Highlights COVID-19 patients are at increased risk of thromboembolic complications. Escalated-dose thromboprophylaxis may help reduce the rate of thromboembolic events. The bleeding risk is highest for patients treated with therapeutic anticoagulation.

Thrombosis of unusual venous sites encompasses a large part of consultative hematology and is encountered routinely by practicing hematologists. Contrary to the more commonly encountered lower extremity venous thrombosis and common cardiovascular disorders, the various thromboses outlined in this review have unique presentations, pathophysiology, workup, and treatments that all hematologists should be aware of. This review attempts to outline the most up to date literature on cerebral, retinal, upper extremity, hepatic, portal, splenic, mesenteric, and renal vein thrombosis, focusing on the incidence, pathophysiology, provoking factors, and current recommended treatments for each type of unusual thrombosis to provide a useful and practical review for the hematologist. K E Y W O R D Santicoagulation, coagulation disorder, hypercoagulable, venous thrombosis

While common forms of arterial disease such as stroke and myocardial infarction are well studied and appropriate treatment algorithms are well described, occasionally, practitioners will encounter patients with thrombosis in other arteries; the cause and treatment of which is not entirely obvious or well studied. In this section, we will review the current data on arterial thrombosis, describing anatomic sources and hypercoagulable associations, and outline the epidemiology, pathophysiology, clinical presentation, etiology, and treatment of intracardiac thrombus, primary aortic mural thrombus, visceral infarctions, and cryptogenic limb ischemia. (Table 1). | ARTERIAL THROMBOS IS-ANATOMIC CONS IDER ATIONSArterial thrombosis most often occurs in association with atherosclerosis. In cryptogenic cases, arterial thrombosis may result from an anatomic source, the most common of which is cardioembolic, such as intracardiac thrombus, atrial appendage thrombus, patent foramen ovale with paradoxical embolus, and valvular vegetation.The minimal workup we consider in truly cryptogenic cases is assessment for a cardioembolic source ( Figure 1) including a transthoracic echocardiogram in conjunction with injection of agitated saline contrast and color Doppler imaging in order to detect a patent foramen ovale. Due to the unique nature of intracardiac thrombi and primary aortic mural thrombi, the following sections will outline the epidemiology, etiology, and management of these entities. | INTR AC ARD IAC THROMB ILeft ventricular (LV) thrombus most commonly occur after myocar- K E Y W O R D Sarterial thrombosis, coagulation disorder, hypercoagulable, infarction

Importance Mechanical heart valves (MHVs) pose significant thrombogenic risks to pregnant women and their fetuses, yet the choice of anticoagulation in this clinical setting remains unclear. Various therapeutic strategies carry distinct risk profiles that must be considered when making the decision about optimal anticoagulation. Objective We sought to review existing data and offer recommendations for the anticoagulation of pregnant women with MHVs, as well as management of anticoagulation in the peripartum period. Evidence Acquisition We performed a literature review of studies examining outcomes in pregnant women receiving systemic anticoagulation for mechanical valves, and also reviewed data on the safety profiles of various anticoagulant strategies in the setting of pregnancy. Results Warfarin has been shown to increase rates of embryopathy and fetal demise, although it has traditionally been the favored anticoagulant in this setting. Low-molecular-weight heparin, when dosed appropriately with close therapeutic monitoring, has been shown to be safe for both mother and fetus. Conclusions and Relevance We favor the use of low-molecular-weight heparin with appropriate dosing and monitoring for the anticoagulation of pregnant women with MHVs. Data suggest that this approach minimizes the thrombotic risk associated with the valve while also providing safe and effective anticoagulation that can be easily managed in the peripartum period. Target Audience Obstetricians and gynecologists, family physicians. Learning Objectives After completing this activity, the learner should be better able to: describe the clinical considerations in choosing an anticoagulation strategy for a pregnant patient with an MHV; evaluate the existing data about the safety profile of various anticoagulation strategies and the potential benefits and risks of each approach to the mother and fetus; and discuss one recommended approach to management of mechanical valves in the pregnant patient and assess the clinical nuances associated with each individual patient's decision.

Enzalutamide, a novel, oral androgen receptor antagonist used for the treatment of metastatic, castration-resistant prostate cancer, has been shown to improve overall and progression-free survival, prolong time to initiation of chemotherapy, reduce skeletal-related events, and carry a favorable adverse effect profile. Metastatic prostate cancer is a disease of older men, a population with an increased incidence of medical comorbidities warranting anticoagulation. Prostate cancer itself, along with some of its therapies, is also prothrombotic. Enzalutamide interacts with several anticoagulants through various mechanisms, making their concurrent use clinically challenging. As such, complex decisions about anticoagulation in these patients are frequently encountered by treating physicians. In this review, we describe the potential interactions between enzalutamide and various anticoagulants, and suggest management paradigms based on the current body of knowledge for patients with atrial fibrillation, venous thromboembolism, and mechanical heart valves.