Long-term effects of irbesartan on plasma aldosterone concentration and left atrial volume in hypertensive patients.

BACKGROUND:Plasma aldosterone concentration (PAC) is related to cardiac remodeling in patients with hypertension. However, we do not know the detailed relationship between changes in PAC and regression of left atrial (LA) volume following long-term treatment with angiotensin II receptor blocker (ARB) or calcium-channel blocker (CCB). OBJECTIVE:The aim of this study was to investigate the effects of anti-hypertensive monotherapy, an ARB irbesartan or a CCB amlodipine, on PAC and LA reverse remodeling in hypertensive patients. METHODS:A total of 48 patients with untreated hypertension were randomly assigned to irbesartan (ARB group, n=26) and amlodipine (CCB group, n=22). We examined the correlation between LA volume index (LAVI) and other echocardiographic parameters or PAC (n=40) at the baseline and after 12 months of treatment. RESULTS:After 12 months, blood pressure (BP) decreased similarly in both groups. LAVI and PAC significantly decreased in the ARB group, but not in the CCB group (-16±8% vs. 22±9%, p<0.01, -16±9% vs. 11±9%, p<0.05). Larger %-decrease in PAC was associated with larger %-reduction of LAVI in the ARB group (r=0.54, p<0.05), but not in the CCB group. CONCLUSIONS:While BP reduction was similar between the two groups, decrease in LA volume was larger in the ARB group than in the CCB group. Decrease in LA volume was larger in patients with a greater decrease in PAC than in those with smaller decrease in PAC. ARB may facilitate reverse remodeling of LA through decreases in PAC in hypertensive patients.