Objectives: This study was designed to evaluate the long-term effects of combination therapy with an angiotensin-converting enzyme inhibitor and a beta-adrenergic blocking agent on the relation between the decrease in arterial pressure at rest and during exercise and the decrease in left ventricular mass.
Background: A variety of antihypertensive drugs including angiotensin-converting enzyme inhibitors and beta-blockers have been shown to reduce ventricular hypertrophy, although little is known about combination therapy and the time course of such a reduction.
Methods: Twenty-one patients with previously untreated essential hypertension were treated with a low dose combination of 50 mg of atenolol and 10 mg of enalapril once daily for 39 months. Cardiovascular findings were assessed by two-dimensionally guided M-mode echocardiography in the pretreatment phase and after 6 and 39 months of combination therapy.
Results: Combination therapy reduced arterial pressure at rest from 161/108 to 130/86 mm Hg (p less than 0.001) and exercise arterial pressure at 100 W from 192/112 to 167/95 mm Hg (p less than 0.001). After 6 months of treatment, significant decreases in interventricular septal thickness (9%, p less than 0.001), posterior wall thickness (9%, p less than 0.001) and left ventricular mass index (16%, p less than 0.001) were demonstrated on the echocardiogram. After 39 months of therapy, reductions in these values were 28% (p less than 0.001), 29% (p less than 0.001) and 40% (p less than 0.001), respectively.
Conclusions: Long-term treatment with combination therapy of atenolol and enalapril produced significant reductions in arterial pressure at rest and during exercise accompanied by a marked reduction of left ventricular mass. However, whereas arterial pressure decreased immediately and remained unchanged, left ventricular mass decreased more gradually and continued to decrease throughout the treatment period of greater than 3 years. Despite this marked reduction in left ventricular mass, left ventricular pump function was well preserved during rest and exercise.