Abstract 4855: Long-term Effect of Efonidipine Therapy on Plasma Aldosterone and Left Ventricular Mass Index in Patients With Essential Hypertension
Background. Aldosterone (ALD) breakthrough often occurs and is an important issue during long-term treatment with angiotensin-converting enzyme inhibitors (ACE-I) and angiotensin receptor blockers (ARB). Previous studies showed that ALD breakthrough the incidence of ALD breakthrough was between 22–53% after 12 months. Recently, it has been reported that efonidipine, a T-type and L-type calcium channel blocker, decreases plasma levels of ALD. However, long-term effects of efonidipine on plasma levels of ALD and left ventricular mass index (LVMI) remain unknown in patients with hypertension.
Methods and Results. Sixty stable outpatients with essential hypertension who had received amlodipine and ACE-I or ARB for more than one year were randomized to two groups [amlodipine group (n=30): continuous amlodipine treatment at a stable dose; efonidipine group (n=30): amlodipine (5mg/day) was changed to efonidipine at a dose of 40mg/day]. There was no difference in the baseline characteristics including LVMI and plasma levels of ALD between two groups. In the amlodipine group, there were no significant changes in blood pressure, LVMI or plasma levels of ALD during 18 months. In the efonidipine group, blood pressure did not change after replacement of amlodipine by efonidipine, although there was a significant decrease in plasma levels of ALD after 6 months and the decrease of ALD was sustained for 18 months (106±49 pg/mL at baseline, 76±30 pg/mL at 6 months, 79±43 pg/mL at 9 months, 77±34 pg/mL at 18 months) and plasma ALD level eventually increased again in only 2 patients (7% aldosterone breakthrough). In addition, LVMI was significantly decreased after 18 months (121±25 vs. 114±21 g/m2, p<0.05). There was a significant correlation between changes in LVMI and % changes of ALD in the efonidipine group (r=0.427, p=0.018).
Conclusion. These findings indicate that the effect of efonidipine on suppression of plasma ALD was sustained for at least 18 months and that long-term efonidipine therapy decreases LVMI in patients with essential hypertension