Abstract 3621: Effect of T-Type Calcium Channel Blocker Versus L-Type Calcium Channel Blocker on Aldosterone in Patients with Hypertension
Background. To prevent cardiovascular disease, targeting aldosterone (ALD) synthesis and release may be clinically important. Recently, efonidipine, a T-type and L-type calcium channel blocker has been demonstrated to possess the ability to inhibit ALD synthesis and secretion in vitro. This study compared the effects of efonipidine on neurohumoral factors especially ALD levels with those of amlodipine, L-type calcium channel blocker, in patients with hypertension.
Methods. Forty stable outpatients (average age, 67.4±1.0 years) with essential hypertension who had received antihypertensive treatment with amlodipine (average dose 6.2±0.4mg once a day) for more than a year were enrolled in this study. Blood sampling was performed before regimen modification and 6months after amlodipine was replaced by efonidipine. Blood samples were assessed for serum potassium and serum creatinine, plasma levels of neurohumoral factors such as norepinephrine (NE), plasma active rennin concentration (PARC), ALD and brain natriuretic peptide (BNP).
Results. After the replacement of amlodipine by efonidipine, there were no significant changes in blood pressure demonstrating almost equal hypotensive effects of the two drugs. However, the heart rate was significantly decreased (72.0±1.3 vs. 69.8±1.3 beats/min, p<0.005) after the replacement of amlodipine by efonidipine. With respect to the effects of efonidipine on neurohumoral factors, the plasma concentrations of NE, PARC and BNP did not change after replacement. However, plasma ALD level decreased significantly from 97.7±7.9 pg/mL to 79.7±5.6 pg/mL (p<0.0001). The changes in the ALD level correlated with the baseline value of ALD before replacement of amlodipine by efonidipine (r=−0.769, p<0.0001). Following the replacement of amlodipine by efonidipine, plasma ALD levels significantly decreased in patients with or without angiotensin-converting enzyme inhibitor or angiotensin receptor blocker treatment and in patients with or without chronic heart failure.
Conclusions. Efonidipine significantly decreases heart rate and plasma ALD level compared with amlodipine treatment in hypertensive patients.