Feasibility Study of Unfractionated Heparin in Acute Chest Syndrome

Unfractionated Heparin in Acute Chest Syndrome: A Pilot Feasibility Randomized Controlled Trial of Unfractionated Heparin vs. Standard of Care in Acute Chest Syndrome

The purpose of this study is to determine the feasibility of performing a larger multicenter phase III trial to assess the effects of unfractionated heparin (UFH) in acute chest syndrome (ACS). Prespecified feasibility criteria consists of the ability to enroll potential study participants, which includes the timely notification of hospitalized patients with ACS, the capacity to consent eligible individuals, and the ability to appropriately randomize eligible patients within 24 hours of diagnosis. Additional feasibility objectives involve ensuring appropriate eligibility criteria, proper administration of the study drug, and the ability to completely and accurately collect clinical data of interest. The final aim of our pilot study is to provide preliminary data, with respect to treatment effect and variance, to allow sample size calculation in a larger trial given the lack of data available to help guide this process. The investigators hypothesize that the use of UFH in ACS will result in a decrease in the duration of hospitalization and improve other clinical outcomes, such as the duration of hypoxemia and duration of moderate to severe pain.

Inclusion Criteria:

• Diagnosis of ACS defined as a new pulmonary infiltrate involving at least one segment of the lung on a chest x-ray or chest CT scan with 2 or more of the following: chest pain, tachypnea, dyspnea, cough, hypoxemia, or body temperature greater than or equal to 38.0 degrees Celsius
• Hemoglobin electrophoresis confirming HbSS, SC, or B0 (historical records sufficient)
• Age greater than or equal to 18

Exclusion Criteria:

• Any absolute contraindication to heparin
• Platelet count less than 50 per microliter (current admission)
• Historical diagnosis of moyamoya disease as documented in medical records
• Historical diagnosis of proliferative retinopathy as documented in medical records
• Current participation in a chronic exchange transfusion program
• Underlying hypercoagulable disorder other than sickle cell disease
• Currently receiving therappeutic anticoagulation
• Currently receiving antiplatelet agents
• Currently receiving estrogen containing oral contraceptives
• Chest CT scan documented PE performed as standard of care prior to study enrollment (current admission)