Impact of perioperative low-molecular-weight heparin therapy on clinical events of elderly patients with prior coronary stents implanted > 12 months undergoing non-cardiac surgery: a randomized, placebo-controlled trial.

BACKGROUND: Little is known about the safety and efficacy of discontinuing antiplatelet therapy via LMWH bridging therapy in elderly patients with coronary stents implanted for > 12 months undergoing non-cardiac surgery. This randomized trial was designed to compare the clinical benefits and risks of antiplatelet drug discontinuation via LMWH bridging therapy. METHODS: Patients were randomized 1:1 to receive subcutaneous injections of either dalteparin sodium or placebo. The primary efficacy endpoint was cardiac or cerebrovascular events. The primary safety endpoint was major bleeding. RESULTS: Among 2476 randomized patients, the variables (sex, age, body mass index, comorbidities, medications, and procedural characteristics) and percutaneous coronary intervention information were not significantly different between the bridging and non-bridging groups. During the follow-up period, the rate of the combined endpoint in the bridging group was significantly lower than in the non-bridging group (5.79% vs. 8.42%, p = 0.012). The incidence of myocardial injury in the bridging group was significantly lower than in the non-bridging group (3.14% vs. 5.19%, p = 0.011). Deep vein thrombosis occurred more frequently in the non-bridging group (1.21% vs. 0.4%, p = 0.024), and there was a trend toward a higher rate of pulmonary embolism (0.32% vs. 0.08%, p = 0.177). There was no significant difference between the groups in the rates of acute myocardial infarction (0.81% vs. 1.38%), cardiac death (0.24% vs. 0.41%), stroke (0.16% vs. 0.24%), or major bleeding (1.22% vs. 1.45%). Multivariable analysis showed that LMWH bridging, creatinine clearance < 30 mL/min, preoperative hemoglobin < 10 g/dL, and diabetes mellitus were independent predictors of ischemic events. LMWH bridging and a preoperative platelet count of < 70 × 109/L were independent predictors of minor bleeding events. CONCLUSIONS: This study showed the safety and efficacy of perioperative LMWH bridging therapy in elderly patients with coronary stents implanted > 12 months undergoing non-cardiac surgery. An alternative approach might be the use of bridging therapy with half-dose LMWH. TRIAL REGISTRATION: ISRCTN65203415.

Structured benefit-risk assessment for enoxaparin, in the context of its label extension, for the extended treatment of deep vein thrombosis and pulmonary embolism, and prevention of its recurrence in patients with active cancer.

PURPOSE: Guidelines recommend low-molecular-weight heparins (LMWHs) for patients with cancer-associated thrombosis. However, until recently, only dalteparin and tinzaparin were approved in the European Economic Area (EEA) for these patients. This study compares the benefit-risk profile of enoxaparin with dalteparin and tinzaparin for the extended treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE), and prevention of recurrence in adult patients with active cancer. METHODS: A semi-quantitative structured benefit-risk assessment was conducted for the label-extension application of enoxaparin based on the benefit-risk action team descriptive framework: define decision context; determine key benefit and risk outcomes; identify data sources; extract data; interpret results. RESULTS: The key benefits were defined as reduced all-cause mortality and venous thromboembolism (VTE) recurrence (including symptomatic DVT, fatal PE or non-fatal PE); the key risks were major and non-major bleeding of clinical significance, and heparin-induced thrombocytopenia (HIT). Enoxaparin demonstrated comparable effects for the reduction of VTE recurrence and all-cause mortality versus other EEA-approved LMWHs (dalteparin, tinzaparin). There was no evidence of a significant difference between enoxaparin and the comparator groups with regard to incidence of major and non-major bleeding. The data on HIT were too limited to assess the difference between the two groups. CONCLUSIONS: The assessment demonstrated a favourable benefit-risk profile for enoxaparin similar to that of other EEA-approved LMWHs for the treatment of DVT and PE and the prevention of recurrence in patients with active cancer and thus supported the label-extension approval.

Early Time Courses of Recurrent Venous Thromboembolism and Bleeding during Apixaban or Dalteparin Therapy for Patients with Cancer.

