Fibrinolytic (thrombolytic) therapy in pulmonary embolism and deep vein thrombosis

INTRODUCTION

Thrombolytic agents activate plasminogen to form plasmin, resulting in the accelerated lysis of thrombi. As a result, thrombolytic agents have been used in a variety of thrombotic disorders including acute myocardial infarction, pulmonary embolism (PE), and deep vein thrombosis (DVT).

The efficacy, indications, contraindications, and adverse effects of thrombolytic therapy in PE and DVT are discussed here. In addition, the types of thrombolytic agents and regimens are reviewed. Alternative treatment modalities and anticoagulation for PE and DVT are discussed elsewhere. (See "Treatment of acute pulmonary embolism" and "Treatment of deep vein thrombosis" and "Anticoagulation in acute pulmonary embolism" and "Inferior vena cava filters".)

PULMONARY EMBOLISM

Typically, only patients in whom the diagnosis of pulmonary embolism (PE) has been confirmed should be considered for thrombolytic therapy because the adverse effects of thrombolytic therapy can be devastating. The indications and potential benefits must be carefully weighed against the risk of adverse effects for each patient. In addition, the patient's values and preferences should be considered. As an example, is the patient willing to risk intracranial hemorrhage to try a therapy that may only accelerate physiologic improvement?

Efficacy — The impact of thrombolytic therapy compared to anticoagulation alone has been well studied. The evidence suggests that thrombolytic therapy accelerates clot lysis and is associated with short-term physiologic benefits, but has not been shown to improve mortality (figure 1) .

Mortality — No clinical trial or meta-analysis has been large enough to conclusively demonstrate that thrombolytic therapy followed by anticoagulation confers a greater mortality benefit than anticoagulation alone. This is illustrated by three studies, which evaluated different populations: