Study of Myocardial Interstitial Fibrosis in Hyperaldosteronism

Study of Myocardial Interstitial Fibrosis in Hyperaldosteronism Noninvasive Comparative Study in Humans of the Respective Cardiovascular Effects of Hyperaldosteronism and Hypertension by Magnetic Resonance Imaging

Animal models have demonstrated the role of aldosterone in left ventricular remodeling involving fibrosis, apoptosis and hypertrophy. Myocardial fibrosis is a risk factor for serious arrhythmia and sudden death in ischemic and idiopathic hypertrophic heart disease. It is accepted that patients with primary aldosteronism have a higher prevalence of LV hypertrophy , arterial involvement and increased cardiovascular risk. In humans, a link has been demonstrated between aldosterone and heart failure as well as the benefit of the administration of an anti -aldosterone drug to lower mortality in this population , regardless of blood pressure level . The administration of spironolactone ( aldosterone ) in hypertensive rats has prevented the occurrence of aortic fibrosis . Plasma aldosteronism in humans has been associated with inflammation, fibrosis and aortic stiffness . However, primary aldosteronism is generally associated with so-called secondary hypertension . Chronic hypertension alone is a recognized etiological factor of myocardial hypertrophy ( myocardial fibrosis very advanced ) . The purpose of this study is to investigate the effects of MRI hyperaldosteronism on the heart.

Cross-sectional study with double analysis (A and B) with 2 x 2 sub-groups (ratio control/case 1/1)

• clinical situation: subjects are hypertensive. 20 subjects with primary aldosteronism will be compared to 20 patients with essential arterial hypertension
• clinical situation are normotensive subjects, 20 subjects with secondary aldosteronism loss in congenital salt (Bartter's syndrome / Gitelman) will be compared to 20 healthy volunteers. Controls (essential hypertension and healthy volunteers) are matched for age, sex and body size in two experimental groups (HAP and Gitelman). All subjects were recruited by the CIC of the European Georges Pompidou Hospital (Paris).

• Patients with primary hyperaldosteronism:

  • Aldosterone / renin plasma ratio SUP 64 pmol / mU
  • aldosterone in a semi-sitting position SUP 500pmol / l or an aldosteronuria> 63nmol/24h,
  • Both under neutral treatment for at least 15 days (alpha-blocker, calcium channel blockers, central inhibitors). BMI = 35 kg / m².

• For patients with secondary hyperaldosteronism :

  • Documented diagnosis by the detection of mutation (s) homozygous or compound heterozygous for the gene SLC12A3 encoding CLCNKB chloride channel, or the gene encoding the HTSC Na-Cl cotransport thiazide sensitive.
  • Normal blood pressure (mean of three consecutive measurements of SBP INF 140 mmHg and DBP INF 90 mmHg measured in a semi-sitting position after 5 minutes of rest).

• For hypertensive patients :

  • Hypertension diagnosed on an average of three consecutive BP measurements = 140 and / or = 90 mmHg in the supine position after 5 minutes of rest or average daytime PA SUP 135/85 mmHg in ambulatory blood pressure monitoring (ABPM) in self-measurement , the presence of one or more antihypertensive medications regardless of the BP level.
  • No argument for secondary hypertension (renal artery stenosis, hypermineralocorticoidism, pheochromocytoma, iatrogenic ...) or negative balance of secondary hypertension.
  • BMI < 35 kg/m2.

• For healthy subjects :

  • Normal blood pressure (mean of three consecutive measurements of SBP INF 140 mmHg and DBP INF 90 mmHg measured in a semi-sitting position after 5 minutes of rest).
  • Absence of HA known or detected on determinations carried out during the study (see criteria for PAHs).
  • BMI <35 kg / m²
  • Laboratory tests (hematological and biochemical blood tests, urinalysis, serology and Research toxic) within normal limits or clinically acceptable for age and sex.