Thrombolysis for Acute Pulmonary Embolism

Physicians caring for patients with acute pulmonary embolism (PE) are often faced with the dilemma whether to «limit» therapy to heparin anticoagulation or administer thrombolytics. Assessment of right ventricular dysfunction may be useful in guiding therapeutic decisions in PE. Haemodynamically stable patients without echocardiographic (or CT) evidence of right ventricular (RV) dysfunction (non-massive PE) have an excellent in-hospital prognosis and should thus be treated with heparin alone, preferably with weight-adjusted low molecular weight heparin. At the other end of the spectrum, unstable patients in cardiogenic shock (massive PE) must receive immediate thrombolysis or, in the presence of absolute contraindications to thrombolytic agents, undergo interventional or surgical pulmonary artery recanalisation. Recently, evidence has accumulated that normotensive patients with RV dysfunction (submassive PE) may also have a high mortality and complication risk during the acute phase. To date, only one study has investigated the possible benefits of thrombolysis compared to heparin alone in this latter patient population. Although the study could show a significant difference in favor of thrombolysis wirth regard to the primary combined end point (mortality or need for escalation of treatment), it did not find a pure survival benefit for patients receiving thrombolytic treatment. The optimal treatment (thrombolysis vs heparin alone) of patients with submassive PE will now be addressed by a large multinational controlled trial which is about to begin very soon.