Background: Nitrates are often administrated with a variety of other pharmacologic agents in the management of chronic heart failure (CHF). However, limited information is available concerning the long-term effects in patients with evidence of left ventricular (LV) dysfunction after acute myocardial infarction (AMI) already treated with standard heart failure therapy.
Methods: In a randomized, double-blind, placebo-controlled trial, we evaluated the effects of a 60 mg dose of isosorbide-5-mononitrate (IS-5-MN) given daily for 11 months to 47 patients with clinical or echocardiographic evidence of left ventricular dysfunction after acute myocardial infarction. Forty-five patients received a placebo.
Results: Invasive hemodynamic measurements did not show any difference between the treatment regimens. Overall changes in echocardiographic measurements were not significantly different between IS-5-MN therapy and the placebo groups. However, in a prespecified subgroup with left ventricular ejection fraction < or =40% at baseline, IS-5-MN therapy resulted in a lesser increase of end-diastolic volume index than the placebo (P =.047). IS-5-MN significantly reduced the serum concentration of atrial natriuretic peptide (mean 20.0 pmol/L, 95% CI 7.7-32.3, P =.002), whereas the placebo did not (P =.041 for the difference between the groups). The proportion of patients taking diuretics was significantly reduced in the IS-5-MN group, from 30 of 44 to 20 of 44 (P =.02), but not with placebo, which remained at 27 of 43 (P = 1.0, with P =.048 for the difference between the regimens).
Conclusions: Oral, long-term IS-5-MN therapy resulted in lower atrial natriuretic peptide levels and reduced the need for additional diuretics. Less LV dilatation was observed in patients with more severe LV dysfunction at baseline.