Antithrombin III and Hypercoagulability in Smokers

Abstract

It is known that various coagulation tests such as the thromboplastin generation test (TGT), thrombin generation (TG), levels of factor VIII or antithrombin III have been found to be abnormal in individuals with intravascular coagulation or having an increased tendancy to thrombosis. The aim of this study was to evaluate the role of the TGT, TG, factor VIII and antithrombin III assays in the diagnosis of possible mild intravascular coagulation in patients undergoing cardiac catheterization who had a history of smoking. In addition to these four tests, a routine coagulogram was performed for a total of 13 tests. It appeared that smokers had more abnormal tests (7.3/patient) than the controls (3.3/patient). The greatest association was between TGT and TG (29.6%) and TG and AT-III (25.9%). If by definition, hypercoagulability is present where 3 or more of these 4 mentioned tests were abnormal, then five patients were found to be in this category; all, except one, formed clots. In the patients (50) with a history of smoking, a third were found to have the TGT and the TG abnormal; however, the most striking observation in this group was in the antithrombin III where it was noted to be low in forty-five percent of the patients compared to the controls (patients having catheterization and were non-smokers) whose antithrombin III was found to be decreased in only five percent of the individuals. It is concluded that determination of antithrombin III may be of more importance in assisting the detection of hypercoagulability, especially in the smoking population, than the TGT, TG, or factor VIII.