A Study to Evaluate AntiThrombotic Therapy to Lessen Complications of COVID-19 (Enrolling by Invitation Only)


About this study

The purpose of this study is to establish whether therapeutic-dose parenteral anticoagulation improves outcomes (reduces intubation or mortality) by 30 days after randomization.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria:

  • Patients ≥ 18 years of age.
  • Willing and able to provide (possibly through a substitute decision maker) informed consent.
  • Require hospitalization anticipated to last ≥ 72 hours for microbiologically-confirmed COVID-19.
  • Enrolled < 72 hours of hospital admission or of COVID-19 confirmation.

Exclusion Criteria:

  • Patients < 18 years of age.
  • Requirement for chronic mechanical ventilation via tracheostomy prior to hospitalization.
  • Patients for whom the intent is to not use pharmacologic thromboprophylaxis.
  • Active bleeding.
  • Risk factors for bleeding, including:
    • intracranial surgery or stroke within 3 months;
    • history of intracerebral arteriovenous malformation;
    • cerebral aneurysm or mass lesions of the central nervous system;
    • intracranial malignancy;
    • history of intracranial bleeding;
    • history of bleeding diatheses (e.g., hemophilia);
    • history of gastrointestinal bleeding within previous 3 months;
    • thrombolysis within the previous 7 days;
    • presence of an epidural or spinal catheter;
    • recent major surgery 200 mmHg, dBP > 120 mmHg);
    • other physician-perceived contraindications to anticoagulation.
  • Platelet count 2.0, or baseline aPTT > 50.
  • Hemoglobin < 80 g/L (to minimize the likelihood of requiring red blood cell transfusion if potential bleeding were to occur).
  • Acute or subacute bacterial endocarditis.
  • History of heparin induced thrombocytopenia (HIT) or other heparin allergy including hypersensitivity.
  • Current use of dual antiplatelet therapy.
  • Patients with an independent indication for therapeutic anticoagulation.
  • Patients in whom imminent demise is anticipated and there is no commitment to active ongoing intervention.
  • Anticipated transfer to another hospital that is not a study site within 72 hours.
  • Enrollment in other trials related to anti-coagulation or antiplatelet therapy

Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status

Rochester, Minn.

Mayo Clinic principal investigator

Vivek Iyer, M.D., M.P.H.

Closed for enrollment

More information


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