Guidelines for prophylaxis and anti-thrombotic treatment for patients with COVID-19. Consensus of the Latin American Cooperative Group on Hemostasis and Thrombosis (CLAHT) / Guía de profilaxia y tratamiento antitrombótico para pacientes con COVID-19. Consenso del Grupo Cooperativo Latinoamericano en Hemostasia y Trombosis (CLAHT)

Coagulopathy and thrombosis associated with coronavirus disease 2019 (COVID-19) represent a major issue in the management of this disease. In the past months, clinical studies have demonstrated that COVID-19 patients present with a particular hypercoagulable state, in which a markedly increased D-dimer concomitant with increased levels of fibrinogen are observed. This hypercoagulable state leads to an increased risk of thrombosis, which seems to be higher among those patients with critical symptoms of COVID-19. The best therapeutic approach to prevent thrombotic events in COVID-19 has not been determined yet and several questions regarding thromboprophylaxis therapy, such as the time to initiate anticoagulation, type of anticoagulant and dose regimen, have emerged among physicians. To address these concerns, several medical societies have published position papers to provide the opinion of thrombosis experts on the management of coagulopathy and thrombosis associated with COVID-19. In line with this, the Latin America Cooperative Group of Hemostasis and Thrombosis (Grupo CLAHT) has constituted a panel of experts in thrombosis and hemostasis to discuss the available data on this topic. The aim of this review is to summarize the current evidence regarding hemostatic impairment and thrombotic risk in COVID-19 and to provide a carefully revised opinion of Latin American experts on the thromboprophylaxis and management of thrombotic events and coagulopathy in patients with suspected COVID-19.

La coagulopatía y la trombosis asociadas a la enfermedad por coronavirus 2019 (COVID-19) representan un problema importante en el manejo de esta enfermedad. Los estudios clínicos de los últimos meses han demostrado que los pacientes con COVID-19 presentan un estado de hipercoagulabilidad particular, en el que se observa un aumento notable del dímero D concomitante con niveles elevados de fibrinógeno. El estado de hipercoagulabilidad conduce a un mayor riesgo de trombosis, que parece ser mayor entre aquellos pacientes con síntomas críticos de COVID-19. El mejor enfoque terapéutico para prevenir los eventos trombóticos en esta nueva enfermedad aún no se ha determinado y han surgido varias preguntas con respecto a la tromboprofilaxia, como el momento adecuado para iniciar la anticoagulación, el tipo de anticoagulante y el régimen de dosis. Para abordar estas preocupaciones, varias sociedades médicas han publicado artículos de posición para brindar la opinión de expertos en trombosis sobre el manejo de la coagulopatía y trombosis asociadas a COVID-19. Grupo Cooperativo Latinoamericano de Hemostasia y Trombosis (Grupo CLAHT) ha convocado a un panel de expertos en trombosis y hemostasia para discutir los datos disponibles sobre este tema. El objetivo de esta revisión es resumir la evidencia actual con respecto al deterioro hemostático y el riesgo trombótico en el COVID-19 y proporcionar una opinión cuidadosamente revisada de los expertos latinoamericanos sobre la tromboprofilaxis y el manejo de eventos trombóticos y coagulopatía en pacientes con sospecha de COVID-19.

Thrombosis questions from the inpatient wards.

The multifaceted pathophysiologic processes that comprise thrombosis and thromboembolic diseases take on a particular urgency in the hospitalized setting. In this review, we explore 3 cases of thrombosis from the inpatient wards: purpura fulminans, cancer-associated thrombosis with thrombocytopenia, and coronavirus disease 2019 (COVID-19) and the use of dose-escalated anticoagulation therapy and antiplatelet agents. We discuss the evaluation and management of purpura fulminans and the roles of plasma transfusion, protein C and antithrombin replacement, and anticoagulation in treating this disease. We present a framework for evaluating the etiologies of thrombocytopenia in cancer and review 2 strategies for anticoagulation management in patients with cancer-associated thrombosis and thrombocytopenia, including recent prospective data supporting the use of dose-modified anticoagulation based on platelet count. Last, we dissect the major clinical trials of therapeutic- and intermediate-dose anticoagulation and antiplatelet therapy in hospitalized patients with COVID-19, reviewing key recommendations from consensus guidelines while highlighting ways in which institutional and patient-tailored practices regarding antithrombotic therapies in COVID-19 may differ. Together, the cases highlight the diverse and dramatic presentations of macro- and microvascular thrombosis as encountered on the inpatient wards.

