Coagulation Disorder, BloodAPTTO-EXTNCT07418099
External Multicenter Validation of the APTTO Model for Prolonged APTT Using Clot Waveform Analysis
An observational study of Coagulation Disorder, Blood and Prolonged APTT, run by Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz at 16 sites in Spain.
Trial summary
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. Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Coagulation Disorder, Blood, Prolonged APTT
- What is being tested?
- Clot waveform analysis-based risk stratification (APTTO models)
- How many people
- 1,500 participants
- Where
- 16 sitesSpain
- Study dates
- 13 Jan 2026to Mar 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Any age
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Study population: The study population includes pediatric and adult patients undergoing routine coagulation testing in clinical practice who present with isolated prolongation of activated partial thromboplastin time (APTT) and normal prothrombin time (PT). Patients may be evaluated in the preoperative setting or during routine clinical care for other indications. All laboratory data, including clot waveform analysis (CWA), are generated as part of standard diagnostic procedures, without additional blood sampling or modification of clinical management. Patients receiving anticoagulant therapy that may prolong APTT are included, provided that PT remains within the normal range. The study uses pseudonymized data obtained from electronic medical records and laboratory systems, with no direct patient contact and no anticipated risks beyond routine care.
Who may be able to join
- Patients of any age (pediatric and adult populations) undergoing coagulation testing with:
- Prolonged activated partial thromboplastin time (APTT), defined as an APTT ratio ≥ 1.25.
- Normal prothrombin time (PT), according to local laboratory reference ranges.
- Availability of clot waveform analysis (CWA) data obtained during routine APTT testing using:
- Optical coagulation analyzers (ACL TOP platform).
- Silica-based APTT reagent (SynthASil®).
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- Completion of the standard laboratory evaluation for prolonged APTT as part of routine clinical care, when clinically indicated.
- Samples collected and processed in accordance with the standardized preanalytical protocol defined in the study SOP.
- Patients evaluated in either:
- Preoperative assessment, or
- Routine clinical practice (non-preoperative setting).
Who cannot join
- Prolonged prothrombin time (PT) or combined prolongation of PT and APTT.
- 2- Inadequate preanalytical conditions, defined as non-compliance with the study SOP, including but not limited to:
- Incorrect blood-to-anticoagulant ratio.
- Delayed plasma processing beyond protocol-defined time limits.
- Inadequate centrifugation or plasma quality.
- 3. Absence of required CWA data or unavailable clot waveform images.
- 4. Samples in which APTT values are outside the measurable range of the analyzer, preventing extraction of CWA-derived parameters.
- 5- Patients with missing essential clinical or laboratory data required for application of the APTTO models.
Trial locations and contacts
16 sites in 1 country. Contact the study team or a site near you to ask about taking part.
16 sites in 1 country
Spain16 sites, 16 recruiting
- Recruiting
Hospital de la Santa Creu i Sant Pau
Barcelona
Noèlia Vilalta Seto, MD, PhD, +34 932 91 90 00, nvilalta@santpau.cat
- Recruiting
Hospital Universitario Severo Ochoa
Leganés, Madrid
Ramón Rodríguez Rodríguez, MD, +34 91 481 80 00, ramon.rodriguez@salud.madrid.org
- Recruiting
Hospital Universitario Arnau De Vilanova
Lleida
Albert Tugués Peiró, MD, +34 973 24 81 00, atugues.lleida.ics@gencat.cat
- Recruiting
Hospital Universitario 12 de Octubre
Madrid
Nerea Castro Quismondo, MD, +34 913 90 80 00, nerecq@hotmail.com
- Not yet recruiting
Hospital Universitario Clínico San Carlos
