EFFECTS OF EARLY ADMINISTRATION OF A HIGHLY PURIFIED HYALURONIDASE PREPARATION (GL ENZYME) ON MYOCARDIAL INFARCT SIZE

Abstract

79 patients with suspected myocardial infarction entered a randomised trial to establish the safety of early intravenous administration of a highly purified hyaluronidase preparation (GL enzyme) and to assess its effects on eventual infarct size as measured by electrocardiographic, enzymatic, and scintigraphic criteria. Of the 71 patients with infarction, 35 received GL enzyme and 36 placebo within 6 h of the onset of chest pain. GL enzyme injected into a peripheral vein produced no adverse changes in the clinical, haemodynamic, biochemical, or haematological variables studied. GL enzyme reduced precordial electrocardiographic indices of infarct size as reflected by a diminution (p<0·02) in the degree of both R wave loss and Q wave development. In addition, the number of leads developing pathological Q waves (NΔQ≥2), a sign of progression from ischaemia to necrosis, was reduced (p<0·05) after GL nzyme treatment. However, there were no significant differences in infarct size as measured by cumulative creatine kinase MB isoenzyme release or technietium-99m pyrophosphate scintigraphic infarct area, or in clinical outcome during the hospital stay. Interpretation of the enzymatic and scintigraphic data was complicated by chance bias in pre-treatment randomisation which resulted in more (p<0·05) patients with severe haemodynamic impairment (and hence probably larger infarct sizes) entering the GL enzyme group. Nonetheless, a favourable effect of GL enzyme on infarct size was demonstrated by precordial electrocardiographic QRS mapping, where each patient acts as his or her own control.