How I treat pediatric venous thromboembolism in the DOAC era.

ABSTRACT: The direct oral anticoagulants (DOACs) rivaroxaban and dabigatran are newly licensed for the treatment and prevention of venous thromboembolism (VTE) in children and mark a renaissance in pediatric anticoagulation management. They provide a convenient option over standard-of-care anticoagulants (heparins, fondaparinux, and vitamin K antagonists) because of their oral route of administration, child-friendly formulations, and significant reduction in monitoring. However, limitations related to therapeutic monitoring when needed and the lack of approved reversal agents for DOACs in children raise some safety concerns. There is accumulating experience of safety and efficacy of DOACs in adults for a broad scope of indications; however, the cumulative experience of using DOACs in pediatrics, specifically for those with coexisting chronic illnesses, is sparse. Consequently, clinicians must often rely on their experience for treating VTE and extrapolate from data in adults while using DOACs in children. In this article, the authors share their experience of managing 4 scenarios that hematologists are likely to encounter in their day-to-day practice. Topics addressed include (1) appropriateness of indication; (2) use for special populations of children; (3) considerations for laboratory monitoring; (4) transition between anticoagulants; (5) major drug interactions; (6) perioperative management; and (7) anticoagulation reversal.

Rivaroxaban in Rheumatic Heart Disease-Associated Atrial Fibrillation.

BACKGROUND: Testing of factor Xa inhibitors for the prevention of cardiovascular events in patients with rheumatic heart disease-associated atrial fibrillation has been limited. METHODS: We enrolled patients with atrial fibrillation and echocardiographically documented rheumatic heart disease who had any of the following: a CHA2DS2VASc score of at least 2 (on a scale from 0 to 9, with higher scores indicating a higher risk of stroke), a mitral-valve area of no more than 2 cm2, left atrial spontaneous echo contrast, or left atrial thrombus. Patients were randomly assigned to receive standard doses of rivaroxaban or dose-adjusted vitamin K antagonist. The primary efficacy outcome was a composite of stroke, systemic embolism, myocardial infarction, or death from vascular (cardiac or noncardiac) or unknown causes. We hypothesized that rivaroxaban therapy would be noninferior to vitamin K antagonist therapy. The primary safety outcome was major bleeding according to the International Society of Thrombosis and Hemostasis. RESULTS: Of 4565 enrolled patients, 4531 were included in the final analysis. The mean age of the patients was 50.5 years, and 72.3% were women. Permanent discontinuation of trial medication was more common with rivaroxaban than with vitamin K antagonist therapy at all visits. In the intention-to-treat analysis, 560 patients in the rivaroxaban group and 446 in the vitamin K antagonist group had a primary-outcome event. Survival curves were nonproportional. The restricted mean survival time was 1599 days in the rivaroxaban group and 1675 days in the vitamin K antagonist group (difference, -76 days; 95% confidence interval [CI], -121 to -31; P<0.001). A higher incidence of death occurred in the rivaroxaban group than in the vitamin K antagonist group (restricted mean survival time, 1608 days vs. 1680 days; difference, -72 days; 95% CI, -117 to -28). No significant between-group difference in the rate of major bleeding was noted. CONCLUSIONS: Among patients with rheumatic heart disease-associated atrial fibrillation, vitamin K antagonist therapy led to a lower rate of a composite of cardiovascular events or death than rivaroxaban therapy, without a higher rate of bleeding. (Funded by Bayer; INVICTUS ClinicalTrials.gov number, NCT02832544.).

Development and Validation of the DOAC Score: A Novel Bleeding Risk Prediction Tool for Patients With Atrial Fibrillation on Direct-Acting Oral Anticoagulants.

BACKGROUND: Current clinical decision tools for assessing bleeding risk in individuals with atrial fibrillation (AF) have limited performance and were developed for individuals treated with warfarin. This study develops and validates a clinical risk score to personalize estimates of bleeding risk for individuals with atrial fibrillation taking direct-acting oral anticoagulants (DOACs). METHODS: Among individuals taking dabigatran 150 mg twice per day from 44 countries and 951 centers in this secondary analysis of the RE-LY trial (Randomized Evaluation of Long-Term Anticoagulation Therapy), a risk score was developed to determine the comparative risk for bleeding on the basis of covariates derived in a Cox proportional hazards model. The risk prediction model was internally validated with bootstrapping. The model was then further developed in the GARFIELD-AF registry (Global Anticoagulant Registry in the Field-Atrial Fibrillation), with individuals taking dabigatran, edoxaban, rivaroxaban, and apixaban. To determine generalizability in external cohorts and among individuals on different DOACs, the risk prediction model was validated in the COMBINE-AF (A Collaboration Between Multiple Institutions to Better Investigate Non-Vitamin K Antagonist Oral Anticoagulant Use in Atrial Fibrillation) pooled clinical trial cohort and the Quebec Régie de l'Assurance Maladie du Québec and Med-Echo Administrative Databases (RAMQ) administrative database. The primary outcome was major bleeding. The risk score, termed the DOAC Score, was compared with the HAS-BLED score. RESULTS: Of the 5684 patients in RE-LY, 386 (6.8%) experienced a major bleeding event, within a median follow-up of 1.74 years. The prediction model had an optimism-corrected C statistic of 0.73 after internal validation with bootstrapping and was well-calibrated based on visual inspection of calibration plots (goodness-of-fit P=0.57). The DOAC Score assigned points for age, creatinine clearance/glomerular filtration rate, underweight status, stroke/transient ischemic attack/embolism history, diabetes, hypertension, antiplatelet use, nonsteroidal anti-inflammatory use, liver disease, and bleeding history, with each additional point scored associated with a 48.7% (95% CI, 38.9%-59.3%; P<0.001) increase in major bleeding in RE-LY. The score had superior performance to the HAS-BLED score in RE-LY (C statistic, 0.73 versus 0.60; P for difference <0.001) and among 12 296 individuals in GARFIELD-AF (C statistic, 0.71 versus 0.66; P for difference = 0.025). The DOAC Score had stronger predictive performance than the HAS-BLED score in both validation cohorts, including 25 586 individuals in COMBINE-AF (C statistic, 0.67 versus 0.63; P for difference <0.001) and 11 945 individuals in RAMQ (C statistic, 0.65 versus 0.58; P for difference <0.001). CONCLUSIONS: In individuals with atrial fibrillation potentially eligible for DOAC therapy, the DOAC Score can help stratify patients on the basis of expected bleeding risk.

