External validation of the YEARS diagnostic algorithm for suspected pulmonary embolism

Area of Science:

• Medical Diagnostics
• Cardiology
• Pulmonary Medicine

Background:

• Validated diagnostic algorithms are crucial for managing suspected pulmonary embolism (PE).
• The YEARS study introduced a simplified strategy to reduce computed tomography pulmonary angiography (CTPA) use.
• External validation of this strategy is essential.

Purpose of the Study:

• To externally validate the YEARS diagnostic algorithm in an independent patient cohort.
• To assess the safety and efficacy of the YEARS algorithm in ruling out PE.

Main Methods:

• Retrospective analysis of data from three prospective cohort studies of outpatients with suspected PE.
• Application of the YEARS algorithm, which includes clinical signs of deep vein thrombosis, hemoptysis, and PE as the most likely diagnosis.
• D-dimer testing thresholds adjusted based on YEARS criteria and age.

Main Results:

• The YEARS algorithm could have ruled out PE in 1423 (42.9%) of 3314 patients without imaging.
• Only 17 (1.2%) patients initially diagnosed with PE had no YEARS criteria and a D-dimer < 1000 ng/mL.
• A subgroup of 272 patients with no YEARS criteria and a D-dimer < 1000 ng/mL but above their age-adjusted cutoff had a 6.3% PE diagnosis rate.

Conclusions:

• The YEARS diagnostic algorithm demonstrates external validity and appears to safely exclude PE in an independent cohort.
• Caution is warranted for patients meeting specific criteria: no YEARS items and a D-dimer below 1000 ng/mL but above their age-adjusted cutoff.
• The findings support the YEARS algorithm's potential to reduce unnecessary imaging for PE diagnosis.