BACKGROUND: In patients with acute venous thromboembolism (VTE), the rates of recurrence and major bleeding are highest during the first weeks of anticoagulation. The CARAVAGGIO trial demonstrated noninferiority of apixaban to dalteparin for treatment of cancer-associated VTE without an increased risk of major bleeding. We compared the early time course of VTE recurrence and major bleeding events of apixaban compared with dalteparin at 7, 30, and 90 days of treatment in patients with cancer-associated VTE. METHODS: The study design of the CARAVAGGIO trial has been described. Eligible patients were randomly assigned to receive monotherapy with either apixaban or dalteparin for 6 months. The primary efficacy outcome was the incidence of objectively confirmed recurrent VTE. The primary safety outcome was major bleeding. RESULTS: In 1,155 patients, recurrent VTE after 7, 30, and 90 days occurred in 6 (1%), 15 (2.6%), and 27 (4.7%) patients in the apixaban arm versus 5 (0.9%), 20 (3.5%), and 36 (6.2%) patients respectively in the dalteparin arm. By day 7, 30, and 90, major bleeding events had occurred in 3 (0.5%), 9 (1.6%), and 16 (2.8%) patients in the apixaban group versus 5 (0.9%), 11 (1.9%), and 17 (2.9%) patients in the dalteparin group. CONCLUSION: The frequencies of recurrent VTE and major bleeding events at 7, 30, and 90 days of apixaban compared with dalteparin were similar in patients with cancer-associated VTE. This supports the use of apixaban for the initiation and early phase of anticoagulant therapy in cancer-associated VTE.

Efficacy and Safety of Apixaban versus Dalteparin as a Treatment for Cancer-Associated Venous Thromboembolism: A Systematic Review and Meta-Analysis.

Background and Objectives: Venous thromboembolism (VTE) is common in cancer patients. Anticoagulant therapy with low-molecular-weight heparins (LMWHs) and direct oral anticoagulants (DOACs), such as dalteparin and apixaban, have demonstrated efficacy and safety. However, more comparative research of these drugs is still needed. This study aimed to synthesize evidence on the efficacy of apixaban compared to dalteparin in reducing recurrent VTE, major bleeding, and clinically relevant non-major bleeding associated with cancer. Materials and Methods: We systematically searched the PubMed, Scopus, Web of Science, Embase, Cochrane Library, and ClinicalTrials databases up to 5 January 2023, for randomized controlled trials comparing apixaban versus dalteparin as treatment for cancer-associated VTE. Five studies were included. Effects according to meta-analyses were reported as relative risks (RRs) and their 95% confidence intervals (CIs). Results: It was found that 33 of 734 (4.5%) patients treated with apixaban and 56 of 767 (7.3%) with dalteparin had recurrent VTE as the efficacy outcome (RR 0.49, 95% CI 0.15-1.58, I2 38%). Major bleeding occurred in 25 of 734 patients treated with apixaban (3.4%) and 27 of 767 with dalteparin (3.5%) (RR 1.29, 95% CI 0.31-5.27, I2 59%). Likewise, clinically relevant non-major bleeding occurred in 64 of 734 patients treated with apixaban (8.7%) and 46 of 767 (5.9%) with dalteparin (RR 1.52, 95% CI 1.05-2.19, I2 0%). Conclusions: Apixaban showed a lower risk of recurrent VTE than dalteparin in patients with cancer-associated VTE, albeit with no statistical difference. Statistical significance was observed for no major clinically relevant bleeding but not for major bleeding.

Prophylactic Dose of Dalteparin in Pregnant Women With History of Venous Thromboembolisms and/or Thrombophilia: Real-World Data.

