Supraprophylactic Anti-Factor Xa Levels Are Associated with Major Bleeding in Neurosurgery Patients Receiving Prophylactic Enoxaparin.

BACKGROUND: Prior studies demonstrated reduced risk for venous thromboembolism (VTE) in neurosurgical patients secondary to prophylaxis with both heparin and low-molecular-weight heparin. The ability to monitor low-molecular-weight heparin by obtaining anti-factor Xa (anti-Xa) serum levels provides an opportunity to evaluate safety and efficacy. The aim of this study was to describe characteristics of patients who have anti-Xa levels outside of the goal range (0.2-0.4/0.5 IU/mL) and investigate incidence of major bleeding and VTE. METHODS: A single-center, retrospective, observational study was conducted on neurosurgical patients receiving enoxaparin for VTE prophylaxis between August 2019 and December 2020. Significance testing was conducted via Fisher exact test and independent samples t test. RESULTS: The study included 85 patients. Patients were less likely to have an anti-Xa level in the goal range if they were male, had a higher weight, or were morbidly obese. Three neuroendovascular patients (3.5%) experienced a major bleed. Serum anti-Xa levels were significantly higher in patients who experienced major bleeds compared with patients who did not (0.45 ± 0.16 IU/mL vs. 0.28 ± 0.09 IU/mL, P = 0.003). Patients with a supraprophylactic anti-Xa level (>0.5 IU/mL) were more likely to experience a major bleed (P = 0.005). One VTE event occurred: the patient experienced a pulmonary embolism with anti-Xa level at goal. CONCLUSIONS: Anti-Xa-guided enoxaparin dosing for VTE prophylaxis in neurosurgical patients may help prevent major bleeding. These data suggest that a higher anti-Xa level may predispose patients to major bleeding. Further evaluation is needed to identify the goal anti-Xa level for VTE prophylaxis in this population.

Effect of Antithrombotic Therapy on Clinical Outcomes in Outpatients With Clinically Stable Symptomatic COVID-19: The ACTIV-4B Randomized Clinical Trial.

Importance: Acutely ill inpatients with COVID-19 typically receive antithrombotic therapy, although the risks and benefits of this intervention among outpatients with COVID-19 have not been established. Objective: To assess whether anticoagulant or antiplatelet therapy can safely reduce major adverse cardiopulmonary outcomes among symptomatic but clinically stable outpatients with COVID-19. Design, Setting, and Participants: The ACTIV-4B Outpatient Thrombosis Prevention Trial was designed as a minimal-contact, adaptive, randomized, double-blind, placebo-controlled trial to compare anticoagulant and antiplatelet therapy among 7000 symptomatic but clinically stable outpatients with COVID-19. The trial was conducted at 52 US sites between September 2020 and June 2021; final follow-up was August 5, 2021. Prior to initiating treatment, participants were required to have platelet count greater than 100 000/mm3 and estimated glomerular filtration rate greater than 30 mL/min/1.73 m2. Interventions: Random allocation in a 1:1:1:1 ratio to aspirin (81 mg orally once daily; n = 164), prophylactic-dose apixaban (2.5 mg orally twice daily; n = 165), therapeutic-dose apixaban (5 mg orally twice daily; n = 164), or placebo (n = 164) for 45 days. Main Outcomes and Measures: The primary end point was a composite of all-cause mortality, symptomatic venous or arterial thromboembolism, myocardial infarction, stroke, or hospitalization for cardiovascular or pulmonary cause. The primary analyses for efficacy and bleeding events were limited to participants who took at least 1 dose of trial medication. Results: On June 18, 2021, the trial data and safety monitoring board recommended early termination because of lower than anticipated event rates; at that time, 657 symptomatic outpatients with COVID-19 had been randomized (median age, 54 years [IQR, 46-59]; 59% women). The median times from diagnosis to randomization and from randomization to initiation of study treatment were 7 days and 3 days, respectively. Twenty-two randomized participants (3.3%) were hospitalized for COVID-19 prior to initiating treatment. Among the 558 patients who initiated treatment, the adjudicated primary composite end point occurred in 1 patient (0.7%) in the aspirin group, 1 patient (0.7%) in the 2.5-mg apixaban group, 2 patients (1.4%) in the 5-mg apixaban group, and 1 patient (0.7%) in the placebo group. The risk differences compared with placebo for the primary end point were 0.0% (95% CI not calculable) in the aspirin group, 0.7% (95% CI, -2.1% to 4.1%) in the 2.5-mg apixaban group, and 1.4% (95% CI, -1.5% to 5.0%) in the 5-mg apixaban group. Risk differences compared with placebo for bleeding events were 2.0% (95% CI, -2.7% to 6.8%), 4.5% (95% CI, -0.7% to 10.2%), and 6.9% (95% CI, 1.4% to 12.9%) among participants who initiated therapy in the aspirin, prophylactic apixaban, and therapeutic apixaban groups, respectively, although none were major. Findings inclusive of all randomized patients were similar. Conclusions and Relevance: Among symptomatic clinically stable outpatients with COVID-19, treatment with aspirin or apixaban compared with placebo did not reduce the rate of a composite clinical outcome. However, the study was terminated after enrollment of 9% of participants because of an event rate lower than anticipated. Trial Registration: ClinicalTrials.gov Identifier: NCT04498273.

