A study, published in Drugs under Experimental and Clinical Research, compared the regressive effect of cilnidipine on left ventricular mass (LVM) with that of quinapril. In all, 60 patients with mild essential hypertension (age >39 years) were randomized into two groups – 30 patients received cilnidipine (10 mg) while another 30 were administered quinapril (10 mg). The patients underwent echocardiography before and 12 months after drug treatment. Sixteen patients in each group were subjected to 123I-metaiodobenzylguanidine (MIBG) cardiac imaging before and 12 months after drug treatment. In both the groups, systolic and diastolic BP significantly decreased to similar levels. In the cilnidipine group, both end-diastolic and end-systolic diameters and posterior wall thickness significantly decreased, while only end-systolic diameter was found to decrease significantly in the quinapril group. LVM (206 +/- 36 g to 189 +/- 40 g, for the quinapril group; 195 +/- 60 g to 171 +/- 48 g, for the cilnidipine group) and the LVM index (127 +/- 20 g/m², to 116 +/- 20 g/m², for the quinapril group, 121 +/- 32 g/m² to 106 +/- 24 g/m² for the cilnidipine group) significantly decreased in both the groups. On MIBG imaging, the heart-to-mediastinum ratio significantly increased and the washout rate significantly decreased in the cilnidipine group, after drug treatment. There were no significant changes in MIBG parameters in the quinapril group. Cilnidipine led to a greater reduction in LVM in essential hypertension in comparison with quinapril, possibly on account of the long-term suppression of the cardiac sympathetic nervous system.