Abstract 14263: Asessment of Pulmonary Vascular Reserve Using Pharmacologic Stress Testing in Patients With Fontan Physiology
Bibliographic record
Abstract
Introduction: The presence of pulmonary vascular disease (PVD) may be under-recognized during standard hemodynamic evaluation in patients with Fontan physiology. Assessment of pulmonary vascular reserve (VR) (Δ pulmonary artery pressure/Δ cardiac index) utilizing pharmacologic stress testing could be a better way of identifying PVD in pediatric patients. The objective of this study is to diagnose Fontan patients with PVD utilizing pharmacologic stress testing. Hypothesis: Pharmacologic stress testing will unmask Fontan patients as having PVD. Methods: Single center record review of cardiac catheterizations with dobutamine administration in Fontan patients from January 2021 to June 2022. Following acquisition of baseline data on room air, a dobutamine infusion was started at 5 mcg/kg/min with dose escalation as needed until an appropriate heart rate response was achieved. Hemodynamics were reassessed at each dose interval, but data are reported at the highest cardiac index (CI). Abnormal VR was defined as > 3 mmHg/l. Results: Eighteen Fontan patients (87% male) were included. Median age at the time of catheterization was 14 (IQR 11, 16) years with mean duration of Fontan circulation of 9.9 ± 3.9 years. The primary indication for catheterization was exercise intolerance (65%). Dobutamine administration did not result in a significant change in indexed pulmonary vascular resistance (PVRi) (2.1 ± 0.8 v 2.4 ± 1.31 iWU, p = 0.21) or Fontan pressure (12 [IQR 11, 14] v 14 (IQR 12, 15), p=1.0]. Eight patients had a PVRi ≥ 2.0 iWu at baseline; while 4 (22% of the cohort) had a PVRi < 2.0 iWU at baseline but had an abnormal VR. Conclusions: PVD is common in Fontan patients but may be missed in some patients without pharmacologic stress testing. Accurate diagnosis of PVD will allow for optimization of Fontan circulation with pulmonary vasodilators.
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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 | 0.001 | 0.002 |
| 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) | 0.003 | 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".