OpenSAFELY: impact of national guidance on switching anticoagulant therapy during COVID-19 pandemic.

BACKGROUND: Early in the COVID-19 pandemic, the National Health Service (NHS) recommended that appropriate patients anticoagulated with warfarin should be switched to direct-acting oral anticoagulants (DOACs), requiring less frequent blood testing. Subsequently, a national safety alert was issued regarding patients being inappropriately coprescribed two anticoagulants following a medication change and associated monitoring. OBJECTIVE: To describe which people were switched from warfarin to DOACs; identify potentially unsafe coprescribing of anticoagulants; and assess whether abnormal clotting results have become more frequent during the pandemic. METHODS: With the approval of NHS England, we conducted a cohort study using routine clinical data from 24 million NHS patients in England. RESULTS: 20 000 of 164 000 warfarin patients (12.2%) switched to DOACs between March and May 2020, most commonly to edoxaban and apixaban. Factors associated with switching included: older age, recent renal function test, higher number of recent INR tests recorded, atrial fibrillation diagnosis and care home residency. There was a sharp rise in coprescribing of warfarin and DOACs from typically 50-100 per month to 246 in April 2020, 0.06% of all people receiving a DOAC or warfarin. International normalised ratio (INR) testing fell by 14% to 506.8 patients tested per 1000 warfarin patients each month. We observed a very small increase in elevated INRs (n=470) during April compared with January (n=420). CONCLUSIONS: Increased switching of anticoagulants from warfarin to DOACs was observed at the outset of the COVID-19 pandemic in England following national guidance. There was a small but substantial number of people coprescribed warfarin and DOACs during this period. Despite a national safety alert on the issue, a widespread rise in elevated INR test results was not found. Primary care has responded rapidly to changes in patient care during the COVID-19 pandemic.

Treatments Associated with Lower Mortality among Critically Ill COVID-19 Patients: A Retrospective Cohort Study.