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.

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.

Rivaroxaban Plus Aspirin Versus Aspirin Alone After Endovascular Revascularization for Symptomatic PAD: Insights From VOYAGER PAD.

BACKGROUND: Rivaroxaban plus aspirin compared with aspirin alone reduced major cardiac and ischemic limb events after lower extremity revascularization (LER) in the VOYAGER PAD (Vascular Outcomes Study of ASA Along With Rivaroxaban in Endovascular or Surgical Limb Revascularization for Peripheral Artery Disease) trial. The effect has not been described in patients undergoing endovascular LER. METHODS: The VOYAGER PAD trial randomized 6564 patients with symptomatic peripheral artery disease to a double-blinded treatment with 2.5 mg of rivaroxaban BID or matching placebo and 100 mg of aspirin daily. The primary efficacy outcome was a composite of acute limb ischemia, major amputation of a vascular pathogenesis, myocardial infarction, ischemic stroke, or cardiovascular death. The principal safety end point was Thrombolysis in Myocardial Infarction major bleeding. A prespecified subgroup of patients who underwent endovascular revascularization was included. RESULTS: Endovascular LER occurred in 4379 (66.7%) patients and surgical LER in 2185 (33.3%). Over a 3-year follow-up, rivaroxaban reduced the risk of the primary outcome by 15% (hazard ratio [HR], 0.85 [95% CI, 0.76-0.96]) with an absolute risk reduction of 0.92% at 6 months and 1.04% at 3 years and a consistent benefit in those receiving endovascular (HR, 0.89 [95% CI, 0.76-1.03]) or surgical LER (HR, 0.81 [95% CI, 0.67-0.98]; P interaction=0.43). For endovascular-treated patients, rivaroxaban reduced the risk of acute limb ischemia or major amputation of a vascular pathogenesis by 30% (HR, 0.70 [95% CI, 0.54-0.90]; P=0.005) with an absolute risk reduction of 1.0% at 6 months and 2.0% at 3 years compared with aspirin alone. Among endovascular-treated patients, the median duration of concomitant dual antiplatelet therapy with clopidogrel treatment was 31 days (interquartile range, 30-58). There was a consistent benefit for rivaroxaban regardless of background clopidogrel. Thrombolysis in Myocardial Infarction major bleeding was significantly higher for the rivaroxaban and aspirin group for the endovascular cohort (HR, 1.66 [95% CI, 1.06-2.59]) with an absolute risk increase of 0.9% at 3 years with no increase in intracranial or fatal bleeding observed (HR, 0.86 [95% CI, 0.40-1.87]; P=0.71). Mortality with rivaroxaban was higher in the endovascular-treated patients (HR, 1.24 [95% CI, 1.02-1.52]), although this finding was isolated to specific regions. CONCLUSIONS: Rivaroxaban added to aspirin or dual antiplatelet therapy after LER for peripheral artery disease reduces ischemic risk and increases major bleeding without an increased risk of intracranial or fatal bleeding. These benefits are consistent in those treated with endovascular and surgical approaches with significant benefits for major adverse limb events. These data support the use of rivaroxaban in addition to aspirin or dual antiplatelet therapy after endovascular intervention for symptomatic peripheral artery disease.

Comparative Effectiveness and Safety of Direct Oral Anticoagulants and Warfarin in Patients With Atrial Fibrillation and Chronic Liver Disease: A Nationwide Cohort Study.