Women with a history of venous thromboembolisms (VTEs) and/or thrombophilia are at increased risk of VTE during pregnancy. We analysed our cohort of such women who were treated with a prophylactic doses of dalteparin. 152 pregnant women with 179 pregnancies were classified into 3 groups: (1) previous VTE without thrombophilia (122 pregnancies); (2) previous VTE with thrombophilia (26 pregnancies) and (3) thrombophilia only (31 pregnancies). They were treated with prophylactic dalteparin in the prepartum and postpartum periods or only in the postpartum period. Occurrences of symptomatic VTE and bleeding episodes were followed, as well as dalteparin discontinuation and anti-Xa activity. Symptomatic deep vein thrombosis occurred in 4 women (2.2%) with 2 episodes in group 1 (in the postpartum period) and 2 episodes in group 2 (one in the prepartum and another in the postpartum period). Seven episodes (3.9%) of minor bleeding occurred. Dalteparin was not stopped in any women. Anti-Xa levels were within the prophylactic range. Our real-world data show a low incidence of thrombosis and minor bleeding in pregnant women treated with prophylactic dalteparin. The incidence of recurrent VTE was lower than that reported in women with similar risk, but without prophylactic anticoagulation.

[Modern anticoagulation with factor Xa inhibitors in oncology: is the gastrointestinal bleeding rate (also) decisive?] / Moderne Antikoagulation mit FXa-Inhibitoren in der Onkologie: Ist die gastrointestinale Blutungsrate (mit)-entscheidend?

The increased risk of thrombosis and bleeding with an active tumor disease is known as the so-called "thrombo-hemorrhagic syndrome", which places high demands on anticoagulation. There are currently 4 randomized, prospective studies on the use of new, non-vitamin K dependent oral anticoagulants (NOAC) for the treatment of venous thromboembolism (VTE) that have occurred in oncology. The FXa inhibitors rivaroxaban, edoxaban and twice apixaban were each used in individual studies versus the standard therapeutic agent dalteparin. Since there is no direct head-to-head comparison of the FXa inhibitors mentioned within a study, the largest study - always compared to dalteparin - was evaluated for each NOAC. The studies were analyzed with regard to their effectiveness, safety, fatal bleeding rates, the risk of gastrointestinal bleeding (GIB) and other differences using descriptive statistics. With dalteparin, the mean VTE recurrence rate was approximately 9% over a 6-month treatment period. All three FXa inhibitors were not inferior to dalteparin in terms of potency. The VTE recurrence rate was - 2.3% lower in edoxaban and apixaban-treated patients and - 5.0% in rivaroxaban-treated patients. In terms of safety, there was an increased rate of severe bleeding (both + 2.4%) for rivaroxaban and edoxaban compared to dalteparin; in particular, the number of GIBs was significantly increased. In contrast, the number of severe bleeding was not increased for apixaban, as was the case for various bleeding types including GIB. In the Apixaban study, the overall rate of severe GIB, which accounted for about 50% of all severe bleeding, and that of clinically relevant non-severe bleeding, were the lowest. The FXa inhibitors are not inferior to the standard therapy with dalteparin in the VTE recurrence rate in oncological patients. The GIB rate appears to be an important predictive factor for the safety of this group of substances, so that tumor location, gastrointestinal risk factors and other individual criteria should be given greater consideration in future therapy decisions for or against an FXa inhibitor.

A phase 2 pharmacodynamic dose-finding, safety, and efficacy study of dalteparin for pediatric venous thromboembolism treatment in children with and without cancer.

Data from registrational trials of pediatric venous thromboembolism (VTE) treatment are sparse, especially among cancer patients. We conducted a prospective, multicenter, open-label trial (NCT00952380) on dose-finding, safety, and efficacy (measured by 90-day risks of clinically relevant bleeding [CRB] and symptomatic recurrent VTE [srVTE]) of twice-daily subcutaneous dalteparin for acute VTE treatment in patients ≤18 years old. Among 38 patients (cancer, n = 26; noncancer, n = 12), median dalteparin dose requirements per kilogram varied with age but not cancer status. Risks of CRB and srVTE were <4% in cancer and noncancer subgroups. Dalteparin is an important FDA-approved treatment for pediatric VTE, particularly with cancer.

Recurrent venous thromboembolism and major bleeding in patients with localised, locally advanced or metastatic cancer: an analysis of the Caravaggio study.

