Native heart valve thrombosis associated with COVID-19 - a report of 4 cases.

Native heart valve thrombosis (NHVT) is a rare valvular pathology, usually associated with prothrombotic state or disturbed intracardiac blood flow related to structural valve abnormalities. While different venous and arterial thromboembolic complications of COVID-19 have been widely described, so far NHVT has not been reported in the context of the disease. The authors describe 4 cases of NHVT associated with COVID-19, revealed on aortic, mitral (2 patients) and tricuspid valve. In a 29-yearold male with mild pneumonia, large thrombus developed on bicuspid aortic valve (BAV), which resulted in fatal brain emboli. In a 76-yearold male with a history of rheumatoid arthritis (RA) being in a recovery period after COVID-19, central retinal artery occlusion (CRAO) was the first sign of mitral valve thrombus, which disappeared after 3 weeks, during apixaban use. Such therapy was also successful in a 46-yearold female with multiple cardiovascular risk factors in whom mitral valve thrombus was found in a routine echocardiography after she got COVID-19 the third time. In a 75-year-old man with moderate COVID-19 pneumonia and bacterial coinfection, coexistent transient focal LV dysfunction and tricuspid valve thrombus were observed. The patient was treated with apixaban as well; however, in this case only reduction in the thrombus size was seen after 4 months therapy. The authors indicate that in patients with COVID-19 and NHVT, other prothrombotic conditions can usually be found. This complication may involve different valves and occur irrespective of COVID-19 severity. Interdisciplinary evaluation of such patients is necessary.

Acute femoral artery occlusion in a male with Duhring disease and COVID-19 pneumonia treated with baricitinib.

Arterial thromboembolic events (ATE) in COVID-19, similarly as venous thromboembolism (VTE), are observed mainly in severely ill patients. ATE include brain, heart, aortic, and peripheral ischemic complications which usually aggravate a course of the disease leading to lifethreatening conditions. A CASE REPORT: The authors describe a case of a 53-year-old male with Duhring disease in the remission period admitted due to severe COVID-19 pneumonia. The patient was treated with ceftriaxone (2000 mg once daily), dexamethasone (8 mg once daily), enoxaparin (60 mg twice daily), baricitinib (4 mg once daily), and remdesivir (200 mg on the first day, followed by 100 mg within 4 consecutive days); he required high flow oxygen therapy. On day 5 of hospitalization, he began to suffer from pain of the right lower extremity; in physical examination the limb was cold with absent femoral, popliteal, and pedal pulses. Urgent computed tomography angiography revealed total occlusion of the right superficial femoral artery (SFA) in the absence of any atherosclerotic plaques in the aorta. The patient was intubated and transferred to department of vascular surgery, where a giant clot was removed from SFA. Unfortunately, the patient outcome was unfavorable due to respiratory failure progression. The authors underline that ATE may occur even in anticoagulated patients and that association of some therapeutic options of COVID-19, like janus kinase (JAK) inhibitors use with an increased risk of ATE, should not be excluded.

Retroperitoneal hematoma in COVID-19 patients - case series.

COVID-19 patients, particularly those with severe pulmonary involvement, are at an increased thromboembolic risk related, among various causes, to the cytokine storm and excessive activation of the coagulation cascade and platelets. Different intensity of anticoagulation for them is proposed, mainly with low molecular weight heparins (LMWHs); in a confirmed pulmonary embolism (PE) the therapeutic dose of LMWH is routinely used. Some authors suggest that hemorrhagic complications in COVID-19 patients are rare. At the same time, one can find reports on internal bleeding, including retroperitoneal hematoma (RPH) and other abdominal hematomas. CASE REPORTS: The authors describe 5 cases (3 of those aged more than 80 years) with giant RPHs and with moderate/severe COVID-19 pneumonia, treated before RPH diagnosis with different enoxaparin doses. The therapeutic dose was given to the male with verified PE limited to the segmental/subsegmental pulmonary arteries and initially to the female in whom echocardiography was strongly suggestive of PE, yet this diagnosis was excluded on CT angiography. In one patient, the enoxaparin dose was escalated from 40 mg bd to 60 mg bd after the D-dimer increase. Two patients had bleeding complications despite the enoxaparin dose restricted to 40 mg/daily or bd. Two males had a coexistent psoas hematoma while in only one female there was a coexistent femoral hematoma. RPHs occurred between day 4 and 14 of hospitalization and all were treated conservatively. Three patients who died were particularly charged, so their deaths were not merely directly associated with RPH, which was closely analyzed in one autopsy performed. The authors underline that the choice of anticoagulation intensity in patients with COVID-19 pneumonia without venous thromboembolism seems sometimes difficult but recent publications indicate the low prophylactic enoxaparin dose as an optimal option. Anticoagulation dose escalation based only on the D-dimer level may not be appropriate for certain patients; moreover, the D-dimer increase is commonly observed during internal bleeding.