SpainSUMMARY Serum malondialdehyde-like material (MDA-LM), as an index of lipid peroxidation, and the serum enzymes CK, CK-MB, LDH, LDH1 and, a-HBDH were evaluated in a group of 26 patients with acute myocardial infarction (AMI), seven with angina pectoris (AP), and in a normal control group of 94 subjects. MDA-LM values were within the normal range in AP patients, while in AMI patients a significant increase in serum MDA-LM was observed in the days following the acute event, reaching a maximum 6-8 days later, when 90% of the patients had values higher than the upper normal limit (mean + 2SD) of the control group.A significant correlation was found between the integrated concentration-time MDA-LM curve and the integrated serum enzymes activity curves reached during the nine days after the acute event.The "in vivo" relevance of the increased serum MDA-LM in the post-infarct period is unknown at the present, but as lipid peroxides are known to harm cellular structures and to inhibit prostacyclin synthesis, it may be of interest with regard to the long term secondary effects in AMI patients.Malondialdehyde is a known stable product of lipid peroxidation.' 2 Therefore, the evaluation of the malondialdehyde-like material (MDA-LM) by the thiobarbituric acid reaction may be used to decide whether a process of lipid peroxidation has taken place.Lipid peroxidation is thought to be involved in various pathological conditions, among others, platelet activation,3 tissue destruction4 and various inflammatory processes.5Since acute myocardial infarction (AMI) may be related to a thromboembolic process,6 to tissular destruction, and to a secondary inflammatory process, it seemed reasonable to expect a raised MDA-LM concentration in the serum of the patients. In order to evaluate this possibility, serum MDA-LM was quantified in a group of AMI patients.
Material and methodsMDA-LM values were studied in a population of 94 normal fasting subjects between the ages of 23 and 70 (40 men, mean = 45 yr, and 54 women, mean = Accepted for publication 17 January 1983 42 yr), from the Preventive Medicine Clinic in our Hospital, all without cardiovascular or haematological complications and without diabetes, dislipaemias or other metabolic disorders. All control subjects studied denied having received any medication known to modify platelet function in the 15 days prior to sampling.
PATIENTSThirty-three patients were studied, They were classified into two groups: 26 patients with AMI (17 men, mean = 55 yr; 9 women, mean = 60 yr), and seven patients with angina pectoris (AP) (4 men, mean = 49 yr; 3 women, mean = 65 yr), diagnosed according to usual electrocardiographic, enzymatic and clinical criteria.7 The only criterion for admission of the patients into the study was the diagnosis of AMI or AP during the time the project was being carried out.Samples were taken from the cubital vein of each patient on various days from the time of their admission up to nine days afterwards in the case of AMI patients, and up to four days after admission ...