Is the incidence of deep vein thrombosis following myocardial infarction decreasing?

A trial was undertaken to compare the effectiveness of the antiplatelet drug, flurbiprofen, and subcutaneous heparin in the prevention of deep vein thrombosis following acute myocardial infarction. The original aim of the study could not be fulfilled as the incidence of isotopically-determined venous thrombosis in the group of control patients was only 9.5%. The incidence in all three groups was too low to assess the effectiveness of flurbiprofen prophylaxis. It is suggested that the low incidence may be related to the recent practice of early physiotherapy and ambulation in coronary care units. The patients who developed venous thrombosis were, on average, a little older than those who did not. No differences were observed in blood viscosity, plasma antithrombin III concentration or mean coronary prognostic index. The low incidence of venous thrombosis following acute myocardial infarction suggests a need to reassess the practice of prophylactic anticoagulant therapy in this condition.