Incidence and Management of Isolated Subsegmental Pulmonary Embolism.
Bibliographic record
Abstract
Abstract Abstract 2989 Poster Board II-965 Introduction: The use of computed tomographic pulmonary angiography (CTPA) in patients with suspected pulmonary embolism (PE) has improved the visualization of subsegmental pulmonary arteries. However, the clinical significance of subsegmental PE is unclear. In the PIOPED Study, PE limited to subsegmental pulmonary arteries was most prevalent among patients with low-probability ventilation/perfusion (V/Q) scans. Patients with non-diagnostic (low or intermediate) V/Q scans can be safely managed without anticoagulation. The incidence and clinical management of subsegmental PE remains uncertain. Objective: To evaluate the incidence and clinical management of subsegmental PE in patients with suspected acute PE. Methods: This is a retrospective cohort study of consecutive patients with suspected acute PE undergoing CTPA at the Ottawa Hospital from Jan 1, 2007 to Dec 31, 2008. Subsegmental PE was defined as one or more pulmonary artery filling defects located in the subsegmental level, with no filling defects visualized at more proximal pulmonary artery levels. All patients were followed for a minimum of 6 months after the index PE. Results: A total of 78 (10.4%, 95% CI: 8.4 to 12.8%) cases of subsegmental PE were identified out of 748 cases of PE diagnosed by CTPA. Forty-three (77%) of these had a single isolated subsegmental filling defect. Data could be extracted in 56 (72%) of the 78 cases. Among these 56 patients, 18 (32%) had unprovoked PE. Further investigations were performed in 50 patients (Ultrasonography (U/S) of legs (n=38), U/S and V/Q scan (n=11) or V/Q scan alone (n=1)). Deep vein thrombosis was detected in 12 patients and two patients had a high probability V/Q scan. Forty-eight (86%) patients were anticoagulated. All patients with concurrent DVT or high probability V/Q scan were started on anticoagulation therapy. Two patients experienced a major bleeding episode after anticoagulation. Out of the 8 patients left untreated, there were no recurrent VTE. Conclusion: Isolated subsegmental PE represents approximately 10% of all acute PE diagnosed by CTPA. Patients with subsegmental PE diagnosed on CTPA are more commonly receiving anticoagulation than not. Further studies are needed to establish the risk benefit ratio of anticoagulation therapy in patients with subsegmental PE diagnosed on CTPA. Disclosures: No relevant conflicts of interest to declare.
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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 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| 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".