Angiotensin-converting enzyme inhibitor therapy affects left ventricular mass in patients with ejection fraction >40% after acute myocardial infarction

Objectives. We tested the hypothesis that angiotensin-converting enzyme (ACE) inhibitor therapy decreases left ventricular (LV) mass in patients with a left ventricular ejection fraction (LVEF) >40% and no evidence of heart failure after their first acute Q wave myocardial infarction (MI). Background. Recently, ACE inhibitor therapy has been shown to have an early mortality benefit in unselected patients with acute MI, including patients without heart failure and a LVEF >35%. However, the effects on LV mass and volume in this patient population have not been studied. Methods. Thirty five patients with a LVEF >40% after their first acute Q wave MI were randomized to titrated oral ramipril (n = 20) or conventional therapy (control, n = 15). Magnetic resonance imaging (MRI) performed an average of 7 days and 3 months after MI provided LV volumes and mass from summated serial short-axis slices. Results. Left ventricular end diastolic volume index did not change in ramipril-treated patients (62 +/- 16 [SD] to 66 +/- 17 ml/m(2)) or in control patients (62 +/- 16 to 68 +/- 17 ml/m(2)), and stroke volume index increased significantly in both groups. Pow ever, LV mass index decreased in ramipril-treated patients (82 +/- 18 to 73 +/- 19 g/m(2), p = 0.0002) but not in the control patients (77 +/- 15 to 79 +/- 23 g/m(2)). Systolic arterial pressure did not change in either group at 3-month follow-up. Conclusions. In patients with a LVEF >40% after acute MI, ramipril decreased LV mass, and blood pressure and LV function were unchanged after 3 months of therapy. Whether the decrease in mass represents a sustained effect that is associated with a decrease in morbid events requires further investigation.