BACKGROUND: The benefit-risk profile of direct oral anticoagulants (DOACs) compared with warfarin, and between DOACs in patients with atrial fibrillation (AF) and chronic liver disease is unclear. METHODS: We conducted a new-user, retrospective cohort study of patients with AF and chronic liver disease who were enrolled in a large, US-based administrative database between January 1, 2011, and December 31, 2017. We assessed the effectiveness and safety of DOACs (as a class and individually) compared with warfarin, and between DOACs in patients with AF and chronic liver disease. The primary outcomes were hospitalization for ischemic stroke/systemic embolism and hospitalization for major bleeding. Inverse probability treatment weights were used to balance the treatment groups on measured confounders. RESULTS: Overall, 10 209 participants were included, with 4421 (43.2%) on warfarin, 2721 (26.7%) apixaban, 2211 (21.7%) rivaroxaban, and 851 (8.3%) dabigatran. The incidence rates per 100 person-years for ischemic stroke/systemic embolism were 2.2, 1.4, 2.6, and 4.4 for DOACs as a class, apixaban, rivaroxaban, and warfarin, respectively. The incidence rates per 100 person-years for major bleeding were 7.9, 6.5, 9.1, and 15.0 for DOACs as a class, apixaban, rivaroxaban, and warfarin, respectively. After inverse probability treatment weights, the risk of hospitalization for ischemic stroke/systemic embolism was significantly lower between DOACs as a class (hazard ratio [HR], 0.64 [95% CI, 0.46-0.90]) or apixaban (HR, 0.40 [95% CI, 0.19-0.82]) compared with warfarin, but not significantly different between rivaroxaban versus warfarin (HR, 0.76 [95% CI, 0.47-1.21]) or rivaroxaban versus apixaban (HR, 1.73 [95% CI, 0.91-3.29]). Compared with warfarin, the risk of hospitalization for major bleeding was lower with DOACs as a class (HR, 0.69 [95% CI, 0.58-0.82]), apixaban (HR, 0.60 [95% CI, 0.46-0.78]), and rivaroxaban (HR, 0.79 [95% CI, 0.62-1.0]). However, the risk of hospitalization for major bleeding was higher for rivaroxaban versus apixaban (HR, 1.59 [95% CI, 1.18-2.14]). CONCLUSIONS: Among patients with AF and chronic liver disease, DOACs as a class were associated with lower risks of hospitalization for ischemic stroke/systemic embolism and major bleeding versus warfarin. However, the incidence of clinical outcomes among patients with AF and chronic liver disease varied between individual DOACs and warfarin, and in head-to-head DOAC comparisons.

Direct factor Xa inhibitors and the risk of cancer and cancer mortality: A Danish population-based cohort study.

BACKGROUND: Preclinical animal studies have suggested that myeloid cell-synthesized coagulation factor X dampens antitumor immunity and that rivaroxaban, a direct factor Xa inhibitor, can be used to promote tumor immunity. This study was aimed at assessing whether patients with atrial fibrillation taking direct factor Xa inhibitors have lower risk of cancer and cancer-related mortality than patients taking the direct thrombin inhibitor dabigatran. METHODS AND FINDINGS: This nationwide population-based cohort study in Denmark included adult patients with atrial fibrillation and without a history of cancer, who started taking a factor Xa inhibitor or dabigatran between 2011 and 2015. Data on medical history, outcomes, and drug use were acquired through Danish healthcare registries. The primary outcome was any cancer. Secondary outcomes were cancer-related mortality and all-cause mortality. Outcome events were assessed during 5 years of follow-up in an intention-to-treat analysis. The propensity score-based inverse probability of treatment weighting was used to compute cumulative incidence and subdistribution hazard ratios (SHRs) and corresponding 95% confidence intervals (CIs), with death as a competing event. Propensity scores were estimated using logistic regression and including in the model sex, age group at index date, comorbidities, and use of comedications. A total of 11,742 patients with atrial fibrillation starting a factor Xa inhibitor and 11,970 patients starting dabigatran were included. Mean age was 75.2 years (standard deviation [SD] 11.2) in the factor Xa cohort and 71.7 years (SD 11.1) in the dabigatran cohort. On the basis of the propensity score-weighted models, after 5 years of follow-up, no substantial difference in the cumulative incidence of cancer was observed between the factor Xa inhibitor (2,157/23,711; 9.11%, 95% CI [8.61%,9.63%]) and dabigatran (2,294/23,715; 9.68%, 95% CI [9.14%,10.25%]) groups (SHR 0.94, 95% CI [0.89,1.00], P value 0.0357). We observed no difference in cancer-related mortality (factor Xa inhibitors cohort 1,028/23,711; 4.33%, 95% CI [4.02%,4.68%]. Dabigatran cohort 1,001/23,715; 4.22%, 95% CI [3.83%,4.66%]; SHR 1.03, 95% CI [0.94,1.12]), but all-cause mortality was higher in the factor Xa inhibitor cohort (factor Xa inhibitors cohort 7,416/23,711; 31.31%, 95% CI [30.37%,32.29%]. Dabigatran cohort 6,531/23,715; 27.56%, 95% CI [26.69%,28.45%]; HR 1.17, 95% CI [1.13,1.21]). The main limitations of the study were the possibility of residual confounding and the short follow-up period. CONCLUSIONS: In this population based cohort study, factor Xa inhibitor use was not associated with an overall lower incidence of cancer or cancer-related mortality when compared to dabigatran. We did observe an increase in all-cause mortality in the factor Xa inhibitor cohort.

An Analysis of Delayed Bleeding in Cases of Colorectal Endoscopic Submucosal Dissection Due to Types of Direct Oral Anticoagulants in Japan.

BACKGROUND & AIMS: Reported rates of delayed bleeding (DB) after endoscopic resection using direct oral anticoagulants (DOACs) are high and heterogeneous. This large-scale multicenter study analyzed cases of DB after colorectal endoscopic submucosal dissection related to various types of DOACs in Japan (the ABCD-J study) with those associated with warfarin. METHODS: We retrospectively reviewed 1019 lesions in patients treated with DOACs and 459 lesions in patients treated with warfarin among 34,455 endoscopic submucosal dissection cases from 47 Japanese institutions between 2012 and 2021. The DB rate (DBR) with each DOAC was compared with that with warfarin. Risk factors for DB in patients treated with DOACs or warfarin were also investigated. RESULTS: The mean tumor sizes in the DOAC and warfarin groups were 29.6 ± 14.0 and 30.3 ± 16.4 mm, respectively. In the DOAC group, the DBR with dabigatran (18.26%) was significantly higher than that with apixaban (10.08%, P = .029), edoxaban (7.73%, P = .001), and rivaroxaban (7.21%, P < .001). Only rivaroxaban showed a significantly lower DBR than warfarin (11.76%, P = .033). In the multivariate analysis, heparin bridging therapy (odds ratio [OR], 2.18; 95% confidence interval [CI], 1.27-3.73, P = .005), rectal location (2.01, 1.28-3.16, P = .002), and procedure time ≥55 minutes (2.43, 1.49-3.95, P < .001) were significant risk factors for DB in the DOAC group. The DB risk in the DOAC group (OR, (95% CI)) was 2.13 (1.30-3.50) and 4.53 (2.52-8.15) for 1 and 2 significant risk factors, respectively. CONCLUSIONS: Dabigatran was associated with a higher DBR than other DOACs, and only rivaroxaban was associated with a significantly lower DBR than warfarin.

