Perils of Antithrombotic Transitions: Effect of Oral Factor Xa Inhibitors on the Heparin Antifactor Xa Assay
BACKGROUND:Oral factor Xa inhibitors (OFXais) may interfere with the heparin antifactor Xa (antiXa) assay. The best method to measure heparin activity during the transition from an OFXai to intravenous (IV) unfractionated heparin (UFH) remains unknown. This study aimed to assess the safety and effectiveness of transitioning from an OFXai to UFH. METHODS:A retrospective analysis was conducted of patients with supratherapeutic antiXa levels on UFH who received either apixaban or rivaroxaban within 72 h prior to UFH initiation at NYU Langone Health (NYULH). The primary objective was to identify the incidence of interference on the heparin antiXa assay due to OFXai exposure in the previous 72 h. The secondary outcomes included the indication for transition to UFH and the rate of thromboembolic and bleeding events. RESULTS:A total of 93 patients with supratherapeutic antiXa activity levels with prior OFXai use were reviewed. Moderate renal impairment, defined as CrCl less than 49 mL/min, was present in 67 (72%) patients. The primary indication for transition from OFXai to UFH was in anticipation for a procedure, and it occurred in 37 (40%) patients. There were three major bleeding events and three clinically relevant non-major bleeding events. No thromboembolic events occurred. CONCLUSIONS:This study assessed the prevalence of supratherapeutic antiXa levels and clinical outcomes during the transition from OFXais to UFH. Healthcare systems should develop guidelines to assist clinicians in monitoring antiXa activity in patients undergoing a transition from an OFXai to UFH. It is also important to assess the patient's underlying thromboembolic and bleeding risks.
Increased Dead Space Ventilation and Refractory Hypercapnia in Patients With Coronavirus Disease 2019: A Potential Marker of Thrombosis in the Pulmonary Vasculature [Case Report]
Objectives/UNASSIGNED:Mortality rates in intubated coronavirus disease 2019 patients remain markedly elevated. Some patients develop sudden refractory hypercapnia and hypoxemia not explained by worsening pulmonary parenchymal disease. This case series highlights clinical findings and management of coronavirus disease 2019 patients with refractory hypercapnia despite maximal/optimal ventilatory support. Hypercapnia could not be explained by worsening lung disease or other common factors, and thus, a pulmonary vascular etiology was suggested. The pillars of management were targeted to improve pulmonary vascular patency via aggressive anticoagulation and support right ventricular function. Data Sources/UNASSIGNED:Four consecutive patients with confirmed coronavirus disease 2019 infection with sudden hypercapnia and hypoxemia were included. Data Synthesis/UNASSIGNED:removal was discontinued in three patients over the ensuing 3 weeks, and one patient was discharged home. Conclusions/UNASSIGNED:We speculate that thromboinflammation with pulmonary microvasculature occlusion leads to a sudden increase in dead space and shunt resulting in severe hypercapnia and hypoxemia in coronavirus disease 2019 patients. Early identification of these physiologic and clinical biomarkers could trigger the institution of therapies aiming to reverse the hypercoagulable state and support right ventricular function.
Assessment of patients post reversal with idarucizumab
Idarucizumab, a fully humanized Fab antibody fragment, is indicated for reversal of dabigatran's anticoagulant activity. Idarucizumab neutralizes the anticoagulant effects of dabigatran by binding to dabigatran and its metabolite. In the full analysis of 503 patients, idarucizumab fully reversed the anticoagulant effect of dabigatran in more than 98% of patients. Real-world clinical experience with idarucizumab for dabigatran reversal remains limited. We report 11 real-world clinical cases in which idarucizumab was administered for dabigatran reversal in the setting of bleed (bleeding cohort nâ€‰=â€‰5) or emergent procedure (emergent procedure cohort, nâ€‰=â€‰6). Coagulation tests and clinical outcomes were assessed before and after idarucizumab administration. Clinical outcomes included thromboembolic events and hemostasis. The median (IQR) aPTT (seconds) before versus after idarucizumab was 40.4 (36.1) versus 27.3 (6.2) (bleeding cohort) and 50.1 (13.4) versus 26.5 (8.1) (emergent procedure cohort). The median (IQR) INR before and after idarucizumab was 2.0 (1.1) versus 1.2 (0.1) (bleeding cohort) and 1.1 (0.5) versus 1.1 (0.3) (emergent procedure cohort). Hemostasis was achieved in 4/5 patients in the bleeding cohort and 5/6 patients in the emergent procedure cohort. Thrombotic events occurred in four patients with a median time (IQR) from idarucizumab administration of 7.4 (4.3-14.7) days. Idarucizumab achieved adequate dabigatran reversal as evident by normalization of aPTT, INR, and achieving hemostasis. However, our data demonstrates a high thrombotic risk associated with dabigatran reversal with idarucizumab than previously reported.
A retrospective analysis of the periprocedural management of oral anticoagulants in patients undergoing interventional radiology procedures
Limited evidence is available to guide periprocedural management of oral anticoagulants in the setting of interventional radiology (IR) procedures. For direct oral anticoagulants, therapy interruption (TI) is based on medication half-life and procedural bleeding risk. Periprocedural management of warfarin includes INR monitoring, and possible bridging with parenteral anticoagulants. It is unknown if these recommendations apply to IR procedures. To evaluate bleeding complications and thromboembolic events following periprocedural management of the factor Xa (FXa) inhibitors or warfarin in patients undergoing IR procedures. We performed a retrospective, observational study at NYU Langone Health (NYULH) of all adult patients who underwent an IR procedure from January 2015 to July 2017 and were receiving apixaban, rivaroxaban, or warfarin. Patients who were pregnant or who had a mechanical heart valve were excluded. At NYULH, TI is not required for FXa inhibitors, and an INRâ€‰<â€‰3 is recommended for patients on warfarin undergoing low risk procedures. For moderate/high risk procedures, TI for 48Â h or 72Â h with reduced renal function, is recommended for FXa inhibitors, and an INRâ€‰<â€‰1.5 is recommended for patients on warfarin. We evaluated 350 IR procedures, with a total of 174 low bleeding risk and 176 moderate/high bleeding risk. The 30-day major bleeding rate was 0.9%, clinically relevant non-major bleeding rate was 3%, minor bleeding rate was 1% and thromboembolic event rate was 1%. The periprocedural oral anticoagulation management strategy at NYULH appears safe given the low 30-day incidence of bleeding and thromboembolic events.
