YEARS Algorithm for Pulmonary Embolism (PE)

Why Use

Reduces use of CTPA by 14% compared with the current standard algorithm (absolute reduction) and by 8.7% compared with the age-adjusted D-dimer threshold, such that patients younger than 50 years also benefit from the YEARS algorithm. Provides for simple and efficient diagnostic management of patients with suspected PE, and is more compatible with the demands of clinical practice. Reduces false positives, overdiagnosis, and overutilization of CTPA investigations in all age groups, in addition to reducing unnecessary exposure to ionizing radiation.

When to Use

Hemodynamically stable patients ≥18 years old with clinically suspected acute pulmonary embolism (PE). Note: this study included patients with suspected acute PE in both inpatient and outpatient settings. Note that the original study did not include patients who: Were treated with therapeutic doses of anticoagulants initiated 24 hours or more before eligibility assessment. Have a life expectancy less than 3 months or geographic inaccessibility precluding follow up. Have an allergy to intravenous contrast agent.

Formula

Pearls / Pitfalls

Consists of the three most predictive criteria of the Wells' Score for PE : clinical signs of deep vein thrombosis (DVT), hemoptysis, and whether PE is the most likely diagnosis. Also incorporates variable D-dimer thresholds, depending on the number of criteria fulfilled. In patients with no YEARS items and D-dimer <1,000 ng/mL fibrinogen equivalent units (FEU), or with one or more YEARS items and D-dimer <500 ng/mL FEU, PE was considered excluded. All other patients had CT pulmonary angiogram (CTPA). It's imperative to know if your institution reports D-dimer in FEU or D-dimer units (DDU). This tool displays cutoffs for D-dimer reported as FEU. An approximate conversion that is often referenced is FEU = DDU * 2.

Advice

It's imperative to know if your institution reports D-dimer in FEU or DDU. This tool displays cutoffs for D-dimer reported as FEU. An approximate conversion that is often referenced is FEU = DDU * 2. PE was excluded (and CTPA deemed unnecessary) in patients who who fell below the D-dimer thresholds set by the YEARS algorithm. 3-month incidence of venous thromboembolism (VTE) of patients who did not undergo CTPA was 0.43%. This is similar to the traditional two-tier Wells' Score (0.34%).