Effects of olmesartan on the renin-angiotensin-aldosterone system for patients with essential hypertension after cardiac surgery--investigation using a candesartan change-over study.

BACKGROUND: Various angiotensin II receptor blockers are widely used for the treatment of hypertension in recent years. The results of large-scale clinical studies have shown that they have various efficacies: not only hypotensive effects but also organ protective effects. In this study, the effects of a change-over from candesartan to olmesartan on renin-angiotensin-aldsterone system, cardiomegaly and peripheral circulation were studied.

METHODS: Participants enrolled in this trial were outpatients with essential hypertension after cardiac surgery who had received candesartan for more than one year. Fifty-six patients switched from candesartan to olmesartan. The primary endpoints were 1) renin activity, angiotensin II, aldosterone, and 2) left ventricular mass index (LVMI).

RESULTS: It was clear that angiotensin II and aldosterone are decreased by the potent hypotensive effects of olmesartan in a change-over from candesartan to olmesartan. Since LVMI and BNP were decreased, inhibitory effects on myocardial hypertrophy were also confirmed.

CONCLUSION: In the present study, left ventricular hypertrophy and on arterial compliance were inhibited by a decrease in angiotensin II and aldosterone due to the change-over to olmesartan. In the future, protective effects on organs will be clarified by long-term observations.