Abstract
Thrombolytic therapy accelerates the dissolution of acute pulmonary embolism and is
potentially lifesaving. The goal of this article is to offer a critical analysis of
the use of thrombolytic therapy in this setting. Guidelines have been written and
modified and new ones have been published over the past several years. Although an
evidence base exists, unanswered questions remain. Despite the potential benefit of
rapid clot lysis, nonpathologic thrombi are also lysed, so that thrombolytic therapy
can cause significant bleeding complications. Massive acute pulmonary embolism is
the clearest indication for these drugs, and although thrombolysis has been studied
in submassive pulmonary embolism, this scenario remains more controversial. Traditionally,
thrombolytic agents have been delivered intravenously, but intraembolic therapy via
a pulmonary artery catheter has gained momentum. Few randomized trials have been conducted,
however. Only three agents have been approved for use in the United States: streptokinase,
urokinase, and tissue-type plasminogen activator. Urokinase is not currently available
for use in the United States. The latter agent has been most widely used on the basis
of proven benefit with a relatively short (2-hour) infusion. Newer, unapproved agents
include tenecteplase and reteplase. Risk stratification in acute pulmonary embolism
is important in determining which patients are the most appropriate candidates for
thrombolysis, with careful consideration of contraindications.
Keywords
pulmonary embolism - deep venous thrombosis - thrombolytic therapy - right ventricular
function - catheter-based embolectomy