Identifying the highest risk vascular patients: Insights from the XATOA registry.

BACKGROUND: Patients with coronary and peripheral artery disease (PAD) have a residual risk of major adverse cardiovascular and limb events despite standards of care. Among patients with coronary artery disease (CAD) and/or PAD selected for low dose rivaroxaban (2.5 mg BID) and aspirin, we sought to determine the highest risk vascular patients. METHODS: Xarelto pluc Acetylsalicylic acid: Treatment patterns and Outcomes in patients with Atherosclerosis (XATOA) is a single-arm registry of CAD and/or PAD patients. All participants were initiated on low dose rivaroxaban (2.5 mg BID) and aspirin. We report the incidence risk of major adverse cardiovascular events (MACE) or major adverse limb events (MALE) and major bleeding. A classification and regression tree analysis determined independent subgroups. RESULTS: Between November 2018 and May 2020, 5,808 participants were enrolled in XATOA; 5,532 were included in the full analysis. The median follow-up (interquartile range) was 462 (371-577) days. The incidence risk per 100 patient-years of MACE or MALE was highest among participants with polyvascular disease (2 or more vascular beds affected, n = 2,889). The incidence risk was 9.16 versus 2.48 per 100 patient-years in polyvascular and nonpolyvascular patients respectively. Other subgroups of high-risk patients included participants 75 years or older, with a history of diabetes, heart failure, or chronic renal insufficiency (CRI). Rates of major bleeding were low overall. A classification and regression tree analysis showed that polyvascular disease was the most dominant factor separating higher from lower risk participants, and this was heightened with CRI or diabetes. CONCLUSION: Patients with polyvascular disease represent a substantial subset of patients in clinical practice and should be prioritized to receive maximal medical therapy including low dose rivaroxaban (2.5 mg BID) and aspirin.

Drug-Drug Interactions in the Treatment of Cancer-Associated Venous Thromboembolism with Direct Oral Anticoagulants.

Venous thromboembolism (VTE) is a frequent complication of cancer, and management of cancer-associated thrombosis (CAT) is challenging due to increased risks of bleeding and recurrent VTE. Recent trials have shown an acceptable efficacy and safety of direct oral anticoagulants (DOACs) in the treatment of CAT compared to low-molecular weight heparin. Although DOACs provide an effective and convenient treatment option in CAT, the need to assess the risk of drug-drug interactions (DDI) with antineoplastic therapies poses a barrier to their use in clinical practice. With the aim of supporting the assessment of CAT patients for treatment with DOAC, this review provides a comprehensive overview of the compatibility of antineoplastic therapies with the individual DOACs (apixaban, dabigatran, edoxaban, and rivaroxaban). Using several data sources, we characterized 100 widely used antineoplastic agents with regard to their effect on p-glycoprotein and cytochrome P450, both important in the transport and elimination of DOACs. This enabled us to evaluate 400 "DOAC-antineoplastic agent"-pairs regarding their likelihood to interact (unlikely, potential, or likely), ultimately leading to clinical recommendations on the appropriateness of concomitant use for each pair. A potential or likely DDI was identified for 12% of the evaluated pairs. For nearly all antineoplastic agents, at least one DOAC was considered compatible.

Comparative Safety and Effectiveness of Warfarin or Rivaroxaban Versus Apixaban in Patients With Advanced CKD and Atrial Fibrillation: Nationwide US Cohort Study.

