Microvascular dysfunction and sympathetic hyperactivity in women with supra-normal left ventricular ejection fraction...

Area of Science:

• Cardiology
• Cardiovascular Imaging
• Clinical Medicine

Background:

• A supra-normal left ventricular ejection fraction (snLVEF) phenotype (LVEF > 65%) is associated with increased mortality.
• The underlying mechanisms for this association remain unclear.

Purpose of the Study:

• To investigate the prevalence and clinical significance of snLVEF in relation to sex.
• To explore potential mechanisms, including microvascular function and autonomic regulation, associated with snLVEF.

Main Methods:

• 1367 patients underwent rest/adenosine stress 13N-ammonia PET imaging.
• Patients were categorized by LVEF, with a subcohort followed for major adverse cardiac events (MACE).
• Coronary flow reserve (CFR) and heart rate reserve (% HRR) were assessed during stress testing.

Main Results:

• snLVEF prevalence was higher in women (31.3%) than men (18.8%).
• In women, snLVEF was associated with reduced CFR and % HRR, independent predictors of snLVEF.
• Women with snLVEF had a significantly higher risk of MACE compared to women with normal LVEF; this association was not observed in men.

Conclusions:

• snLVEF is linked to increased MACE risk in women, but not men.
• Microvascular dysfunction and heightened sympathetic tone in women may underlie the association between snLVEF and adverse cardiac events.