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.

Association of Bleeding Severity With Mortality in Extended Thromboprophylaxis of Medically Ill Patients in the MAGELLAN and MARINER Trials.

BACKGROUND: Extended thromboprophylaxis has not been widely implemented in acutely ill medical patients because of bleeding concerns. The MAGELLAN (Multicenter, Randomized, Parallel Group Efficacy and Safety Study for the Prevention of Venous Thromboembolism in Hospitalized Medically Ill Patients Comparing Rivaroxaban With Enoxaparin) and MARINER (Medically Ill Patient Assessment of Rivaroxaban Versus Placebo in Reducing Post-Discharge Venous Thrombo-Embolism Risk) trials evaluated whether rivaroxaban compared with enoxaparin or placebo could prevent venous thromboembolism without increased bleeding. We hypothesized that patients with major bleeding but not those with nonmajor clinically relevant bleeding would be at an increased risk of all-cause mortality (ACM). METHODS: We evaluated all bleeding events in patients taking at least 1 dose of study drug and their association with ACM in 4 mutually exclusive groups: (1) no bleeding, or first event was (2) nonmajor clinically relevant bleeding, (3) major bleeding, or (4) trivial bleeding. Using a Cox proportional hazards model adjusted for differences in baseline characteristics associated with ACM, we assessed the risk of ACM after such events. RESULTS: Compared with patients with no bleeding, the risk of ACM for patients with nonmajor clinically relevant bleeding was not increased in MARINER (hazard ratio, 0.43; P=0.235) but was increased in MAGELLAN (hazard ratio, 1.74; P=0.021). Major bleeding was associated with a higher incidence of ACM in both studies, whereas trivial bleeding was not associated with ACM in either study. CONCLUSIONS: Patients with major bleeding had an increased risk of ACM, whereas nonmajor clinically relevant bleeding was not consistently associated with an increased risk of death. These results inform the risk-benefit calculus of extended thromboprophylaxis in medically ill patients. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: MAGELLAN, NCT00571649. URL: https://www. CLINICALTRIALS: gov; Unique identifier: MARINER, NCT02111564.

Rivaroxaban versus no anticoagulation for post-discharge thromboprophylaxis after hospitalisation for COVID-19 (MICHELLE): an open-label, multicentre, randomised, controlled trial.

BACKGROUND: Patients hospitalised with COVID-19 are at risk for thrombotic events after discharge; the role of extended thromboprophylaxis in this population is unknown. METHODS: In this open-label, multicentre, randomised trial conducted at 14 centres in Brazil, patients hospitalised with COVID-19 at increased risk for venous thromboembolism (International Medical Prevention Registry on Venous Thromboembolism [IMPROVE] venous thromboembolism [VTE] score of ≥4 or 2-3 with a D-dimer >500 ng/mL) were randomly assigned (1:1) to receive, at hospital discharge, rivaroxaban 10 mg/day or no anticoagulation for 35 days. The primary efficacy outcome in an intention-to-treat analysis was a composite of symptomatic or fatal venous thromboembolism, asymptomatic venous thromboembolism on bilateral lower-limb venous ultrasound and CT pulmonary angiogram, symptomatic arterial thromboembolism, and cardiovascular death at day 35. Adjudication was blinded. The primary safety outcome was major bleeding. The primary and safety analyses were carried out in the intention-to-treat population. This trial is registered at ClinicalTrials.gov, NCT04662684. FINDINGS: From Oct 8, 2020, to June 29, 2021, 997 patients were screened. Of these patients, 677 did not meet eligibility criteria; the remaining 320 patients were enrolled and randomly assigned to receive rivaroxaban (n=160 [50%]) or no anticoagulation (n=160 [50%]). All patients received thromboprophylaxis with standard doses of heparin during hospitalisation. 165 (52%) patients were in the intensive care unit while hospitalised. 197 (62%) patients had an IMPROVE score of 2-3 and elevated D-dimer levels and 121 (38%) had a score of 4 or more. Two patients (one in each group) were lost to follow-up due to withdrawal of consent and not included in the intention-to-treat primary analysis. The primary efficacy outcome occurred in five (3%) of 159 patients assigned to rivaroxaban and 15 (9%) of 159 patients assigned to no anticoagulation (relative risk 0·33, 95% CI 0·12-0·90; p=0·0293). No major bleeding occurred in either study group. Allergic reactions occurred in two (1%) patients in the rivaroxaban group. INTERPRETATION: In patients at high risk discharged after hospitalisation due to COVID-19, thromboprophylaxis with rivaroxaban 10 mg/day for 35 days improved clinical outcomes compared with no extended thromboprophylaxis. FUNDING: Bayer.

