OC 26.1 - Transient ischemic attacks (TIAs) and ischemic strokes are leading events in hereditary thrombotic thrombocytopenic purpura (hTTP)

Sunday, June 25, 2023

14:45 – 15:00 ET

Room: 510

Session Available As: On-Demand

Presenting Author(s)

Erika Tarasco, PhD

Postdoc
INSELSPITAL, University Hospital Bern University Clinic of Hematology & Central Hematology Laboratory
Bern, Bern, Switzerland

Co-Author(s)

OS

Odile Stalder

Statistician
University of Bern, CTU, Bern, Switzerland
Bern, Bern, Switzerland
KF

Kenneth D. Friedman

MD
Division of Hematology and Oncology, Medical College of Wisconsin, Versiti Blood Center of Wisconsin, Milwaukee, WI, US
Milwaukee, Wisconsin, United States
JG

James N. George

MD
Department of Biostatistics & Epidemiology, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, United States
Oklahoma City, Oklahoma, United States
IH

Ingrid Hrachovinova

head of laboratory
National Reference Laboratory for Disorders in Hemostasis, Institute of Hematology and Blood Transfusion, Prague, Czech Republic
Prague, Hlavni mesto Praha, Czech Republic
Paul N. Knöbl, MD

Prof.
Division of Hematology and Hemostasis, Department of Medicine, University of Vienna, Vienna, Austria
Vienna, Wien, Austria
MM

Masanori Matsumoto

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

Reinhard Schneppenheim

Prof.
Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Hamburg, Hamburg, Germany
Av

Anne Sophie von Krogh

Prof.
Department of Hematology ,St Olavs Hospital Trondheim University Hospital, Trondheim, Norway,
Throndheim, Nord-Trondelag, Norway
BL

Bernhard Lämmle

Professor
Center for Thrombosis and Hemostasis, University Medical Center of the Johannes Gutenberg University, Mainz
Mainz, Rheinland-Pfalz, Germany
JK

Johanna A. Kremer-Hovinga

Professor
Centre of Laboratory Medicine Section Hemostasis Inselspital Bern
Bern, Bern, Switzerland

Background: Arterial thrombotic events (ATE: mainly, ischemic strokes and TIAs) are one of the leading cause of death worldwide. Large population studies showed an association between low ADAMTS13 activity and increased risk of ATEs. ADAMTS13 is the principle von Willebrand factor (vWF) size regulator. Absence of ADAMTS13 cause clumping of ultra-large vWF multimers and platelet, microvascular thrombosis and end-organ ischemia. Bi-allelic ADAMTS13 mutations result in severe ADAMTS13 deficiency and hTTP characterized by recurring episodes, with considerable morbidity and premature mortality.

Aims: Estimation of the prevalence of ischemic strokes and TIAs in large hTTP patient cohort.

Methods: We analyzed the occurrence of ATEs, specifically strokes and TIAs in confirmed hTTP patients enrolled in the International Hereditary TTP Registry from birth until the end of December 2022. Ethics/IRB approval was obtained for all participating sites; informed consent from all patients or their guardians before enrollment.

Results: By end 2022 the Registry enrolled 186 hTTP patients. Their median age at enrolment was 27.8 years (range 0.10-75).
During the study period 11/186 hTTP patients died, with seven deaths (63%) caused by an ATE. Moreover 48 patients experienced 91 strokes/TIAs. Up to the age of 10, 20 and 50 years, 5.4%, 10% and 40% of patients suffered from at least one stroke/TIA, with the steepest increase in the 4th decade (figure). The prevalence of strokes/TIA in hTTP is much higher and occur earlier than in the general population where 16% of strokes occur in people aged 15-49 years.

Conclusion(s): ATEs are leading events and contribute to morbidity and mortality in hTTP. Strokes and TIAs in hTTP patients occur at a younger age than in the general population, with 10% of patients suffering from a first stroke/TIA already in childhood. We highlighted the need to increase awareness and treatment to reduce the burden and mortality of hTTP.

Learning Objectives:

The aim of this presentation is to raise awarness of hTTP in the hematology community
To assess the frequency of atero-thromboembolic (ATE) events in hTTP patients
To identify key aspects to help patiehts to be diagnosed with hTTP