Madrid
Cristina García Sánchez, MD, +34 913 30 30 00, cgarciasanchez@salud.madrid.org
- Recruiting
Hospital Universitario Fundación Jiménez Díaz
Madrid
Diego Velasco Rodríguez, MD, PhD, diegovelascorodriguez@gmail.com
Nuria Revilla, MD, PhD, nuria.revilla@quironsalud.es
- Recruiting
Hospital Universitario Gregorio Marañón
Madrid
Cristina Pascual Izquierdo, MD, PhD, +34 91 586 80 00, crisizquierdo3@yahoo.es
Alicia Ortiz López, MD, aliorlo11@gmail.com
- Not yet recruiting
Hospital Universitario Puerta de Hierro
Madrid
Cristina Fernández Maqueda, MD, +34 91 191 60 00, Cristinat.maqueda@gmail.com
- Recruiting
Hospital Universitario Ramón y Cajal
Madrid
Pilar Massó Asensio, MD, +34 91 336 80 00, pmasso@salud.madrid.org
- Not yet recruiting
Hospital Clínico Universitario Virgen de la Arrixaca
Murcia
Vanessa Roldán Schilling, MD, PhD, +34 968 369 500, vroldans@um.es
- Recruiting
Clínica Universidad de Navarra
Pamplona
María Marcos Jubilar, MD, PhD, +34 948 25 54 00, mmarcos.3@unav.es
- Not yet recruiting
Hospital Clínico Universitario de Salamanca
Salamanca
José Ramón González Porras, MD, PhD, +34 923 29 11 00, jrgp@usal.es
- Recruiting
Complexo Hospitalario Universitario de Santiago
Santiago de Compostela
Matilde Rodríguez Ruiz, MD, +34 981 95 10 00, matilde.rodriguez.ruiz@sergas.es
- Recruiting
Hospital Clínico Universitario de Valladolid
Valladolid
Carolina Bombín Canal, MD, +34 983 42 00 00, cbombin@saludcastillayleon.es
- Not yet recruiting
Complexo Hospitalario Universitario De Vigo
Vigo
María Elsa López Ansoar, MD, +34 986 51 47 51, elsa.lopez.ansoar@sergas.es
- Recruiting
Hospital Clínico Universitario Lozano Blesa
Zaragoza
Olga Gavín Sebastián, MD, PhD, +34 976 76 57 00, ogavin@salud.aragon.es
About this study
Official title: Multicenter External Validation of the APTTO Predictive Model Based on Clot Waveform Analysis for the Assessment of Prolonged Activated Partial Thromboplastin Time
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.
Read the detailed description
This multicenter observational cohort study is designed to externally validate the APTTO predictive models in patients with prolonged APTT and normal prothrombin time evaluated in routine clinical practice across multiple hospitals, and to prospectively assess their perioperative clinical implementation and utility.
During the external-validation phase, the original APTTO model coefficients and predefined cut-offs are applied without recalibration, re-estimation, or modification of clinical management. Model discrimination, calibration, classification performance at the predefined cut-offs, decision-analytic performance, and robustness across clinical, analytical, and preanalytical conditions are evaluated.
At Hospital Universitario Fundación Jiménez Díaz, a prospective perioperative implementation phase begins on 1 October 2026. In eligible preoperative patients with isolated prolonged APTT, normal prothrombin time, and no clinically relevant bleeding history, APTTO is used as a clinical decision-support tool. In patients classified as low probability according to the prespecified pathway, hematological clearance for surgery may be issued without awaiting completion of deferred etiological testing, according to clinical judgment. The impact of implementation on time from Anesthesiology referral to hematological clearance, subsequent time to surgery, resource use, and perioperative safety is evaluated by comparison with the pre-implementation cohort.
From 1 January 2027, participating centers continue prospective recruitment restricted to a dedicated preoperative cohort using standardized perioperative pathway milestones and variables. Perioperative safety outcomes are assessed through 30 days after surgery.
No additional blood sampling or laboratory testing is required solely for research purposes.
The external-validation analyses are performed using the frozen APTTO models, without model updating or data-driven threshold optimization.
