Sex Differences in Aging-related Myocardial Stiffening Quantitatively Measured with MR Elastography.
Level 4 - case-series / case-control
Cross-sectional observational imaging study in healthy volunteers
PubMed 38780427 · doi:10.1148/ryct.230140
What was done
A prospective cross-sectional study evaluated the feasibility of quantitative MR elastography (MRE) to measure left ventricular (LV) myocardial shear stiffness across age and sex. A 5-minute MRE acquisition was added to a clinical MRI protocol in 109 healthy volunteers (57 women, 52 men; age range: 18–84 years; mean age: 40 ± 18 years) recruited between November 2018 and September 2019. Linear regression models assessed associations and interaction terms between age, sex, MRE stiffness, and standard cardiac MRI metrics.
What was found
LV myocardial shear stiffness significantly increased with age in women (slope = 0.03 ± 0.01 kPa/year, P = .009) but not in men (slope = 0.008 ± 0.009 kPa/year, P = .38). In female volunteers, LV ejection fraction increased with age (0.23% ± 0.08 per year, P = .005) and LV end-systolic volume decreased (-0.20 ± 0.07 mL/m² per year, P = .003). Conventional MRI parameters (T1, strain, LV mass) showed no significant age-sex interaction (P > .05). Myocardial shear stiffness did not correlate with ejection fraction, stroke volume, body mass index, or strain (P > .05), but weakly correlated with indexed LV end-diastolic volume (slope = -3 ± 1 kPa/mL/m², P = .004, r² = 0.08) and indexed LV end-systolic volume (-1.6 ± 0.5 kPa/mL/m², P = .003, r² = 0.08).
Why it matters
This study provides noninvasive biomechanical evidence that natural aging causes disproportionate LV myocardial stiffening in females compared to males. These findings may help explain the higher female predisposition to heart failure with preserved ejection fraction and highlight MRE as a sensitive noninvasive imaging tool.
Limits
The study is cross-sectional rather than longitudinal, inferring aging trajectories from single time-point assessments. The sample size is modest (n = 109) and restricted to healthy volunteers at a single center, precluding direct evaluation of clinical outcomes or disease states.
Cited by
- supports As humans age, the heart shrinks and myocardial tissue becomes stiffer.