BACKGROUND: Patients with cancer-associated venous thromboembolism (VTE) have a high risk of VTE recurrence and anticoagulant treatment-related bleeding, but the correlation of these risks with the cancer stage is unclear. METHODS: We evaluated the risks of VTE recurrence and treatment-related major bleeding according to the cancer stage in patients with VTE and solid cancer randomised to apixaban or dalteparin in the Caravaggio study. Cancer stage was categorised by expert cancer physicians according to pre-specified criteria, and study outcomes were adjudicated by an independent committee unaware of cancer stage and treatment allocation. RESULTS: Of the 1034 patients included in this analysis, 217 (21.0%) had localised cancer, 279 (27.0%) locally advanced cancer and 503 (48.7%) metastatic cancer. Cancer stage was undetermined in 35 patients (3.4%). VTE recurrence and major bleeding rates were 2.8% and 3.2% in patients with localised cancer, respectively. In comparison to patients with localised cancer, the VTE recurrence rate was higher in patients with locally advanced cancer (7.5%, hazard ratio [HR] = 2.8, 95% confidence interval [CI] = 1.1-6.9) and metastatic cancer (8.7%, HR = 3.3, CI = 1.4-7.7, CI). Patients with metastatic cancer had numerically increased major bleedings compared to those with localised cancer (5.2%, HR = 1.65, CI = 0.7-3.8). The efficacy and safety of apixaban and dalteparin across patients with different cancer stages were consistent with the findings observed in the overall patients with cancer randomised in the study. CONCLUSIONS: Patients with locally advanced and metastatic cancer have a higher rate of VTE recurrence than patients with localised cancer with no statistically significant difference in treatment-related major bleeding.

Effects of dalteparin on anti-Xa activities cannot be predicted in critically ill COVID-19 patients.

Critically ill COVID-19 patients are at high risk of thromboembolic events despite routine-dosed low-molecular-weight heparin thromboprophylaxis. However, in recent randomized trials increased-intensity thromboprophylaxis seemed futile and possibly even harmful. In this explorative pharmacokinetic (PK) study we measured anti-Xa activities on frequent timepoints in 15 critically ill COVID-19 patients receiving dalteparin and performed PK analysis by nonlinear mixed-effect modelling. A linear one-compartment model with first-order kinetics provided a good fit. However, wide interindividual variation in dalteparin absorption (variance 78%) and clearance (variance 34%) was observed, unexplained by routine clinical covariates. Using the final PK model for Monte Carlo simulations, we predicted increased-intensity dalteparin to result in anti-Xa activities well over prophylactic targets (0.2-0.4 IU/mL) in the majority of patients. Therapeutic-intensity dalteparin results in supratherapeutic anti-Xa levels (target 0.6-1.0 IU/mL) in 19% of patients and subtherapeutic levels in 22%. Therefore, anti-Xa measurements should guide high-intensity dalteparin in critically ill COVID-19 patients.

Renal function and clinical outcome of patients with cancer-associated venous thromboembolism randomized to receive apixaban or dalteparin. Results from the Caravaggio trial

The effect of renal impairment (RI) on risk of bleeding and recurrent thrombosis in cancer patients treated with direct oral anticoagulants for venous thromboembolism (VTE) is undefined. We ran a prespecified analysis of the randomized Caravaggio study to evaluate the role of RI as a risk factor for bleeding or recurrence in patients treated with dalteparin or apixaban for cancerassociated VTE. RI was graded as moderate (creatinine clearance between 30-59 mL/minute; 275 patients) and mild (between 60- 89 mL/minute; 444 patients). In the 1142 patients included in this analysis, the incidence of major bleeding was similar in patients with moderate vs. no or mild RI (HR 1.06-95% CI: 0.53-2.11), with no difference in the relative safety of apixaban and dalteparin. Recurrent VTE was not different in moderate vs. no or mild RI (HR=0.67, 95% CI: 0.38-1.20); in moderate RI, apixaban reduced recurrent VTE compared to dalteparin (HR=0.27, 95% CI: 0.08-0.96; P for interaction 0.1085). At multivariate analysis, no association was found between variation of renal function over time and major bleeding or recurrent VTE. Advanced or metastatic cancer was the only independent predictor of major bleeding (HR=2.84, 95% CI: 1.20-6.71), with no effect of treatment with apixaban or dalteparin. In our study, in cancer patients treated with apixaban or dalteparin, moderate RI was not associated with major bleeding or recurrent VTE. In patients with moderate renal failure, the safety profile of apixaban was confirmed with the potential for improved efficacy in comparison to dalteparin. ClinicalTrials.gov identifier: NCT03045406.

