(40) - Improvement in Acquired Von Willebrand Syndrome with Aortic Valve Opening in Patients with Centrifugal Continuous Flow Left Ventricular Assist Devices

Abstract

PurposeLack of pulsatility in patients supported with continuous flow left ventricular assist device (cfLVAD) has been associated with the development of the acquired von Willebrand syndrome and bleeding. We examine the effect of pulsatility with aortic valve opening on von Willebrand factor (vWF) studies.MethodsVenous blood samples were obtained pre cfLVAD implantation and at days 30, 180 and beyond. Using platelet poor plasma obtained from centrifugation, vWF Antigen (Ag)% and vWF Collagen Binding Activity (CBA)% were measured using ELISA and vWF CBA:Ag ratios derived. Transthoracic echo was performed to document aortic valve opening.Results23 HeartWare cfLVAD patients (HeartWare International, Inc., MA, USA) were prospectively studied. Compared to baseline (1.04±0.43), vWF CBA:Ag ratio fell by 0.43±0.42 at day 30 (p<0.01), with some recovery beyond day 180 (0.19±0.69 below baseline, p=NS compared to baseline). In patients where the aortic valve was closed at d30 vWF CBA:Ag was 0.46±0.42 below baseline (P<0.01), whereas where the aortic valve was open vWF CBA:Ag was 0.19±0.38 (P=NS), Figure. Beyond day 180, in those in whom the aortic valve remained closed, vWF CBA:Ag was non-significantly decreased by 0.31±0.8 (P=0.16) compared to baseline, whereas in those where the valve was open, the ratio had returned to baseline levels (vWF CBA:Ag 0.01±0.46 below baseline, P=NS), Figure.ConclusionvWF CBA:Ag ratios tend to improve with time of support beyond 180 days. Aortic valve opening in centrifugal cfLVAD supported patients is associated with a better vWF CBA:Ag profile with an improvement of acquired von Willebrand syndrome following medium to long term support. PurposeLack of pulsatility in patients supported with continuous flow left ventricular assist device (cfLVAD) has been associated with the development of the acquired von Willebrand syndrome and bleeding. We examine the effect of pulsatility with aortic valve opening on von Willebrand factor (vWF) studies. Lack of pulsatility in patients supported with continuous flow left ventricular assist device (cfLVAD) has been associated with the development of the acquired von Willebrand syndrome and bleeding. We examine the effect of pulsatility with aortic valve opening on von Willebrand factor (vWF) studies. MethodsVenous blood samples were obtained pre cfLVAD implantation and at days 30, 180 and beyond. Using platelet poor plasma obtained from centrifugation, vWF Antigen (Ag)% and vWF Collagen Binding Activity (CBA)% were measured using ELISA and vWF CBA:Ag ratios derived. Transthoracic echo was performed to document aortic valve opening. Venous blood samples were obtained pre cfLVAD implantation and at days 30, 180 and beyond. Using platelet poor plasma obtained from centrifugation, vWF Antigen (Ag)% and vWF Collagen Binding Activity (CBA)% were measured using ELISA and vWF CBA:Ag ratios derived. Transthoracic echo was performed to document aortic valve opening. Results23 HeartWare cfLVAD patients (HeartWare International, Inc., MA, USA) were prospectively studied. Compared to baseline (1.04±0.43), vWF CBA:Ag ratio fell by 0.43±0.42 at day 30 (p<0.01), with some recovery beyond day 180 (0.19±0.69 below baseline, p=NS compared to baseline). In patients where the aortic valve was closed at d30 vWF CBA:Ag was 0.46±0.42 below baseline (P<0.01), whereas where the aortic valve was open vWF CBA:Ag was 0.19±0.38 (P=NS), Figure. Beyond day 180, in those in whom the aortic valve remained closed, vWF CBA:Ag was non-significantly decreased by 0.31±0.8 (P=0.16) compared to baseline, whereas in those where the valve was open, the ratio had returned to baseline levels (vWF CBA:Ag 0.01±0.46 below baseline, P=NS), Figure. 23 HeartWare cfLVAD patients (HeartWare International, Inc., MA, USA) were prospectively studied. Compared to baseline (1.04±0.43), vWF CBA:Ag ratio fell by 0.43±0.42 at day 30 (p<0.01), with some recovery beyond day 180 (0.19±0.69 below baseline, p=NS compared to baseline). In patients where the aortic valve was closed at d30 vWF CBA:Ag was 0.46±0.42 below baseline (P<0.01), whereas where the aortic valve was open vWF CBA:Ag was 0.19±0.38 (P=NS), Figure. Beyond day 180, in those in whom the aortic valve remained closed, vWF CBA:Ag was non-significantly decreased by 0.31±0.8 (P=0.16) compared to baseline, whereas in those where the valve was open, the ratio had returned to baseline levels (vWF CBA:Ag 0.01±0.46 below baseline, P=NS), Figure. ConclusionvWF CBA:Ag ratios tend to improve with time of support beyond 180 days. Aortic valve opening in centrifugal cfLVAD supported patients is associated with a better vWF CBA:Ag profile with an improvement of acquired von Willebrand syndrome following medium to long term support. vWF CBA:Ag ratios tend to improve with time of support beyond 180 days. Aortic valve opening in centrifugal cfLVAD supported patients is associated with a better vWF CBA:Ag profile with an improvement of acquired von Willebrand syndrome following medium to long term support.