Experimental studies demonstrated that
mineralocorticoid antagonists prevent or reverse myocardial
fibrosis. Therefore, we tested the hypothesis that the
aldosterone antagonist canrenone can improve left ventricular diastolic function in
essential hypertension. Using digitized M-mode echocardiography and 24-hour blood pressure monitoring (ABPM), we realized a prospective, randomized, controlled study on 34 never-treated essential hypertensives with
left ventricular diastolic dysfunction. Echocardiogram and ABPM were repeated after 6 months of effective
antihypertensive treatment with
ACE inhibitors and
calcium antagonists (second evaluation) and then after a 6-month period with 17 patients randomly assigned to add
canrenone 50 mg/d to the previous treatment (third evaluation). At the basal evaluation 32 patients had left ventricular concentric
hypertrophy, and 2 patients had left ventricular concentric remodeling. All the patients had normal left ventricular systolic function. At the second evaluation blood pressure was reduced (P<0.0001), left ventricular mass index decreased (P<0.0001), and diastolic function improved (P<0.0001). After randomization, the
canrenone and control groups had similar 24-hour blood pressure and left ventricular morpho-functional characteristics. At the third evaluation, despite unchanged blood pressure and similar decrease of left ventricular mass index, the
canrenone group, compared with control group, showed a significantly greater increase in left ventricular diastolic indices. In
essential hypertension, a low dose of
aldosterone antagonist added to
antihypertensive treatment significantly improved left ventricular diastolic function. This improvement, not accounted for by changes in blood pressure and left ventricular mass, can be therefore ascribed to a direct action of the
drug on the myocardium.