective spinal surgery? SUMMARY OF BACKGROUND DATA: VTE can lead to significant morbidity after adult spine surgery, yet postoperative VTE prophylaxis practices vary considerably. The management of preoperative AC/AP medication is similarly heterogeneous. MATERIALS AND METHODS: Delphi method of consensus development consisting of three rounds (January 26, 2021, to June 21, 2021). RESULTS: Twenty-one spine surgeons were invited, and 20 surgeons completed all rounds of questioning. Consensus (>70% agreement) was achieved in 26/27 items. Group consensus stated that preoperative Direct Oral Anticoagulants should be stopped two days before surgery, warfarin stopped five days before surgery, and all remaining AC/AP medication and aspirin should be stopped seven days before surgery. For restarting AC/AP medication postoperatively, consensus was achieved for low-risk/medium-risk/high-risk patients in 5/5 risk factors (VTE history/cardiac/ambulation status/anterior approach/operation). The low/medium/high thresholds were POD7/POD5/POD2, respectively. For VTE chemoprophylaxis, consensus was achieved for low-risk/medium-risk/high-risk patients in 12/13 risk factors (age/BMI/VTE history/cardiac/cancer/hormone therapy/operation/anterior approach/staged separate days/staged same days/operative time/transfusion). The one area that did not gain consensus was same-day staged surgery. The low-threshold/medium-threshold/high-threshold ranges were postoperative day 5 (POD5) or none/POD3-4/POD1-2, respectively. Additional VTE chemoprophylaxis considerations that gained consensus were POD1 defined as the morning after surgery regardless of operating finishing time, enoxaparin as the medication of choice, and standardized, rather than weight-based, dose given once per day. CONCLUSIONS: In the first known Delphi study to address anticoagulation/antiplatelet recommendations for elective spine surgery (preoperatively and postoperatively); our Delphi consensus recommendations from 20 spine surgeons achieved consensus on 26/27 items. These results will potentially help standardize the management of preoperative AC/AP medication and VTE chemoprophylaxis after adult elective spine surgery.

A Review of FXIa Inhibition as a Novel Target for Anticoagulation.

Limitations of vitamin K antagonists as chronic oral anticoagulant therapy have largely been supplanted by direct factor IIa and factor Xa inhibitor oral anticoagulants with similar efficacy but an overall better safety profile, lack of routine monitoring, and very limited drug-drug interactions compared with agents such as warfarin. However, an increased risk of bleeding remains even with these new-generation oral anticoagulants in fragile patient populations, in patients requiring dual or triple antithrombotic therapy, or high bleed risk surgeries. Epidemiologic data in patients with hereditary factor XI deficiency and preclinical studies support the notion that factor XIa inhibitors have the ability to be an effective but potentially safer alternative to existing anticoagulants, based on their ability to prevent thrombosis directly within the intrinsic pathway without affecting hemostatic mechanisms. As such, various types of factor XIa inhibitors have been studied in early phase clinical studies, including inhibitors of the biosynthesis of factor XIa with antisense oligonucleotides or direct inhibitors of factor XIa using small peptidomimetic molecules, monoclonal antibodies, aptamers, or natural inhibitors. In this review, we discuss how different types of factor XIa inhibitors work and present findings from recently published Phase II clinical trials across multiple indications, including stroke prevention in atrial fibrillation, dual pathway inhibition with concurrent antiplatelets post-myocardial infarction, and thromboprophylaxis of orthopaedic surgery patients. Finally, we refer to ongoing Phase III clinical trials of factor XIa inhibitors and their potential to provide definitive answers regarding their safety and efficacy in preventing thromboembolic events in specific patient groups.

Periprocedural Management of Patients With Atrial Fibrillation Receiving a Direct Oral Anticoagulant Undergoing a Digestive Endoscopy.

