IS OXIDATIVE STRESS CAUSALLY LINKED TO UNSTABLE ANGINA-PECTORIS - A STUDY IN 100 CAD PATIENTS AND MATCHED CONTROLS

Objective: Unstable angina pectoris often leads to acute myocardial in farction. Since lipid peroxidation is thought to be causally related t o chronic and acute events in atherosclerosis and coronary artery dise ase, we measured lipid peroxidation products and vitamin E in 100 pati ents with coronary artery disease and compared them to a matched contr ol group. Methods: 50 consecutive patients with stable angina pectoris (SAP) and 50 consecutive patients with unstable angina pectoris (UAP) were studied and compared to 100 clinically healthy individuals. In a ddition to conventional lipid and lipoprotein analysis, malondialdehyd es were measured as thiobarbituric acid reactive substances (TEARS). L ipid hydroperoxides were assayed with the colorimetric methylene blue method. alpha-Tocopherol was quantitated by HPLC after extraction of s erum with hexane-ethanol. In the patient group conjugated dienes were also measured. Results: As expected, patients had significantly higher cholesterol, triglyceride LDL-C and Lp(a) values and lower HDL-C valu es than controls. When patients were divided into groups with SAP and UAP respectively, peroxides and TEARS were significantly higher in the latter group as compared to patients with SAP and to controls. Conjug ated dienes were also significantly higher in patients with UAP as com pared to patients with SAP. Total plasma alpha-tocopherol was comparab le in all three groups, whereas the alpha-tocopherol content per LDL p article was lowest in patients with UAP, followed by patients with SAP and then controls. Conclusion: It is concluded that lipid peroxidatio n parameters are increased in patients with UAP and discriminate SAP f rom UAP patients. (C) 1997 Elsevier Science B.V.