Age- and sex-differences and reference values for ventricular strain by cardiovascular magnetic resonance imaging in adults without cardiovascular disease or cardiovascular disease risk factors
Bibliographic record
Abstract
BACKGROUND: Myocardial deformation measured by myocardial strain is an important marker of cardiovascular disease (CVD). We aimed to establish normal values and examine age- and sex-differences in left and right ventricular (LV, RV) strain using feature tracking cardiovascular resonance (FT-CMR) in adults free of CVD in the community. METHODS: Framingham Heart Study Offspring participants without CVD, hypertension, or diabetes completed CMR (1.5T) (n=903, 59% (533/903) women, 36-88 years of age). Global longitudinal, circumferential, and radial strain (GLS, GCS, and GRS, respectively) were measured by semi-automated LV and RV myocardial segmentation of short-axis, 2-chamber, and 4-chamber images with cvi42 (v.5.13, Circle Cardiovascular Imaging, Calgary, Canada). RESULTS: Mean LV GLS, GCS, and GRS were -17.8±2.5%, -19.7±2.4%, and 34.9±6.9%, respectively; RV GLS, GCS, and GRS were -20.4±4.0%, -11.7±3.5%, and 19.1±6.5%, respectively. All strain values were of greater magnitude in women than men (all p<0.005). LV and RV GCS and GRS were of greater magnitude (more negative and more positive, respectively) with increasing age (all p<0.001), but GLS was not associated with age. Stratified analysis by sex showed LV and RV GCS and GRS were greater in magnitude with increasing age in women (all p<0.001), whereas no age associations in men were observed. CONCLUSION: We provide FT-CMR reference values for LV and RV strain in a large, community-dwelling U.S. adult cohort free of CVD and CVD risk factors. Women demonstrated greater magnitude LV and RV GCS and GRS with increasing age. The clinical implications of sex-differences in ventricular strain and mechanical remodeling with age deserve further study.
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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 | 0.004 |
| 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 | 0.001 | 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".