In low-risk patients with suspected PE, PERC was not inferior to a conventional strategy. The PERC group underwent 10% fewer CTPA studies, had a decreased ED length of stay of 36 minutes, and a decrease in hospital admission of 3.3%.

This large, retrospective study found the prevalence of PE in hospitalized patients discharged with a diagnosis of syncope was 0.15% to 2.1%; 0.35% to 2.63% at 90-day follow up.  This was much lower than the PESIT trial, at 17.3%.

Treatment with lytics for acute PE (mostly massive or with arrest) in pregnancy out to 6 weeks postpartum was associated with 94% overall maternal survival and 88% fetal survival.  Major bleeding occurred in 17% of pregnant women and 58% of those in the postpartum period.

In this systematic review, the D-Dimer was 100% sensitive in low risk Geneva (0-3), intermediate-risk Geneva (4-10), and Wells non-high risk (≤4) for detecting PE. Specificity dropped (more false-positives) as age increased in the Wells non-high risk patients.

There was a low yield (1.6%) for PE testing among those who were Pulmonary Embolism Rule-out Criteria (PERC) negative.

Patients in an ED setting with a low pretest probability based on the Wells score, and a negative D-dimer were safely ruled out for pulmonary embolism without further diagnostic imaging.

Low dose perfusion-only (LDQ) nuclear scan (the "Q" of the V/Q scan) or CTPA are the imaging studies of choice to diagnose PE in pregnant women.  LDQ (using one-third the normal technetium) had high accuracy and lower radiation dose and may be preferred over CTPA, assuming the CXR is normal.

The prevalence of PE in patients with syncope may be far less that the PESIT trial indicated: 1.4% vs. 17%.

If clinical gestalt for PE is low, use PERC to rule out PE.  If not ruled out, use a validated tool to determine pretest probability of PE: Wells, Revised Geneva, or simplified versions of either score.  If non-high or "unlikely" pretest probability, order D-dimer, adjusting for age (<500 or <age x 10).  If D-dimer is negative, PE is ruled out.  If positive, order CT pulmonary angiogram.

A simplified Geneva Score is safe to use in place of the Geneva score and is straightforward, with each criterion being worth one point.  Low to Intermediate pretest probability plus negative D-dimer with the simplified Geneva ruled out PE as well as the regular Geneva score.