Diagnostic Strategies for Excluding Pulmonary Embolism in Clinical Outcome Studies

Diagnostic Strategies for Excluding Pulmonary Embolism in Clinical Outcome Studies

A Systematic Review

From St. Elisabeth Hospital, Tilburg; Medisch Spectrum Twente, Enschede; University of Maastricht, Maastricht; and Academic Medical Centre, Amsterdam, the Netherlands.

Abstract

Background: Pulmonary embolism is a common clinical disorder that is associated with high morbidity and mortality if untreated. It is important to confirm or rule out the diagnosis in patients with clinical suspicion of the disease.

Purpose: To evaluate various diagnostic strategies for excluding pulmonary embolism.

Data Sources: MEDLINE (1966 to February 2003), EMBASE, and DARE; study investigators; and reference lists.

Study Selection: Prospective clinical outcome studies.

Data Extraction: The researchers recorded the frequency of symptomatic venous thromboembolism over 3 months of follow-up in patients in whom pulmonary embolism had been excluded according to various strategies. Strategies were divided into three categories according to the number of rounds of diagnostic tests needed to exclude pulmonary embolism.

Data Synthesis: 25 studies involving more than 7000 patients were included. In all referred patients, two strategies—normal results on pulmonary angiography or lung scintigraphy and normal D-dimer levels combined with low clinical probability—safely excluded pulmonary embolism (failure rates ≤ 3%). In the second round of diagnostic tests, in patients who had had a nondiagnostic lung scan, both pulmonary angiography and serial leg testing for venous thrombosis were accurate and safe. When D-dimer testing combined with clinical probability was inconclusive, a normal perfusion lung scan safely excluded pulmonary embolism. Accumulating evidence shows that normal results on spiral computed tomography may also safely exclude the disease.

Conclusions: Many diagnostic strategies to exclude pulmonary embolism have been evaluated in consecutive patients. Interest is likely to increase in a simple, fast strategy, starting with a normal perfusion lung scan or a combination of normal D-dimer levels and low clinical probability. After the initial round of testing, a reliable diagnostic method, such as angiography or lung scintigraphy, is warranted.

Article and Author Information

Potential Financial Conflicts of Interest: None disclosed.
Requests for Single Reprints: Marieke J.H.A. Kruip, MD, Department of Internal Medicine, St. Elisabeth Hospital, Postbus 90151, 5000 LC Tilburg, the Netherlands; e-mail, evert.janssen{at}zonnet.nl.
Current Author Addresses: Drs. Kruip and van der Heul: Department of Internal Medicine, St. Elisabeth Hospital, Postbus 90151, 5000 LC Tilburg, the Netherlands.
Dr. Leclercq: Department of Internal Medicine, Medisch Spectrum Twente, Postbus 50000, 7500 KA Enschede, the Netherlands.
Dr. Prins: Department of Clinical Epidemiology and Technology Assessment, University of Maastricht, Postbus 616, NL 6200 MD Maastricht, the Netherlands.
Dr. Büller: Department of Vascular Medicine, Academic Medical Centre, Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands.
Author Contributions: Conception and design: M.J.H.A. Kruip, M.G.L. Leclercq, M.H. Prins, H.R. Büller.
Analysis and interpretation of the data: M.J.H.A. Kruip, M.G.L. Leclercq, C. van der Heulm, M.H. Prins, H.R. Büller.
Drafting of the article: M.J.H.A. Kruip, C. van der Heul.
Critical revision of the article for important intellectual content: M.J.H.A. Kruip, M.G.L. Leclercq, C. van der Heul, M.H. Prins, H.R. Büller.
Final approval of the article: M.J.H.A. Kruip, M.H. Prins, H.R. Büller.
Provision of study materials or patients: M.J.H.A. Kruip.
Statistical expertise: M.H. Prins.
Collection and assembly of data: M.J.H.A. Kruip.