INTRODUCTION: The periprocedural management of patients with atrial fibrillation (AF) using a direct oral anticoagulant (DOAC) undergoing elective gastrointestinal (GI) endoscopic procedure remains uncertain. We investigated the safety of a standardized periprocedural DOAC management strategy. METHODS: The Periprocedural Anticoagulation Use for Surgery Evaluation cohort study enrolled adult patients receiving a DOAC (apixaban, rivaroxaban, or dabigatran) for AF scheduled for an elective procedure or surgery. This analysis addresses patients undergoing digestive endoscopy. Standardized periprocedural management consisted of DOAC interruption 1 day preendoscopy with resumption 1 day after procedure at low-moderate risk of bleeding or 2 days in case of a high bleeding risk. Thirty-day outcomes included GI bleeding, thromboembolic events, and mortality. RESULTS: Of 556 patients on a DOAC (mean [SD] age of 72.5 [8.6] years; 37.4% female; mean CHADS 2 score 1.7 [1.0]), 8.6% were also on American Society of Anesthesiology (ASA) and 0.7% on clopidogrel. Most of the patients underwent colonoscopies (63.3%) or gastroscopies (14.0%), with 18.9% having both on the same procedural day. The mean total duration of DOAC interruption was 3.9 ± 1.6 days. Four patients experienced an arterial thromboembolic event (0.7%, 0.3%-1.8%) within 24.2 ± 5.9 days of DOAC interruption. GI bleeding events occurred in 2.5% (1.4%-4.2%) within 11.1 ± 8.1 days (range: 0.6; 25.5 days) of endoscopy, with major GI bleeding in 0.9% (0.4%-2.1%). Three patients died (0.5%; 0.2%-1.6%) 15.6-22.3 days after the endoscopy. DISCUSSION: After a contemporary standardized periprocedural management strategy, patients with AF undergoing DOAC therapy interruption for elective digestive endoscopy experienced low rates of arterial thromboembolism and major bleeding.

Perioperative Management of Vitamin K Antagonists and Direct Oral Anticoagulants: A Systematic Review and Meta-analysis.

BACKGROUND: The management of patients who are receiving chronic oral anticoagulation therapy and require an elective surgery or an invasive procedure is a common clinical scenario. RESEARCH QUESTION: What is the best available evidence to support the development of American College of Chest Physicians guidelines on the perioperative management of patients who are receiving long-term vitamin K agonist (VKA) or direct oral anticoagulant (DOAC) and require elective surgery or procedures? STUDY DESIGN AND METHODS: A literature search including multiple databases from database inception through July 16, 2020, was performed. Meta-analyses were conducted when appropriate. RESULTS: In patients receiving VKA (warfarin) undergoing elective noncardiac surgery, shorter (< 3 days) VKA interruption is associated with an increased risk of major bleeding. In patients who required VKA interruption, heparin bridging (mostly with low-molecular-weight heparin [LMWH]) was associated with a statistically significant increased risk of major bleed, representing a very low certainty of evidence (COE). Compared with DOAC interruption 1 to 4 days before surgery, continuing DOACs may be associated with higher risk of bleeding demonstrated in some, but not all studies. In patients who needed DOAC interruption, bridging with LMWH may be associated with a statistically significant increased risk of bleeding, representing a low COE. INTERPRETATION: The certainty in the evidence supporting the perioperative management of anticoagulants remains limited. No high-quality evidence exists to support the practice of heparin bridging during the interruption of VKA or DOAC therapy for an elective surgery or procedure, or for the practice of interrupting VKA therapy for minor procedures, including cardiac device implantation, or continuation of a DOAC vs short-term interruption of a DOAC in the perioperative period.

Perioperative Management of Anticoagulant and Antiplatelet Therapy.

Anticoagulant and Antiplatelet Drug ManagementManagement of patients on an anticoagulant or antiplatelet drug who require surgery or an invasive procedure is a common clinical problem. Douketis and Spyropoulos provide an evidence-based but practical approach to managing anticoagulants and antiplatelet drugs in the perioperative setting.