- Conditions
- Coagulation Disorder, Blood, Prolonged APTT
- Being tested
- Clot waveform analysis-based risk stratification (APTTO models)
- Keywords
- Activated Partial Thromboplastin Time, Prolonged APTT, Clot Waveform Analysis, CWA, Preoperative Assessment, Predictive Model, Diagnostic Algorithm, Risk Stratification, Decision Support Systems, Hemostasis, Coagulation Disorders, Lupus Anticoagulant, Coagulation Factor Deficiency, von Willebrand Disease, Laboratory Automation, Clinical Decision-Making, Surgical Delay, Resource Utilization
- Medical subject headings
- Blood Coagulation Disorders, Hemostatic Disorders, von Willebrand Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Clot waveform analysis-based risk stratification (APTTO models)Other
Application of the APTTO predictive models (APTTO1 and APTTO2) to clot waveform analysis parameters generated during routine activated partial thromboplastin time testing, for research purposes only. The model output does not influence clinical management or surgical decision-making during the study.
| Study group | Role | What they receive |
|---|---|---|
| Patients with prolonged activated partial thromboplastin time (APTT) | Patients with prolonged activated partial thromboplastin time (APTT) and normal prothrombin time undergoing routine laboratory evaluation. Clot waveform analysis (CWA) data and clinical information are collected prospectively as part of standard care and analyzed using the APTTO predictive models. No additional diagnostic or therapeutic procedures are performed. Receives: Other: Clot waveform analysis-based risk stratification (APTTO models) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Discriminatory performance of the APTTO model
Discrimination of the APTTO1 and APTTO2 models for identifying the cause of prolonged activated partial thromboplastin time (APTT), assessed by the area under the receiver operating characteristic curve (AUC) in an independent multicenter cohort.
Measured: Baseline (at the time of prolonged APTT laboratory assessment)
Secondary outcomes (9)
Calibration-in-the-large of the APTTO model
Calibration-in-the-large of the APTTO1 and APTTO2 models assessing agreement between predicted and observed probabilities in an independent multicenter cohort.
Measured: Baseline (at the time of prolonged APTT laboratory assessment)
Calibration slope of the APTTO model
Calibration slope of the APTTO1 and APTTO2 models, evaluating the relationship between predicted and observed risk across the probability spectrum.
Measured: Baseline (at the time of prolonged APTT laboratory assessment)
Overall prediction error of the APTTO model
Overall prediction error of the APTTO1 and APTTO2 models, assessed using the Brier score.
Measured: Baseline (at the time of prolonged APTT laboratory assessment)
Clinical utility of the APTTO model assessed by decision curve analysis
Net clinical benefit of the APTTO models compared with investigate-all and investigate-none strategies, assessed by decision curve analysis across clinically plausible threshold probabilities.
Measured: Baseline (at the time of prolonged APTT laboratory assessment)
Diagnostic accuracy of predefined APTTO cut-offs
Sensitivity, specificity, positive predictive value, and negative predictive value of predefined APTTO cut-offs for identifying pathological causes of prolonged APTT.
Measured: Baseline (at the time of prolonged APTT laboratory assessment)
Interobserver agreement in clot waveform morphology classification
Agreement between local investigators and central reader (blinded to clinical data) for qualitative clot waveform morphology classification, assessed using Cohen´s kappa or Fleiss´kappa statistics, as appropriate.
Measured: Baseline (at the time of prolonged APTT laboratory assessment)
Estimated impact of the APTTO algorithm on preoperative workflow
Estimated potential reduction in time to surgical cleareance and avoidance of additional etiologic testing based on application of the APTTO algorithm.
Measured: Baseline (model-based estimation using timing data from index APTT laboratory assessment through surgical clearance)
Association between clot waveform morphology and severity of factor deficiency
Assessment of the association between clot waveform morphology, particularly strictly normal waveform patterns, and the severity of intrinsic pathway factor deficiencies in patients with prolonged activated partial thromboplastin time (APTT). This analysis aims to determine whether a normal waveform is associated with higher residual factor levels and a lower likelihood of clinically relevant deficiency.
During the course of the study, additional exploratory objectives were incorporated to further investigate the clinical and physiological implications of clot waveform analysis. In particular, the relationship between strictly normal waveform morphology and the severity of factor deficiency will be evaluated prospectively in the remaining study cohort.
Measured: During the preoperative evaluation period
Clinical impact of APTTO implementation in preoperative management
Evaluation of the clinical impact of implementing a clot waveform analysis-based diagnostic strategy (APTTO) in the preoperative management of prolonged activated partial thromboplastin time (APTT). This analysis will compare patients managed before and after implementation of APTTO at the development center, time to surgical clearance, and perioperative outcomes.
