Decreased ventricular reserve in individuals with thoracic aortic disease
Bibliographic record
Abstract
Abstract Background Thoracic aortic disease (TAD) – including aortic aneurysm and dissection – are life-threatening conditions. In addition to causing acute aortic syndromes, TAD may chronically increase left-ventricular (LV) -arterial loading and adverse cardiac remodeling, potentially causing heart failure. How TAD changes LV function, particularly during exercise (i.e., LV reserve), has received little attention. Purpose To compare changes in LV hemodynamics and effective arterial elastance (Ea) during sub-maximal exercise in individuals with TAD, to age-matched older (OC) and younger controls (YC) without TAD. Methods Clinically stable patients with TAD (n=12 total; 25% female, 66±12 yrs; aneurysm, n=5; dissection, n=7), without contraindications to magnetic resonance imaging (MRI) were enrolled and compared to healthy OC (n=9, 44% female, 66±6 yrs) and YC (n=6, 43% female, 29±6 yrs) without TAD. Supine LV hemodynamic (end-diastolic, end-systolic and stroke volume [EDV, ESV, SV], ejection fraction [EF], and cardiac output [CO]) were assessed from real-time cardiac MRI at rest, and during stages of progressive stepping exercise starting at ~25-30% of their peak upright power output (Stage 1), until they reached a rating of perceived exertion >5/10 (Final Stage). Resting and exercise Ea was calculated as the product of SV x (0.9 x systolic blood pressure) assessed from an MRI-compatible automatic oscillometric blood pressure cuff. Groups were compared using one-way (resting values) or repeated measures ANOVA (exercise responses). Results At rest, all three groups showed comparable LVEF (TAD: 57.5±5.7%; OC: 58.3±5.9%; YC: 55.7±3.9%), LV size (i.e. EDV; TAD: 166±44 mL; OC: 176±46 mL; YC: 187±62 mL), and Ea (TAD: 1.11±0.19 mmHg/m; OC: 1.17±0.34 mmHg/mL; YC: 0.94±0.22 mmHg/mL) - P>0.10 for all. There was a significant group-by-exercise interaction for exercise CO augmentation (P<0.001, Fig 1) with a trend for progressively blunted exercise CO augmentation across YC (+6.7±1.8 L/min) to OC (+5.0±1.4 L/min) and to TAD (+3.6±1.5 L/min). From rest to the final stage of exercise (Fig 2), patients with TAD had a greater relative increase in Ea (+10%) versus OC (-4%, P=0.02) and YC (-2%, P=0.08). This coincided with a lesser decrease in ESV in TAD (-5%) vs. OC (-13%, P=0.03) and YC (-12%, P=0.01) which, combined with a comparable increase in EDV for all groups, resulted in a blunted increase in EF in TAD (+5.3%, P=0.03) compared to OC (+8.1%, P=0.03) and YC (+8.9%, P=0.03). Responses did not differ for TAD patients with or without surgical repair (P>0.10 for all). Conclusions Patients with TAD show decreased cardiac reserve during sub-maximal exercise, secondary to higher effective arterial elastance and a blunted ability to reduce ESV. These features may predispose to adverse cardiac remodeling and heart failure, particularly when afterload is further increased by age- and/or chronic disease-related vascular stiffening.Cardiac output in TAD, OC and YCArterial elastance and LV responses
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| 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) | 0.000 | 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 teacher head, 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".