BACKGROUND: Mortality in critically ill COVID-19 patients remains high. Although randomized controlled trials must continue to definitively evaluate treatments, further hypothesis-generating efforts to identify candidate treatments are required. This study's hypothesis was that certain treatments are associated with lower COVID-19 mortality. METHODS: This was a 1-yr retrospective cohort study involving all COVID-19 patients admitted to intensive care units in six hospitals affiliated with Yale New Haven Health System from February 13, 2020, to March 4, 2021. The exposures were any COVID-19-related pharmacologic and organ support treatments. The outcome was in-hospital mortality. RESULTS: This study analyzed 2,070 patients after excluding 23 patients who died within 24 h after intensive care unit admission and 3 patients who remained hospitalized on the last day of data censoring. The in-hospital mortality was 29% (593 of 2,070). Of 23 treatments analyzed, apixaban (hazard ratio, 0.42; 95% CI, 0.363 to 0.48; corrected CI, 0.336 to 0.52) and aspirin (hazard ratio, 0.72; 95% CI, 0.60 to 0.87; corrected CI, 0.54 to 0.96) were associated with lower mortality based on the multivariable analysis with multiple testing correction. Propensity score-matching analysis showed an association between apixaban treatment and lower mortality (with vs. without apixaban, 27% [96 of 360] vs. 37% [133 of 360]; hazard ratio, 0.48; 95% CI, 0.337 to 0.69) and an association between aspirin treatment and lower mortality (with vs. without aspirin, 26% [121 of 473] vs. 30% [140 of 473]; hazard ratio, 0.57; 95% CI, 0.41 to 0.78). Enoxaparin showed similar associations based on the multivariable analysis (hazard ratio, 0.82; 95% CI, 0.69 to 0.97; corrected CI, 0.61 to 1.05) and propensity score-matching analysis (with vs. without enoxaparin, 25% [87 of 347] vs. 34% [117 of 347]; hazard ratio, 0.53; 95% CI, 0.367 to 0.77). CONCLUSIONS: Consistent with the known hypercoagulability in severe COVID-19, the use of apixaban, enoxaparin, or aspirin was independently associated with lower mortality in critically ill COVID-19 patients.

Anticoagulation for COVID-19 Patients: A Bird's-Eye View.

Coronavirus disease 2019 (COVID-19) is a systemic disease that can be life-threatening involving immune and inflammatory responses, and that can result in potentially lethal complications, including venous thrombo-embolism (VTE). Forming an integrative approach to thrombo-prophylaxis and coagulation treatment for COVID-19 patients ensues. We aim at reviewing the literature for anticoagulation in the setting of COVID-19 infection to provide a summary on anticoagulation for this patient population. COVID-19 infection is associated with a state of continuous inflammation, which results in macrophage activation syndrome and an increased rate of thrombosis. Risk assessment models to predict the risk of thrombosis in critically ill patients have not yet been validated. Currently published guidelines suggest the use of prophylactic intensity over intermediate intensity or therapeutic intensity anticoagulant for patients with critical illness or acute illness related to COVID-19 infection. Critically ill COVID-19 patients who are diagnosed with acute VTE are considered to have a provoking factor, and, therefore, treatment duration should be at least 3 months. Patients with proximal deep venous thrombosis or pulmonary embolism should receive parenteral over oral anticoagulants with low-molecular-weight heparin or fondaparinux preferred over unfractionated heparin. In patients with impending hemodynamic compromise due to PE, and who are not at increased risk for bleeding, reperfusion may be necessary. Internists should remain updated on new emerging evidence regarding anticoagulation for COVID-19 patients. Awaiting these findings, we invite internists to perform individualized decisions that are unique for every patient and to base them on clinical judgment for risk assessment.

Medically Ill hospitalized Patients for COVID-19 THrombosis Extended ProphyLaxis with rivaroxaban ThErapy: Rationale and Design of the MICHELLE Trial.