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.

Postdischarge thromboembolic outcomes and mortality of hospitalized patients with COVID-19: the CORE-19 registry.

Thromboembolic events, including venous thromboembolism (VTE) and arterial thromboembolism (ATE), and mortality from subclinical thrombotic events occur frequently in coronavirus disease 2019 (COVID-19) inpatients. Whether the risk extends postdischarge has been controversial. Our prospective registry included consecutive patients with COVID-19 hospitalized within our multihospital system from 1 March to 31 May 2020. We captured demographics, comorbidities, laboratory parameters, medications, postdischarge thromboprophylaxis, and 90-day outcomes. Data from electronic health records, health informatics exchange, radiology database, and telephonic follow-up were merged. Primary outcome was a composite of adjudicated VTE, ATE, and all-cause mortality (ACM). Principal safety outcome was major bleeding (MB). Among 4906 patients (53.7% male), mean age was 61.7 years. Comorbidities included hypertension (38.6%), diabetes (25.1%), obesity (18.9%), and cancer history (13.1%). Postdischarge thromboprophylaxis was prescribed in 13.2%. VTE rate was 1.55%; ATE, 1.71%; ΑCM, 4.83%; and MB, 1.73%. Composite primary outcome rate was 7.13% and significantly associated with advanced age (odds ratio [OR], 3.66; 95% CI, 2.84-4.71), prior VTE (OR, 2.99; 95% CI, 2.00-4.47), intensive care unit (ICU) stay (OR, 2.22; 95% CI, 1.78-2.93), chronic kidney disease (CKD; OR, 2.10; 95% CI, 1.47-3.0), peripheral arterial disease (OR, 2.04; 95% CI, 1.10-3.80), carotid occlusive disease (OR, 2.02; 95% CI, 1.30-3.14), IMPROVE-DD VTE score ≥4 (OR, 1.51; 95% CI, 1.06-2.14), and coronary artery disease (OR, 1.50; 95% CI, 1.04-2.17). Postdischarge anticoagulation was significantly associated with reduction in primary outcome (OR, 0.54; 95% CI, 0.47-0.81). Postdischarge VTE, ATE, and ACM occurred frequently after COVID-19 hospitalization. Advanced age, cardiovascular risk factors, CKD, IMPROVE-DD VTE score ≥4, and ICU stay increased risk. Postdischarge anticoagulation reduced risk by 46%.

Prognostic factors for VTE and bleeding in hospitalized medical patients: a systematic review and meta-analysis.

There may be many predictors of venous thromboembolism (VTE) and bleeding in hospitalized medical patients, but until now, systematic reviews and assessments of the certainty of the evidence have not been published. We conducted a systematic review to identify prognostic factors for VTE and bleeding in hospitalized medical patients and searched Medline and EMBASE from inception through May 2018. We considered studies that identified potential prognostic factors for VTE and bleeding in hospitalized adult medical patients. Reviewers extracted data in duplicate and independently and assessed the certainty of the evidence using the Grading of Recommendations Assessment, Development, and Evaluation approach. Of 69 410 citations, we included 17 studies in our analysis: 14 that reported on VTE, and 3 that reported on bleeding. For VTE, moderate-certainty evidence showed a probable association with older age; elevated C-reactive protein (CRP), D-dimer, and fibrinogen levels; tachycardia; thrombocytosis; leukocytosis; fever; leg edema; lower Barthel Index (BI) score; immobility; paresis; previous history of VTE; thrombophilia; malignancy; critical illness; and infections. For bleeding, moderate-certainty evidence showed a probable association with older age, sex, anemia, obesity, low hemoglobin, gastroduodenal ulcers, rehospitalization, critical illness, thrombocytopenia, blood dyscrasias, hepatic disease, renal failure, antithrombotic medication, and presence of a central venous catheter. Elevated CRP, a lower BI, a history of malignancy, and elevated heart rate are not included in most VTE risk assessment models. This study informs risk prediction in the management of hospitalized medical patients for VTE and bleeding; it also informs guidelines for VTE prevention and future research.

Effect of Anticoagulant Therapy for 6 Weeks vs 3 Months on Recurrence and Bleeding Events in Patients Younger Than 21 Years of Age With Provoked Venous Thromboembolism: The Kids-DOTT Randomized Clinical Trial.

