Impact of delay in clinical presentation on the diagnostic management and prognosis of patients with suspected pulmonary embolism

Background: The non-specific clinical presentation of pulmonary embolism (PE) frequently leads to delay in its diagnosis. Aims: To assess the impact of delay in presentation on the diagnostic management and clinical outcome of patients with suspected PE. Methods: For this post-hoc analysis, we used the combined data of two large multi-center, prospective studies that investigated the diagnostic management of patients with suspected PE. Patients presenting > 7 days from the onset of symptoms were contrasted to those presenting within 7 days as regards the safety of excluding PE on the basis of a clinical decision rule (CDR) combined with D-dimer testing. Patients were followed for 3 months to assess the rates of recurrent venous thromboembolism (VTE) and mortality. Results: Diagnostic delay (presentation > 7 days) was present in 754 (18.6%) of the total of 4044 patients. The failure rate of an unlikely clinical probability and normal D-dimer test was 0.5% (95% CI: 0.01- 2.7) for patients with and 0.5% (95% CI: 0.2-1.2) for those without diagnostic delay. D-dimer testing yielded a sensitivity of 99% (95%CI: 96-99%) and 98% (95%CI: 97-99%) in these groups respectively. PE patients with diagnostic delay more frequently had centrally located PE (41% vs. 26%, P > 0.001). The cumulative rates of recurrent VTE (4.6% vs. 2.7%, P = 0.14) and mortality (7.6% vs. 6.6%, P = 0.31) were not different for patients with and without diagnostic delay. Conclusions: PE can be safely excluded based on a CDR and D-dimer testing in patients with a delayed clinical presentation. Diagnostic delay for patients who survived acute PE was associated with a more central PE location although this did not affect the clinical outcome at 3 months.