Aortic thrombosis as a dramatic vascular complication in COVID-19 disease.

OBJECTIVE: To report clinical outcomes of COVID-19 related acute aortic thrombosis (AAT). METHODS: Consecutive COVID-19 patients presenting with AAT between April 2020 and August 2021 were included retrospectively. Clinical and radiological data were prospectively collected. RESULTS: Ten patients (men, 90%; mean age, 64 ± 2 years) were included. At the time of AAT diagnosis, four patients were in intensive care unit. Median time between diagnosis of COVID-19 and AAT was 5 days [IQR 0-8.5]. Clinical presentation was acute lower limb ischaemia (n=9) and mesenteric ischaemia (n=2). Thrombus localization was the abdominal aorta (n=5), the thoracic aorta (n=2) or both (n=3), with the following embolic sites: lower limbs (n=9), renal arteries (n=3), superior mesenteric artery (n=2), splenic artery (n=1), cerebral arteries (n=1). Revascularization was performed in 9 patients, using open (n=6), endovascular (n=2) or hybrid techniques (n=1). Three patients required reinterventions. The 30-day mortality was 30%. Three major amputations were performed in two patients, resulting in a free-amputation survival rate of 50% after a median follow-up of 3,5 months [IQR 2-4.1]. CONCLUSION: AAT is a rare and devastating complication of COVID-19 disease, responsible for high mortality and amputation rates.

Cardiac Computed Tomography to exclude left atrial appendage thrombus in atrial arrhythmias prior to electrical cardioversion during the COVID-19 pandemic.

Nil.

Long COVID endotheliopathy: hypothesized mechanisms and potential therapeutic approaches.

SARS-CoV-2-infected individuals may suffer a multi-organ system disorder known as "long COVID" or post-acute sequelae of SARS-CoV-2 infection (PASC). There are no standard treatments, the pathophysiology is unknown, and incidence varies by clinical phenotype. Acute COVID-19 correlates with biomarkers of systemic inflammation, hypercoagulability, and comorbidities that are less prominent in PASC. Macrovessel thrombosis, a hallmark of acute COVID-19, is less frequent in PASC. Female sex at birth is associated with reduced risk for acute COVID-19 progression, but with increased risk of PASC. Persistent microvascular endotheliopathy associated with cryptic SARS-CoV-2 tissue reservoirs has been implicated in PASC pathology. Autoantibodies, localized inflammation, and reactivation of latent pathogens may also be involved, potentially leading to microvascular thrombosis, as documented in multiple PASC tissues. Diagnostic assays illuminating possible therapeutic targets are discussed.

Transjugular intrahepatic portosystemic shunt, local thrombaspiration, and lysis for management of fulminant portomesenteric thrombosis and atraumatic splenic rupture due to vector-vaccine-induced thrombotic thrombocytopenia: a case report.