Importance: Among patients younger than 21 years of age, the optimal duration of anticoagulant therapy for venous thromboembolism is unknown. Objective: To test the hypothesis that a 6-week duration of anticoagulant therapy for provoked venous thromboembolism is noninferior to a conventional 3-month therapy duration in patients younger than 21 years of age. Design, Setting, and Participants: Randomized clinical trial involving 417 patients younger than 21 years of age with acute, provoked venous thromboembolism enrolled at 42 centers in 5 countries from 2008-2021. The main exclusions were severe anticoagulant deficiencies or prior venous thromboembolism. Patients without persistent antiphospholipid antibodies and whose thrombi were resolved or not completely occlusive upon repeat imaging at 6 weeks after diagnosis underwent randomization. The final visit for the primary end points occurred in January 2021. Interventions: Total duration for anticoagulant therapy of 6 weeks (n = 207) vs 3 months (n = 210) for provoked venous thromboembolism. Main Outcomes and Measures: The primary efficacy and safety end points were centrally adjudicated symptomatic recurrent venous thromboembolism and clinically relevant bleeding events within 1 year blinded to treatment group. The primary analysis was noninferiority in the per-protocol population. The noninferiority boundary incorporated a bivariate trade-off that included an absolute increase of 0% in symptomatic recurrent venous thromboembolism with an absolute risk reduction of 4% in clinically relevant bleeding events (1 of 3 points on the bivariate noninferiority boundary curve). Results: Among 417 randomized patients, 297 (median age, 8.3 [range, 0.04-20.9] years; 49% female) met criteria for the primary per-protocol population analysis. The Kaplan-Meier estimate for the 1-year cumulative incidence of the primary efficacy outcome was 0.66% (95% CI, 0%-1.95%) in the 6-week anticoagulant therapy group and 0.70% (95% CI, 0%-2.07%) in the 3-month anticoagulant therapy group, and for the primary safety outcome, the incidence was 0.65% (95% CI, 0%-1.91%) and 0.70% (95% CI, 0%-2.06%). Based on absolute risk differences in recurrent venous thromboembolism and clinically relevant bleeding events between groups, noninferiority was demonstrated. Adverse events occurred in 26% of patients in the 6-week anticoagulant therapy group and in 32% of patients in the 3-month anticoagulant therapy group; the most common adverse event was fever (1.9% and 3.4%, respectively). Conclusions and Relevance: Among patients younger than 21 years of age with provoked venous thromboembolism, anticoagulant therapy for 6 weeks compared with 3 months met noninferiority criteria based on the trade-off between recurrent venous thromboembolism risk and bleeding risk. Trial Registration: ClinicalTrials.gov Identifier: NCT00687882.

Rivaroxaban for Thromboprophylaxis after Hospitalization for Medical Illness.

BACKGROUND: Patients who are hospitalized for medical illness remain at risk for venous thromboembolism after discharge, but the role of extended thromboprophylaxis in the treatment of such patients is a subject of controversy. METHODS: In this randomized, double-blind trial, medically ill patients who were at increased risk for venous thromboembolism on the basis of a modified International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) score of 4 or higher (scores range from 0 to 10, with higher scores indicating a higher risk of venous thromboembolism) or a score of 2 or 3 plus a plasma d-dimer level of more than twice the upper limit of the normal range (defined according to local laboratory criteria) were assigned at hospital discharge to either once-daily rivaroxaban at a dose of 10 mg (with the dose adjusted for renal insufficiency) or placebo for 45 days. The primary efficacy outcome was a composite of symptomatic venous thromboembolism or death due to venous thromboembolism. The principal safety outcome was major bleeding. RESULTS: Of the 12,024 patients who underwent randomization, 12,019 were included in the intention-to-treat analysis. The primary efficacy outcome occurred in 50 of 6007 patients (0.83%) who were given rivaroxaban and in 66 of 6012 patients (1.10%) who were given placebo (hazard ratio, 0.76; 95% confidence interval [CI], 0.52 to 1.09; P=0.14). The prespecified secondary outcome of symptomatic nonfatal venous thromboembolism occurred in 0.18% of patients in the rivaroxaban group and 0.42% of patients in the placebo group (hazard ratio, 0.44; 95% CI, 0.22 to 0.89). Major bleeding occurred in 17 of 5982 patients (0.28%) in the rivaroxaban group and in 9 of 5980 patients (0.15%) in the placebo group (hazard ratio, 1.88; 95% CI, 0.84 to 4.23). CONCLUSIONS: Rivaroxaban, given to medical patients for 45 days after hospital discharge, was not associated with a significantly lower risk of symptomatic venous thromboembolism and death due to venous thromboembolism than placebo. The incidence of major bleeding was low. (Funded by Janssen Research and Development; MARINER ClinicalTrials.gov number, NCT02111564 .).

