β-Blockers vs. Angiotensin-Converting Enzyme Inhibitors in Hypertension

Abstract

Both beta-blockers and angiotensin-converting enzyme (ACE) inhibitors have been shown to cause left ventricular hypertrophy regression in hypertensive patients. So far, no study allowed a true comparison of these drugs in this regard. Therefore, 56 hypertensive patients (38 newly recognized and 18 without any antihypertensive drugs for more than 2 months, mean of 9.5+/-14 months) were randomized to enalapril (En, n = 30) or a beta-blocker, bisoprolol (Bi, n = 26), once daily and underwent before and after 2 and 6 months on treatment (a) office and 24-h ambulatory monitoring of BP, (b) M-mode echo assessment of left ventricular mass (LVM) index and fractional shortening (FS), and (c) Doppler evaluation of left ventricular filling. All recordings were read blindly by two observers. The intraobserver coefficient of variation of LVM was 9%. After 6 months, office BP (146+/-18/90+/-10 vs. 170+/-14/104+/-8 mm Hg) and 24-h BP(120+/-17/77+/-9 vs. 138+/-15/90+/-9 mm Hg) were similarly reduced with both drugs. The LVM index was significantly reduced (p < 0.001) (Bi, 11%; En, 7%) and FS was unchanged. The early to late diastolic left ventricular flow ratio (E/A) was increased with bisoprolol (1.06+/-0.29 vs. 0.85+/-0.17, p < 0.0001) but not with enalapril (0.95+/-0.24 vs. 0.88+/-0.34), but this was mainly due to heart rate reduction with bisoprolol. We found no correlation between the reductions in 24-h BP and in LVM index. Bisoprolol and enalapril were similarly effective in lowering blood pressure (BP) in the office and during 24-h monitoring and in reducing the left ventricular mass index in hypertensive patients.