RATIONALE & OBJECTIVE: Head-to-head data comparing the effectiveness and safety of oral anticoagulants in patients with atrial fibrillation (AF) and advanced chronic kidney disease (CKD) are lacking. We compared the safety and effectiveness of warfarin or rivaroxaban versus apixaban in patients with AF and non-dialysis-dependent CKD stage 4/5. STUDY DESIGN: Propensity score-matched cohort study. SETTING & PARTICIPANTS: 2 nationwide US claims databases, Medicare and Optum's deidentified Clinformatics Data Mart Database, were searched for the interval from January 1, 2013, through March 31, 2022, for patients with nonvalvular AF and CKD stage 4/5 who initiated warfarin versus apixaban (matched cohort, n=12,488) and rivaroxaban versus apixaban (matched cohort, n = 5,720). EXPOSURES: Warfarin, rivaroxaban, or apixaban. OUTCOMES: Primary outcomes included major bleeding and ischemic stroke. Secondary outcomes included all-cause mortality, major gastrointestinal bleeding, and intracranial bleeding. ANALYTICAL APPROACH: Cox regression was used to estimate HRs, and 1:1 propensity-score matching was used to adjust for 80 potential confounders. RESULTS: Compared with apixaban, warfarin initiation was associated with a higher rate of major bleeding (HR, 1.85; 95% CI, 1.59-2.15), including major gastrointestinal bleeding (1.86; 1.53-2.25) and intracranial bleeding (2.15; 1.42-3.25). Compared with apixaban, rivaroxaban was also associated with a higher rate of major bleeding (1.69; 1.33-2.15). All-cause mortality was similar for warfarin (1.08; 0.98-1.18) and rivaroxaban (0.94; 0.81-1.10) versus apixaban. Furthermore, no statistically significant differences for ischemic stroke were observed for warfarin (1.14; 0.83-1.57) or rivaroxaban (0.71; 0.40-1.24) versus apixaban, but the CIs were wide. Similar results were observed for warfarin versus apixaban in the positive control cohort of patients with CKD stage 3, consistent with randomized trial findings. LIMITATIONS: Few ischemic stroke events, potential residual confounding. CONCLUSIONS: In patients with AF and advanced CKD, rivaroxaban and warfarin were associated with higher rates of major bleeding compared with apixaban, suggesting a superior safety profile for apixaban in this high-risk population. PLAIN-LANGUAGE SUMMARY: Different anticoagulants have been shown to reduce the risk of stroke in patients with atrial fibrillation, such as warfarin and direct oral anticoagulants like apixaban and rivaroxaban. Unfortunately, the large-scale randomized trials that compared direct anticoagulants versus warfarin excluded patients with advanced chronic kidney disease. Therefore, the comparative safety and effectiveness of warfarin, apixaban, and rivaroxaban are uncertain in this population. In this study, we used administrative claims data from the United States to answer this question. We found that warfarin and rivaroxaban were associated with increased risks of major bleeding compared with apixaban. There were few stroke events, with no major differences among the 3 drugs in the risk of stroke. In conclusion, this study suggests that apixaban has a better safety profile than warfarin and rivaroxaban.

High Risk of Stroke in Patients With Worsening Heart Failure, Reduced Ejection Fraction, Coronary Heart Disease and Sinus Rhythm: Risk Prediction Score Analysis From the COMMANDER-HF Trial.

BACKGROUND: Patients with heart failure with reduced ejection fraction (HFrEF) and sinus rhythm have a heightened risk of stroke. Whether anticoagulation benefits these patients is uncertain. In this post hoc analysis of the A Study to Assess the Effectiveness and Safety of Rivaroxaban in Reducing the Risk of Death, Myocardial Infarction, or Stroke in Participants with Heart Failure and Coronary Artery Disease Following an Episode of Decompensated Heart Failure (COMMANDER-HF) trial we evaluated how a previously validated risk model consisting of 3 variables (history of prior stroke, insulin-treated diabetes, and N-terminal pro-B-type natriuretic peptide level) would perform, compared with plasma d-dimer, for stroke prediction and estimation of the benefit of low-dose rivaroxaban. METHODS AND RESULTS: Stroke risk and treatment effect were computed across risk score and plasma d-dimer tertiles. Risk score was available in 58% of the COMMANDER-HF population (n = 2928). Over a median follow-up of 512 days (range 342-747 days), 60 patients experienced a stroke (14.6 per 1000 patient-years). The risk model did not identify patients at higher risk of stroke and showed a low overall prognostic performance (C-index = 0.53). The effect of rivaroxaban on stroke was homogeneous across risk score tertiles (P-interaction = .67). Among patients in whom the risk score was estimated, d-dimer was available in 2343 (80%). d-dimer had an acceptable discrimination performance for stroke prediction (C-index = 0.66) and higher plasma d-dimer concentrations were associated with higher rates of stroke (ie, tertile 3 vs tertile 1, hazard ratio 3.65, 95% confidence interval 1.59-8.39, P = .002). Treatment with low-dose rivaroxaban reduced the incidence of stroke in patients at highest risk by d-dimer levels (ie, >515 ng/mL, hazard ratio 0.42, 95% confidence interval 0.18-0.95, P-interaction = .074), without any safety concerns. CONCLUSIONS: In our analysis, plasma d-dimer concentrations performed better than a previously described 3-variable risk score for stroke prediction in patients with heart failure with reduced ejection fraction, a recent clinical worsening and sinus rhythm as enrolled in the COMMANDER-HF trial. In these patients, a raised plasma d-dimer concentration identified patients who might benefit most from rivaroxaban.

Rivaroxaban vs placebo for extended antithrombotic prophylaxis after laparoscopic surgery for colorectal cancer.

The clinical benefit of extended prophylaxis for venous thromboembolism (VTE) after laparoscopic surgery for cancer is unclear. The efficacy and safety of direct oral anticoagulants for this indication are unexplored. PROphylaxis of venous thromboembolism after LAParoscopic Surgery for colorectal cancer Study II (PROLAPS II) was a randomized, double-blind, placebo-controlled, investigator-initiated, superiority study aimed at assessing the efficacy and safety of extended prophylaxis with rivaroxaban after laparoscopic surgery for colorectal cancer. Consecutive patients who had laparoscopic surgery for colorectal cancer were randomized to receive rivaroxaban (10 mg once daily) or a placebo to be started at 7 ± 2 days after surgery and given for the subsequent 3 weeks. All patients received antithrombotic prophylaxis with low-molecular-weight heparin from surgery to randomization. The primary study outcome was the composite of symptomatic objectively confirmed VTE, asymptomatic ultrasonography-detected deep vein thrombosis (DVT), or VTE-related death at 28 ± 2 days after surgery. The primary safety outcome was major bleeding. Patient recruitment was prematurely closed due to study drug expiry after the inclusion of 582 of the 646 planned patients. A primary study outcome event occurred in 11 of 282 patients in the placebo group compared with 3 of 287 in the rivaroxaban group (3.9 vs 1.0%; odds ratio, 0.26; 95% confidence interval [CI], 0.07-0.94; log-rank P = .032). Major bleeding occurred in none of the patients in the placebo group and 2 patients in the rivaroxaban group (incidence rate 0.7%; 95% CI, 0-1.0). Oral rivaroxaban was more effective than placebo for extended prevention of VTE after laparoscopic surgery for colorectal cancer without an increase in major bleeding. This trial was registered at www.clinicaltrials.gov as #NCT03055026.