Rationale and design for the study of rivaroxaban to reduce thrombotic events, hospitalization and death in outpatients with COVID-19: The PREVENT-HD study.

BACKGROUND: COVID-19 is associated with both venous and arterial thrombotic complications. While prophylactic anticoagulation is now widely recommended for hospitalized patients with COVID-19, the effectiveness and safety of thromboprophylaxis in outpatients with COVID-19 has not been established. STUDY DESIGN: PREVENT-HD is a double-blind, placebo-controlled, pragmatic, event-driven phase 3 trial to evaluate the efficacy and safety of rivaroxaban in symptomatic outpatients with laboratory-confirmed COVID-19 at risk for thrombotic events, hospitalization, and death. Several challenges posed by the pandemic have necessitated innovative approaches to clinical trial design, start-up, and conduct. Participants are randomized in a 1:1 ratio, stratified by time from COVID-19 confirmation, to either rivaroxaban 10 mg once daily or placebo for 35 days. The primary efficacy end point is a composite of symptomatic venous thromboembolism, myocardial infarction, ischemic stroke, acute limb ischemia, non-central nervous system systemic embolization, all-cause hospitalization, and all-cause mortality. The primary safety end point is fatal and critical site bleeding according to the International Society on Thrombosis and Haemostasis definition. Enrollment began in August 2020 and is expected to enroll approximately 4,000 participants to yield the required number of end point events. CONCLUSIONS: PREVENT-HD is a pragmatic trial evaluating the efficacy and safety of the direct oral anticoagulant rivaroxaban in the outpatient setting to reduce major venous and arterial thrombotic events, hospitalization, and mortality associated with COVID-19.

Medically Ill hospitalized Patients for COVID-19 THrombosis Extended ProphyLaxis with rivaroxaban ThErapy: Rationale and Design of the MICHELLE Trial.

BACKGROUND: The devastating Coronavirus disease (COVID-19) pandemic is associated with a high prothrombotic state. It is unclear if the coagulation abnormalities occur because of the direct effect of SARS-CoV-2 or indirectly by the cytokine storm and endothelial damage or by a combination of mechanisms. There is a clear indication of in-hospital pharmacological thromboprophylaxis for every patient with COVID-19 after bleed risk assessment. However, there is much debate regarding the best dosage regimen, and there is no consensus on the role of extended thromboprophylaxis. DESIGN: This study aims to evaluate the safety and efficacy of rivaroxaban 10 mg once daily for 35 ± 4 days versus no intervention after hospital discharge in COVID-19 patients who were at increased risk for VTE and have received standard parenteral VTE prophylaxis during hospitalization. The composite efficacy endpoint is a combination of symptomatic VTE, VTE-related death, VTE detected by bilateral lower limbs venous duplex scan and computed tomography pulmonary angiogram on day 35 ± 4 posthospital discharge and symptomatic arterial thromboembolism (myocardial infarction, nonhemorrhagic stroke, major adverse limb events, and cardiovascular death) up to day 35 ± 4 posthospital discharge. The key safety outcome is the incidence of major bleeding according to ISTH criteria. SUMMARY: The MICHELLE trial is expected to provide high-quality evidence around the role of extended thromboprophylaxis in COVID-19 and will help guide medical decisions in clinical practice.1.

Prevention of Venous Thromboembolism in Acutely Ill Medical Patients: A New Era.

Venous thromboembolism (VTE) is the leading preventable cause of death in hospitalized patients and data consistently show that acutely ill medical patients remain at increased risk for VTE-related morbidity and mortality in the post-hospital discharge period. Prescribing extended thromboprophylaxis for up to 45 days following an acute hospitalization in key patient subgroups that include more than one-quarter of hospitalized medically-ill patients represents a paradigm shift in the way hospital-based physicians think about VTE prevention. Advances in the field of primary thromboprophylaxis in acutely-ill medical patients using validated VTE and bleeding risk assessment models have established key patient subgroups at high risk of VTE and low risk of bleeding that may benefit from both in-hospital and extended thromboprophylaxis. The direct oral anticoagulants betrixaban and rivaroxaban are now U.S. Food and Drug Administration-approved for in-hospital and extended thromboprophylaxis in medically ill patients and provide net clinical benefit in these key subgroups. Coronavirus disease-2019 may predispose patients to VTE due to excessive inflammation, platelet activation, endothelial dysfunction, and hemostasis. The optimum preventive strategy for these patients requires further investigation. This article aims to review the latest concepts in predicting and preventing VTE and discuss the new era of extended thromboprophylaxis in hospitalized medically ill patients.