BACKGROUND: The devastating Coronavirus disease (COVID-19) pandemic is associated with a high prothrombotic state. It is unclear if the coagulation abnormalities occur because of the direct effect of SARS-CoV-2 or indirectly by the cytokine storm and endothelial damage or by a combination of mechanisms. There is a clear indication of in-hospital pharmacological thromboprophylaxis for every patient with COVID-19 after bleed risk assessment. However, there is much debate regarding the best dosage regimen, and there is no consensus on the role of extended thromboprophylaxis. DESIGN: This study aims to evaluate the safety and efficacy of rivaroxaban 10 mg once daily for 35 ± 4 days versus no intervention after hospital discharge in COVID-19 patients who were at increased risk for VTE and have received standard parenteral VTE prophylaxis during hospitalization. The composite efficacy endpoint is a combination of symptomatic VTE, VTE-related death, VTE detected by bilateral lower limbs venous duplex scan and computed tomography pulmonary angiogram on day 35 ± 4 posthospital discharge and symptomatic arterial thromboembolism (myocardial infarction, nonhemorrhagic stroke, major adverse limb events, and cardiovascular death) up to day 35 ± 4 posthospital discharge. The key safety outcome is the incidence of major bleeding according to ISTH criteria. SUMMARY: The MICHELLE trial is expected to provide high-quality evidence around the role of extended thromboprophylaxis in COVID-19 and will help guide medical decisions in clinical practice.1.

Efficacy and safety of direct-acting oral anticoagulants compared to vitamin K antagonists in COVID-19 outpatients with cardiometabolic diseases.

BACKGROUND: It remains uncertain if prior use of oral anticoagulants (OACs) in COVID-19 outpatients with multimorbidity impacts prognosis, especially if cardiometabolic diseases are present. Clinical outcomes 30-days after COVID-19 diagnosis were compared between outpatients with cardiometabolic disease receiving vitamin K antagonist (VKA) or direct-acting OAC (DOAC) therapy at time of COVID-19 diagnosis. METHODS: A study was conducted using TriNetX, a global federated health research network. Adult outpatients with cardiometabolic disease (i.e. diabetes mellitus and any disease of the circulatory system) treated with VKAs or DOACs at time of COVID-19 diagnosis between 20-Jan-2020 and 15-Feb-2021 were included. Propensity score matching (PSM) was used to balance cohorts receiving VKAs and DOACs. The primary outcomes were all-cause mortality, intensive care unit (ICU) admission/mechanical ventilation (MV) necessity, intracranial haemorrhage (ICH)/gastrointestinal bleeding, and the composite of any arterial or venous thrombotic event(s) at 30-days after COVID-19 diagnosis. RESULTS: 2275 patients were included. After PSM, 1270 patients remained in the study (635 on VKAs; 635 on DOACs). VKA-treated patients had similar risks and 30-day event-free survival than patients on DOACs regarding all-cause mortality, ICU admission/MV necessity, and ICH/gastrointestinal bleeding. The risk of any arterial or venous thrombotic event was 43% higher in the VKA cohort (hazard ratio 1.43, 95% confidence interval 1.03-1.98; Log-Rank test p = 0.029). CONCLUSION: In COVID-19 outpatients with cardiometabolic diseases, prior use of DOAC therapy compared to VKA therapy at the time of COVID-19 diagnosis demonstrated lower risk of arterial or venous thrombotic outcomes, without increasing the risk of bleeding.

COVID-19-Associated Ischemic Stroke in a Patient on Therapeutic Anticoagulation.

INTRODUCTION: The coronavirus disease 2019 (COVID-19) has been associated with a hypercoagulable state, increasing the risk for ischemic stroke. In select cases, patients are already on anticoagulation therapy. Such examples highlight the severity of COVID-19's hyperthrombotic state, and raise questions regarding optimal stroke prevention in these patients. CASE REPORT: An 84-year-ool male with past medical history of chronic obstructive pulmonary disease, hypertension, and paroxysmal atrial fibrillation was admitted for respiratory failure secondary to COVID-19 pneumonia. He was continued on his home apixaban 5 mg twice daily. On day 2 of admission, he developed a new aphasia, and right-sided facial droop. Computed tomography (CT) head was unrevealing. CT angiography did not show large vessel occlusion. CT perfusion demonstrated a left middle cerebral artery ischemic penumbra, without core. He was not eligible for thrombolysis or thrombectomy interventions. Later CT head confirmed L middle cerebral artery infarct. The patient's D-dimer was 1,184 ng/mL on day 1 of admission, and increased to 111,574 by day 4. His hypoxia worsened, requiring intubation and transfer to the ICU. He experienced further clinical decline and eventual demise. CONCLUSION: Ischemic stroke in anticoagulated patients with COVID-19 has been previously reported. Such cases emphasize the severity of the coronavirus virus associated hypercoagulable state. A majority of reported cases have occurred in patients continuing their ambulatory therapy. Overall, such cases are likely underreported. There are current trials comparing therapeutic versus prophylactic dose anticoagulation in patients with COVID-19. There are no studies specifically addressing anticoagulation agent failure in these patients. Further research is required this area to determine the optimal therapy for patients with COVID-19.

