An evaluation of 200 consecutive patients with spontaneous or recurrent thrombosis for primary hypercoagulable states

Two hundred consecutive patients who were referred for evaluation of spontaneous or recurrent thrombosis were investigated for possible hypercoagulable states to determine the relative frequencies of these conditions in the Australian population and to identify features that would indicate which patients should be investigated with the expensive battery of tests for hypercoagulable states. Thirty-two percent were found to have prolongation of the postvenous occlusion euglobulin clot lysis time (PVO-ELT), 32% were found to have elevated levels of plasminogen activator inhibitor-1 (PAI) and 66% were found to have reduced release of tissue plasminogen activator (tPA). Antiphospholipid antibodies were found in 12%. Hereditary antithrombin III deficiency was found in 2%. Hereditary deficiency of the naturally-occurring anti-coagulant factors protein C and protein S was found in 2%. Age, sex, site of thrombosis (venous or arterial), or presence of a family history was not helpful in predicting a group more likely to have abnormal investigation results. Reduced fibrinolytic activity and the presence of antiphospholipid antibodies are the most common findings in patients with thromboembolic disease. Further prospective studies are required to assess the natural history and appropriate management of patients with these abnormalities.