Adaptive D-dimer safely rules out embolism

Adaptive D-dimer thresholds had very low missed pulmonary embolism rates while reducing imaging.
*Systematic review/meta-analysis of prospective diagnostic studies; Level 1.

Citation

Graziani M, Akerboom B, Freund Y, et al. Chest. 2026. doi:10.1016/j.chest.2026.09.030.

Background

Standard pulmonary embolism evaluation uses clinical judgment plus a D-dimer cutoff, often 500 ng/mL, to decide who needs chest imaging. Higher adjusted cutoffs may reduce unnecessary scans, but safety concerns remain.

Patients

12,194 adults with suspected acute pulmonary embolism in 6 prospective studies. Studies only enrolling children or pregnant patients were excluded.

Intervention

Age-adjusted or clinical-probability-adjusted D-dimer thresholds used to rule out pulmonary embolism without imaging.

Control

Conventional fixed D-dimer cutoff of 500 ng/mL; not tested through direct randomization in most studies.

Outcome

Diagnostic failure: confirmed clot, pulmonary embolism-related death, or unexplained death after pulmonary embolism was ruled out.

Follow-up Period

3 months.

Results

Outcome Pooled result Patients/events
Overall diagnostic failure 0.12% (95% CI 0.06% to 0.26%) 7 events among 5,698 patients
Diagnostic failure in the adaptive window 0.50% (95% CI 0.20% to 1.11%) 7 events among 1,468 patients
Imaging avoided 60.8% (95% CI 49.2% to 71.2%) Across included studies

Adaptive window: D-dimer above 500 ng/mL but below the adjusted cutoff.

Results came from prospective management studies. Some analyses excluded patients lost to follow-up, protocol deviations, or anticoagulation started for other reasons.

Limitations

No definitive direct randomized comparison with the fixed 500 ng/mL cutoff. D-dimer tests and algorithms varied. Subgroup evidence was limited for cancer, very old age, and pregnancy. Unexplained deaths may overestimate missed pulmonary embolism.

Funding

No external funding; no conflicts declared.

Clinical Application

Use validated adaptive D-dimer algorithms in low-risk suspected pulmonary embolism to safely reduce unnecessary chest imaging.