Effects of Long-term Enalapril Therapy on Cardiac Structure and Function in Patients With Left Ventricular Dysfunction: Results of the SOLVD Echocardiography Substudy

Abstract

Background Studies of Left Ventricular Dysfunction (SOLVD) demonstrated that enalapril therapy significantly improved the clinical course of patients with left ventricular (LV) dysfunction. The goals of this substudy were to evaluate changes in LV structure and function in SOLVD patients and to test the hypothesis that enalapril inhibits remodeling in patients with LV dysfunction. Methods and Results Patients entering both the prevention and treatment arms of SOLVD from 5 of the 23 clinical centers were recruited for this substudy. The 301 patients who participated underwent Doppler-echocardiographic evaluation according to standard protocol before randomization to either enalapril or placebo and again after 4 and 12 months of therapy. Recorded data were analyzed in a blinded fashion at a central core laboratory. Analysis of baseline clinical characteristics showed that patients enrolled in the substudy were generally representative of the SOLVD population, although prevention arm patients were slightly overrepresented in the substudy group (69.8% compared with 61.9% of remaining SOLVD patients). The enalapril group demonstrated significant reductions in the mitral annular E-wave–to–A-wave velocity ratio (due predominantly to a reduction in E-wave velocity), and this response was different from that seen in the placebo group ( P =.030). Changes in the E-to-A ratio in the enalapril group correlated significantly with changes in plasma atrial natriuretic peptide ( r =.56; P ≤.01). LV end-diastolic and end-systolic volumes increased in placebo but not enalapril-treated patients, and the differences in response between the treatment groups were significant ( P =.025 and .019, respectively). LV mass tended to increase in placebo patients and to be reduced in enalapril-treated patients, and the difference in response between the groups was highly significant ( P ≤.001). Conclusions These data demonstrate that enalapril attenuates progressive increases in LV dilatation and hypertrophy in patients with LV dysfunction. The results support the possibility that the favorable effects of enalapril reported in the SOLVD trials were related to inhibition of LV remodeling.