In a parallel group randomized trial we compared the echocardiographically documented effects of clonidine (cl) versus nifedipine (nf) on left ventricular hypertrophy (LVH) and muscle mass (LVM) in hypertensive subjects. Twenty-one patients with concentric LVH (thickness of interventricular septum, IVS, and left posterior wall, LPW, above 11 mm) were given a 2D and M-mode echocardiogram before (pre) and 12 and 24 weeks, respectively, after therapy was initiated (mean oral cl dosage 150 μg; nf, 30 mg/day). At the end of the follow-up period in the cl group blood pressure declined by an average of 16/11 mm Hg compared with 30/20 mm Hg in the nf group (intergroup differences, NS). The thickness of the IVS decreased from a mean of 15.0 ± 1.9 mm and 15.1 ± 1.5 pre-therapy to 12.6 ± 2.3 for cl (p = 0.0001) and 13.1 ± 1.5 mm for nf (p = 0.001) after 24 weeks, respectively. This was similar to the regression of the LV posterior wall with 14.7 ± 1.5 and 14.5 ± 1.6 mm pretherapy to 12.0 ± 1.1 in the cl group (p = 0.0001) and 12.7 ± 1.7 for nf(p = 0.006). As the internal LV-diameter were relatively constant over the treatment period, the calculated values for LVM dropped from a mean of 406.5 ± 125.9 and 401.4 ± 106.6 to 274.8 ± 78.7 and 297.5 ± 85.0 g, respectively, corresponding to −31.6 ± 11.0% for cl(p = 0.0001) and −25.2 ± 12.6% for nf (p = 0.0001). The differences in treatment did not gain significance. We conclude that clonidine and nifedipine in intermediate dosages induce a comparable regression of LVH in hypertensive subjects; this leads to a remarkable reduction of LVM for both drug regimens after 24 weeks. The considerable decrease of 30-25% in LVM are presumably due to the high baseline data for LVH and LVM. In contrast to the major drop of blood pressure, only minor changes for LV internal diameters and fractional shortening could be observed.
Address correspondence and reprint requests to Prof. Dr. P. Kleine at Medizinische Klinik, Podbielskistr. 380, im Krankenhaus Oststadt der Medizinischen Hochschule Hannover, D-3000 Hannover, Federal Republic of Germany.
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