Stimulation of Endogenous Fibrinolysis
130 131Intravenous or intra-arterial thrombolytic therapy in acute myocardial infarction, venous thrombosis, or pulmonary embolism is a dramatic clinical intervention. However, it may cause adverse effects such as bleeding, its thrombolytic effect is unpredictable, and its long-term benefits are controversial. More importantly, its contribution in reducing thrombotic mortality in the population can only be limited, since the majority of patients with fatal coronary thrombosis 1 or fatal pulmonary embolism 2 die before they receive medical attention. In contrast, chronic stimulation of endogenous fibrinolysis appears a more realistic and feasible approach to thrombosis in the community, since it can be used preventively. Like the tortoise in Figure 1, such therapy is slow, steady and subtle; like the hare in Figure 1, thrombolytic therapy can make occasional impressive leaps, but can be unpredictable, sometimes dangerous, and may distract both our attention and our resources from the problem of prevention. In assessing comparative approaches in the race against untimely thrombosis, we should remember the fable of the tortoise and the hare: the slow approach may be better in the end (Figure 1). In addition, there is increasing evidence that stimulation of endogenous fibrinolysis may be beneficial in diseases where tissue fibrin is excessive, e.g., venous dermatitis, vasculitis, and the collagen disorders. Endogenous or exogenous fibrinolysis? The tortoise and the hare. (Reproduced by kind permission of Jean Macdonald).