Myocardial tissue deformation is reduced in subjects with coronary microvascular dysfunction but not rescued by treatment with ranolazine
Bibliographic record
Abstract
BACKGROUND: Patients with coronary microvascular dysfunction (CMD) often have diastolic dysfunction, representing an important therapeutic target. Ranolazine-a late sodium current inhibitor-improves diastolic function in animal models and subjects with obstructive coronary artery disease (CAD). HYPOTHESIS: We hypothesized that ranolazine would beneficially alter diastolic function in CMD. METHODS: To test this hypothesis, we performed retrospective tissue tracking analysis to evaluate systolic/diastolic strain, using cardiac magnetic resonance imaging cine images acquired in a recently completed, randomized, double-blind, placebo-controlled, crossover trial of short-term ranolazine in subjects with CMD and from 43 healthy reference controls. RESULTS: Diastolic strain rate was impaired in CMD vs controls (circumferential diastolic strain rate: 99.9% ± 2.5%/s vs 120.1% ± 4.0%/s, P = 0.0003; radial diastolic strain rate: -199.5% ± 5.5%/s vs -243.1% ± 9.6%/s, P = 0.0008, case vs control). Moreover, peak systolic circumferential strain (CS) and radial strain (RS) were also impaired in cases vs controls (CS: -18.8% ± 0.3% vs -20.7% ± 0.3%; RS: 35.8% ± 0.7% vs 41.4% ± 0.9%; respectively; both P < 0.0001), despite similar and preserved ejection fraction. In contrast to our hypothesis, however, we observed no significant changes in left ventricular diastolic function in CMD cases after 2 weeks of ranolazine vs placebo. CONCLUSIONS: The case-control comparison both confirms and extends our prior observations of diastolic dysfunction in CMD. That CMD cases were also found to have subclinical systolic dysfunction is a novel finding, highlighting the utility of this retrospective approach. In contrast to previous studies in obstructive CAD, ranolazine did not improve diastolic function in CMD.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 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 | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".