Background: Use of CT in the evaluation of PE has increased across all clinical settings without improving mortality. Contrast CT carries the risks of radiation exposure, contrast-induced nephropathy, and incidental findings that require further investigation. The authors highlight evidence-based strategies for evaluation of PE, focusing on delivering high-value care.
Study design: Clinical guideline.
Setting: Literature review of studies across all adult clinical settings.
Synopsis: The clinical guidelines committee of the American College of Physicians conducted a literature search surrounding evaluation of suspected acute PE. From their review, they concluded:
- Pretest probability should initially be determined based on validated prediction tools (Wells score, Revised Geneva);
- In patients found to have low pretest probability and meeting the pulmonary embolism rule-out criteria (PERC), clinicians can forego d-dimer testing;
- In those with intermediate pretest probability or those with low pre-test probability who do not pass PERC, d-dimer measurement should be obtained;
- The d-dimer threshold should be age adjusted and imaging should not be pursued in patients whose d-dimer level falls below this cutoff, while those with positive d-dimers should receive CT pulmonary angiography (CTPA); and
- Patients with high pretest probability should undergo CTPA (or V/Q scan if CTPA is contraindicated) without d-dimer testing.
Bottom line: In suspected acute PE, first determine pretest probability using Wells and Revised Geneva, and then use this probability in conjunction with the PERC and d-dimer (as indicated) to guide decisions about imaging.
Citation: Raja AS, Greenberg JO, Qaseem A, Denberg TD, Fitterman N, Schuur JD. Evaluation of patients with suspected acute pulmonary embolism: best practice advice from the clinical guidelines committee of the American College of Physicians. Ann Intern Med. 2015;163(9):701-711.