PB0853 - Comparison of VWF:RCo/VWF:Ag ratios with the VWF large multimer indices in patients with aortic stenosis

Monday, June 26, 2023

18:30 – 19:30 ET

Room: Exhibition

Co-Author(s)

HH

Hisanori Horiuchi, MD& PhD

Professor
Institute of Development, Aging and Cancer, Tohoku University
Sendai, Miyagi, Japan

Co-Author(s)

NO

Noriyuki Okubo

Staff
Department of Clinical Laboratory Medicine, Tohoku University Hospital
Sendai, Miyagi, Japan
SS

Shingo Sugawara

Section Chief
Department of Clinical Laboratory Medicine, Tohoku University Hospital
Sendai, Miyagi, Japan
TF

Tohru Fujiwara

Lecturer
Department of Clinical Laboratory Medicine, Tohoku University Hospital
Sendai, Miyagi, Japan
YE

Yuka Eura

Staff Scientist
Department of Molecular Pathogenesis, National Cerebral and Cardiovascular Center
Suita, Osaka, Japan

Presenting Author(s)

KK

Koichi Kokame, PhD (he/him/his)

Director
Department of Molecular Pathogenesis, National Cerebral and Cardiovascular Center
Suita, Osaka, Japan

Co-Author(s)

MH

Masaki Hayakawa

Assistant Professor
Department of Blood Transfusion Medicine
Kashihara, Nara, Japan
MM

Masanori Matsumoto

Professor
Department of Blood Transfusion Medicine, Nara Medical University, Kashihara, Nara, Japan
Kashihara, Nara, Japan
YK

Yasunori Kawate

Scientific Research, Scientific Affairs
Sysmex Corporation
Kobe, Hyogo, Japan
SF

Shin-ichi Fujimaki

Manager
Department of Clinical Laboratory Medicine, Tohoku University Hospital
Sendai, Miyagi, Japan

Background: Excessive shear stress in blood stream cleaves high molecular weight multimers of von Willebrand factors (VWF) and causes acquired von Willebrand syndrome (AVWS). While the current standard diagnostic method is VWF multimer analysis that is western blotting under non-reducing conditions. It is unclear whether a ratio of VWF ristocetin co-factor activity (VWF:RCo) to VWF antigen levels (VWF:Ag) of < 0.7, which is used for the diagnosis of hereditary von Willebrand disease, is useful for the diagnosis of shear stress-induced AVWS.

Aims: To evaluate VWF:RCo/VWF:Ag/ < 0.7 in the diagnosis of aortic stenosis-associated AVWS

Methods: VWF:RCo/VWF:Ag ratios were compared with the VWF large multimer index as a reference, which represents the percentage of a patient’s VWF high molecular weight multimer ratio to that of standard plasma in the VWF multimer analysis.

Results: We analyzed plasmas of 382 patients with aortic stenosis that is known to generated unphysiologically high shear stress, 27 patients with peripheral artery disease (PAD), and 30 healthy participants. We assumed a large multimer index of < 80% as AVWS since 59.0% of severe AS patients had the indices of < 80%, while no healthy participants or PAD patients exhibited the indices of < 80%. The VWF:RCo/VWF:Ag ratios, measured by an automated blood coagulation analyzer, were correlated with the indices (rs=0.470, p< 0.001). When the ratio < 0.7 was used as a cut-off point, the sensitivity and specificity to VWF large multimer indices of < 80% were 0.437 and 0.826, respectively.

Conclusion(s): VWF:RCo/VWF:Ag ratios < 0.7 may indicate AVWS with high specificity, but low sensitivity.