PLASMA LEUKOCYTE ELASTASE CONCENTRATION IN ANGIOGRAPHICALLY DIAGNOSED CORONARY-ARTERY DISEASE

Objective: To evaluate the clinical usefulness of leukocyte elastase determination in the diagnosis of coronary artery disease (CAD). Background: Recent research has shown the important role of elastase, a proteolytic enzyme released by neutrophils, in the pathogenesis of CAD. Methods: 141 patients underwent coronary angiography during investigation of chest pain and/or heart valve disease. Ninety-six had coronary lesions and 45 non-stenotic coronaries. The patients were characterized as regards presence or absence of angina (stable or unstable), family history of CAD, smoking, diabetes mellitus, hypertension, leukocyte ,counts, and plasma lipid and elastase concentrations. Among CAD-group patients, those with simple atheromatous plaques were distinguished from those with complex plaques. Results: Elastase concentrations were greater in the CAD group than in the non-CAD group (49.7+/-2.8 mu g.l(-1); as against 29.5+/-2.2 mu g.l(-1); P<0.001), and greater among complex-plaque CAD patients than among simple-plaque CAD patients (65.2+/-5.3 mu g.l(-1) as against 38.6+/-1.9 mu g.l(-1), P<0.001). Logistic regression analysis showed ja) that the risk of CAD varied with elastase concentration, angina status, age and sex, increasing by 11% for every 1 mu g.l(-1) increase in elastase concentration; and (b) that among CAD patients the risk of complex plaques was greatest for those with unstable angina and high elastase concentration, increasing by 6% for every 1 mu g.l(-1) increase in elastase concentration. Conclusions: Peripheral blood leukocyte elastase concentration is a sensitive diagnostic marker of CAD. High values suggest the presence of complex atheromatous plaques.