WHRT World Heart Corp. (MM)

World Heart Corporation (WorldHeart) (Nasdaq:WHRT), a developer of mechanical circulatory systems, today announced that an investigator-initiated study that includes patients who had received the Levacor ventricular assist device (VAD) was the subject of a presentation in the Emerging New Technologies Section at the Fifth European Mechanical Circulatory Support Summit. Preliminary clinical data suggests that the Levacor VAD does not cause acquired von Willebrand Factor (vWF) deficiency, a condition that is linked to serious bleeding disorders(1) and that has been associated with the use of current VADs.(2, 3, 4)

"Depletion of the large protein multimers of the vWF is strongly correlated with bleeding disorders and bleeding is one of the most prevalent adverse events associated with the use of VADs," commented Dr. James W. Long, M.D., Ph.D(5), Director of Advanced Cardiac Care at INTEGRIS Baptist Medical Center. As he explains, "Shear forces generated within blood pumps can disrupt the large protein multimer of the vWF, thereby compromising blood clotting. Any device that avoids disturbing the clotting system like this could reduce the risk of bleeding complications allowing for expanded use of VADs for the treatment of heart failure."

In the study, von Willebrand multimers were compared in six subjects supported by the Levacor VAD investigational device with ten subjects who received another continuous flow rotary pump. Von Willebrand multimers were measured pre-implant, at various intervals post-implant up to 90 days and after device removal. In all Levacor VAD recipients, the important large multimer of the vWF was preserved. In contrast, the large multimers of the vWF were depleted in all of the other ten recipients. These differences were statistically significant (p value