Abstract 20735: Clinical Impact of Early Changes in von Willebrand Factor in Patients Supported With Left Ventricular Assist Device Therapy
Introduction: Left ventricular assist device (LVAD) therapy is known to alter von Willebrand factor (vWF) activity and function. Most data reflect changes late while on chronic support. Very limited data examine early changes in vWF stratified by device type with little correlation to adverse events.
Methods: From February 2007 to December 2015, 321 patients underwent primary LVAD implant at our Clinic. Median age at implant was 62 years (range, 18-82) and 258 (80%) were male. Von Willebrand Factor activity and antigen measured before and early after LVAD were stratified by device type (HeartMate II (n=246) and HeartWare HVAD (n=43)), and correlated to thrombotic and hemorrhagic adverse events.
Results: After HeartMate II implantation, vWF activity significantly decreased within a median of 2.3 months after implant (preop: 191 vs. postop: 130, p<0.001, while after HeartWare HVAD implantation, the decrease in vWF activity was not significantly reduced at a median of 2 months after implant (preop: 185 vs. postop: 145, p= 0.07) (Figure, left). vWF antigen was significantly reduced after HeartMate II implant (preop: 230 vs. postop: 187, p<0.001), but not after HeartWare HVAD implant (p=0.1) (Figure, right). Neither preop nor postop vWF activity to antigen ratio predicted GI bleeding (p=0.57, p=0.18, respectively). Postop vWF activity to antigen ratio did significantly predict hemolysis (p=0.02) and stroke (p=0.004) during follow-up.
Conclusions: Significant reductions in vWF activity and antigen are seen after HeartMate II implantation, even early after initiation of support, while this was not appreciated to the same extent after HeartWare implant. No correlation between vWF activity to antigen ratio and bleeding events were observed, while these levels were significantly correlated to stroke and hemolysis. Understanding these changes observed even early after LVAD and differences between devices will assist in patient counseling and clinical approach.
Author Disclosures: S. Schettle: None. B. Boilson: None. S. Maltais: None. D. Joyce: None. L. Joyce: None. R. Daly: None. J. Stulak: None.
- © 2016 by American Heart Association, Inc.