Heparin-Associated Thrombocytopenia: A Comparison of Three Heparin Preparations

Abstract

We performed a prospective, double-blind study of the incidence of thrombocytopenia in 149 patients randomly assigned to treatment with one of three heparin preparations—from bovine lung, from intestinal-mucosa A, or from intestinal-mucosa O. Thrombocytopenia developed in 21 patients (platelets, 9 per liter): 13 of the 50 receiving bovine lung heparin, four of 45 receiving intestinal-mucosa-A heparin, and four of 54 receiving intestinal-musoca-O heparin (P<0.005). There was a significantly increased incidence of thrombocytopenia in the bovine-lung group (P<0.002); estimated incidence rates after nine days of treatment were 24 per cent in this group and 7 per cent in the combined intestinal-mucosa A and O groups. Thrombocytopenia appeared in the bovine-lung group on Days 3 to 16, in the intestinal-mucosa-A group on Days 4 to 12, and in the intestinal-mucosa-0 group on Days 3 to 7; it disappeared in all groups three to eight days after discontinuation of heparin. A total of 121 patients were subsequently given warfarin for four to six months, and thrombocytopenia was not observed. (N Engl J Med. 1980; 303:902–7.)