Rivaroxaban vs Dalteparin in Cancer-Associated Thromboembolism: A Randomized Trial.

BACKGROUND: Direct oral anticoagulants (DOACs) are an alternative to low-molecular-weight heparin for treating cancer-associated VTE. RESEARCH QUESTION: Is rivaroxaban as efficient and safe as dalteparin to treat patients with cancer-associated VTE? STUDY DESIGN AND METHODS: In a randomized open-label noninferiority trial, patients with active cancer who had proximal DVT, pulmonary embolism (PE), or both were assigned randomly to therapeutic doses of rivaroxaban or dalteparin for 3 months. The primary outcome was the cumulative incidence of recurrent VTE, a composite of symptomatic or incidental DVT or PE, and worsening of pulmonary vascular or venous obstruction at 3 months. RESULTS: Of 158 randomized patients, 74 and 84 patients were assigned to receive rivaroxaban and dalteparin, respectively. Mean age was 69.4 years, and 115 patients (76.2%) had metastatic disease. The primary outcome occurred in 4 and 6 patients in the rivaroxaban and dalteparin groups, respectively (both the intention-to-treat and per-protocol populations: cumulative incidence, 6.4% vs 10.1%; subdistribution hazard ratio [SHR], 0.75; 95% CI, 0.21-2.66). Major bleeding occurred in 1 and 3 patients in the rivaroxaban and dalteparin groups, respectively (cumulative incidence, 1.4% vs 3.7%; SHR, 0.36; 95% CI, 0.04-3.43). Major or clinically relevant nonmajor bleeding occurred in 9 and 8 patients in the rivaroxaban and dalteparin groups, respectively (cumulative incidence, 12.2% vs 9.8%; SHR, 1.27; 95% CI, 0.49-3.26). Overall, 19 patients (25.7%) and 20 patients (23.8%) died in the rivaroxaban and dalteparin groups, respectively (hazard ratio, 1.05; 95% CI, 0.56-1.97). INTERPRETATION: In this trial comparing rivaroxaban and dalteparin in the treatment of cancer-associated VTE, the number of patients was insufficient to reach the predefined criteria for noninferiority, but efficacy and safety results were consistent with those previously reported with DOACs. An updated meta-analysis of randomized trials comparing DOACs with low-molecular-weight heparin in patients with cancer-associated VTE is provided. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT02746185; URL: www. CLINICALTRIALS: gov.

Apixaban and Dalteparin for the Treatment of Venous Thromboembolism in Patients with Different Sites of Cancer.

Efficacy and safety of anticoagulant treatment for venous thromboembolism (VTE) may vary in patients with different cancer sites. We evaluated the rates of VTE recurrence and major bleeding and the relative efficacy and safety of 6-month treatment with oral apixaban or subcutaneous dalteparin in patients with different cancer sites randomized in the Caravaggio study. Primary cancer was located at gastrointestinal sites in 375 patients (32.5%), lung in 200 (17.3%), breast in 155 (13.4%), genitourinary sites in 139 (12%), gynecological sites in 119 (10.3%), and was hematological in 85 patients (7.4%). Rates of VTE recurrence were 10.9% in patients with gynecological, 8.8% with gastrointestinal, 6.5% with genitourinary, and 5.5% with lung cancer with lower rates in the other sites of cancer. Rates of major bleeding were 7.2% in patients with genitourinary and 4.8% with gastrointestinal cancer, with lower rates in patients with other sites of cancer. The observed absolute risk difference in VTE recurrence in favor of apixaban was 11.9% in patients with gynecological, 5.5% with lung, 3.7% with genitourinary cancer, and 0.6% with gastrointestinal cancer. None of the risk differences was statistically significant. The rates of major bleeding in patients treated with apixaban or dalteparin was similar across patients with different cancer sites. In conclusion, recurrences appear to be more common in patients with gastrointestinal and gynecological cancer and major bleedings in patients with genitourinary and gastrointestinal cancer. Oral apixaban is a valid oral alternative to subcutaneous dalteparin for the treatment of a large spectrum of patients with cancer-associated VTE.

