Prometheus-Study: Diagnostics.

The object of this study is to evaluate four clinical decision rules in the exclusion of pulmonary embolism (Wells rule, revised Geneva score, simplified Wells rule and simplified revised Geneva score). They will be evaluated for safety and clinical utility, both alone and in combination with a D-dimer test. Also, the clinical decision rule according to Wells is evaluated in patients with a suspected recurrent pulmonary embolism: whether it is safe to withhold anticoagulant treatment in patients in whom suspected recurrent pulmonary embolism is excluded based on an unlikely Wells score combined with a normal D-dimer test.

1. To assess four different clinical decision rules (Wells rule, revised Geneva decision rule, simplified Wells rule and simplified revised Geneva decision rule) in the exclusion of pulmonary embolism;

2. To evaluate the safety of withholding anticoagulant treatment in patients in whom recurrent PE is excluded on the basis of a pre-specified algorithm (using the Wells rule).

Moment of diagnostic workup for PE and 3 month follow up (one telephone call).

In case of a first PE, a CT scan is performed in the following combination of tests:

1. Decision rules disagree with each other (one (or more) indicating ‘unlikely’ probability, other(s) indicating a ‘likely’ probability);

2. All four decision rules indicate a ‘likely' probability for PE;

3. All four decision rules indicate an ‘unlikely’ probability for PE but D-dimer is abnormal.


In case of a recurrent pulmonary embolism, the Wells rule will prefer, a CT is performed in case of (figure 1b):

1. A high probability of the Wells score;

2. A combination of a low probability of the Wells score and an abnormal D-dimer.