An observational study in Deep Venous Thrombosis and Pulmonary Embolism, sponsored by University of Texas Southwestern Medical Center. Active, not recruiting at 14 sites in United States. Open to participants aged 8 Years to 21 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-06-08.
Sponsored by University of Texas Southwestern Medical Center · Observational
This is a multi-center prospective cohort study of patients with first-episode deep venous thrombosis and pulmonary embolism.
Subjects will be identified from the clinical setting and approached to participate in this observational study where participants will be enrolled at 3 different sites and referred from several more sites and have: cardiopulmonary exercise testing and pulmonary function testing at The Institute of Exercise and Environmental Medicine (IEEM), UTSW Exercise Facility, Cardiac MRI and MRI for pulmonary perfusion at Children's Medical Center and MR Spectroscopy and MR for Muscle Perfusion at the Advanced Imaging Research Center (AIRC) performed in Dallas over a 3 day research visit at week 12 and Month 12. Blood is collected for biomarkers at these visits and multiple questionnaires are completed by participants.
774 studies on the registry are indexed under Venous Thrombosis; 124 are open to participants now.
This study's enrollment of 115 is below the median of 288 across 283 observational studies indexed under Venous Thrombosis.
Browse Venous Thrombosis studies →University of Texas Southwestern Medical Center is the lead sponsor of 990 studies on the registry; 201 are open to participants now.
Of its 135 completed or terminated interventional studies of FDA-regulated products, 100 (74%) have results posted.
Counted across the registry records on this site, refreshed daily.
Study population will include children (defined as persons who have not attained the legal age for consent to treatments or procedures involved in the research, under the applicable law of the jurisdiction in which the research will be conducted), and patients (defined as individuals in a clinical setting with whom there is a treatment relationship).
Participants must meet the eligibility criteria in order to participate in this trial.
Exclusion Criteria:
Additional exclusion criteria for participants with PE:
The target accrual is based on the primary endpoint (exercise intolerance and dyspnea on exertion). To achieve adequate power and precision in the primary analysis, the target enrollment is 80 children. Both males and females of all races and ethnic groups are eligible for this study.
Diagnostic Test: Blood draw (Visit 1) · Diagnostic Test: Blood draw (Visits 2 and 3)
A positive control group that has not had pulmonary embolism (PE) but is prescribed physical activity restrictions expected to produce a similar deconditioning effect as patients with PE will be enrolled from UT Southwestern only (cohort 1) or children who are no prescribed physical activity restrictions and are otherwise considered healthy (cohort 2). The target accrual of the positive control group is based on feasibility and availability of funds and will be limited to 25 controls.
Diagnostic Test: Blood draw (Visits 2 and 3)
Labs will be drawn at Visit 1, also referred to as screening (within 60 days of diagnosis) with the standard of care labs drawn.
Labs will be drawn at Visit 2 (12 weeks post-diagnosis with a range of 10-16 weeks) and Visit 3 (12 months ± 30 days) for research purposes only and will be collected at Children's Medical Center and processed at UT Southwestern Medical Center.
Change in exercise capacity
Measured objectively by peak oxygen uptake (VO2) as a percent predicted based on ml/min/kg of lean body mass during cardiopulmonary exercise testing (CPET)
Time frame: 3 months and 12 months post-diagnosis
Change in dyspnea on exertion (DOE)
measured using Borg questionnaire and defined as a mean difference of \> 1 between those with and without exercise intolerance at the end of the warm-up and submaximal work rates during CPET
Time frame: 3 months and 12 months post-diagnosis
Change in cardiac maladaptation
Measured as ventriculo-arterial coupling ratio in response to exercise (change in Ea/Emax from rest to peak intensity exercise) during exercise cardiac magnetic resonance imaging (MRI)
Time frame: 3 months and 12 months post-diagnosis
Change in pulmonary/ventilatory limitations
Measured as VE/VCO2 in participants with and without exercise intolerance during cardiopulmonary testing
Time frame: 3 months and 12 months post-diagnosis
Change in muscle metabolic aberrations
Measured by % phosphocreatine (PCr) depletion (Δ %PCr) during exercise using 31P magnetic resonance spectroscopy on 7 Tesla in participants with and without exercise intolerance
Time frame: 3 months and 12 months post-diagnosis
Change in pulmonary vascular obstruction score in participants with and without exercise intolerance (Quantitative assessment)
Quantitative Assessment: Measured using Qanadli Index scale (range 0-40; 0=minimum score and 40=maximum score) at pulmonary embolism diagnosis and 3 months post-diagnosis.