Using big data to retrospectively validate the COMPASS-CAT risk assessment model: considerations on methodology.

External validation is a prerequisite in order for a prediction model to be introduced into clinical practice. Nonetheless, methodologically intact external validation studies are a scarce finding. Utilization of big datasets can help overcome several causes of methodological failure. However, transparent reporting is needed to standardize the methods, assess the risk of bias and synthesize multiple validation studies in order to infer model generalizability. We describe the methodological challenges faced when using multiple big datasets to perform the first retrospective external validation study of the Prospective Comparison of Methods for thromboembolic risk assessment with clinical Perceptions and AwareneSS in real life patients-Cancer Associated Thrombosis (COMPASS-CAT) Risk Assessment Model for predicting venous thromboembolism in patients with cancer. The challenges included choosing the starting point, defining time sensitive variables that serve both as risk factors and outcome variables and using non-research oriented databases to form validated definitions from administrative codes. We also present the structured plan we used so as to overcome those obstacles and reduce bias with the target of producing an external validation study that successfully complies with prediction model reporting guidelines.

Incidence of Venous Thromboembolism and Mortality in Patients with Initial Presentation of COVID-19.

Venous thromboembolism (VTE) has emerged as an important issue in patients with COVID-19. The purpose of this study is to identify the incidence of VTE and mortality in COVID-19 patients initially presenting to a large health system. Our retrospective study included adult patients (excluding patients presenting with obstetric/gynecologic conditions) across a multihospital health system in the New York Metropolitan Region from March 1-April 27, 2020. VTE and mortality rates within 8 h of assessment were described. In 10,871 adults with COVID-19, 118 patients (1.09%) were diagnosed with symptomatic VTE (101 pulmonary embolism, 17 deep vein thrombosis events) and 28 patients (0.26%) died during initial assessment. Among these 146 patients, 64.4% were males, 56.8% were 60 years or older, 15.1% had a BMI > 35, and 11.6% were admitted to the intensive care unit. Comorbidities included hypertension (46.6%), diabetes (24.7%), hyperlipidemia (14.4%), chronic lung disease (12.3%), coronary artery disease (11.0%), and prior VTE (7.5%). Key medications included corticosteroids (22.6%), statins (21.2%), antiplatelets (20.6%), and anticoagulants (20.6%). Highest D-Dimer was greater than six times the upper limit of normal in 51.4%. Statin and antiplatelet use were associated with decreased VTE or mortality (each p < 0.01). In COVID-19 patients who initially presented to a large multihospital health system, the overall symptomatic VTE and mortality rate was over 1.0%. Statin and antiplatelet use were associated with decreased VTE or mortality. The potential benefits of antithrombotics in high risk COVID-19 patients during the pre-hospitalization period deserves study.

External validation of the IMPROVE-DD risk assessment model for venous thromboembolism among inpatients with COVID-19.

There is a need to discriminate which COVID-19 inpatients are at higher risk for venous thromboembolism (VTE) to inform prophylaxis strategies. The IMPROVE-DD VTE risk assessment model (RAM) has previously demonstrated good discrimination in non-COVID populations. We aimed to externally validate the IMPROVE-DD VTE RAM in medical patients hospitalized with COVID-19. This retrospective cohort study evaluated the IMPROVE-DD VTE RAM in adult patients with COVID-19 admitted to one of thirteen Northwell Health hospitals in the New York metropolitan area between March 1, 2020 and April 27, 2020. VTE was defined as new-onset symptomatic deep venous thrombosis or pulmonary embolism. To assess the predictive value of the RAM, the receiver operating characteristic (ROC) curve was plotted and the area under the curve (AUC) was calculated. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. Of 9407 patients who met study criteria, 274 patients developed VTE with a prevalence of 2.91%. The VTE rate was 0.41% for IMPROVE-DD score 0-1 (low risk), 1.21% for score 2-3 (moderate risk), and 5.30% for score ≥ 4 (high risk). Approximately 45.7% of patients were classified as high VTE risk, 33.3% moderate risk, and 21.0% low risk. Discrimination of low versus moderate-high VTE risk demonstrated sensitivity 0.971, specificity 0.215, PPV 0.036, and NPV 0.996. ROC AUC was 0.703. In this external validation study, the IMPROVE-DD VTE RAM demonstrated very good discrimination to identify hospitalized COVID-19 patients at low, moderate, and high VTE risk.

