EFFECTS OF THE ANGIOTENSIN-CONVERTING ENZYME-INHIBITOR ENALAPRIL ON THE LONG-TERM PROGRESSION OF LEFT-VENTRICULAR DILATATION IN PATIENTS WITH ASYMPTOMATIC SYSTOLIC DYSFUNCTION

Background. Patients with heart failure and reduced left ventricular (LV) ejection fraction (EF) manifest progressive LV dilatation, which is prevented by angiotensin converting enzyme (ACE) inhibitors. In patients with asymptomatic LV systolic dysfunction, in whom there is less activation of the renin-angiotensin system, ventricular remodeling might be less rapid and the benefit of ACE inhibitors less discernible. Methods and Results. One hundred eight patients enrolled in the Studies of Left Ventricular Dysfunction (SOLVD) Prevention Trial, with left ventricular ejection fraction less-than-or-equal-to 0.35 but without clinical heart failure, underwent radionuclide ventriculograms, and 49 underwent left heart catheterizations. Measurements were made before and after double-blinded randomization to enalapril (2.5 to 20 mg/d) or placebo. Repeated-measures analysis of all time points showed significant differences for change in end-diastolic volume (EDV) between enalapril and placebo groups. Significant difference between the enalapril and placebo groups (P<.05) was present for change in EDV at 1 year within the catheterization study and at a mean of 25 months within the radionuclide study. Radionuclide EDV increased in placebo patients (119+/-28 to 124+/-33 mL/m2, mean+/-SD) and decreased in enalapril patients (120+/-25 to 113+/-25 mL/m2). Differences between the two groups were significantly less than previously described in patients with symptomatic heart failure (P<.02), with less increase in LV volumes in the placebo group and less decrease in volumes in the enalapril group. Conclusions. Chronic ACE inhibitor treatment slows or reverses LV dilatation in patients with asymptomatic LV systolic dysfunction. Compared with symptomatic patients, asymptomatic patients manifest a slower rate of spontaneous LV dilatation and less reduction in LV volumes by enalapril.