INTRODUCTION: Recombinant adenoviral vector vaccines against severe acute respiratory syndrome coronavirus 2 have been observed to be associated with vaccine-induced immune thrombotic thrombocytopenia. Though vaccine-induced immune thrombotic thrombocytopenia is a rare complication after vaccination with recombinant adenoviral vector vaccines, it can lead to severe complications. In vaccine-induced immune thrombotic thrombocytopenia, the vector vaccine induces heparin-independent production of platelet factor 4 autoantibodies, resulting in platelet activation and aggregation. Therefore, patients suffering from vaccine-induced immune thrombotic thrombocytopenia particularly present with signs of arterial or venous thrombosis, often at atypical sites, but also signs of bleeding due to disseminated intravascular coagulation and severe thrombocytopenia. We describe herein a rare case of fulminant portomesenteric thrombosis and atraumatic splenic rupture due to vaccine-induced immune thrombotic thrombocytopenia. This case report presents the diagnosis and treatment of a healthy 29-year-old male Caucasian patient suffering from an extended portomesenteric thrombosis associated with atraumatic splenic rupture due to vaccine-induced immune thrombotic thrombocytopenia after the first dose of an adenoviral vector vaccine against severe acute respiratory syndrome coronavirus 2 [ChAdOx1 nCoV-19 (AZD1222)]. Therapeutic management of vaccine-induced immune thrombotic thrombocytopenia initially focused on systemic anticoagulation avoiding heparin and the application of steroids and intravenous immune globulins as per the recommendations of international societies of hematology and hemostaseology. Owing to the atraumatic splenic rupture and extended portomesenteric thrombosis, successful management of this case required splenectomy with additional placement of a transjugular intrahepatic portosystemic shunt to perform local thrombaspiration, plus repeated local lysis to reconstitute hepatopetal blood flow. CONCLUSION: The complexity and wide spectrum of the clinical picture in patients suffering from vaccine-induced immune thrombotic thrombocytopenia demand an early interdisciplinary diagnostic and therapeutic approach. Severe cases of portomesenteric thrombosis in vaccine-induced immune thrombotic thrombocytopenia, refractory to conservative management, may require additional placement of a transjugular intrahepatic portosystemic shunt, thrombaspiration, thrombolysis, and surgical intervention for effective management.

Thrombosis of Medium-Sized and Large Arteries During Covid-19 Infection: Results of the COVIVASC Study.

BACKGROUND: COVID-19 infection is associated not only with venous thromboses but also with arterial thromboses (COV-ATs) in relation with an endothelial dysfunction, a coagulopathy and rhythm disorders. The incidence, the topography, and the prognosis of COV-ATs remain poorly known. The objective of this study was to report the overall experience of the Greater Paris University Hospitals (Assistance Publique - Hopitaux de Paris, AP-HP) during the first pandemic wave of COVID-19 infection. METHODS: After approval by the ethics committee, a study using the AP-HP clinical data warehouse was carried out between March and May 2020. Overall, 124,609 patients had a polymerase chain reaction for COVID-19 in our hospitals, of which 25,345 were positive. From 20,710 exploitable stays, patients tested positive for COVID who presented an episode of acute COV-AT (except coronary and intracranial arteries) were selected on the basis of the French medical classification for clinical procedures codes. The data are presented as absolute values with percentages and/or means with standard deviation. RESULTS: Over the studied period, 60 patients (aged 71±14 years, 42 men) presented a COV-AT at the time of their hospitalization, an incidence of 0.2%. The arterial complication occurred 3±7 days after the COVID infection and was inaugural in 30% of the cases (n = 18). The sites of COV-AT were the lower extremities (n = 35%, 58%), the abdominal aorta (n = 10%, 17%), the thoracic aorta (n = 7%, 12%), the upper limbs (n = 7%, 12%), the cerebral arteries (n = 7%, 12%), the digestive arteries (n = 6%, 10%), the renal arteries (n = 2%, 3%), and the ophthalmic artery (n = 1%, 2%). Multiple COV-ATs were observed in 13 patients (22%). At the time of diagnosis, 20 (33%) patients were in intensive care, including six (10%) patients who were intubated. On computed tomography angiography, COVID lesions were classified as moderate and severe in 25 (42%) and 21 (35%) cases, respectively. Revascularization was attempted in 27 patients (45%), by open surgery in 16 cases, using endovascular techniques in 8 cases and with a hybrid approach in three cases. Six patients (22%) required reinterventions. The duration of hospitalization was 12±9 days. Early mortality (in-hospital or at 30 days) was 30% (n = 18). Nine (15%) patients presented severe nonlethal ischemic complications. CONCLUSIONS: Arterial involvement is rare during COVID-19 infection. The aorta and the arteries of the limbs are the privileged sites. The morbi-mortality of these patients is high. Future studies will have to determine if the systematization of anticoagulation therapy decreases the incidence and the severity of the condition.

COVID-19-related Peripheral Arterial Thrombosis Treated in a Large Health Maintenance Organization.

