[Diagnosis and therapy of pulmonary embolism]

Abstract

Management of venous thromboembolism has long been characterized by a high degree of complexity and a disappointing lack of both efficacy and efficiency. The non-specific clinical signs of acute pulmonary embolism (PE) and the limitations of earlier imaging procedures such as the lung scan and pulmonary angiography led to the development of numerous sophisticated, multi-step diagnostic algorithms which, however, have proved extremely difficult to implement in clinical practice. As a result, the diagnosis of potentially life-threatening PE was frequently missed in many patients who subsequently died of the disease without receiving appropriate treatment, while other patients unnecessarily underwent a battery of invasive, time consuming procedures due to a vague, poorly documented clinical suspicion. Recently, the development of structured models for assessment of clinical pre-test probability, the widespread use of D-dimer testing in the outpatient setting, and particularly the technical advances of multidetector-row CT scan, had an enormous impact on our strategy for approaching patients with suspected PE. Contemporary diagnostic algorithms based on the above modalities are not only efficient and reliable but also simple and practicable. Furthermore, the importance of right ventricular (RV) dysfunction, even in the absence of overt hemodynamic instability, was recognized, and a number of studies demonstrated the value of echocardiography and laboratory biomarkers for risk stratification of PE. At present, low molecular weight heparins are increasingly becoming established as the treatment of choice for hemodynamically stable patients without RV dysfunction (non-massive PE), while consensus exists that patients with massive PE and cardiogenic shock necessitate emergency removal of pulmonary thrombus using thrombolytic agents, surgical embolectomy, or catheter-based thrombus aspiration. On the other hand, the treatment of stable patients with RV dysfunction (submassive PE) remains the subject of debate, and a large randomized trial is urgently needed to address the possible clinical benefits of thrombolysis in this setting.