Evaluation of factors predisposing to arterial thrombosis in coronary artery disease.

Estimation of antithrombin III, alpha 2 macroglobulin and alpha 1 antitrypsin in patients with stable and unstable angina and acute myocardial infarction (15 cases each) were carried out. Twenty age, sex and weight matched healthy subjects were included as controls. Mean platelet factor 4(PF4) levels measured in 10 cases of each subgroup were significantly elevated in myocardial infarction (MI) (48.4 +/- 15.16 ng/ml) and III unstable angina patients (44.7 +/- 15.9 ng/ml) as compared to controls (25.42 +/- 12.47 ng/ml; P less than 0.01). Mean antithrombin III (AT III) levels were markedly reduced in all patients with MI (39.65 +/- 12.8% of normal pooled plasma) and unstable angina (37.9 +/- 16.6% of normal pooled plasma) and in 9 patients with stable angina. Alpha I antitrypsin and alpha 2 macroglobulin levels in these cases showed no significant difference compared to normals. Reduced AT III in coronary artery disease suggests a prethrombotic tendency in these patients. Raised PF4 levels in acute phase of the disease suggests heightened platelet activation.