Testing the APTTO clot-waveform tool to identify causes of prolonged APTT

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This multicenter observational cohort uses routine laboratory data from several Spanish hospitals to externally validate the APTTO predictive model in patients with prolonged APTT and normal PT. All data, including clot waveform analysis parameters generated on ACL TOP analyzers with SynthASil reagent, are collected as part of standard care without extra blood draws or changes to clinical management. The original APTTO coefficients and predefined cut-offs will be applied without recalibration to measure discrimination, calibration, and decision-analytic performance, and secondary subgroup and sensitivity analyses will examine robustness. The study follows TRIPOD guidance for prediction-model validation.

Why it matters

Who can join: the full rules

Inclusion Criteria:

1. 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.
2. Availability of clot waveform analysis (CWA) data obtained during routine APTT testing using:

   * Optical coagulation analyzers (ACL TOP platform).
   * Silica-based APTT reagent (SynthASil®).
3. Completion of the standard laboratory evaluation for prolonged APTT as part of routine clinical care, when clinically indicated.
4. Samples collected and processed in accordance with the standardized preanalytical protocol defined in the study SOP.
5. Patients evaluated in either:

   * Preoperative assessment, or
   * Routine clinical practice (non-preoperative setting).

Exclusion Criteria:

1. 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.

Where it's running

• Hospital Universitario Severo Ochoa
  Leganés, Madrid, Spain Recruiting
• Hospital de la Santa Creu i Sant Pau
  Barcelona, Spain Recruiting
• Hospital Universitario Arnau De Vilanova
  Lleida, Spain Recruiting
• Hospital Universitario 12 de Octubre
  Madrid, Spain Recruiting
• Hospital Universitario Fundación Jiménez Díaz
  Madrid, Spain Recruiting
• Hospital Universitario Gregorio Marañón
  Madrid, Spain Recruiting

Study contacts

• Principal investigator: Diego Velasco Rodríguez, MD, PhD — Hospital Universitario Fundación Jiménez Díaz / IIS-FJD
• Study coordinator: Diego Velasco Rodríguez, MD, PhD
• Email: diego.velascor@quironsalud.es
• Phone: +34 669 98 04 32

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

• Comparing tranexamic acid dosing during heart surgery with cardiopulmonary bypass

  This research will test whether three different tranexamic acid dosing schedules keep fibrinolysis suppressed longer and limit bleeding in adults having elective heart surgery with cardiopulmonary bypass.

  Recruiting University of Ioannina · Ioannina · NCT07164300

• Monitoring transfusions during anesthesia in emergency situations

  This study is looking at how blood transfusions are done during emergency surgeries to help improve future treatment guidelines for patients.

  Recruiting Erasme University Hospital · Anderlecht · NCT06403163

• Evaluating platelet activation in patients with heart support devices

  This study is testing how well platelets work in patients with severe heart failure who are getting or have received a heart support device to see if it can help prevent complications.

  Recruiting Scientific Institute San Raffaele · Milan, MI · NCT03255928

• Investigation of genetics related to blood diseases

  This study is trying to understand the genetics behind blood diseases by collecting samples and health information from people with these conditions and their family members.

  Recruiting St. Jude Children's Research Hospital · Memphis, Tennessee · NCT02720679

• Assessing blood coagulation in bleeding and clotting disorders

  This study is testing how well different blood tests can help understand blood clotting issues in people with bleeding or clotting disorders being treated at UTHealth Houston.

  Recruiting at 2 sites The University of Texas Health Science Center, Houston · Houston, Texas and 1 other locations · NCT00178594

• Studying how genetic testing can improve medication use in patients

  This study is trying to see if using genetic testing can help doctors choose the right medications for patients with heart diseases, inflammatory bowel diseases, and autoimmune diseases to improve their treatment outcomes.

  Recruiting University of Chicago · Chicago, Illinois · NCT01280825

How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.