HEPARIN INDUCED PLATELET-AGGREGATION - INVITRO CONFIRMATION OF THROMBOTIC COMPLICATIONS - ASSOCIATED WITH HEPARIN-THERAPY

Abstract

Eleven patients who developed thromboembolic complications while receiving heparin were studied for a possible adverse reaction to heparin as the cause of their progressive thrombosis. Fifteen additional patients who were receiving heparin for recurrent thromboembolism, but who did not develop signs of thrombotic complications, were studied as patient controls. The most significant finding was an abnormal in vitro [platelet] aggregation response to heparin alone in all patients who developed complications who were tested for it (64%). None of the patient controls demonstrated this abnormality. Thrombocytopenia was noted in all of the former but in only 1 of the latter. Results of prothrombin times, fibrinogen and fibrin split products eliminated disseminated intravascular coagulation as the cause of the thrombocytopenia in most cases. An approach to the early detection of the abnormal heparin response is presented and guidelines for its therapeutic management are recommended.