rivaroxaban and Anemia--Sickle-Cell

The incidence of venous thromboembolism (VTE) in adult patients with sickle cell disease (SCD) is high. However, overlapping features between the clinical presentation of VTE and SCD complications and a low index of suspicion for thrombosis can influence patient management decisions. VTE in SCD can therefore present management challenges to the clinical hematologist. Herein, we present 3 distinct clinical vignettes that are representative of our clinical practice with SCD patients. These vignettes are discussed with specific reference to the hypercoagulable state in SCD patients, recent VTE diagnosis and anticoagulant therapy guidelines from the general population, and evaluation of the risk of bleeding as a result of long-term exposure to anticoagulant therapy. We examine current diagnostic and treatment options, highlight limitations of the existing clinical prognostic models that offer personalized guidance regarding the duration of anticoagulation, and propose a clinical approach to guide the decision to extend anticoagulation beyond 3 months.

Topics: Adult; Anemia, Sickle Cell; Anticoagulants; Factor Xa Inhibitors; Female; Humans; Male; Pregnancy; Pregnancy Complications; Rivaroxaban; Venous Thromboembolism

The contribution of coagulation activation to the pathogenesis of sickle cell disease (SCD) remains incompletely defined. We evaluated the efficacy and safety of rivaroxaban, an oral direct factor Xa inhibitor, in subjects with sickle cell anemia.. In this pilot, single-center, randomized, double-blind, placebo-controlled, crossover study, eligible subjects with sickle cell anemia received rivaroxaban or placebo. The effect of rivaroxaban on coagulation activation, endothelial activation, inflammation, and microvascular blood flow was evaluated.. Fourteen patients (HbSS - 14; females - 9) with mean age of 38 ± 10.6 years were randomized to receive rivaroxaban 20 mg daily or placebo for 4 weeks and, following a 2-week washout phase, were "crossed-over" to the treatment arm opposite to which they were initially assigned. Mean adherence to treatment with rivaroxaban, assessed by pill counts, was 85.6% in the first treatment period and 93.6% in the second period. Treatment with rivaroxaban resulted in a decrease from baseline of thrombin-antithrombin complex versus placebo (-34.4 ug/L [95% CI: -69.4, 0.53] vs. 0.35 ug/L [95% CI: -3.8, 4.5], p = .08), but the difference was not statistically significant. No significant differences were observed in changes from baseline of D-dimer, inflammatory, and endothelial activation markers or measures of microvascular blood flow. Rivaroxaban was well tolerated.. Rivaroxaban was safe but did not significantly decrease coagulation activation, endothelial activation, or inflammation. Rivaroxaban did not improve microvascular blood flow. Adequately powered studies are required to further evaluate the efficacy of rivaroxaban in SCD. Clinicaltrials.gov Identifier: NCT02072668.

Topics: Adult; Anemia, Sickle Cell; Blood Coagulation; Cross-Over Studies; Double-Blind Method; Factor Xa Inhibitors; Female; Humans; Male; Middle Aged; Pilot Projects; Rivaroxaban; Treatment Outcome

Sickle cell disease (SCD) is a hematological disorder characterized by sickling of red blood cells. Patients are at increased risk of venous thromboembolism. There are no guidelines for the management of venous thromboembolism in sickle cell disease specifically in terms of the anticoagulant of choice.. Here, we report a case of a 30-year-old lady with past medical history of sickle cell disease who came with chest pain and shortness of breath.. We found that she has bilateral pulmonary embolism (PE).. She was started on rivaroxaban.. The patient was followed for 18 months, she did not suffer from recurrence of PE, and she did not develop any complications related to rivaroxaban.. We concluded that rivaroxaban is effective in treating PE in sicklers and also it is safe.

Topics: Adult; Anemia, Sickle Cell; Anticoagulants; Factor Xa Inhibitors; Female; Humans; Pulmonary Embolism; Rivaroxaban; Treatment Outcome; Venous Thromboembolism

The use of rivaroxaban in patients with hemoglobinopathies and thrombotic events has not been studied extensively. Here we present eight cases of such patients, five receiving rivaroxaban for stroke and systemic embolism prevention due to non-valvular atrial fibrillation and three for deep vein thrombosis treatment. The follow-up period ranged from 6 to 34 months. During this period none of the patients experienced any thrombotic or bleeding event.There were no other adverse events reported. Further studies with larger numbers of patients with hemoglobinopathies are needed to determine the use of rivaroxaban and ensure its safety in this patient setting.

Topics: Adult; Aged; Anemia, Sickle Cell; beta-Thalassemia; Factor Xa Inhibitors; Female; Follow-Up Studies; Hemoglobinopathies; Humans; Male; Middle Aged; Rivaroxaban; Stroke; Thromboembolism; Treatment Outcome

Activation of coagulation and vascular inflammation are prominent features of sickle cell disease (SCD). Previously, we have shown that inhibition of tissue factor (TF) attenuates activation of coagulation and vascular inflammation in mouse models of SCD. In this study, we examined the mechanism by which coagulation proteases enhance vascular inflammation in sickle BERK mice. To specifically investigate the contribution of FXa and thrombin, mice were fed chow containing either rivaroxaban or dabigatran, respectively. In addition, we used bone marrow transplantation to generate sickle mice deficient in either protease activated receptor-1 (PAR-1) or protease activated receptor-2 (PAR-2) on nonhematopoietic cells. FXa inhibition and PAR-2 deficiency in nonhematopoietic cells attenuated systemic inflammation, measured by plasma levels of interleukin-6 (IL-6). In contrast, neither thrombin inhibition nor PAR-1 deficiency in nonhematopoietic cells affected plasma levels of IL-6 in sickle mice. However, thrombin did contribute to neutrophil infiltration in the lung, independently of PAR-1 expressed by nonhematopoietic cells. Furthermore, the TF-dependent increase in plasma levels of soluble vascular cell adhesion molecule-1 in sickle mice was not mediated by FXa or thrombin. Our data indicate that TF, FXa, and thrombin differentially contribute to vascular inflammation in a mouse model of SCD.

Topics: Anemia, Sickle Cell; Animals; Anticoagulants; Antithrombins; Benzimidazoles; beta-Alanine; Bone Marrow Transplantation; Dabigatran; Disease Models, Animal; Factor Xa; Factor Xa Inhibitors; Female; Immunoenzyme Techniques; Inflammation; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Morpholines; Receptor, PAR-1; Receptor, PAR-2; Rivaroxaban; Thiophenes; Thrombin; Vascular Diseases