Heparin dosage, level, and resistance in SARS-CoV2 infected patients in intensive care unit.

INTRODUCTION: Patients with COVID-19 frequently exhibit a hypercoagulable state with high thrombotic risk, particularly those admitted to intensive care units (ICU). Thromboprophylaxis is mandatory in these patients; nevertheless, thrombosis still occurs in many cases. Thus, the problem of assessing an adequate level of anticoagulation in ICU patients becomes evident during the COVID-19 pandemic. The aim of this study was to evaluate the heparin resistance and the efficacy of heparin monitoring using an anti-Xa activity assay. METHODS: Thirty-seven heparin-treated patients admitted to ICU for SARS-CoV-2 pneumonia were retrospectively studied for antifactor Xa activity (anti-Xa), activated partial thromboplastin time (APTT), Antithrombin, Fibrinogen, D-Dimer, Factor VIII, von Willebrand Factor, and the total daily amount of heparin administered. The correlation between APTT and anti-Xa was evaluated for unfractionated heparins (UFH). The correlations between the daily dose of UFH or the dosage expressed as IU/kg b.w. for low molecular weight heparin (LMWH) and anti-Xa were also evaluated. RESULTS: Twenty-one patients received calcium heparin, 8 sodium heparin, and 8 LMWH. A moderate correlation was found between APTT and anti-Xa for UFH. APTT did not correlate with coagulation parameters. 62% of UFH and 75% of LMWH treated patients were under the therapeutic range. About 75% of patients could be considered resistant to heparin. CONCLUSIONS: SARS-COV2 pneumonia patients in ICU have frequently heparin resistance. Anti-Xa seems a more reliable method to monitor heparin treatment than APTT in acute patients, also because the assay is insensitive to the increased levels of fibrinogen, FVIII, and LAC that are common during the COVID-19 inflammatory state.

Outpatient management of chronic warfarin therapy at a pharmacist-run anticoagulation clinic during the COVID-19 pandemic.

As a result of infection control regulations during the coronavirus disease 2019 (COVID-19) pandemic, anticoagulation clinics have been required to adjust their practices in order to continue providing safe and effective services for their patients. In accordance with a guidance document issued by the Anticoagulation Forum, The Brooklyn Hospital Center (TBHC) anticoagulation clinic in Brooklyn, New York implemented measures including telemedicine follow-ups instead of in-person clinic visits, extending the interval of INR testing, and reviewing eligible candidates for transition from warfarin to direct oral anticoagulants. This study describes the outcomes of one hospital-based clinic location in the 3 months before and after COVID-19 became a significant concern in the New York City area. The primary outcome of time-in-therapeutic range (TTR) for patients receiving warfarin was 60.6 % and 65.8 % in the pre-COVID and post-COVID groups, respectively (p = 0.21). For secondary outcomes, there was no difference in percent of therapeutic INRs (51.5 % pre-COVID v. 44.8 % post-COVID, p = 0.75) or percent of INRs ≥ 4.5 (2.3 % pre-COVID v. 4 % post-COVID, p = 0.27). Based on the data reported in this study, the short-term changes implemented at TBHC's anticoagulation clinic did not appear to cause reductions in safety and efficacy of chronic warfarin therapy management.

