Acquired von Willebrand Syndrome: An Under-Recognized Cause of Major Bleeding in the Cardiac Intensive Care Unit

Background: Acquired von Willebrand syndrome (AvWS) in the setting of congenital heart disease is an under-recognized cause of bleeding in the pediatric cardiac critical care unit. Methods: Fourteen patients diagnosed with AvWS admitted to the cardiac intensive care unit at the Children’s National Health System between December 2009 and September 2015 were identified with subsequent chart review and case analysis. Results: Of the 14 patients included in this study, 4 patients were on ventricular-assist devices, 6 patients were on extracorporeal membrane oxygenation, and 4 were patients with congenital heart disease not receiving any mechanical circulatory support. All patients identified manifested persistent severe bleeding, despite appropriate management of anticoagulation and blood product administration based on the established protocols. Detailed hemostatic testing including quantitative von Willebrand factor (vWF) multimer analysis revealed decreased high-molecular-weight multimers (HMWMs) and absent ultra-HMWM, consistent with AvWS in all patients. Eight patients received treatment with vWF concentrate, one patient with desmopressin, and five recovered without specific treatment. Bleeding ceased in all but one patient. Conclusions: Acquired von Willebrand syndrome is an uncommon but important cause of bleeding in pediatric patients with cardiac disease. A high index of clinical suspicion with knowledge of the characteristic clinical scenario in addition to low levels of vWF multimers is required to manage and diagnose AvWS. Although the optimal management of AvWS in this patient population is unclear, vWF concentrates are available and appear to be efficacious for controlling life-threatening bleeding.