External Validation of a Venous Thromboembolic Risk Score for Cancer Outpatients with Solid Tumors: The COMPASS-CAT Venous Thromboembolism Risk Assessment Model.

BACKGROUND: Current risk assessment models (RAMs) for prediction of venous thromboembolism (VTE) risk in the outpatient cancer population have shown poor predictive value in many of the most common cancers. The Comparison of Methods for Thromboembolic Risk Assessment with Clinical Perceptions and AwareneSS in Real Life Patients-Cancer Associated Thrombosis (COMPASS-CAT) RAM was derived in this patient population and predicted patients at high risk for VTE even after initiation of chemotherapy. We sought to externally validate this RAM. MATERIALS AND METHODS: Patients aged ≥18 years who presented to a tertiary care center between January 1, 2014, and December 31, 2016, with invasive breast, ovarian, lung, or colorectal cancers were included. The COMPASS-CAT RAM was applied using our health system's tumor registry and variables that were identified by International Statistical Classification of Diseases and Related Health Problems-9 and -10 codes of the electronic health record and independent chart review. The primary endpoint at 6-month study follow-up was documented VTE. RESULTS: A total of 3,814 patients were included. Documented VTE at 6-month follow-up occurred in 5.85% of patients. Patients stratified into low/intermediate- and high-risk groups had VTE rates of 2.27% and 6.31%, respectively. The sensitivity, specificity, and negative and positive predictive value of the RAM were 95%, 12%, 97.73%, and 6.31%, respectively. Diagnostic accuracy via receiver operating characteristic curve was calculated at 0.62 of the area under the curve. CONCLUSION: In this large retrospective external validation study of the COMPASS-CAT RAM for VTE in patients with cancer undergoing active treatment, model discrimination was moderate and calibration was poor. The model had good negative predictive value. Further prospective validation studies-especially within 6 months of cancer diagnosis-are needed before the model can be implemented into routine clinical practice for primary thromboprophylaxis of high-VTE-risk patients with cancer with solid tumors. IMPLICATIONS FOR PRACTICE: This study provides further guidance for researchers and clinicians in determining clinical and laboratory risk factors associated with development of venous thromboembolism among the ambulatory population of patients being treated for lung, breast, colorectal, or ovarian cancer. It validates the COMPASS-CAT risk model that was developed in this cancer population and suggests that further prospective validation of the model, with more focus on patients within 6 months of their index cancer diagnosis, would likely enhance the accuracy and usefulness of this model as a clinical prediction tool.

Heparin Bridging Therapy for Patients on Chronic Oral Anticoagulants in Periprocedural Settings.

Interruption of chronic anticoagulation due to the bleeding risk associated with an elective procedure may also lead to an elevated risk of thromboembolism. Periprocedural bridging with either unfractionated heparin or low-molecular weight heparin had been the mainstay of therapy for many patients receiving chronic warfarin treatment based on an estimation of a patient's thromboembolic risk. However, recent results from cohort studies and placebo-controlled randomized trials in the periprocedural use of heparin bridging for warfarin-treated patients reveal a consistent two- to three-fold increase in the risk of major bleeding and no benefit in terms of a reduction in the risk of stroke and systemic embolism. The most recent antithrombotic guidance statements suggest that the majority of patients on chronic warfarin, except those at high risk of thromboembolism, may safely interrupt and resume warfarin without heparin bridging in elective periprocedural settings. In addition, data from the use of heparin bridging in patients on direct oral anticoagulants during temporary interruption for an elective procedure also reveal harm and no benefits of this approach. A strategy that considers the pharmacokinetic properties of the direct oral anticoagulants, the bleeding risk of each procedure, and patient renal function would safely obviate the need for heparin bridging. In this review, the authors summarize the major studies of heparin bridging for patients on chronic oral anticoagulants that may lead to a change in practice in periprocedural antithrombotic management and define an evidence-based heparin bridging protocol for those patient groups who may be the candidates for this approach.