Spontaneous portomesenteric thrombosis in a non-cirrhotic patient with SARS-CoV-2 infection.

Intra-abdominal thromboses are a poorly characterised thrombotic complication of COVID-19 and are illustrated in this case. A 42-year-old man with chronic hepatitis B (undetectable viral load, FibroScan 7.4 kPa) developed fever and cough in March 2020. 14 days later, he developed right upper quadrant pain. After being discharged with reassurance, he re-presented with worsening pain on symptom day 25. Subsequent abdominal ultrasound suggested portal vein thrombosis. CT of the abdomen confirmed portal and mid-superior mesenteric vein thromboses. Concurrent CT of the chest suggested COVID-19 infection. While reverse transcription PCR was negative, subsequent antibody serology was positive. Thrombophilia screen excluded inherited and acquired thrombophilia. Having been commenced on apixaban 5 mg two times per day, he is currently asymptomatic. This is the first case of COVID-19-related portomesenteric thrombosis described in the UK. A recent meta-analysis suggests 9.2% of COVID-19 cases develop abdominal pain. Threshold for performing abdominal imaging must be lower to avoid this reversible complication.

Bilateral, vertical supranuclear gaze palsy following unilateral midbrain infarct.

A 60-year-old man recently admitted for bipedal oedema, endocarditis and a persistently positive COVID-19 swab with a history of anticoagulation on rivaroxaban for atrial fibrillation, transitional cell carcinoma, cerebral amyloid angiopathy, diabetes and hypertension presented with sudden onset diplopia and vertical gaze palsy. Vestibulo-ocular reflex was preserved. Simultaneously, he developed a scotoma and sudden visual loss, and was found to have a right branch retinal artery occlusion. MRI head demonstrated a unilateral midbrain infarct. This case demonstrates a rare unilateral cause of bilateral supranuclear palsy which spares the posterior commisure. The case also raises a question about the contribution of COVID-19 to the procoagulant status of the patient which already includes atrial fibrillation and endocarditis, and presents a complex treatment dilemma regarding anticoagulation.

Breakthrough venous thromboembolic events in five patients with COVID-19 on direct oral anticoagulants.

WHAT IS KNOWN AND OBJECTIVE: Coronavirus disease 2019 (COVID-19) is associated with increased risk of venous thromboembolism (VTE). Guidance for VTE prophylaxis continues to evolve, including addressing direct oral anticoagulants (DOACs) continued upon hospitalization. CASE SUMMARIES: We present 5 patients hospitalized for COVID-19 while on DOACs. Four patients had atrial fibrillation and had a previous VTE. Four patients developed acute VTE and one developed stroke-like symptoms. Monitoring D-dimer assisted with the detection of VTE. Three patients died, and two were discharged alive. WHAT IS NEW AND CONCLUSION: Therapeutic failure with DOACs appears to be commonplace in COVID-19. Further research is needed to determine whether there is an underlying cause to this association.

Diagnosis, management, and outcomes of venous thromboembolism in COVID-19 positive patients: a role for direct anticoagulants?

Coronavirus disease 2019 (COVID-19) has been associated with an increased risk of thromboembolic complications due to systemic coagulation activation. Little is known about the role of direct anticoagulants (DOACs) in COVID-19 related thrombosis. In this audit we sought to distinguish COVID-19 hospitalised patients with a diagnosis of venous thromboembolism (VTE) and record their outcomes over a period of 3 months (01/02/2020-30/04/2020). A total of 1583 patients were diagnosed with laboratory proven COVID-19 disease. Amongst them, 38 patients (0.82%) suffered VTE (median age 68 years, male/female: 20/18). VTE was the presenting symptom on admission in 71%. Pulmonary embolism was diagnosed in 92% of patients; 5 patients required intensive care and 3 underwent thrombolysis. 27 patients received initial treatment with unfractionated heparin/low molecular weight heparin (LMWH) while 10 were treated with direct anticoagulants (DOACs). After a median follow up of 25 days, 29 (76%) patients were alive while 5 were still hospitalised. Most patients (83%) were discharged on DOACs, no VTE recurrence or bleeding was recorded post-discharge. Our results suggest that direct anticoagulants could be a safe and effective treatment option in selected COVID-19 positive patients who have suffered venous thromboembolism.

