Demonstration of blood pressure-independent noninfarct myocardial fibrosis in primary aldosteronism: a cardiac magnetic resonance imaging study

<p>Background—Primary Aldosteronism (PA) is common and associates with excess cardiovascular morbidity independent of blood pressure. Exposure to aldosterone and sodium leads to cardiac fibrosis and hypertrophy in humans and animals possibly mediated by inflammation and oxidative stress. We aimed to clarify the effects of aldosterone excess on myocardial structure and composition in human subjects with PA and essential hypertension (EH) using contrast-enhanced cardiac MRI (CMR) as well as explore the mechanistic basis for any observed differences.</p> <p>Methods and Results—Twenty seven subjects with recently diagnosed PA and 54 EH controls were recruited. Subjects underwent gadolinium-enhanced CMR; non-infarct related myocardial fibrosis was identified by a diffuse pattern of late gadolinium enhancement (LGE). Patients also underwent assessment of pulse wave velocity (PWV), measurement of circulating superoxide anion and C-reactive protein as well as blood pressure and biochemical assessment. Subjects were well matched with no difference in severity nor duration of hypertension. There was a significant increase in the frequency of non-infarct LGE in PA (70%) when compared to EH subjects (13%; p<0.0001) with no difference in LV mass. PWV, superoxide and CRP were significantly higher in PA subjects.</p> <p>Conclusions—These data illustrate that PA patients exhibit more frequent myocardial fibrosis as demonstrated by LGE using CMR imaging; this finding is independent of blood pressure. This may be mediated partly through inflammation and oxidative stress. This study highlights the importance of specific targeting of aldosterone excess as well as blood pressure reduction to minimise cardiac morbidity in Primary Aldosteronism.</p&gt