Author + information
- Received February 26, 2013
- Revision received October 11, 2013
- Accepted October 17, 2013
- Published online April 1, 2014.
- Anna L. Meyer, MD∗,
- Doris Malehsa, MD†,
- Ulrich Budde, MD‡,
- Christoph Bara, MD†,
- Axel Haverich, MD† and
- Martin Strueber, MD∗∗ ()
- ∗Heart Center Leipzig University, Clinic for Heart Surgery, Leipzig, Germany
- †Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
- ‡AescuLabor Hamburg, Hamburg, Germany
- ↵∗Reprint requests and correspondence:
Dr. Martin Strueber, Heart Center Leipzig University, Clinic for Heart Surgery, Struempellstrasse 39, 04289 Leipzig, Germany.
Objectives The aim of this study was to determine whether differences in continuous flow left ventricular assist devices (LVADs) may lead to differences in the von Willebrand profile and the occurrence of bleeding and thromboembolic events.
Background The HeartMate II (Thoratec Corp., Pleasanton, California) and HeartWare Ventricular Assist Device (HVAD) (HeartWare, Inc., Framingham, Massachusetts) systems are the most frequently implanted LVADs worldwide. In all patients with an axial-flow HeartMate II, acquired von Willebrand syndrome (AvWS) due to the loss of large molecular weight multimers was found. The large molecular weight multimers of the von Willebrand factor (vWF) play a key role in primary hemostasis through interactions with platelets.
Methods This was a retrospective study of the vWF profile and incidence of bleeding and thromboembolic events in 102 patients receiving the HeartMate II (n = 51) and HVAD (n = 51). Between January 2003 and December 2010, vWF testing was performed in 102 of 175 consecutive patients after LVAD implantation.
Results AvWS was found in all patients, demonstrated by a decrease in the high molecular weight multimers of vWF to 30 ± 14% in HeartMate II patients and 34 ± 13% in patients with an HVAD. Significant predictors of vWF antigen included age (p = 0.011), number of days on the device (p = 0.035), C-reactive protein (p < 0.001), and blood group (p = 0.007). Bleeding and thromboembolic event rates were similar. However, lower fractions of vWF antigen and high molecular weight multimers did not correlate with the rate of bleeding complications or thromboembolic events.
Conclusions AvWS developed in all patients after centrifugal or axial flow pump implantation. Different patterns of AvWS were seen between the devices as well as individually. However, the complication rates after implantation were similar.
Dr. Strueber was a primary investigator in the HeartMate II Pilot and the HeartWare HVAD trial and is an expert consultant for HeartWare, Inc., and a member of the European Advisory Board of Thoratec, Inc. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received February 26, 2013.
- Revision received October 11, 2013.
- Accepted October 17, 2013.
- American College of Cardiology Foundation