This objective was incorporated during the course of the study to further assess the clinical implications of APTTO in routine practice and will be evaluated prospectively in the remaining study cohort.
Measured: During the preoperative evaluation period and up to 30 days after surgery.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Feb 2026
- Study start13 Jan 2026
- Primary completionMar 2027 (estimated)
- Study completionMar 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Coagulation Disorder, BloodStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 1,500 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Diego Velasco Rodríguez, Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz
- Investigators
- Diego Velasco Rodríguez, MD, PhD, Principal investigator, Hospital Universitario Fundación Jiménez Díaz / IIS-FJD
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07418099
- Sponsor's protocol ID
- APTTO-EXT-IISFJD-2026
- Other IDs
- Pending ethics committee aprov
- Acronym
- APTTO-EXT
- Status last verified
- Sep 2026
- First submitted
- 26 Jan 2026
- Last updated
- 11 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data will not be shared publicly. Data will be analyzed in aggregated and pseudonymized form exclusively for the objectives of the study, in accordance with applicable data protection regulations and ethics committee approval.
Study at a glance
From the registry record, last updated by the sponsor on 11 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Multicenter External Validation of the APTTO Predictive Model Based on Clot Waveform Analysis for the Assessment of Prolonged Activated Partial Thromboplastin Time
- ClinicalTrials.gov ID
- NCT07418099
- Acronym / sponsor ID
- APTTO-EXT / APTTO-EXT-IISFJD-2026
- Conditions
- Coagulation Disorder, Blood, Prolonged APTT
- Keywords
- Activated Partial Thromboplastin Time, Prolonged APTT, Clot Waveform Analysis, CWA, Preoperative Assessment, Predictive Model, Diagnostic Algorithm, Risk Stratification
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 1,500 participants (estimated)
- Lead sponsor
- Instituto de Investigación Sanitaria de la Fundación Jiménez DíazUniversity, hospital or other
- Study start
- 13 Jan 2026 (actual)
- Primary completion
- Mar 2027 (estimated)
- Study completion
- Mar 2027 (estimated)
- First posted
- 18 Feb 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
This multicenter observational cohort study is designed to externally validate the APTTO predictive models in patients with prolonged APTT and normal prothrombin time evaluated in routine clinical practice across multiple hospitals, and to prospectively assess their perioperative clinical implementation and utility.
During the external-validation phase, the original APTTO model coefficients and predefined cut-offs are applied without recalibration, re-estimation, or modification of clinical management. Model discrimination, calibration, classification performance at the predefined cut-offs, decision-analytic performance, and robustness across clinical, analytical, and preanalytical conditions are evaluated.
At Hospital Universitario Fundación Jiménez Díaz, a prospective perioperative implementation phase begins on 1 October 2026. In eligible preoperative patients with isolated prolonged APTT, normal prothrombin time, and no clinically relevant bleeding history, APTTO is used as a clinical decision-support tool. In patients classified as low probability according to the prespecified pathway, hematological clearance for surgery may be issued without awaiting completion of deferred etiological testing, according to clinical judgment. The impact of implementation on time from Anesthesiology referral to hematological clearance, subsequent time to surgery, resource use, and perioperative safety is evaluated by comparison with the pre-implementation cohort.
From 1 January 2027, participating centers continue prospective recruitment restricted to a dedicated preoperative cohort using standardized perioperative pathway milestones and variables. Perioperative safety outcomes are assessed through 30 days after surgery.
No additional blood sampling or laboratory testing is required solely for research purposes.
