Lit Matters 3: Combining PE Decision Rules is Safe

Pulmonary embolism workup is safer and leaner when pretest probability and D-dimer thresholds are matched correctly. In suspected PE, combining YEARS with age-adjusted D-dimer can reduce CTPA use without increasing missed venous thromboembolism in low- to moderate-risk emergency department patients.

Combining PE Decision Rules

• Low-risk YEARS pathway: Zero YEARS criteria supports a higher D-dimer threshold of 1000 ng/mL FEU in low-pretest-probability suspected PE, a practical way to avoid unnecessary chest imaging.
• Age-adjusted D-dimer use: For low- to moderate-risk patients, age-adjusted D-dimer remains the rule when one or more YEARS criteria are present, preserving sensitivity while limiting overtesting.
• Safety signal at follow-up: Three-month VTE after an initially negative workup was 0.15% with the combined strategy versus 0.80% in control, supporting non-inferior safety.
• Imaging reduction effect: CT imaging fell from 40% to 30.4% with the intervention strategy, a meaningful drop in radiation, contrast exposure, and downstream false positives.
• Why overdiagnosis matters: CTPA has driven a major rise in PE diagnoses, yet one study found a 26% false-positive rate, making diagnostic restraint a real patient-safety issue. We get into the practical implications in the episode.