External validation of the YEARS diagnostic algorithm for suspected pulmonary embolism

J Thromb Haemost. 2020 Dec;18(12):3289-3295. doi: 10.1111/jth.15083. Epub 2020 Oct 23.

Abstract

Background: Validated diagnostic algorithms are used to manage patients with suspected pulmonary embolism (PE). The recently published YEARS study proposed a simplified diagnostic strategy to reduce the use of computed tomography pulmonary angiography.

Objectives: To externally validate this strategy in an independent cohort.

Methods: We analyzed data from three previous prospective cohort studies of outpatients with suspected PE. We retrospectively applied the YEARS algorithm. The three YEARS clinical criteria are: clinical signs of deep vein thrombosis, hemoptysis, and PE as the most likely diagnosis. If zero YEARS criteria are met, a D-dimer < 1000 ng/mL will rule out PE. If ≥1 YEARS criteria are met, a D-dimer < 500 ng/mL will rule out PE.

Results: Of the 3314 patients, 731 (22.1%) had PE. Applying the YEARS diagnostic algorithm, 1423 (42.9%) patients could have had PE ruled out without imaging. Of these patients, 17 (1.2%; 95% confidence interval 0.8-1.9) were diagnosed with PE at initial testing. All 17 had no YEARS item and a D-dimer < 1000 ng/mL. All 17 had a D-dimer level above their age-adjusted cutoff. Among the 272 patients with no YEARS criteria and a D-dimer < 1000 ng/mL but above their age-adjusted D-dimer cutoff, PE was diagnosed in 6.3% (17/272; 95% confidence interval 3.9-9.8).

Conclusion: We provide external validation of the YEARS diagnostic algorithm in an independent cohort. The rule appears to safely exclude PE. However, caution is required in patients with no YEARS item and a D-dimer < 1000 ng/mL but above their age-adjusted D-dimer cutoff.

Keywords: D-dimer; computed tomography; diagnosis; pulmonary embolism; venous thromboembolism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • Fibrin Fibrinogen Degradation Products*
  • Humans
  • Prospective Studies
  • Pulmonary Embolism* / diagnostic imaging
  • Retrospective Studies

Substances

  • Fibrin Fibrinogen Degradation Products