OC 04.2 - Factors influencing time from initial presentation to start of plasma exchange in patients with acute thrombotic thrombocytopenic purpura in the United Kingdom

Saturday, July 9, 2022

1:15 PM – 1:30 PM

Location: ICC Capital Suite Room 14-16

Presentation Format: In-Person

Co-Author(s)

TB

Tom Bull

Consultant Haematologist
West Suffolk NHS Foundation Trust, UK
Bury St Edmunds, England, United Kingdom
RM

Rory McCulloch

Consultant Haematologist
Gloucestershire Hospitals NHS Foundation Trust, Gloucester, UK
Gloucester, England, United Kingdom

Presenting Author(s)

Andrew J. Doyle, MBChB MRCP FRCPath

Consultant Haematologist
Guy's & St Thomas' NHS Foundation Trust
London, England, United Kingdom

Co-Author(s)

PN

Phillip LR Nicolson

Clinical Lecturer
University of Birmingham
Birmingham, England, United Kingdom
RS

Robecca Shaw

Registrar
Royal Liverpool Hospital
Liverpool, England, United Kingdom
Zara Sayar, MBChB MD MRCP FRCPath

Consultant Haematologist
University College London Hospitals NHS Foundation Trust, London, UK; Whittington Hospital, London, UK
London, England, United Kingdom
AL

Alexander Langridge

Haematology Registrar
Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle-upon-Tyne, UK
Newcastle-Upon-Tyne, England, United Kingdom
MP

Michala Pettitt

Study Administrator
Birmingham Centre for Observational and Prospective Studies, Birmingham Surgical Trials Consortium, Birmingham, UK
Birmingham, England, United Kingdom
RP

Rita Perry

Data Manager
Birmingham Centre for Observational and Prospective Studies, Birmingham Surgical Trials Consortium, Birmingham, UK
Birmingham, England, United Kingdom
DT

David Tucker

Consultant Haematologist
Royal Cornwall Hospitals NHS Trust, Truro, UK
Truro, England, United Kingdom
Marie Scully, MD

Professor of Haemostasis and Thrombosis
Department of Haematology, University College London Hospitals, London, UK
London, England, United Kingdom

Background: Diagnosis of acute thrombotic thrombocytopenic (TTP) can be challenging and delays initiating plasma exchange (PEX) may increase morbidity and mortality.

Aims: To assess adherence to national guidelines and understand the causes delaying early PEX.

Methods: Adults ≥18 years presenting to UK hospitals between 2014-2019 with first episode acute TTP and ADAMTS13 level < 10% were included. Time to treatment with PEX was defined as time of the first blood count sample in the laboratory to time of plasma release for PEX from blood bank.

Results: 148 patients treated at 80 hospitals were analysed with clinical outcomes described in Table 1. The median time to treatment was 15 hours (95% CI 11.3-18.7) with 25% receiving PEX within 8-hours and 61% within 24-hours. Age < 60 years, haemoglobin < 100 g/L, presence of fragments and on-site PEX were predictors for PEX initiation within 8 hrs (p = 0.004, < 0.001, 0.001, 0.002 respectively). Travel distance between hospital transfers did not correlate with time to PEX (R2=0.058, p=0.61). Case review of 50 patients (35%) that received PEX >24 hours showed that uncertain/delayed diagnosis to be the most common cause.

Conclusion(s): This is the first national multi-centre audit of time to treatment with PEX for acute TTP. Results show that early treatment rates with PEX are low. Further analysis suggests that difficulties in the diagnosis of TTP in this cohort is a significant component to treatment delays as opposed to transfer and technical aspects of PEX delivery. That 22% of patients initiated PEX over 48 hrs from admission indicates the issue is relatively common. With several deaths occurring in this group, we suggest initiatives to increase early diagnosis should be prioritised.