Comparison of Five Antihypertensive Monotherapies and Placebo for Change in Left Ventricular Mass in Patients Receiving Nutritional-Hygienic Therapy in the Treatment of Mild Hypertension Study (TOMHS)

Abstract

Background Increased left ventricular mass (LVM) by echocardiography is associated with increased risk of cardiovascular disease. Thus, it is of interest to compare the effects of both pharmacological and nonpharmacological approaches to the treatment of hypertension on reduction of LVM. Methods and Results Changes in LV structure were assessed by M-mode echocardiograms in a double-blind, placebo-controlled clinical trial of 844 mild hypertensive participants randomized to nutritional-hygienic (NH) intervention plus placebo or NH plus one of five classes of antihypertensive agents: (1) diuretic (chlorthalidone), (2) β-blocker (acebutolol), (3) α-antagonist (doxazosin mesylate), (4) calcium antagonist (amlodipine maleate), or (5) angiotensin-converting enzyme inhibitor (enalapril maleate). Echocardiograms were performed at baseline, at 3 months, and annually for 4 years. Changes in blood pressure averaged 16/12 mm Hg in the active treatment groups and 9/9 mm Hg in the NH only group. All groups showed significant decreases (10% to 15%) in LVM from baseline that appeared at 3 months and continued for 48 months. The chlorthalidone group experienced the greatest decrease at each follow-up visit (average decrease, 34 g), although the differences from other groups were modest (average decrease among 5 other groups, 24 to 27 g). Participants randomized to NH intervention only had mean changes in LVM similar to those in the participants randomized to NH intervention plus pharmacological treatment. The greatest difference between groups was seen at 12 months, with mean decreases ranging from 35 g (chlorthalidone group) to 17 g (acebutolol group) ( P =.001 comparing all groups). Within-group analysis showed that changes in weight, urinary sodium excretion, and systolic BP were moderately correlated with changes in LVM, being statistically significant in most analyses. Conclusions NH intervention with emphasis on weight loss and reduction of dietary sodium is as effective as NH intervention plus pharmacological treatment in reducing echocardiographically determined LVM, despite a smaller decrease in blood pressure in the NH intervention only group. A possible exception is that the addition of diuretic (chlorthalidone) may have a modest additional effect on reducing LVM.