Abstract 3186


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.


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.


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.


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.


No relevant conflicts of interest to declare.

Author notes


Asterisk with author names denotes non-ASH members.