BACKGROUND: COVID-19 was initially identified as an acute respiratory disease, but it was quickly recognized that multiple organ systems could be affected. Venous thrombosis and pulmonary embolism have been well reported. However, there is a paucity of data on COVID-19-related arterial thrombosis. We examined the incidence, characteristics, treatment, and outcome in patients with acute COVID-19-related arterial thrombosis in a large health maintenance organization (HMO). METHODS: A retrospective multicenter case review was performed from March 2020 to March 2021. Cases were identified through a questionnaire sent to vascular surgeons. Patient characteristics, imaging, treatment, and outcome were reviewed. Successful revascularization was defined as restoration of blood flow with viability of the end organ and absence of death within 30 days. Limb salvage was defined as prevention of major amputation (transtibial or transfemoral) and absence of death in 30 days. RESULTS: There were 37,845 patients admitted with COVID-19 complications during this time. Among this group, 26 patients (0.07%) had COVID-19-related arterial thrombosis. The mean age was 61.7 years (range, 33-82 years) with 20 men (77%) and 6 women (23%). Ethnic minorities comprised 25 of 26 cases (96%). Peripheral arterial disease (PAD) was present in 4 of 26 (15%), active smoking in 1 of 26 (3.8%), and diabetes in 19 of 26 (73%) cases. Most patients developed acute arterial ischemia in the outpatient setting, 20 of 26 (77%). Of the outpatients, 6 of 20 (30%) had asymptomatic COVID-19 and 14 of 20 (70%) had only mild upper respiratory symptoms. Distribution of ischemia was as follows: 23 patients had at least one lower extremity ischemia, one patient had cerebral and lower extremity, one had mesenteric and lower extremity, and one had upper extremity ischemia. Revascularization was attempted in 21 patients, of which 12 of 21 (57%) were successful. Limb salvage was successful in 13 of 26 (50%) patients. The overall mortality was 31% (8/26). CONCLUSIONS: Our experience in a large HMO revealed that the incidence of COVID-19-related arterial thrombosis was low. The actual incidence is likely to be higher since our method of case collection was incomplete. The majority of arterial thrombosis occurred in the outpatient setting in patients with asymptomatic or mild/moderate COVID-19 respiratory disease. Acute ischemia was the inciting factor for hospitalization in these cases. Acute lower extremity ischemia was the most common presentation, and limb salvage rate was lower than that expected when compared to ischemia related to PAD. Arterial thrombosis associated with COVID-19 portends a significantly higher mortality. Education of primary care providers is paramount to prevent delayed diagnosis as most patients initially developed ischemia in the outpatient setting and did not have a high cardiovascular risk profile.

Left Ventricular Thrombus of Unknown Etiology in a Patient With COVID-19 Disease With No Significant Medical History.

The incidence of left ventricular thrombus is relatively low. Ventricular thrombi typically manifest in patients with reduced ejection fraction and post myocardial infarction [1]. The impact of COVID-19's hypercoagulability state is presented here. A 44 year old male who contracted COVID-19, progressed to moderate disease requiring inpatient treatment with supplemental oxygen. During the course of the hospital stay, while receiving National Institutes of Health guideline directed thromboembolism prophylaxis for COVID-19 infected patients [2], the patient developed a left ventricular thrombus which consequently embolized and occluded the left anterior descending and left circumflex coronary arteries requiring rheolytic thrombectomy.

A journey through anticoagulant therapies in the treatment of left ventricular thrombus in post-COVID-19 heparin-induced thrombocytopenia: a case report.

