Design of a randomized, placebo-controlled multicenter trial on the long-term effects of intermittent transdermal nitroglycerin on left ventricular remodeling after acute myocardial infarction
Nitrates are widely used in the treatment of patients with ischemic heart disease and in those with angina following acute myocardial infarction. Short-term studies indicate that the administration of nitrates may prevent left ventricular (LV) dilation and infarct expansion. Animal models suggest that prolonged nitroglycerin use after infarction may limit LV remodeling similar to that observed with angiotensin-converting enzyme inhibitors. However, to date there have been no trials evaluating the effects of nitrates on LV volumes in patients surviving acute myocardial infarction. We therefore performed a randomized double-blind, placebo-controlled trial designed to investigate the long-term (6 month) efficacy of intermittent transdermal nitroglycerin patches on LV remodeling in 291 survivors of acute myocardial infarction. Patients were randomized to receive either placebo or a nitroglycerin patch that delivered 0.4, 0.8, or 1.6 mg/hour. Gated radionuclide angiography was used to assess serial changes in LV ejection and cardiac volumes. The baseline characteristics of the study population were similar in all 4 treatment groups. The study protocol and the main design-related issues are described.