Preservation of von Willebrand factor multimers and function in patients with an EVAHEART centrifugal-type, continuous-flow left ventricular assist device

The high incidence of gastrointestinal (GI) bleeding is a crucial issue in patients with a continuous-flow left ventricular assist device (CF-LVAD). 1 Crow S. John R. Boyle A. et al. Gastrointestinal bleeding rates in recipients of nonpulsatile and pulsatile left ventricular assist devices. J Thorac Cardiovasc Surg. 2009; 137: 208-215 Abstract Full Text Full Text PDF PubMed Scopus (386) Google Scholar , 2 Draper K.V. Huang R.J. Gerson L.B. GI bleeding is patients with continuous-flow left ventricular assist devices; a systematic review and meta-analysis. Gastrointest Endosc. 2014; 80: 435-446 Abstract Full Text Full Text PDF PubMed Scopus (120) Google Scholar The underlying mechanism of this VAD-specific complication has yet to be elucidated completely. However, studies have demonstrated that high-molecular-weight (HMW) von Willebrand factor (vWF) multimers in patients with a CF-LVAD are degraded due to the increased circulatory shear stress, resulting in GI bleeding. 3 Klovaite J. Gustafsson F. Mortensen S.A. et al. Severely impaired von Willebrand factor-dependent platelet aggregation in patients with a continuous-flow left ventricular assist device (HeartMate II). J Am Coll Cardiol. 2009; 53: 2162-2167 Abstract Full Text Full Text PDF PubMed Scopus (224) Google Scholar , 4 Meyer A.L. Malehsa D. Bara C. et al. Acquired von Willebrand syndrome in patients with an axial flow left ventricular assist device. Circ Heart Fail. 2010; 3: 675-681 Crossref PubMed Scopus (229) Google Scholar In addition, it was corroborated that vWF degradation during shear stress involves a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13), known as a vWF-cleaving protease. 5 Bartoli C.R. Restle D.J. Zhang D.M. et al. Pathologic von Willebrand factor degradation with a left ventricular assist device occurs via two distinct mechanisms: mechanical demolition and enzymatic cleavage. J Thorac Cardiovasc Surg. 2015; 149: 281-289 Abstract Full Text Full Text PDF PubMed Scopus (82) Google Scholar Based on these findings, device properties with low shear for the blood components were devised to maintain vWF activity as much as possible. The EVAHEART LVAS (Sun Medical Technology Research Corp., Nagano, Japan) is an implantable centrifugal-type CF-LVAD that was designed with wide blood flow gaps to provide less shear stress and to generate pulsatile, high-flow circulatory support. 6 Yamazaki K. Saito S. Kihara S. et al. Completely pulsatile high flow circulatory support with a constant-speed centrifugal blood pump: mechanisms and early clinical observation. Gen Thorac Cardiovasc Surg. 2007; 55: 158-162 Crossref PubMed Scopus (43) Google Scholar , 7 Saito S. Yamazaki K. Nishinaka T. et al. Post-approval study of a highly pulsed, low-shear-rate, continuous-flow, left ventricular assist device, EVAHEART: a Japanese multicenter study using J-MACS. J Heart Lung Transplant. 2014; 33: 599-608 Abstract Full Text Full Text PDF PubMed Scopus (65) Google Scholar Recently, the advantage of less vWF degradation in the EVAHEART than that in the HeartMate II (St. Jude Medical, Minneapolis, MN) was demonstrated in mock circulatory loops. 8 Bartoli C.R. Kang J. Zhang D. et al. Left ventricular assist device design reduces von Willebrand factor degradation: a comparative study between the HeartMate II and the EVAHEART left ventricular assist system. Ann Thorac Surg. 2017; 103: 1239-1244 Abstract Full Text Full Text PDF PubMed Scopus (36) Google Scholar The data suggest that LVAD design properties could minimize vWF degradation. Thus, it is speculated that the EVAHEART could preserve vWF multimers and function, as it was shown to cause less trauma to the circulating blood, and may contribute to lower incidence of GI bleeding. The aim of this study was to assess the prevalence of GI bleeding in patients with an EVAHEART centrifugal-type CF-LVAD and its relationship with vWF activities, including the degradation of HMW vWF multimers.