The diagnosis of pulmonary embolism (PE) remains a challenge. CT pulmonary angiography (CTPA) for suspected PE has become the primary imaging modality, but concerns regarding overutilization, overdiagnosis, radiation, and costs have led to algorithms that combine a clinical decision rule (CDR) and highly sensitive d-dimer to identify patients in whom PE can be safely excluded without further studies.
..The overwhelming majority of respondents (85%) did not require results of a CDR ± d-dimer before ordering a CTPA. Only 6.7% required a CDR + d-dimer, with others requiring either only a CDR (5.8%) or d-dimer (2.5%). The most common CDR was the Wells score, with only one using the Pulmonary Embolism Rule Out Criteria. Nine of 18 (50%) regional Veterans Integrated Service Networks reported at least one site requiring a CDR before CTPA. An average of 9.6 CTPAs were estimated to be performed per week. Sorted by CDR and d-dimer use, 8 (CDR + d-dimer), 6.9 (CDR only), 8 (d-dimer only), 10.1 (no requirements) CTPA studies were performed weekly. The average CTPA yield for PE was estimated at 11.9% (CDR + d-dimer), 8% (CDR only), 2.5% (d-dimer only), and 7.6% (no requirements).
The vast majority of hospitals within the VA system do not use a CDR ± d-dimer in the evaluation of patients with suspected PE. Utilization of a CDR and d-dimer may decrease CTPA utilization and increase yield, but this assessment is limited by the scope of the survey.