Therapeutic Initial Heparin Dosing for Patients With Clots or Certain Heart Conditions Admitted to the Hospital

Heparin infusions are high-risk medications that must be titrated to effect within a narrow therapeutic anti-Xa range. Prolonging the time to reach the therapeutic range decreases the clinical effectiveness of the infusion and increases the potential for adverse drug events.

The intervention used in this study will be calculating the initial heparin infusion rates described below rather than dosing 18 units/kg/hr for the moderate-intensity protocol and 12 units/kg/hr with a dose cap of 1000 units/hr for the low-intensity protocol.

Moderate-Intensity Protocol (R2 = 0.48) Heparin infusion rate (unit/(kg*hr))=(1004.8-163.5*(1 if female)-4.8*(age in years)+14.6*(actual body weight in kg)-19.3*(BMI in kg/m^2))/(Actual body weight in kg)

Low-Intensity Protocol (R2 = 0.31) Heparin infusion rate (unit/(kg*hr))=(615.5-70.1*(1 if female)-1.7*(age in years)+10.1*(actual body weight in kg)-11.9*(BMI in kg/m^2))/(Actual body weight in kg)

All other components of heparin infusion management will be conducted per Inova Health System standard of care.

Inclusion criteria

• Age > 18 years-old
• Diagnosis by the attending physician with one of the following conditions for which anticoagulation with heparin in an Food & Drug Administration approved indication and considered the standard of care:
• Moderate-intensity anti-Xa protocol: new-onset deep vein thrombosis or pulmonary embolism, or mechanical heart valve
• Low-intensity anti-Xa protocol: atrial fibrillation, acute cardiac syndrome, embolic stroke
• Heparin infusion either has not started or has been initiated in the last 120 minutes

Exclusion criteria

• Use of extracorporeal membrane oxygenation or ventricular assist devices such as Impella pumps
• Diagnosis of thrombophilia/hypercoagulable state
• Concurrent use of direct-acting oral anticoagulants or low molecular weight heparins
• Baseline anti-Xa > 0.7
• Pregnancy