Anticoagulant Reversal Strategies in the Emergency Department Setting: Recommendations of a Multidisciplinary Expert Panel.

Bleeding is the most common complication of anticoagulant use. The evaluation and management of the bleeding patient is a core competency of emergency medicine. As the prevalence of patients receiving anticoagulant agents and variety of anticoagulants with different mechanisms of action, pharmacokinetics, indications, and corresponding reversal agents increase, physicians and other clinicians working in the emergency department require a current and nuanced understanding of how best to assess, treat, and reverse anticoagulated patients. In this project, we convened an expert panel to create a consensus decision tree and framework for assessment of the bleeding patient receiving an anticoagulant, as well as use of anticoagulant reversal or coagulation factor replacement, and to address controversies and gaps relevant to this topic. To support decision tree interpretation, the panel also reached agreement on key definitions of life-threatening bleeding, bleeding at a critical site, and emergency surgery or urgent invasive procedure. To reach consensus recommendations, we used a structured literature review and a modified Delphi technique by an expert panel of academic and community physicians with training in emergency medicine, cardiology, hematology, internal medicine/thrombology, pharmacology, toxicology, transfusion medicine and hemostasis, neurology, and surgery, and by other key stakeholder groups.

Does telehealth improve anticoagulation management in patient service centers (PSC)? A pilot project.

Anticoagulation Management Services (AMS) are known to improve warfarin management in the outpatient setting. The guideline recommendations are well established and indicate that patients who receive a Vitamin K antagonist (VKA) should be under the care of an experienced and specialized anticoagulation clinic (Lip et al. in Chest 154(5):1121-1201, 2018). Warfarin, a VKA, is considered a high risk medication and one of the most common causes of adverse events with poor patient outcomes. Anticoagulation care is assessed by measuring the percent of Time in Therapeutic Range (TTR) in patients receiving a VKA. Evidence shows that a 10% improvement in TTR has been associated with a 10% reduction in adverse event rates. Optimal management over usual medical care should prevent 7 myocardial infarctions, strokes, major bleeds, or deaths per 100 patients/year (Bussey et al. in Pharmacotherapy 9(4):214-219, 1989). Telehealth or telemedicine can be defined as the use of electronic information along with telecommunication technologies to provide medical services to individuals that are in remote locations from each other (Perednia in JAMA 273(6):483-488, 1995; Gray et al in J Thromb Thrombolysis 2019(48):690-693, 2019). This technology allows a provider located at a distant site to use two-way audio visual electronic communication to deliver clinical health care services to a patient who is located at an originating site (Kristian et al. Int J Technol Assess Health Care 28(1):44-51, 2012; Testa and Zimmermann in Telemedicine for managing patients on oral anticoagulant, 2011; Telehealth Services in CMS Manual System Pub 100-04 medicare claims processing, 2019). The goals of the Telehealth Anticoagulation Management Service are to: (1) increase patient satisfaction (2) reduce turnaround time for results by providing the INR (International Normal Ratio) results in real time (3) increase patient compliance to INR testing and (4) improve system wide anticoagulation care by increasing cTTR (center Time in Therapeutic Range) metrics to high quality metrics of 65% and above. The overarching goal of our health system Telehealth program was to develop a collaborative care telemedicine INR model in collaboration with core laboratories (Patient Service Centers or PSCs) in order to improve patient quality metrics on warfarin. In this model, the Tele-ACTS Center (Telehealth Anticoagulation and Clinical Thrombosis Service) team was able to provide distant care for the outpatient population on warfarin maintenance therapy using a virtual telemedicine INR model located in a distant location to the PSC. Using this model, we were able to improve center-based TTR by 45.73%.

Periprocedural Outcomes of Direct Oral Anticoagulants Versus Warfarin in Nonvalvular Atrial Fibrillation.