Comparison of direct oral anticoagulants and warfarin in chronic limb-threatening ischemia.

OBJECTIVE: The role of direct oral anticoagulants (DOACs) in chronic limb-threatening ischemia after revascularization is unknown. Current evidence-based guidelines do not provide clear guidance on the role of anticoagulation or the selection of anticoagulant. Current practice is highly varied and based on provider and patient preference. The purpose of this study was to measure the impact of different anticoagulants on the incidence of major adverse limb events (MALEs) after revascularization for chronic limb-threatening ischemia, major adverse cardiovascular events (MACEs), all-cause mortality, and hospitalization for major bleeding events. METHODS: This was a single-center, observational, retrospective cohort study. Subjects were eligible if they were 18 years or older; underwent endovascular or open revascularization for chronic limb-threatening ischemia, rest pain, or tissue loss; and were subsequently prescribed apixaban, rivaroxaban, or warfarin. The primary end point was the incidence of MALEs, including above-ankle amputation or major index-limb reintervention, within 1 year of index event. Secondary end points included the rate of all-cause mortality, MACEs, and incidence of International Society on Thrombosis and Haemostasis (ISTH) major bleeding. RESULTS: From January 1, 2017, to September 20, 2022, 141 patients met the inclusion and exclusion criteria and were reviewed. The median age was 67 years, with 92 patients prescribed apixaban or rivaroxaban and 49 patients prescribed warfarin. Of these, 42 patients were prescribed triple antithrombotic therapy, 88 dual antithrombotic therapy, and 13 anticoagulant monotherapy. The primary outcome of 1-year MALEs occurred in 36.7% of the warfarin group and 33.7% of the DOAC group (relative risk [RR], 1.09; 95% CI, 0.53-2.25; P = .72). Secondary outcomes of 1-year MACEs (10.2% vs 4.3%; RR, 2.35; 95% CI, 0.60-9.18; P = .18) and 1-year all-cause mortality (26.5% vs 16.3%; RR, 1.63; 95% CI, 0.70-3.78; P = .15) did not differ between the groups. The secondary safety outcome of 1-year ISTH major bleeding occurred in 16.3% of the warfarin group and 4.3% of the DOAC group (RR, 3.76; 95% CI, 1.07-13.19; P = .015). CONCLUSIONS: In patients with chronic limb-threatening ischemia who were revascularized and prescribed anticoagulation with apixaban, rivaroxaban, or warfarin on discharge, no difference in MALEs, MACEs, or all-cause mortality was found. However, 1-year admissions for ISTH major bleeding were significantly higher among patients prescribed warfarin. A randomized trial may confirm these findings.

Cardiac and renal outcomes of direct oral anticoagulants in patients with atrial fibrillation.

BACKGROUND: Oral anticoagulation therapy with warfarin or direct oral anticoagulants (DOACs) is the mainstay for stroke prevention in patients with non-valvular atrial fibrillation (AF). The DOACs might have a lower risk of declining renal function than warfarin. This study aimed to compare renal outcomes among rivaroxaban, edoxaban, dabigatran, and warfarin. METHOD: This cohort study identified 2203 adults with AF who started anticoagulation therapy between 1 July 2013 and 31 December 2020, in a clinical database at a single centre. Inverse probability of treatment weighting was adopted to balance baseline characteristics among four anticoagulants treatment groups. The primary outcome was a composite of cardiac and renal outcomes, involving a ≥30% decline in estimated glomerular filtration rate (eGFR), renal failure and cardiovascular death. RESULTS: After propensity score weighting, dabigatran was associated with significantly lower risks of a ≥30% decline in eGFR (hazard ratio [HR]: .69, 95% confidence interval [CI]: .497-.951, p = .0237), doubling of the serum creatinine level (HR: .49, 95% CI: .259-.927, p = .0282) and the cardiac and renal outcome composite (HR: .67, 95% CI: .485-.913, p = .0115) than warfarin. Rivaroxaban and edoxaban did not show significant protective effects on renal outcomes compared to warfarin. CONCLUSION: In this study, patients treated with dabigatran had significantly reduced risks of declining renal function and composite cardiac and renal events than those treated with warfarin. However, rivaroxaban and edoxaban were not associated with lower risks of any renal outcomes than warfarin. More studies are warranted to investigate and compare the impact of renal function between different DOACs in patients with AF.

Anticoagulation in Patients with Chronic Kidney Disease.

