Myocardial fibrosis in primary aldosteronism

Area of Science:

• Cardiology
• Endocrinology
• Medical Imaging

Background:

• Primary aldosteronism (PA) is a leading cause of secondary hypertension.
• Myocardial fibrosis is increasingly recognized as a contributor to cardiovascular complications in PA.
• Understanding the distinct patterns of myocardial fibrosis and their associations is crucial for risk stratification and management.

Purpose of the Study:

• To investigate the relationship between myocardial fibrosis patterns (focal and diffuse) and clinical, biochemical, and metabolomic characteristics in patients with PA.
• To explore the potential role of L-glutamate metabolism in the pathogenesis of myocardial fibrosis in PA.

Main Methods:

• Cardiac magnetic resonance imaging (CMR) was used to assess focal replacement fibrosis (late gadolinium enhancement, LGE) and diffuse interstitial fibrosis (extracellular volume, ECV) in 54 PA patients.
• Clinical data, biomarkers, echocardiography, and non-targeted metabolomic analysis were performed.

Main Results:

• Patients with LGE exhibited longer hypertension duration, higher blood pressure, left ventricular mass index (LVMI), and NT-proBNP compared to those without LGE.
• Focal fibrosis (LGE) correlated with hypertension duration, blood pressure, and LVMI.
• Diffuse fibrosis (ECV) inversely correlated with plasma renin activity and positively with aldosterone-to-renin ratio, and both fibrosis types correlated with NT-proBNP.
• Metabolomic analysis revealed significant differences in amino acid metabolism, particularly L-glutamate metabolism, between patients with and without LGE, correlating with blood pressure and echocardiographic parameters.

Conclusions:

• In PA, focal myocardial fibrosis is associated with cardiac afterload (hypertension), while diffuse fibrosis is linked to hyperaldosteronism.
• L-glutamate metabolism may be implicated in the development of myocardial fibrosis in PA patients.