Time frame: At diagnosis, 3 months and 12 months post-diagnosis
Change in pulmonary vascular obstruction score in participants with and without exercise intolerance (Qualitative assessment)
Qualitative Assessment: Measured using pulmonary perfusion maps at diagnosis, 3 and 12 months post-diagnosis. Since qualitative, there are no minimum or maximum values.
Time frame: At diagnosis, 3 months and 12 months post-diagnosis
Change in calf muscle perfusion and venous flow in participants with and without exercise intolerance and between affected and non-affected extremity
Measured using extremity arterial spin labelling on 7 Tesla MRI
Time frame: 3 months and 12 months post-diagnosis
Change in dyspnea ratings using Dalhousie Pictorial Scale
Measured at rest, fatigue, and post-exercise in participants with and without exercise intolerance Dalhousie Pictorial Scale measuring Dyspnea and Perceived Exertion (minimum score=4; maximum score=28; higher score means worse dyspnea)
Time frame: 3 months and 12 months post-diagnosis
Change in dyspnea ratings using Borg Dyspnea Scale
Measured at rest, fatigue, and post-exercise in participants with and without exercise intolerance Borg Dyspnea Scale (minimum score=0; maximum score=10; higher score means worse dyspnea)
Time frame: 3 months and 12 months post-diagnosis
Change in dyspnea ratings using Dyspnoea-12 Scale
Measured at rest, fatigue, and post-exercise in participants with and without exercise intolerance Dyspnoea-12 Scale (minimum score=0; maximum score=36; higher score means worse dyspnea)
Time frame: 3 months and 12 months post-diagnosis
Change in dyspnea ratings using Modified Medical Research Council Dyspnea Scale
Measured at rest, fatigue, and post-exercise in participants with and without exercise intolerance Modified Medical Research Council Dyspnea Scale (minimum score=0; maximum score=4; higher score means worse dyspnea)
Time frame: 3 months and 12 months post-diagnosis
Change in inflammatory cytokine biomarker - High-sensitivity CRP
Measure inflammatory cytokine biomarker high-sensitivity CRP (unit of measure: mg/L) in participants with and without exercise intolerance
Time frame: At diagnosis, 3 months and 12 months post-diagnosis
Change in inflammatory cytokine biomarkers - IL-6 and TNF
Measure inflammatory cytokine biomarkers IL-6 and TNF-α (unit of measure: pg/mL) in participants with and without exercise intolerance
Time frame: At diagnosis, 3 months and 12 months post-diagnosis
Change in coagulation biomarker - D-dimer
Measure coagulation biomarker D-dimer (unit of measure: ng/mL) in participants with and without exercise intolerance
Time frame: At diagnosis, 3 months and 12 months post-diagnosis
Change in coagulation biomarker - Thrombin generation
Measure coagulation biomarker thrombin generation (unit of measure: nM·min) in participants with and without exercise intolerance
Time frame: At diagnosis, 3 months and 12 months post-diagnosis
Change in coagulation biomarker - Fibrinolysis assay
Measure coagulation biomarker fibrinolysis assay (unit of measure: % lysis) in participants with and without exercise intolerance
Time frame: At diagnosis, 3 months and 12 months post-diagnosis
This study is active, not recruiting, as verified in Jun 2026. You cannot join it, but the record below documents what was studied.
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University of Texas Southwestern Medical Center