Original Articles

High Molecular Weight von Willebrand Factor Multimer Loss and Bleeding in Patients with Short-Term Mechanical Circulatory Support Devices: A Case Series

^* Divisions of Cardiology and Pulmonary and Critical Care, Cedars-Sinai Medical Center, Los Angeles, California;
^† Cedars-Sinai Comprehensive Transplant Center, Cedars-Sinai Medical Center, Los Angeles, California; and
^‡ Pathology and Laboratory Medicine, Cedars-Sinai Medical Center, Los Angeles, California

Address correspondence to: Oksana Volod, MD, Department of Pathology and Laboratory Medicine, Cedars Sinai, 8700 Beverly Boulevard, Room 4711, Los Angeles, CA 90048. E-mail: oksana.volod@cshs.org

Received: 27 November 2017
Accepted: 2 April 2018

Abstract

Acquired von Willebrand syndrome (VWS) due to loss of high-molecular-weight multimers (HMWMs) has been reported with longer term mechanical devices and is associated with mucosal bleeding, a primary hemostasis type of bleeding. However, little is known whether a similar defect occurs in patients with short-term mechanical circulatory support (STMCS) devices. We reviewed von Willebrand factor (VWF) profiles in patients with STMCS devices who underwent VWS workup from December 2015 to March 2017 at an academic quaternary care hospital. There were a total of 18 patients (57.0 ± 12.7 years old; 83.3% male) including nine with mucosal bleeding and nine with decreasing hemoglobin. The STMCS devices included Impella (n = 11), Impella and right ventricular assist device (n = 2), and an extracorporeal membrane oxygenator (n = 5). The mean HMWM by quantitative VWF multimer analysis was 3.6% ± 1.3% (normal cutoff: 18–34%). In all 10 cases in which VWF activity, fibrinogen, factor VIII, or VWF antigen level were obtained, they were either normal or elevated. All cases demonstrated high normal or elevated levels of low molecular weight multimers (LMWMs). These findings are consistent with type 2 VWS (qualitative defect). This is the first study that quantitatively describes STMCS device–associated HMWM loss, which may contribute to mucosal bleeding. This finding may have implications for intraoperative management during implantation of longer term devices or heart transplantation or other surgery while on STMCS.