Effect of multielement intravascular ultrasound on the anticoagulant potency of enoxaparin

Two patients, treated with enoxaparin and eptifibatide, developed significant guide catheter-associated thrombus while undergoing intravascular ultrasound (IVUS). Using an ex vivo assay, we found that activation of a multielement IVUS catheter resulted in a decrease in anti-Xa activity and a decrease in clot formation time. This effect occurred rapidly and repeatedly after activation of the IVUS catheter.