BACKGROUND: Both atrial fibrillation and venous thromboembolism (VTE) are highly prevalent among patients with chronic kidney disease (CKD). Until recently, warfarin was the most commonly prescribed oral anticoagulant. Direct oral anticoagulants (DOACs) have important advantages and have been shown to be noninferior to warfarin with respect to stroke prevention or recurrent VTE in the general population, with lower bleeding rates. This review article will provide available evidence on the use of DOACs in patients with CKD. SUMMARY: In post hoc analyses of major randomized studies with DOACs for stroke prevention in atrial fibrillation, in the subgroup of participants with moderate CKD, defined as a creatinine clearance (CrCl) of 30-50 mL/min, dabigatran 150 mg and apixaban were associated with lower rates of stroke and systemic embolism, whereas apixaban and edoxaban were associated with lower bleeding and mortality rates, compared with warfarin. In retrospective observational studies in patients with advanced CKD (defined as a CrCl <30 mL/min) and atrial fibrillation, DOACs had similar efficacy with warfarin with numerically lower bleeding rates. All agents warrant dose adjustment in moderate-to-severe CKD. In patients on maintenance dialysis, the VALKYRIE trial, which was designed initially to study the effect of vitamin K on vascular calcification progression, established superiority for rivaroxaban compared with a vitamin K antagonist (VKA) in the extension phase. Two other clinical trials using apixaban (AXADIA and RENAL-AF) in this population were inconclusive due to recruitment challenges and low event rates. In post hoc analyses of randomized studies with DOACs in patients with VTE, in the subgroup of participants with moderate CKD at baseline, edoxaban was associated with lower rates of recurrent VTE, whereas rivaroxaban and dabigatran were associated with lower and higher bleeding rates, respectively, as compared to warfarin. KEY MESSAGES: DOACs have revolutionized the management of atrial fibrillation and VTE, and they should be preferred over warfarin in patients with moderate-to-severe CKD with appropriate dose adjustment. Therapeutic drug monitoring with a valid technique may be considered to guide clinical management in individualized cases. Current evidence questions the need for oral anticoagulation in patients on maintenance dialysis with atrial fibrillation as both DOACs and VKAs are associated with high rates of major bleeding.

The impact of ABCB1, CYP3A4/5 and ABCG2 gene polymorphisms on rivaroxaban trough concentrations and bleeding events in patients with non-valvular atrial fibrillation.

BACKGROUND: The influence of genetic factors on the pharmacokinetics and clinical outcomes of rivaroxaban in patients with non-valvular atrial fibrillation (NVAF) is poorly understood. This study aimed to explore the effects of CYP3A4/5, ABCB1, and ABCG2 gene polymorphisms on the trough concentrations and the bleeding risk of rivaroxaban in NVAF patients. PATIENTS AND METHODS: This study is a prospective multicenter study. The patient's blood samples were collected to detect the steady-state trough concentrations of rivaroxaban and gene polymorphisms. We visited the patients regularly at month 1, 3, 6, and 12 to record bleeding events and medications. RESULTS: A total of 95 patients were enrolled in this study, and 9 gene loci were detected. For the dose-adjusted trough concentration ratio (Ctrough/D) of rivaroxaban, the homozygous mutant type was significantly lower than wild type at ABCB1 rs4148738 locus (TT vs. CC, P = 0.033), and the mutant type was significantly lower than the wild type at ABCB1 rs4728709 locus (AA + GA vs. GG, P = 0.008). ABCB1 (rs1045642, rs1128503), CYP3A4 (rs2242480, rs4646437), CYP3A5 (rs776746), and ABCG2 (rs2231137, rs2231142) gene polymorphisms had no significant effect on the Ctrough/D of rivaroxaban. For the bleeding events, we found that there were no significant differences among genotypes of all gene loci. CONCLUSION: This study found for the first time that ABCB1 rs4148738 and rs4728709 gene polymorphisms had a significant impact on the Ctrough/D of rivaroxaban in NVAF patients. CYP3A4/5, ABCB1, and ABCG2 gene polymorphisms were not associated with the bleeding risk of rivaroxaban.

Clinical and molecular determinants of bleeding-related adverse outcomes in high-grade glioma.

PURPOSE: Cancer is an independent risk factor for the development of venous thromboembolism (VTE). However, patients with high-grade glioma (HGG) including glioblastoma (GBM) are at a particularly high risk of VTE with an incidence up to 20-30% per year. Patients are often placed on anticoagulation if they are found to have VTE. However, patients with primary brain tumors such as HGG are at increased risk for intracerebral hemorrhage (ICH) even without the administration of anticoagulation. The combination of risk factors for ICH with anticoagulation and HGG complicates decision-making. Currently it is not known which of the direct oral anticoagulants (DOACs) are safest for patients with HGG in terms of adverse bleeding-related outcomes such as ICH. Furthermore, a deeper understanding of the clinical and molecular determinants of bleeding-related adverse outcomes in HGG is not fully characterized. METHODS: In this retrospective study, we identified and gathered data on 75 consecutive patients with pathology-confirmed HGG with hospital encounters at two academic medical center hospitals in Austin between July 1, 2017 and June 30, 2022. We compared clinical and treatment-related factors among cohorts who had received various forms of anticoagulation or no anticoagulation. RESULTS: Patients who were on rivaroxaban (3/7 (43%)) had a statistically significant association with more bleeding-related adverse events compared to those on apixaban (0/12 (0%)) or enoxaparin (0/5 (0%), p = 0.022) even though the groups were similar in characteristics including total time on the respective anticoagulation. Patients on anticoagulation vs those never on anticoagulation did not differ in terms of their studied demographic and clinical characteristics. Intriguingly, logistic regression analysis revealed that patients Astrocytoma, isocitrate dehydrogenase (IDH) mutant, grade 4 had a significant association with more adverse bleeding-related events even when controlling for other relevant factors (Odds Ratio compared to reference GBM: 49.4, 95% CI: 2.8, 2084.7; p = 0.013). CONCLUSION: In this study we found that the use of rivaroxaban was associated with more bleeding-related events compared to apixaban and enoxaparin in patients with high-grade glioma. In this study we also found that the diagnosis of astrocytoma, IDH mutant, grade 4 was associated with more bleeding events. However, this is based on a small study and there is a need for larger studies to further evaluate these results.

