Effect of quinapril initiated during progressive remodeling in asymptomatic patients with healed myocardial infarction

Approximately 20% of patients with healed myocardial infarction develop asymptomatic progressive left ventricular (LV) dilation and remodeling and are at increased risk for progression to symptomatic congestive heart failure and premature death. It was the goal of this study to test whether quinapril may interrupt this process and to analyze potential mechanisms. Of 138 patients with an average infarct age of 56 months, 25 had asymptomatic progressive LV dilation and were randomized in a prospective, double-blind study to placebo or quinapril. At baseline (mean ± SEM) ejection fraction was reduced (35 ± 3% and 39 ± 3%) and end-diastolic volume (gated single-photon emission computed tomography) increased (104 ± 9 and 117 ± 12 ml/m2) with placebo (n = 13) and quinapril (n = 12), respectively. Progressive dilation continued in patients taking placebo (6 months: 9.4 ± 5.2 ml/m2, 12 months 24.6 ± 5.4 ml/m2; change from baseline: p <0.05 vs baseline; p <0.05 vs 6 months), but not with quinapril (6 months: −0.9 ± 4.0 ml/m2; 12 months: 4.1 ± 5.2 ml/m2 [p <0.05] vs placebo). Wedge pressure during bicycle exercise was similar at baseline, but at 12 months tended to be lower with quinapril (17 ± 1 mm Hg) than with placebo (24 ± 4 mm Hg, p = 0.1673). Thus, quinapril prevented further progression of asymptomatic LV dilation and remodeling after remote myocardial infarction, possibly due to attenuation of an exercise-induced increase in LV filling pressure.