The Relationship Between D-Dimer Level, Venous Valvular Reflux and Development of the Post-Thrombotic Syndrome after Deep Venous Thrombosis.
Bibliographic record
Abstract
Abstract Background: The pathophysiology of the post-thrombotic syndrome (PTS) is postulated to involve persistent venous thrombosis and valvular reflux. We prospectively studied if d-dimer levels or valvular reflux were associated with subsequent development of the PTS after objectively confirmed deep venous thrombosis (DVT). Methods: Consecutive patients with objectively diagnosed acute symptomatic DVT were recruited at 8 hospital centres in Quebec and Ontario, Canada. Patients attended study visits at Baseline, 1, 4, 8, 12, and 24 months. Blood was taken to measure d-dimer (VIDAS d-dimer; cut off <500 ug/L) at the 4 month visit. A standardized ultrasound assessment for popliteal venous valvular reflux was performed at the 12 month visit. Standardized assessments for PTS (using Villalta scale) were performed at each follow-up visit. Subjects were classified as having developed PTS if the ipsilateral Villalta score was >5 on at least 2 visits starting at the 4 month visit or later or was >5 at the final follow-up visit. Statistical analyses assessed associations between d-dimer level, ipsilateral reflux and PTS. Results: 387 patients were recruited and followed. Mean age was 56 years and 51% were male. PTS developed in 45% of patients. Mean d-dimer was significantly higher in patients who developed PTS compared with those who did not (712.0 vs. 444.0 ug/L; p= 0.02). In logistic regression analyses adjusted for age and warfarin use at the time of d-dimer determination, d-dimer levels significantly predicted PTS (p=0.03). Ipsilateral venous valvular reflux was more frequent in patients with moderate/severe PTS than in patients with no PTS or mild PTS (65% vs. 40% vs. 43%, respectively; p=0.013). Finally, mean d-dimer was higher in patients who developed recurrent VTE during follow-up (n=31) than in those who did not (1126.8 vs. 514.9 ug/L; p=0.05), and d-dimer was an independent predictor of recurrent VTE (p=0.04) after adjustment for other known predictors of recurrence. Conclusion: D-dimer levels measured 4 months after DVT are associated with subsequent development of PTS and are predictive of VTE recurrence. Venous valvular reflux was associated with moderate/severe PTS. Further studies are required to assess whether d-dimer or valvular reflux may be useful in determining which patients are most at risk of developing PTS or severe PTS and who may thus benefit from preventive strategies.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".