Haemorrhagic complications in patients with renal insufficiency during treatment or prophylaxis with dalteparin.

OBJECTIVES: Low-molecular-weight heparins are widely used in clinical practice for the treatment or prophylaxis of venous thromboembolism (VTE). As these drugs are eliminated mainly by renal means, any renal function impairment may lead to higher plasma concentrations and increase the risk of bleeding. This study aims to evaluate whether in clinical practice there is an increase in the occurrence of bleeding in patients with renal insufficiency (RI) during treatment or prophylaxis with dalteparin, and to analyse the risk factors potentially influencing the appearance of such bleeding events. METHODS: Patients were sampled from the Universitary Severo Ochoa Hospital, Leganés, Spain. This was a retrospective cohort study with a 1 year inclusion period, conducted at a Spanish university hospital with 400 beds, on patients undergoing treatment or prophylaxis for VTE with dalteparin for a minimum of 3 days. The main outcome measure was the number of patients who had bleeding events, independently of their severity, during dalteparin administration in patients with RI. RESULTS: 367 patients were included in the study. Bleeding occurred in 17.9% of patients in the group with RI and in 7.3% of patients with normal renal function (NRF). Most haemorrhages in both cohorts were grade 2 on the WHO scale (64.7% in the RI group and 69.2% in the NRF group). Logistic regression analysis allowed the presence of RI (MDRD-4 (Modification of Diet in Renal Disease) <50 mL/min) to be identified as a risk factor. CONCLUSION: Patients with RI treated with dalteparin face a higher risk of bleeding than those with NRF, which seems to make it necessary to monitor and seek new dosage adjustments for these patients.Impact on practice statements: This study yields new data on dalteparin in RI, which has not been widely studied before.

Clinical characteristics and outcomes of incidental venous thromboembolism in cancer patients: Insights from the Caravaggio study.

BACKGROUND: Clinical guidelines advise similar anticoagulant treatment for symptomatic and incidental cancer-associated venous thromboembolism (VTE). We investigated clinical features and outcomes of cancer patients with incidental or symptomatic VTE randomized in the Caravaggio study. OBJECTIVES: We performed a predefined sub-analysis of the Caravaggio study in order to investigate the clinical features and outcomes of incidental and symptomatic VTE in patients with cancer. The relative efficacy and safety of apixaban and dalteparin in patients with incidental and symptomatic VTE was also assessed. METHODS: The Caravaggio study compared apixaban to dalteparin for the 6-month treatment of cancer-associated VTE. The primary efficacy and safety outcomes were recurrent VTE and major bleeding. RESULTS: Two hundred thirty patients (20%) had incidental and 925 (80%) symptomatic VTE. Pulmonary embolism with or without deep vein thrombosis as index event, colorectal cancer, Eastern Cooperative Oncology Group (ECOG) score of 0, and locally advanced or metastatic cancer were more frequent in patients with incidental VTE. Deep vein thrombosis as index event, hematological cancer, and ECOG score of 2 were more frequent in patients with symptomatic VTE. Ten patients (4.3%) with incidental and 68 (7.4%) with symptomatic VTE had recurrent VTE (hazard ratio [HR] 0.57, 95% confidence interval [CI] 0.29-1.10). Major bleeding occurred in 12 (5.2%) patients with incidental VTE and in 33 (3.6%) patients with symptomatic VTE (HR 1.43, 95% CI 0.74-2.77). When comparing apixaban to dalteparin in patients with symptomatic and incidental VTE, the HR for recurrence was 0.73 (95% CI 0.45-1.19) and 0.41 (95% CI 0.11-1.56), respectively, and the HR for major bleeding 0.93 (95% CI 0.47-1.83) and 0.96 (95% CI 0.31-2.96), respectively. CONCLUSIONS: Compared to cancer patients with symptomatic VTE, those with incidental VTE have different clinical features at presentation, with a numerically lower incidence of recurrent VTE and a numerically higher incidence of major bleeding.

