Age- and sex-specific differences in myocardial sympathetic tone and left ventricular remodeling following myocardial injury.

Background: Presentations and outcomes of acute myocardial infarction (MI) differ between women and men, with the worst outcomes being reported in younger women. Mental stress induced ischemia and sympathetic activation have been suggested to play a prominent role in the pathogenesis of MI in younger women, however, the impact of sex hormones on these parameters remains unknown.

Methods: The effect of sex hormones and age on myocardial infarct size and myocardial sympathetic activity (MSA) was assessed in male and female, as well as young (4-6 months) and aged (20-22 months) FVB/N mice (n = 106, 60 gonadectomized and 46 sham-operated animals) who underwent in vivo [C]meta-hydroxyephedrine ([C]mHED) positron emission tomography (PET) and cardiac magnetic resonance (CMR) imaging 24 h after a 30 min myocardial ischemic injury.

Age- and sex-related variations in extracellular vesicle profiling for the assessment of cardiovascular risk: the EVaging index.

Extracellular vesicles (EVs) offer valuable diagnostic and prognostic insights for cardiovascular (CV) diseases, but the influence of age-related chronic inflammation ("inflammaging") and sex differences on EV profiles linked to CV risk remains unclear. This study aimed to use EV profiling to predict age and stratify patients by CV risk. We developed an EVaging index by analyzing surface antigen profiles of serum EVs from 625 participants, aged 20 to 94 years, across varying CV risk groups.

miR-24-3p secreted as extracellular vesicle cargo by cardiomyocytes inhibits fibrosis in human cardiac microtissues.

Background And Aims: Cardiac fibrosis in response to injury leads to myocardial stiffness and heart failure. At the cellular level, fibrosis is triggered by the conversion of cardiac fibroblasts (CF) into extracellular matrix-producing myofibroblasts. miR-24-3p regulates this process in animal models.