Pulmonary embolism

Pulmonary Embolism Rule-Out Criteria Is Safe for Low-Risk Patients

The use of pulmonary embolism rule-out criteria (PERC) for the ruling out of subsequent thromboembolic events is safe for very low-risk patients presenting to the emergency department (ED), a new study showed.

In the PROPER trial, the researchers assessed 1916 patients (mean age 44 years) with a low gestalt clinical probability of PE across 14 EDs in France. Each patient was randomly assigned to either the PERC group (n = 962) or the control group (n = 954).

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Ultimately, 1749 patients completed the trial. PE was diagnosed in 14 PERC patients (1.5%) vs 26 control patients (2.7%) at initial presentation, and in 1 PERC patient (0.1%) vs 0 control patients during follow-up. Approximately 13% of PERC patients underwent CTPA compared with 23% of control patients.

The researchers noted that the PERC group had significantly a lower median length of emergency department stay (mean reduction 36 minutes) and hospital admission (difference of 3.3%) vs controls.

“Among very low-risk patients with suspected PE, randomization to a PERC strategy vs conventional strategy did not result in an inferior rate of thromboembolic events over 3 months,” the researchers concluded. “These findings support the safety of PERC for very low-risk patients presenting to the emergency department.”

—Christina Vogt


Freund Y, Cachanado M, Aubry A, et al. Effect of the pulmonary embolism rule-out criteria on subsequent thromboembolic events among low-risk emergency department patients: the PROPER randomized clinical trial. JAMA. 2018;319(6):559-566. doi:10.1001/jama.2017.21904.