Dalteparin and Rivaroxaban Sequential Use in Cancer Patients with Venous Thromboembolism.

OBJECTIVE: To determine the effect and safety of sequential treatment with the low-molecular-weight heparin dalteparin and the direct oral anticoagulants rivaroxaban in patients with cancer- associated venous thromboembolism (VTE). STUDY DESIGN: Observational study. PLACE AND DURATION OF STUDY: Department of Oncology, the Second Affiliated Hospital of Soochow University, between January 2017 and September 2019. METHODOLOGY: Patients with active cancer, diagnosed with VTE and who received sequential treatment with dalteparin and rivaroxaban, were retrospectively reviewed. Logistic regression analysis was used to identify risk factors associated with VTE recurrence. RESULTS: Ninety-nine patients with active cancer were enrolled in the study. The median delteparin treatment time was nine days (5-20 days), and 2.8 months (1-6 months) for rivaroxaban. Sixty (60.6%) patients had eliminated VTE, and 39 (39.4%) had persistent VTE, but with relieved symptoms. No major bleeding was observed. Eleven (11.1%) patients had minor bleeding, including melena (5.1%), hematuria (3.0%), vaginal bleeding (1.0%), gingival bleeding (1.0%), and subcutaneous hemorrhage (1.0%). During the 6 months follow-up period, one (1.0%) developed pulmonary embolism, and seven (7.1%) experienced recurrent VTE. Univariate logistic regression analysis showed that bleeding occurrence and anticoagulant treatment duration were the two significant factors affecting VTE recurrence (p<0.05). CONCLUSION: Maintenance of rivaroxaban after initial dalteparin treatment could effectively reduce the risk of VTE recurrence and was well tolerated by patients with cancer-associated VTE. However, in the clinical practice, the treatment duration is often insufficient, so it is essential to follow-up these patients to ensure sufficient treatment time. Key Words: Venous thromboembolism, Low-molecular-weight heparins, Directly oral anticoagulants, Cancer.

Dalteparin in Newborn Thrombosis, Time for a New Starting Dose.

BACKGROUND: Neonatal thrombosis is a frequently encountered complication in a neonatal intensive care unit. Dalteparin can be used to treat thrombosis in newborn infants. OBJECTIVES: In this study, we evaluate the current recommended starting dose of 129 ± 43 U/kg/24 h, hypothesizing that this dose is too low to reach therapeutic anti-Xa levels. METHODS: From 2008 until 2017, all infants treated with dalteparin in the University Medical Centre Utrecht were included in this study. In this retrospective cohort study, the correlation between dose and anti-Xa level was observed. RESULTS: Sixty-six infants were included. The most common thrombus types were catheter-related (29 patients, 44%) and venous sinus thrombosis (28 patients, 43%). The mean dalteparin dose needed for the first adequate anti-Xa level (0.5-1.0 IU/mL) was 297.6 U/kg/12 h. Two infants developed a first bleeding episode under dalteparin therapy; they both had anti-Xa levels in the therapeutic range. CONCLUSION: The increase of the starting dose of dalteparin will lead to earlier therapeutic levels of anti-Xa in the studied population and appears to be safe. However, this needs to be evaluated in further study.

Population Pharmacokinetic Analysis of Dalteparin in Pediatric Patients With Venous Thromboembolism.

