Acute pulmonary embolism (PE) is a relatively common cardiovascular emergency. Clots originating in the leg veins may become detached and obstruct the lung vessels. This obstruction may lead to a rise of pressure in the pulmonary circulation and possibly to life-threatening heart failure.
PE is a difficult diagnosis that may be missed because of non-specific complaints. On the other hand, early diagnosis is fundamental since immediate treatment is highly effective. Depending on how critical the patient's condition is on admission, initial therapy is primarily aimed either at life-saving restoration of blood flow through the occluded pulmonary arteries or at prevention of potentially deadly recurrences (new episodes) of PE.
The first edition of the ESC Clinical Practice Guidelines on PE was published in 2000. The 2008 update focuses on:
- currently available and validated methods of diagnosis
- prognostic evaluation (prediction of outcome and death risk)
- therapy of PE; and
- management in specific situations such as pregnancy
In contrast to previous guidelines, we decided to grade the body of evidence supporting both treatment and diagnosticprocedures, because the latter are of particular importance in the management of PE.
For diagnostic tests, the most robust data come from large-scale accuracy or outcome studies. Accuracy studies are designed to establish the value of a diagnostic test (sensitivity and specificity) by comparing test results to a so-called gold standard. Outcome studies evaluate patient outcomes when a given diagnostic test or strategy is used for clinical decision-making. Apart from individual diagnostic tests, the present guidelines review and propose specific diagnostic algorithms, that is combinations of tests which permit the confirmation or exclusion of PE in clinical practice using a step-by-step approach. A further section of the guidelines is devoted to prognostic assessment of PE by reviewing and grading the clinical, ultrasound and laboratory findings which allow us to estimate the death and complication risk during the early, in-hospital phase of the disease. This assessment and the classification of PE into high-risk, low-risk and intermediate-risk is particularly useful for guiding treatment strategies which are reviewed in the next section of the guideline.