[Endothelial function assessment by positron emission tomography in patients with hypercholesterolemia]

Area of Science:

• Cardiovascular Medicine
• Diagnostic Imaging
• Metabolic Disorders

Background:

• Hypercholesterolemia is a known precursor to endothelial dysfunction (ED), a condition that facilitates atherogenesis.
• ED is an early indicator in the development of atherosclerosis and a marker for coronary artery disease (CAD).
• Early detection of ED in dyslipidemia is crucial for preventing cardiovascular events.

Purpose of the Study:

• To evaluate endothelial function (EF) using Positron Emission Tomography (PET) in asymptomatic patients.
• The study focused on patients with a recent diagnosis of dyslipidemia and no prior history of ischemic heart disease or lipid-lowering treatment.
• To establish a baseline for EF assessment in newly diagnosed dyslipidemic individuals.

Main Methods:

• Fourteen asymptomatic patients with recent dyslipidemia (< 6 months) underwent comprehensive assessment.
• Tests included lipid profile, blood glucose, and a three-phase 13N-ammonia PET scan (rest, cold pressor test, and adenosine stress).
• Endothelial function was quantified by calculating coronary flow reserve (CFR), endothelial-dependent vasodilatation index (EDVI), and the percentage change in coronary blood flow during the cold pressor test (% Delta CF).

Main Results:

• A high prevalence of endothelial dysfunction (79%) was observed in patients with dyslipidemia.
• Key hemodynamic parameters were significantly lower than established normal values: rest coronary flow (0.44 vs. 0.57), CPT coronary flow (0.57 vs. 0.88), stress coronary flow (1.24 vs. 1.81), EDVI (1.28 vs. 1.53), and % Delta CF (29.08% vs. 53%).
• While CFR was also lower (2.79 vs. 3.15), the difference was not statistically significant (p=0.198).

Conclusions:

• 13N-ammonia PET imaging is effective in detecting endothelial dysfunction in asymptomatic patients with early-stage dyslipidemia.
• The study highlights a significant prevalence of ED in this patient group, underscoring the need for early intervention.
• PET imaging provides a valuable tool for assessing cardiovascular risk in patients with newly diagnosed dyslipidemia.