Abstract 3186

Background

Several clinical decision rules (CDRs) are available for the exclusion of acute pulmonary embolism (PE). This prospective multi-center study compared the safety and clinical utility of four CDRs (Wells rule, revised Geneva score, simplified Wells rule and simplified revised Geneva score) in excluding PE in combination with D-dimer testing.

Methods

Clinical probability of patients with suspected acute PE was assessed using a computerized based “black box”, which calculated all CDRs and indicated the next diagnostic step. A “PE unlikely” result according to all CDRs in combination with a normal D-dimer result excluded PE, while patients with “PE likely” according to at least one of the CDRs or an abnormal D-dimer result underwent CT-scanning. Patients in whom PE was excluded were followed for three months.

Results

807 consecutive patients were included and PE prevalence was 23%. The number of patients categorized as “PE unlikely” ranged from 62% (simplified Wells rule) to 72% (Wells rule). Combined with a normal D-dimer level, the CDRs excluded PE in 22–24% of patients. The total failure rates of the CDR-D-dimer combinations were similar (1 failure, 0.5– 0.6%, upper 95% CI 2.9– 3.1%). Despite 30% of the patients had discordant CDR outcomes, PE was missed in none of the patients with discordant CDRs and a normal D-dimer result.

Conclusions

All four CDRs show similar safety and clinical utility for exclusion of acute PE in combination with a normal D-dimer level. With this prospective validation, the more straightforward simplified scores are ready for use in clinical practice.

Disclosures:

No relevant conflicts of interest to declare.

Author notes

*

Asterisk with author names denotes non-ASH members.