This article describes the population pharmacokinetics (PK) of dalteparin in pediatric patients with venous thromboembolism (VTE). A prospective multicenter open-label study was conducted in children who required anticoagulation for the treatment of VTE. The study population included children with and without cancer. The goal was to describe the pharmacokinetics of dalteparin using anti-Xa as a surrogate marker and to determine the dose required to achieve therapeutic anti-Xa levels (0.5-1.0 IU/mL). The anti-Xa data were supplemented with 2 published studies and analyzed using population pharmacokinetic approaches. The pharmacokinetics of dalteparin following subcutaneous injection in pediatric patients was described by a 1-compartment model with linear absorption and elimination. Body weight was added as a covariate on both CL/F and Vd/F as a power function with fixed exponents of 0.75 and 1.0, respectively. The estimates of CL/F and Vd/F in the full model were 929 mL/h and 7180 mL, respectively, for a reference female patient aged 12 years with body weight of 43 kg. Body weight-normalized CL/F decreased with age. Cancer status and sex did not have significant effects on CL/F and Vd/F. Simulations were conducted to select starting doses of dalteparin that would rapidly achieve therapeutic anti-Xa levels. These simulations suggested that the recommended starting doses of dalteparin administered subcutaneously in pediatric patients of different age cohort groups for treatment of VTE were 150 IU/kg every 12 hours (1 month to <2 years), 125 IU/kg every 12 hours (≥2 to <8 years), and 100 IU/kg every 12 hours (≥8 to <19 years).

Bleeding with Apixaban and Dalteparin in Patients with Cancer-Associated Venous Thromboembolism: Results from the Caravaggio Study.

BACKGROUND: Direct oral anticoagulants are recommended for the treatment of cancer-associated thrombosis (CAT) as an alternative to low-molecular-weight heparin (LMWH), but an increased bleeding risk in patients with gastrointestinal cancer was reported. The Caravaggio study compared apixaban and dalteparin for the treatment of patients with CAT. Here we describe sites of bleeding, associated cancer sites, clinical presentation, and course of major bleeding in patients included in the Caravaggio study. METHODS: The Caravaggio study was a multinational, randomized, open-label, noninferiority study. Bleeding events and the severity of major bleedings were adjudicated by a committee unaware of treatment allocation using predefined criteria; for the purpose of this analysis, data were analyzed in the safety population. RESULTS: Major bleeding occurred in 22 of 576 patients on apixaban (3.8%) and in 23 of 579 patients on dalteparin (4.0%). The sites of major bleeding and their distribution according to the type of cancer were similar between the two treatment groups. Major bleeding occurred in nine patients with gastrointestinal cancer in each treatment group. The clinical presentation of major bleeding was severe or fatal in 6 patients on apixaban and in 5 patients on dalteparin, while the clinical course was severe in 5 patients on apixaban and in 7 patients on dalteparin. CONCLUSION: Apixaban is a safe alternative to LMWH for the treatment in patients with CAT. No excess in gastrointestinal bleeding was observed in patients who received apixaban, including those with gastrointestinal cancer.

Inadequate prophylactic effect of low-molecular weight heparin in critically ill COVID-19 patients.

PURPOSE: The aim of this study was to investigate potential markers of coagulopathy and the effects of thromboprophylaxis with low-molecular-weight heparin (LMWH) on thromboelastography (TEG) and anti-factor Xa in critically ill COVID-19 patients. MATERIAL AND METHODS: We conducted a prospective study in 31 consecutive adult intensive care unit (ICU) patients. TEG with and without heparinase and anti-factor Xa analysis were performed. Standard thromboprophylaxis was given with dalteparin (75-100 IU/kg subcutaneously). RESULTS: Five patients (16%) had symptomatic thromboembolic events. All patients had a maximum amplitude (MA) > 65 mm and 13 (42%) had MA > 72 mm at some point during ICU stay. Anti-factor Xa activity were below the target range in 23% of the patients and above target range in 46% of patients. There was no significant correlation between dalteparin dose and anti-factor Xa activity. CONCLUSIONS: Patients with COVID-19 have hypercoagulability with high MA on TEG. The effect of LMWH on thromboembolic disease, anti-factor Xa activity and TEG was variable and could not be reliably predicted. This indicates that standard prophylactic doses of LMWH may be insufficient. Monitoring coagulation and the LMWH effect is important in patients with COVID-19 but interpreting the results in relation to risk of thromboembolic disease poses difficulties.