P1769Microvascular resistance increases with left ventricular mass in hypertrophic cardiomyopathy
Bibliographic record
Abstract
Abstract Introduction Hypertrophic cardiomyopathy is often associated with myocardial ischemia despite lack of focal epicardial coronary stenoses and this is partially attributable to microvascular dysfunction. The index of microvascular resistance (IMR) is a hemodynamic index that is independent of epicardial stenoses and reflects coronary microvascular function. Purpose To investigate the relationship between microvascular dysfunction and the degree of hypertrophy in hypertrophic cardiomyopathy patients. Methods We performed a prospective study to assess epicardial and microvascular coronary hemodynamics in 12 subjects with hypertrophic cardiomyopathy undergoing diagnostic coronary angiography. A pressure-temperature sensor coronary guidewire was used with intracoronary injections of room-temperature saline to measure mean coronary transit time during rest and hyperemia induced with intravenous adenosine. IMR was calculated by multiplying mean coronary transit time during hyperemia by distal coronary pressure in each subject. Left ventricular mass was calculated from baseline echocardiographic studies using established methods. Continuous variables are shown as mean ± standard deviation. Results Six subjects were male; mean age was 59.8±11.6 years. Baseline body mass index was 30.5±6.1 kg/m2 and left ventricular ejection fraction was 76.7% ± 11.0% with mean left ventricular mass 230.1±76.6 grams by echocardiography. Ten subjects had asymmetric septal hypertrophy; one subject had marked apical hypertrophy and one subject had asymmetric septal and inferolateral hypertrophy. Resting left ventricular outflow tract gradient was 59.4±37.8 mmHg and increased to 90.0±54.1 mmHg with Valsalva maneuver. Systolic anterior motion of the mitral valve was present in 10 subjects. Hemodynamic variables included coronary flow reserve (2.1±1.2); hyperemic mean transit time (0.29±0.15 sec.), and IMR (21.7±10.2). Index of microvascular resistance was strongly positively correlated with left ventricular mass (Figure 1; Pearson r=0.68, p=0.021). Figure 1. IMR is correlated with LV mass Conclusion(s) Microvascular dysfunction as assessed by IMR is strongly correlated with left ventricular mass and may contribute to symptoms in patients with hypertrophic cardiomyopathy.
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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 | 0.001 |
| 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 | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.004 | 0.001 |
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".