BACKGROUND: Heparin-induced thrombocytopenia (HIT) is an immune-mediated adverse drug reaction associated with thrombosis. Clinical scoring systems and the presence of anti-platelet factor 4 (anti-PF4)/heparin antibodies determine the diagnosis. CASE PRESENTATION: A 57-year-old man who was treated with acenocoumarol due to a chronic left ventricular thrombus was admitted to the hospital for severe SARS-CoV-2 pneumonia and pulmonary embolism. The patient was started on bemiparin and discharged. Left lower limb acute arterial ischemia and thrombocytopenia were diagnosed 18 days later. Computed tomography angiography revealed a large left ventricular thrombus and multiple arterial thrombi. Left femoral-popliteal thromboembolectomy was performed. Anti-PF4/heparin antibodies confirmed an HIT diagnosis. Fondaparinux (7.5 mg/24 h) was initiated, but cardiac surgery was necessary. Bivalirudin was used during surgery, with an initial load (1.25 mg/kg) and maintenance infusion (2.5 mg/kg/h). The cardiac thrombus was extracted, but the patient experienced a postsurgical myocardial infarction. Percutaneous cardiovascular intervention (PCI) required a bivalirudin load (0.75 mg/kg) and maintenance infusion (1.75 mg/kg/h). No coronary lesions were detected, and argatroban was started afterwards (0.5 µg/kg/min). When the platelet count exceeded 100 × 109/L, acenocoumarol was initiated. Thereupon, acetylsalicylic acid (100 mg/24 h) was added. No other complications have been reported to date. CONCLUSION: The clinical presentation of intraventricular and multiple arterial thrombi is remarkable. SARS-CoV-2 infection likely contributed to a hypercoagulable state. The management of patients with HIT undergoing cardiac surgery is challenging. If surgery cannot be delayed, then treatment with bivalirudin is recommended. Additionally, this drug is recommended for PCI. Bivalirudin is safe and well-tolerated in both procedures.

Gore Cardioform ASD device thrombus weeks after COVID-19 infection.

Device-related thrombosis and device-related endocarditis after atrial septal defect (ASD) transcatheter closure are extremely rare. It is known that COVID-19 infection could lead to a thrombotic microangiopathy-like phenomenon. We present the case of a 14-year-old female who developed fever and was found to have a thrombus on the right atrial side of the ASD closure device weeks after an asymptomatic COVID-19 infection and negative COVID-19 test 2 days before transcatheter ASD closure. Although there is no certainty that the thrombus was related to the prior COVID-19 infection, the possibility of an ongoing COVID-19-related hypercoagulable state should be entertained.

Occam's Razor and Managing Acute Thrombosis in the COVID-19 Era.

The COVID-19 pandemic has profoundly influenced the practice of medicine in Australia over the last 24 months. Recently, the development of several vaccines to COVID-19 has been accompanied by reports of an associated rare syndrome of thrombosis and thrombocytopaenia (VITTS). The possibility of this rare disorder confronts all clinicians who deal with acute thrombosis, particularly given the prevalence of patients who have recently been immunised. However, VITTS remains rare, and we believe unnecessary focus on its potential diagnosis may distract from other more common causes of acute thrombosis. We discuss this with reference to a recent case at our institution.

How to recognize and manage COVID-19-associated coagulopathy.

COVID-19 is frequently associated with abnormalities on coagulation testing and a coagulopathy driven by inflammation, intravascular coagulation activation, and microvascular thrombosis. Elevated D-dimer is the most common finding and is a predictor of adverse outcomes including thrombosis, critical illness, and death. Although COVID-19-associated coagulopathy has some similarities to disseminated intravascular coagulation, the platelet count is usually preserved, coagulation times are usually normal or minimally prolonged, and thrombosis is more common than bleeding, at least in noncritically ill patients. Bleeding is uncommon but may be a significant problem in critically ill patients, including those who may develop a consumptive coagulopathy with frank disseminated intravascular coagulation and those on extracorporeal membrane oxygenation. Blood product support to correct coagulopathy is reserved for bleeding patients or those requiring invasive procedures. Current recommendations suggest that all hospitalized patients should receive at least a prophylactic dose of anticoagulation. Results from a multiplatform randomized clinical trial suggest that therapeutically dosed anticoagulation may improve outcomes, including the need for organ support and mortality in moderately ill patients but not in those requiring critical care. The results of ongoing trials evaluating the impact of different antithrombotic strategies (therapeutic agents and intensity) on COVID-19 outcomes are eagerly awaited and are expected to have important implications for patient management. We also discuss COVID-19 vaccine-associated cytopenias and bleeding as well as vaccine-induced thrombotic thrombocytopenia, in which thrombosis is associated with thrombocytopenia, elevated D-dimer, and, frequently, hypofibrinogenemia.