COVID-19 and Its Implications for Thrombosis and Anticoagulation.

Venous thromboembolism, occlusion of dialysis catheters, circuit thrombosis in extracorporeal membrane oxygenation (ECMO) devices, acute limb ischemia, and isolated strokes, all in the face of prophylactic and even therapeutic anticoagulation, are features of novel coronavirus disease 2019 (COVID-19) coagulopathy. It seems well established at this time that a COVID-19 patient deemed sick enough to be hospitalized, should receive at least prophylactic dose anticoagulation. However, should some hospitalized patients have dosage escalation to intermediate dose? Should some be considered for full-dose anticoagulation without a measurable thromboembolic event and how should that anticoagulation be monitored? Should patients receive postdischarge anticoagulation and with what medication and for how long? What thrombotic issues are related to the various medications being used to treat this coagulopathy? Is antiphospholipid antibody part of this syndrome? What is the significance of isolated ischemic stroke and limb ischemia in this disorder and how does this interface with the rest of the clinical and laboratory features of this disorder? The aims of this article are to explore these questions and interpret the available data based on the current evidence.

Ischemic Stroke in the Young.

The purpose of this article is to address several challenging questions in the management of young patients (those age 60 and under) who present with ischemic stroke. Do genetic thrombophilic states, strongly associated with venous thrombosis, independently cause arterial events in adults? Should cases of patent foramen ovale be closed with mechanical devices in patients with cryptogenic stroke? What are the optimal treatments for cerebral vein thrombosis, carotid artery dissection, and antiphospholipid syndrome and are DOACs acceptable treatment for these indications? What is the mechanism underlying large vessel stroke in patients with COVID-19? This is a narrative review. We searched PubMed and Embase and American College of physicians Journal club database for English language articles since 2000 looking mainly at randomized clinical trials, Meta analyses, Cochran reviews as well as some research articles viewed to be cutting edge regarding anticoagulation and cerebrovascular disease. Searches were done entering cerebral vein thrombosis, carotid dissection, anticoagulation therapy and stroke, antiphospholipid antibody and stroke, stroke in young adults, cryptogenic stroke and anticoagulation, patent foramen ovale and cryptogenic stroke, COVID-19 and stroke.

Post-hospital discharge venous thromboembolism prophylaxis in medically ill patients.

There is a widely expressed concern about an unmet need for post hospitalization venous thromboembolism (VTE) prophylaxis in medically ill patients, however, physicians and hospitals have been slow to implement this measure. Recommendations against extended VTE prophylaxis in medical patients from the American Society of Hematology (ASH) in 2018 and the withholding of approval of betrixiban by the European Medicines Agency also in 2018 may have been influential in this regard. Furthermore, rivaroxaban the other drug approved for this indication in the U.S has not yet been approved in Europe. In addition, hospital administrators, those monitoring expenses in the U.S, have been reluctant to support a treatment which will mostly involve outpatients. Internal medicine physicians, hospitalists and nursing home physicians have not shared the fervor for post hospital VTE prophylaxis, whether with anticoagulants or aspirin, that their orthopedic surgery colleagues have, particularly in hip and knee arthroplasty. This is despite an increased risk of post hospital discharge thrombosis in both groups of patients. Enter hospitalized patients with COVID-19, a potentially severe medical illness with high hospitalization related thrombosis risk, and questions arise as to whether these medical patients, who are clearly more hypercoagulable during hospitalization than those in previous studies, should warrant post hospital discharge prophylaxis.

Methodological Issues and Controversies in COVID-19 Coagulopathy: A Tale of Two Storms.

Venous thromboembolism, occlusion of dialysis catheters, circuit thrombosis in ECMO devices, all in the face of prophylactic and sometimes even therapeutic anti-coagulation, are frequent features of COVID-19 coagulopathy. The trials available to guide clinicians are methodologically limited. There are several unresolved controversies including 1) Should all hospitalized patients with COVID-19 receive prophylactic anti-coagulation? 2) Which patients should have their dosage escalated to intermediate dose? 3) Which patients should be considered for full-dose anti-coagulation even without a measurable thromboembolic event and how should that anti-coagulation be monitored? 4) Should patients receive post-discharge anti-coagulation? 5) What thrombotic issues are related to the various medications being used to treat this coagulopathy? 6) Is anti-phospholipid anti-body part of this syndrome? 7) How do the different treatments for this disease impact the coagulation issues? The aims of this article are to explore these questions and interpret the available data based on the current evidence.