BACKGROUND: Direct oral anticoagulants (DOACs) are surpassing warfarin as the anticoagulant of choice for stroke prevention in nonvalvular atrial fibrillation. DOAC outcomes in elective periprocedural settings have not been well elucidated and remain a source of concern for clinicians. The aim of this meta-analysis was to evaluate the periprocedural safety and efficacy of DOACs versus warfarin in patients with nonvalvular atrial fibrillation. METHODS: We reviewed the literature for data from phase III randomized controlled trials comparing DOACs with warfarin in the periprocedural period among patients with nonvalvular atrial fibrillation. Substudies from 4 trials (RE-LY [Randomized Evaluation of Long-Term Anticoagulation Therapy], ROCKET AF [Rivaroxaban Once Daily Oral Direct Factor Xa Inhibitor Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation], ARISTOTLE [Apixaban for the Prevention of Stroke in Subjects With Atrial Fibrillation], and ENGAGE-AF [Effective Anticoagulation With Factor xA Next Generation in Atrial Fibrillation]) were included in the meta-analysis. DOACs as a group and warfarin were compared in terms of the 30-day pooled risk for stroke/systemic embolism, major bleeding, and death, according to whether the study drug was interrupted or not periprocedurally. The overall relative risk (RR) was estimated with a random-effects model. The I2 test was used to assess heterogeneity in RR among the studies. RESULTS: In the uninterrupted anticoagulant strategy, there were no differences in the rates of stroke/systemic embolism (pooled risk, 0.6% [29 events/4519 procedures] versus 1.1% [31/2971]; RR, 0.70; 95% confidence interval [CI], 0.41-1.18) and death (1.4% versus 1.8%; RR, 0.77; 95% CI, 0.53-1.12) between DOACs and warfarin and significantly fewer major bleeding events (2.0% versus 3.3%; RR, 0.62; 95% CI, 0.47-0.82) with DOACs compared to warfarin. Under an interrupted strategy, there was no significant difference between DOACs versus warfarin for stroke/systemic embolism (0.4% [41/9260] versus 0.5% [31/7168]; RR, 0.95; 95% CI, 0.59-1.55), major bleeding (2.1% versus 2.0%; RR, 1.05; 95% CI, 0.85-1.30), and death (0.7% versus 0.6%; RR, 1.24; 95% CI, 0.76-2.04). The studies were homogeneous ( I2=0.0%) for all calculated pooled associations except for the RR of death in the interrupted strategy ( I2=26.3%). CONCLUSIONS: The short-term safety and efficacy of DOACs and warfarin are not different in patients with nonvalvular atrial fibrillation periprocedurally. Under an uninterrupted anticoagulation strategy, DOACs are associated with a 38% lower risk of major bleeding compared with warfarin.

Comparative effectiveness, safety, and costs of rivaroxaban and warfarin among morbidly obese patients with atrial fibrillation.

BACKGROUND: There are limited data regarding clinical outcomes and healthcare resource utilization of direct oral anticoagulants (DOACs) in patients with atrial fibrillation (AF) who are morbidly obese (body mass index >40 kg/m2 or body weight >120 kg). METHODS: Using data from 2 US healthcare claims databases, we identified patients initiating rivaroxaban or warfarin who had ≥1 medical claim with an AF diagnosis, a diagnostic code for morbid obesity (ICD-9: 278.01, V85.4%; ICD-10: E66.01%, E66.2%, Z68.4%), and a minimum continuous enrollment of 12 months before and 3 months after treatment initiation. Patients were excluded if they had mitral stenosis, a mechanical heart valve procedure, an organ/tissue transplant, or an oral anticoagulant prescription prior to the index date. Rivaroxaban and warfarin patients were 1:1 propensity score matched. Conditional logistic regression was used to compare ischemic stroke/systemic embolism and major bleeding risk. Generalized linear models were used to compare healthcare resource utilization and costs. RESULTS: A total of 3563 matched pairs of morbidly obese AF patients treated with rivaroxaban or warfarin were identified. The majority (81.4%) of patients in the rivaroxaban cohort were receiving the 20 mg dose. The rivaroxaban and warfarin cohorts were well balanced after propensity score matching. The risks of ischemic stroke/systemic embolism and major bleeding were similar for rivaroxaban and warfarin users (stroke/systemic embolism: 1.5% vs 1.7%; odds ratio [OR]: 0.88; 95% confidence interval [CI]: 0.60, 1.28; P = .5028; major bleeding: 2.2% vs 2.7%; OR: 0.80; 95% CI: 0.59, 1.08; P = .1447). Total healthcare costs including medication costs per patient per year (PPPY) were significantly lower with rivaroxaban versus warfarin ($48,552 vs $52,418; P = .0025), which was primarily driven by lower hospitalization rate (50.2% vs 54.1%; P = .0008), shorter length of stay (7.5 vs 9.1 days; P = .0010), and less outpatient service utilization (86 vs 115 visits PPPY; P < .0001). CONCLUSIONS: Morbidly obese AF patients treated with rivaroxaban had comparable risk of ischemic stroke/systemic embolism and major bleeding as those treated with warfarin, but lower healthcare resource utilization and costs.