Acute ophthalmic artery occlusion in a COVID-19 patient on apixaban.

We report a case of ophthalmic artery occlusion (OAO) in a young patient with COVID-19 infection that was on therapeutic anticoagulation with apixaban for deep venous thrombosis (DVT). A 48-year-old man with obesity was hospitalized with a severe form of COVID-19 infection, complicated with acute respiratory failure, septic shock, dilated cardiomyopathy and fungemia. Despite treatment with prophylactic enoxaparin (initial D-Dimer 1.14 µg/ml FEU (normal < 0.05 µg/ml FEU), D-Dimer increased to above 20 µg/ml FEU and patient continued to spike high fevers. This prompted further investigations and upper and lower extremities DVTs were confirmed and managed with enoxaparin 1 mg/kg twice daily. D-dimer level decreased to 4.98 µg/ml FEU while on therapeutic anticoagulation. Three weeks later pending hospital discharge, the anticoagulation was switched to oral apixaban 10 mg twice daily. Patient developed acute severe right eye visual loss of no light perception and was diagnosed with incomplete OAO. D-Dimer was elevated at 2.13 µg/ml FEU. Stroke etiological work-up found no embolic sources, resolution of the dilated cardiomyopathy and negative antiphospholipid antibodies. Treatment was changed to enoxaparin and no thrombotic events were encountered to date. Ocular vascular complications have not yet been reported in COVID-19. Controversy exists on the best management algorithm for the hypercoagulable state associated to COVID-19 Either direct oral anticoagulants or low-molecular-weight-heparin are considered appropriate at discharge for patients with venous thromboembolism. The optimum regimen for ischemic stroke prevention and the significance of D-Dimer for anticoagulation monitoring in COVID-19 remain unclear.

Direct oral anticoagulant plasma levels' striking increase in severe COVID-19 respiratory syndrome patients treated with antiviral agents: The Cremona experience.

BACKGROUND: Antiviral drugs are administered in patients with severe COVID-19 respiratory syndrome, including those treated with direct oral anticoagulants (DOACs). Concomitant administration of antiviral agents has the potential to increase their plasma concentration. A series of patients managed in the Cremona Thrombosis Center were admitted at Cremona Hospital for SARS-CoV-2 and started antiviral drugs without stopping DOAC therapy. DOAC plasma levels were measured in hospital and results compared with those recorded before hospitalization. METHODS: All consecutive patients on DOACs were candidates for administration of antiviral agents (lopinavir, ritonavir, or darunavir). Plasma samples for DOAC measurement were collected 2to 4 days after starting antiviral treatment, at 12 hours from the last dose intake in patients on dabigatran and apixaban, and at 24 hours in those on rivaroxaban and edoxaban. For each patient, C-trough DOAC level, expressed as ng/mL, was compared with the one measured before hospitalization. RESULTS: Of the 1039 patients hospitalized between February 22 and March 15, 2020 with COVID-19 pneumonia and candidates for antiviral therapy, 32 were on treatment with a DOAC. DOAC was stopped in 20 and continued in the remaining 12. On average, C-trough levels were 6.14 times higher during hospitalization than in the pre-hospitalization period. CONCLUSION: DOAC patients treated with antiviral drugs show an alarming increase in DOAC plasma levels. In order to prevent bleeding complications, we believe that physicians should consider withholding DOACs from patients with SARS-CoV-2 and replacing them with alternative parenteral antithrombotic strategies for as long as antiviral agents are deemed necessary and until discharge.