Low-Dose Rivaroxaban as Extended Prophylaxis Reduces Postdischarge Venous Thromboembolism in Patients With Malignancy and IBD.

BACKGROUND: Despite guidelines suggesting the use of extended prophylaxis for prevention of venous thromboembolism in patients with colorectal cancer and perhaps IBD, routine use is low and scant data exist regarding oral forms of therapy. OBJECTIVE: The purpose was to compare the incidence of postdischarge venous thromboembolism in patients given extended prophylaxis with low-dose rivaroxaban. DESIGN: We used propensity matching to compare pre- and postintervention analyses from a 2-year period before instituting extended prophylaxis. SETTING: All colorectal patients at a single institution were prospectively considered for extended prophylaxis. PATIENTS: Patients with a diagnosis of IBD or colorectal cancer who underwent operative resection were included. INTERVENTIONS: Those considered for extended prophylaxis were prescribed 10 mg of rivaroxaban for 30 days postsurgery. MAIN OUTCOME MEASURES: The primary outcome was venous thromboembolism incidence 30 days postdischarge. The secondary outcome was bleeding rates, major or minor. RESULTS: Of the 498 patients considered for extended prophylaxis, 363 were discharged with rivaroxaban, 81 on baseline anticoagulation, and 54 without anticoagulation. Propensity-matched cohorts based on stoma creation, operative approach, procedure type, and BMI were made to 174 historical controls. After excluding cases of inpatient venous thromboembolism, postoperative rates were lower in the prospective cohort (4.8% vs 0.6%, p = 0.019). In the prospective group, 36 episodes of bleeding occurred, 26 (7.2%) were discharged with rivaroxaban, 8 (9.9%) discharged on other anticoagulants, and 2 (3.7%) with no postoperative anticoagulation. Cases of major bleeding were 1.1% (4/363) in the rivaroxaban group, and each required intervention. LIMITATIONS: The study was limited to a single institution and did not include a placebo arm. CONCLUSIONS: Among patients with IBD and colorectal cancer, extended prophylaxis with low-dose rivaroxaban led to a significant decrease in postdischarge thromboembolic events with a low bleeding risk profile. See Video Abstract . RIVAROXABN EN DOSIS BAJAS COMO PROFILAXIS PROLONGADA REDUCE LA TROMBOEMBOLIA VENOSA POSTERIOR AL ALTA, EN PACIENTES CON NEOPLASIAS MALIGNAS Y ENFERMEDAD INFLAMATORIA INTESTINAL: ANTECEDENTES:A pesar de las normas que sugieren el uso de profilaxis extendida para la prevención del tromboembolismo venoso en pacientes con cáncer colorrectal y tal vez enfermedad inflamatoria intestinal, el uso rutinario es bajo y existen escasos datos sobre las formas orales de terapia.OBJETIVO:Comparar la incidencia de tromboembolismo venoso posterior al alta, en pacientes que recibieron profilaxis prolongada con dosis bajas de rivaroxabán.DISEÑO:Utilizamos el emparejamiento de propensión para comparar un análisis previo y posterior a la intervención de un período de 2 años antes de instituir la profilaxis extendida.AJUSTE:Todos los pacientes colorrectales en una sola institución fueron considerados prospectivamente para profilaxis extendida.PACIENTES:Incluidos pacientes con diagnóstico de enfermedad inflamatoria intestinal o cáncer colorrectal sometidos a resección quirúrgica.INTERVENCIONES:A los considerados para profilaxis extendida se les prescribió 10 mg de rivaroxabán durante 30 días postoperatorios.PRINCIPALES MEDIDAS DE RESULTADO:El resultado primario fue la incidencia de tromboembolismo venoso 30 días después del alta. El resultado secundario fueron las tasas de hemorragia, mayor o menor.RESULTADOS:De los 498 pacientes considerados para profilaxis extendida, 363 fueron dados de alta con rivaroxabán, 81 con anticoagulación inicial y 54 sin anticoagulación. Se realizaron cohortes emparejadas por propensión basadas en la creación de la estoma, abordaje quirúrgico, tipo de procedimiento y el índice de masa corporal en 174 controles históricos. Después de excluir los casos de tromboembolismo venoso hospitalizado, las tasas posoperatorias fueron más bajas en la cohorte prospectiva (4,8% frente a 0,6%, p = 0,019). En el grupo prospectivo ocurrieron 36 episodios de hemorragia, 26 (7,2%) fueron dados de alta con rivaroxaban, 8 (9,9%) fueron dados de alta con otros anticoagulantes y 2 (3,7%) sin anticoagulación posoperatoria. Los casos de hemorragia mayor fueron del 1,1% (4/363) en el grupo de rivaroxabán y cada uno requirió intervención.LIMITACIONES:Limitado a una sola institución y no incluyó un grupo de placebo.CONCLUSIONES:Entre los pacientes con enfermedad inflamatoria intestinal y cáncer colorrectal, la profilaxis extendida con dosis bajas de rivaroxabán condujo a una disminución significativa de los eventos tromboembólicos posteriores al alta, con un perfil de riesgo de hemorragia bajo. (Traducción-Dr. Fidel Ruiz Healy).