Combination of Pulmonary Embolism Rule-out Criteria and YEARS Algorithm in a European Cohort of Patients with Suspected Pulmonary Embolism.

BACKGROUND: Both the YEARS algorithm and the pulmonary embolism (PE) rule-out criteria (PERC) were created to exclude PE with limited diagnostic tests. A diagnostic strategy combining both scores might save additional computed tomography pulmonary angiography (CTPA) scans, but they have never been evaluated in conjunction.

AIM: The aim of this study was to determine the safety and efficiency of combining YEARS and PERC in a single diagnostic strategy for suspected PE.

METHODS: The PERC rule was assessed in 1,316 consecutive patients with suspected PE who were managed according to YEARS. We calculated the absolute difference (with 95% confidence interval [CI]) in failure rate and the number of 'saved' CTPAs for the scenario that PE would have been ruled out without CTPA in the absence of all PERC items.

RESULTS: Using the YEARS algorithm, PE was diagnosed in 189 patients (14%), 680 patients (52%) were managed without CTPA and the 3-month rate of venous thromboembolism in patients in whom PE was ruled out was 0.44% (95% CI: 0.19-1.0). Only 6 of 154 patients (3.9%; 95% CI: 1.4-8.2) with no YEARS items who were referred for CTPA would have been PERC negative, of whom none were diagnosed with PE at baseline or during follow-up (0%; 95% CI: 0-64). Applying PERC before YEARS in all patients would have led to a failure rate of 1.42% (95% CI: 0.87-2.3%), 0.98% (95% CI: 0.17-1.9) more than shown in patients managed by YEARS.

CONCLUSION: Combining YEARS with PERC would have yielded only a modest improvement of efficiency in patients without a YEARS item and an unacceptable failure rate in patients with ≥ 1 YEARS item.