Practice Change: An age adjusted d-dimer cut off for PE evaluation is a safe and effective way to evaluate patients over 50 years old for PEs. I think we should talk to the lab about changing how we report our negative results and start using this ASAP.
Background: The rule: AGE x 10 = D-dimer Cut Off was derived and validated from 4 prospectively gathered data sets in 5182 patients published in BMJ 2010.
This is the external validation study of this rule.
Age-Adjusted D-Dimer Cutoff Levels to Rule Out Pulmonary Embolism: The ADJUST-PE Study
Design/Background: Prospective Multicenter Validation study from 19 centers in Europe to evaluate the previously derived Age Adjusted PE rule.
Population: Consecutive Emergency Department patients with concern for PE
Intervention: For patients with clinically suspected PE, initially evaluated as low risk with Geneva or Wells Score and followed with a ddimer +/- CTPA.
Cut off for d-dimer was AGE x 10 for patients over the age of 50.
Patients between 500 and age cut off did NOT get a CT scan and were followed up for outcome at 3 months.
Primary Outcome: Were there any failures in the patients between 500 and the age adjusted cut off at 3 month FU?
Secondary Outcomes: How many patients did not require CT?
Results: 3346 patients included in the study Of those, 817 were low risk and had a d-dimer <500 331 were low risk and had a d-dimer between 500 and their age adjusted cut off. These patients did NOT get a CT.
- One patient in this group had a non-fatal PE in the next 3 months. (0.3%)
|% pts ruled out with d-dimer||>500 cut off||Age Adjusted Cut off|
Patients >75 yo
Conclusions: This prospective validation study demonstrates age adjusted d-dimer to be a safe and effective way to rule out patients at low risk for PE. If I can safely rule these folks out without the added time of a CT scan and the added risk of contrast, it seems like a win for everyone.