Impact of the Severity of Acquired von Willebrand Syndrome on the Short-Term Prognosis in Patients with Temporary Mechanical Circulatory Support

Background and Objectives: Acquired von Willebrand syndrome (AVWS) develops not only in patients with durable ventricular assist devices but also in patients receiving temporary mechanical circulatory support (MCS). However, its prognostic implication remains unknown. Materials and Methods: Patients who received temporary MCS in our institute between August 2018 and September 2021 were included in this prospective study and the von Willebrand factor multimer analyses were performed following the initiation of temporary MCS supports. The von Willebrand factor large-multimer index was calculated as a normalized ratio of large-multimer proportion among total von Willebrand factor. Association between the large-multimer index and the 30-day survival was investigated. Results: A total of 31 patients (69 years old, 52% men) were included. Median large-multimer index was 63.0% (56.9%, 75.6%). The index was lowest in patients with extracorporeal membrane oxygenation than those receiving support from other devices. A lower index (