Effect of antilipolytic therapy on ST segment elevation during myocardial ischaemia in man.

Abstract

Abnormally high circulating free fatty acid (FFA) levels occur in the early hours of acute myocardial infarction in man. Experimentally, reduction of plasma FFA was shown to reduce myocardial ischemic injury. The effect of lowering plasma FFA by antilipolytic therapy using a nicotinic acid analogue (NAA) was studied in man within 6 h of onset of symptoms of acute myocardial infarction. Myocardial ischemic injury was assessed by continuous recording and computer analysis of ST segment elevation in 15 treated and 15 untreated patients. High dose NAA treatment in 9 patients achieved sustained reduction in FFA over 24 h and a significant fall in ST segment elevation by 1 1/2 h. Of the 9 patients, 7 developed undesirable side effects of flushing, nausea or vomiting. Six patients treated with a low dose NAA regimen achieved smaller reductions in FFA with early FFA escape and a transient reduction of ST segment elevation after 3/4 of an hour but without side-effects. These findings of improved viability of the ischemic myocardium may be explained on the basis of a change in the proportions of lipid and carbohydrate available for oxidation by the ischemic myocardium after reduction of revised serum FFA. Further development of antilipolytic agents for this purpose is indicated.