The external-validation analyses are performed using the frozen APTTO models, without model updating or data-driven threshold optimization.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Patients with prolonged activated partial thromboplastin time (APTT) | – | Other: Clot waveform analysis-based risk stratification (APTTO models)Patients with prolonged activated partial thromboplastin time (APTT) and normal prothrombin time undergoing routine laboratory evaluation. Clot waveform analysis (CWA) data and clinical information are collected prospectively as part of standard care and analyzed using the APTTO predictive models. No additional diagnostic or therapeutic procedures are performed. |
Who may qualify
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- Study population
- The study population includes pediatric and adult patients undergoing routine coagulation testing in clinical practice who present with isolated prolongation of activated partial thromboplastin time (APTT) and normal prothrombin time (PT). Patients may be evaluated in the preoperative setting or during routine clinical care for other indications. All laboratory data, including clot waveform analysis (CWA), are generated as part of standard diagnostic procedures, without additional blood sampling or modification of clinical management. Patients receiving anticoagulant therapy that may prolong APTT are included, provided that PT remains within the normal range. The study uses pseudonymized data obtained from electronic medical records and laboratory systems, with no direct patient contact and no anticipated risks beyond routine care.
Key inclusion criteria (11 listed)
- Patients of any age (pediatric and adult populations) undergoing coagulation testing with:
- Availability of clot waveform analysis (CWA) data obtained during routine APTT testing using:
- Completion of the standard laboratory evaluation for prolonged APTT as part of routine clinical care, when clinically indicated.
- Samples collected and processed in accordance with the standardized preanalytical protocol defined in the study SOP.
- Patients evaluated in either:
Key exclusion criteria (8 listed)
- Prolonged prothrombin time (PT) or combined prolongation of PT and APTT.
- 2- Inadequate preanalytical conditions, defined as non-compliance with the study SOP, including but not limited to:
- Incorrect blood-to-anticoagulant ratio.
- Delayed plasma processing beyond protocol-defined time limits.
- Inadequate centrifugation or plasma quality.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Clot waveform analysis-based risk stratification (APTTO models)Application of the APTTO predictive models (APTTO1 and APTTO2) to clot waveform analysis parameters generated during routine activated partial thromboplastin time testing, for research purposes only. The model output does not influence clinical management or surgical decision-making during the study. | Other | Patients with prolonged activated partial thromboplastin time (APTT) |
Primary outcome
Discriminatory performance of the APTTO model
Time frame: Baseline (at the time of prolonged APTT laboratory assessment)
Discrimination of the APTTO1 and APTTO2 models for identifying the cause of prolonged activated partial thromboplastin time (APTT), assessed by the area under the receiver operating characteristic curve (AUC) in an independent multicenter cohort.
9 secondary outcomes
Calibration-in-the-large of the APTTO model
Time frame: Baseline (at the time of prolonged APTT laboratory assessment)
Calibration slope of the APTTO model
Time frame: Baseline (at the time of prolonged APTT laboratory assessment)
Overall prediction error of the APTTO model
Time frame: Baseline (at the time of prolonged APTT laboratory assessment)
Clinical utility of the APTTO model assessed by decision curve analysis
Time frame: Baseline (at the time of prolonged APTT laboratory assessment)
Diagnostic accuracy of predefined APTTO cut-offs
Time frame: Baseline (at the time of prolonged APTT laboratory assessment)
Interobserver agreement in clot waveform morphology classification
Time frame: Baseline (at the time of prolonged APTT laboratory assessment)
Estimated impact of the APTTO algorithm on preoperative workflow
Time frame: Baseline (model-based estimation using timing data from index APTT laboratory assessment through surgical clearance)
Association between clot waveform morphology and severity of factor deficiency
Time frame: During the preoperative evaluation period
Clinical impact of APTTO implementation in preoperative management
Time frame: During the preoperative evaluation period and up to 30 days after surgery.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Sep 2026.
- Individual participant dataSharing planned: No. Individual participant data will not be shared publicly. Data will be analyzed in aggregated and pseudonymized form exclusively for the objectives of the study, in accordance with applicable data protection regulations and ethics committee approval.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Diego Velasco Rodríguez, MD, PhD principal investigator
Hospital Universitario Fundación Jiménez Díaz / IIS-FJD
16 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Coagulation Disorder, Blood and Prolonged APTT, run by Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz at 16 sites in Spain.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 11 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 11 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 16 sites in Spain. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Diego Velasco Rodríguez, MD, PhD (+34 669 98 04 32, diego.velascor@quironsalud.es), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Discriminatory performance of the APTTO model (time frame: Baseline (at the time of prolonged APTT laboratory assessment)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Sep 2026.