Strategies in suspected venous thrombo-embolism in primary care

This thesis describes strategies for managing suspected venous thrombo-embolism (VTE) in a primary care setting. VTE, compromising deep vein thrombosis (DVT) and pulmonary embolism (PE) is a relatively common condition with an annual incidence of around 2-3 cases per 1000 persons. Most patients with signs and symptoms suggestive for acute VTE are first presented in primary care. In that domain, the primary care physician has to decide if additional testing is needed to confirm or refute a diagnosis. As signs and symptoms of acute VTE can be relatively mild, it is an easy diagnosis to miss. Consequently, the PCP is frequently confronted with a difficult dilemma in these patients: refer all patients would imply not missing a case but also would yield a very low proportion of actually confirmed cases (only around 10%); yet not referring a patients always poses a certain risk of missing acute – and possibly fatal – VTE. This thesis predominantly focuses on tools available to PCPs to help them with this difficult dilemma. In summary, these tools encompass a combination of clinical characteristics (summarized in a clinical decision rule) and D-dimer testing (degradation products of fibrin). In this thesis, it is concluded that in patients with a low risk of having acute VTE (as based on a low score on a clinical decision rule), a negative D-dimer test can safely exclude both DVT and PE. Moreover, such an approach is also feasible and safe if performed by PCPs in primary care. For PCPs the use of a point-of-care D-dimer test is also a safe and convenient approach. These tests provide results within 10 minutes, thereby enabling a safe exclusion of acute VTE during the consultation of the patient.