Actively Recruiting
External Multicenter Validation of the APTTO Model for Prolonged APTT Using Clot Waveform Analysis
Led by Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz · Updated on 2026-05-01
1500
Participants Needed
16
Research Sites
58 weeks
Total Duration
On this page
AI-Summary
What this Trial Is About
Prolonged activated partial thromboplastin time (APTT) is a frequent laboratory finding that may reflect a broad spectrum of underlying conditions, ranging from benign laboratory abnormalities to clinically relevant hemostatic disorders. Clot waveform analysis (CWA), automatically generated during routine APTT testing by optical coagulation analyzers, provides additional quantitative and qualitative information on clot formation dynamics. The APTTO model is a previously developed two-step predictive algorithm based on CWA features designed to estimate the probability of a pathological cause of prolonged APTT and to differentiate lupus anticoagulant from intrinsic pathway factor deficiency or von Willebrand disease. Internal validation has demonstrated good discrimination and calibration. This multicenter observational study aims to perform an external validation of the APTTO model in independent patient cohorts, assessing its discrimination, calibration, and decision-analytic performance without model updating.
CONDITIONS
Official Title
External Multicenter Validation of the APTTO Model for Prolonged APTT Using Clot Waveform Analysis
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Patients of any age, including pediatric and adult, undergoing coagulation testing with prolonged APTT (APTT ratio 21 1.25)
- Normal prothrombin time (PT) based on local lab reference ranges
- Availability of clot waveform analysis data from routine APTT testing using optical coagulation analyzers (ACL TOP platform) and silica-based APTT reagent (SynthASil�ae)
- Completion of standard laboratory evaluation for prolonged APTT as part of routine care when indicated
- Samples collected and processed following the standardized preanalytical protocol in the study SOP
- Patients evaluated during preoperative assessment or routine clinical practice (non-preoperative)
You will not qualify if you...
- Prolonged prothrombin time (PT) or combined prolongation of PT and APTT
- Inadequate preanalytical conditions, including incorrect blood-to-anticoagulant ratio, delayed plasma processing, inadequate centrifugation or plasma quality
- Absence of required clot waveform analysis data or unavailable clot waveform images
- Samples with APTT values outside the measurable range of the analyzer preventing parameter extraction
- Missing essential clinical or laboratory data needed for applying the APTTO models
AI-Screening
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Trial Site Locations
Total: 16 locations
1
Hospital Universitario Severo Ochoa
Leganés, Madrid, Spain
Actively Recruiting
2
Hospital de la Santa Creu i Sant Pau
Barcelona, Spain
Actively Recruiting
3
Hospital Universitario Arnau De Vilanova
Lleida, Spain
Actively Recruiting
4
Hospital Universitario 12 de Octubre
Madrid, Spain
Actively Recruiting
5
Hospital Universitario Clínico San Carlos
Madrid, Spain
Not Yet Recruiting
6
Hospital Universitario Fundación Jiménez Díaz
Madrid, Spain
Actively Recruiting
7
Hospital Universitario Gregorio Marañón
Madrid, Spain
Not Yet Recruiting
8
Hospital Universitario Puerta de Hierro
Madrid, Spain
Not Yet Recruiting
9
Hospital Universitario Ramón y Cajal
Madrid, Spain
Actively Recruiting
10
Hospital Clínico Universitario Virgen de la Arrixaca
Murcia, Spain
Not Yet Recruiting
11
Clínica Universidad de Navarra
Pamplona, Spain
Not Yet Recruiting
12
Hospital Clínico Universitario de Salamanca
Salamanca, Spain
Not Yet Recruiting
13
Complexo Hospitalario Universitario de Santiago
Santiago de Compostela, Spain
Not Yet Recruiting
14
Hospital Clínico Universitario de Valladolid
Valladolid, Spain
Actively Recruiting
15
Complexo Hospitalario Universitario De Vigo
Vigo, Spain
Not Yet Recruiting
16
Hospital Clínico Universitario Lozano Blesa
Zaragoza, Spain
Not Yet Recruiting
Research Team
D
Diego Velasco Rodríguez, MD, PhD
CONTACT
How is the study designed?
Study Type
OBSERVATIONAL
Masking
N/A
Allocation
N/A
Model
N/A
Primary Purpose
N/A
Number of Arms
1
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