REAL-WORLD EXPERIENCE WITH IDARUCIZUMAB FOR THE MANAGEMENT OF DABIGATRAN REVERSAL [Meeting Abstract]
Anticoagulation prescribing patterns in patients with cancer
Cancer is a known hypercoagulable state that leads to an increased risk of venous thromboembolism (VTE). Low molecular weight heparin remains the preferred anticoagulant for VTE in patients with cancer over vitamin K antagonist. However, the preferred anticoagulant in prevention of stroke and systemic embolism in atrial fibrillation (AF) in patients with cancer has yet to be determined. The direct oral anticoagulants (DOACs) are increasingly being utilized; however their role in cancer has only recently been investigated. The objective of this retrospective cohort was to describe real-world anticoagulation prescribing patterns in cancer patients at a large academic medical center between January 1, 2013 and October 31, 2016. We sought to assess the safety, tolerability, and efficacy of DOACs in patients with cancer for either VTE and/or AF. Patient demographic, clinical characteristics, as well as bleeding and thrombotic events were collected. There were 214 patients in our analysis, of which 71 patients (33%) received a DOAC [apixaban (nâ€‰=â€‰22), dabigatran (nâ€‰=â€‰17), and rivaroxaban (nâ€‰=â€‰32)]. There were fewer bleeding events and/or discontinuations in the DOAC group compared to enoxaparin (13 vs. 27, pâ€‰=â€‰0.022). There was no difference in major or minor bleeds or thromboembolic events in comparing DOAC to enoxaparin or DOAC to warfarin. This was a retrospective, single-institution study assessing the safety and efficacy of DOACs compared to warfarin or enoxaparin in patients with cancer. DOACs may represent an alternative to warfarin or enoxaparin in patients with cancer for VTE and/or stroke reduction in AF.
Acquired Coagulopathy and Hemorrhage Secondary to Subcutaneous Heparin Prophylaxis
Unfractionated heparin and low-molecular-weight heparins are commonly used as thromboprophylaxis for hospitalized patients. Though generally considered safe at prophylactic doses, cases of catastrophic hemorrhage have been reported. The proposed mechanism involves bioaccumulation of heparin through saturation of the rapid-elimination pathway in its metabolism. We present an unusual case of an average-weight man with metastatic melanoma who suffered hemorrhage with syncope and end-organ damage while on prophylactic three times daily unfractionated heparin. Coagulation studies were consistent with heparin toxicity. Despite administration of protamine, the clearance of heparin was remarkably delayed, as demonstrated by serial coagulation studies. We review the suspected risk factors for heparin bioaccumulation and the emerging understanding of this unusual adverse event involving a nearly ubiquitous medication.
Managing incidentally diagnosed isolated factor VII deficiency perioperatively: a brief expert consensus report
While isolated factor VII (FVII) deficiency is being more frequently diagnosed owing to improved preoperative screening procedures, there is no specific guideline for perioperative management of such patients. To complicate the issue, FVII activity levels seem to correlate less well with the risk of hemorrhage than the patient's past and family bleeding history do. We have devised expert consensus recommendations for managing such patients perioperatively, taking into consideration the personal and family bleeding history, the FVII activity level and the inherent bleeding risk of the procedure itself. We hope that clinicians will find this a useful tool in the decision-making process, thereby limiting the use of recombinant factor VIIa to those who need it most, and preventing possible thrombotic complications in those without a strong indication for its use.
Role of thrombin as a tumor growth factor
The clinical observation that thrombosis in some patients heralds the onset of malignancy has been recognized for over a century. Thrombin the key terminal enzyme of coagulation also promotes angiogenesis and stimulates tumor-platelet adhesion, adhesion to endothelium, tumor implantation, tumor cell growth and metastasis. The thrombin receptor, a member of the protease-activated receptor family, is expressed on many tumor cell lines and on breast tumor biopsy specimens. In addition to mitogenic effects on fibroblast, smooth muscle cells and endothelial cells, thrombin also exerts direct effects on cancer cells by activation of the cell cycle through downregulation of p27(Kip1) and induction of Skp2, and cyclins D and A. MicroRNA 222, which inhibits p27(Kip1), is upregulated by thrombin. In the transgenic TRAMP mouse model of prostate cancer inhibition of endogenous thrombin by hirudin retards spontaneous tumor growth. Inhibition of thrombin may lead to tumor dormancy and could explain inhibition of tumor growth and metastasis by anticoagulants observed in animal models and a beneficial effect on survival observed in some clinical trials of anticoagulants in cancer patients
Multiple myeloma involving skin and pulmonary parenchyma after autologous stem cell transplantation [Case Report]
ABSTRACT: Pulmonary involvement and skin involvement are rare complications of plasma cell neoplasms. Here we describe what may be the first reported case of a patient with relapse in both of these sites following autologous peripheral blood stem cell transplantation