Incidence Of Thrombocytopenia During Therapy With Bovine Lung And Porcine Gut Mucosal Heparin Preparations

Abstract

Thrombocytopenia complicating heparin therapy is always alarming since the bleeding risk is greatly increased. The observations of Bell et al (Ann Int Med. 85:155, 1976) of a 30% incidence of thrombocytopenia in patients receiving bovine lung heparin was not supported by later reports from Powers et al (JAMA 241:2396, 1979) of only 3.4%. However, the latter study involved the use of heparin prepared from porcine gut mucosal. A prospective randomized study of these two respective heparin preparations was carried out at the VA Lakeside Medical Center on 98 patients to whom heparin therapy was given for the treatment of various forms of thromboembolism. All received a heparin dose that prolonged the activated partial thromboplastin time to l1/2-21/2 times the control level for at least 5 days. 86 patients had heparin for 7 or more days. The observation of platelet counts was carried out for 7 days. 10 patients (10.2%) had a fall in their platelet counts to less than 150×l06/dl during therapy with one of the ten having a platelet count of 95×l06/dl on the 4th day of therapy. All but one of the thrombocytopenias were transient, lasting 1-6 days despite continuation of heparin therapy. Of 49 patients who received porcine heparin, 4 (8.2%) had thrombocytopenia while the incidence was 6 out of 49 (12.2%)in those who received bovine heparin. These results suggest that complications of severe thrombocytopenia are uncommon with heparin derived from both sources.

Heparin-induced Thrombocytopenia

“…Four prospective studies have compared the frequency of thrombocytopenia due to bovine heparin compared with heparin of porcine origin, and all have demonstrated either a significant or a non-significant trend towards increase frequency of thrombocyto penia associated with bovine heparin (table I) [27][28][29][30]. The two studies that did not demon strate a significant difference did not include large numbers of patients.…”

Heparin-induced thrombocytopenia.

“…Although previously controversial, 14 -17 ' 104 it now seems clear that the loss of platelets in HITP is due to platelet aggregation rather than to lysis. For example, after either the discontinuation of heparin 15 ' 16 or the addition of the heparin antagonist protamine, 18 the recovery of platelet count is extremely rapid-too rapid to be •References 6,31,33,35,37,40,41,43,44,46. fReferences 25, 28, 29, 31, 57, 60-65, 69, 72, 100, 103-111. due to the replacement of lysed platelets by bone marrow.…”

Heparin-Induced Thrombocytopenia

“…Four prospective randomized trials compared the frequency of thrombocytopenia in patients treated with either porcine or bovine heparin. [23][24][25][26] Two of the four demonstrated a significantly higher frequency 24 ' 26 and the other two found a trend in the group receiving the bovine heparin, 24 ' 26 but this did not achieve statistical significance. 25 ' 27 When the results of these studies are pooled, the calculated frequency of thrombocytopenia was 15.6% in patients receiving bovine heparin compared with 5.8% in the patients receiving porcine heparin.…”