Left ventricular remodelling in post-myocardial infarction patients with left ventricular ejection fraction 40-50% vs 25-39%. Influence of nisoldipine treatment?

Abstract

Objective: Left ventricular (LV) remodelling following acute myocardial infarction has generally been studied in patients with LV ejection fraction (EF) < 40%, and it has been shown that this process can be attenuated by ACE inhibitors. Little is known regarding LV remodelling in patients with LVEF ≥ 40% or the effects of treatment in this patient cohort. The DEFIANT II study (Doppler Flow and Echocardiography in Functional cardiac insufficiency) included 542 post-infarction patients with LVEF 25-50% without overt heart failure within 13 days following acute myocardial infarction (AMI). They were then randomized to nisoldipine coat-core (CC) or placebo and followed up for 6 months. Design: Two-dimensional echoes were obtained after 8 (5-13) days and 6 months following AMI. Setting: LV end diastolic (ED) and end systolic (ES) volumes (V) were calculated in 503 patients with technically satisfactory paired echoes using the biplabe method of discs in a core laboratory. Subjects: Group A. 217 patients with baseline EF 40-50%, of whom 112 were randomized to nisoldipine and 104 to placebo (one patient was taken off study medication). Group B. 286 patients with EF 25-39%, of whom 145 were randomized to nisoldipine and 141 to placebo. Results: LVEDV was 175 (± 45) ml in Group A vs 203 (± 49) ml in Group B (p = 0.001) at baseline and 184 (± 48) ml vs 213 (± 56) ml (p = 0.001), respectively, at 6 months. LVESV at baseline was 97 (± 42) ml in Group A vs 133 (± 37) ml in Group B (p = 0.001), and 106 (± 34) ml vs 134 (± 45) ml (p = 0.001) at 6 months, respectively. The increase of LVESV was 9 (± 29) ml in Group A vs 2 (± 35) ml in Group B (p = 0.007). LVEF decreased by 2 (± 6)% in Group A vs an increase of 3 (± 6)% in Group B (p = 0.001). Treatment with nisoldipine had no influence on LV volumes in either of the two groups or in the total study group. Conclusion: LV dilatation 6 months following AMI in patients with EF 40-50% was similar in end diastole, but more pronouneced in end systole vs patients with EF 25-39%. LV remodelling did not change significantly after nisoldipine treatment.