P4690Effects of pulmonary artery wedge pressure on right ventricular pulsatile loading in pulmonary hypertension: a reappraisal based on pulmonary arterial isobaric stiffness
Bibliographic record
Abstract
Abstract Background Pulmonary hypertension (PH) is associated with stiffening of pulmonary arteries. Previous studies have suggested that high pulmonary artery wedge pressure (PAWP) in postcapillary PH (Pc-PH) further augments PA stiffness at a given level of pulmonary vascular resistance as compared to pulmonary arterial hypertension (PAH). However, these studies do not take into account differences in distending pressure (mean PA pressure, mPAP), which has an effect on stiffness due to non-linear stress-strain behavior of arteries. Purpose To compare total PA stiffness between Pc-PH and idiopathic PAH (iPAH) studied at similar mPAP (isobaric stiffness). Methods This was an analysis of right heart catheterization results obtained in 112 Pc-PH and 112 iPAH patients extracted from the French PAH network registry and matched for mPAP (median 38 vs 39 mmHg, P=NS), age (70.5 years each) and sex (64% female each). Total PA stiffness was calculated as the ratio of PA pulse pressure to indexed stroke volume. Results Total PA stiffness (n=224) increased with mPAP (Spearman's rho = 0.66) and decreased with PAWP (rho = - 0.17) (each P<0.01). The isobaric stiffness was lower in Pc-PH (median (IQR) = 0.91 (0.64–1.39) mmHg/mL/m2) than in iPAH (1.18 (0.83–1.62) mmHg/mL/m2, P<0.01). The patients were then stratified according to their mPAP (25–35 mmHg, n=74 (37/37); 36–43 mmHg, n=75 (34/41); and 44–66 mmHg, n=75 (41/34)). The isobaric stiffness was lower in Pc-PH than iPAH in the 1st mPAP tertile (0.62 vs 0.83 mmHg/mL/m2, P=0.06), in the 2nd mPAP tertile (0.76 vs 1.22 mmHg/mL/m2, P<0.01) and in the 3rd mPAP tertile (1.41 vs 1.77 mmHg/mL/m2, P<0.01). The pulmonary vascular resistance was lower in Pc-PH than iPAH in every mPAP tertile (each P<0.01). Finally, Pc-PH had a higher indexed stroke volume than iPAH (37 (29–48) vs 32 (27–40) mL/m2, P<0.01) while systolic PA pressure and PA pulse pressure were similar. Conclusion Unexpectedly, the isobaric pulmonary arterial stiffness was lower in Pc-PH than iPAH patients. It is proposed that PAWP attenuates the increase in RV pulsatile loading in PH when the natural high-strain-induced stiffening was accounted for. This may contribute to a less impaired right ventricular-PA coupling leading to higher indexed stroke volume in Pc-PH than iPAH despite similar PA pressure. At every mPAP level, both the lower PA stiffness and lower pulmonary vascular resistance in Pc-PH than in iPAH may contribute to explain differences in the pressure overload-induced right ventricular adaptation between the two diseased groups, a point that deserves to be confirmed by further studies. Acknowledgement/Funding University regular funds
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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 | 0.003 |
| 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 | 0.001 | 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".