D-dimer needs rigorous evaluation

All doctors with patients suspected of having an acute deep venous thrombosis or a pulmonary embolism would love a diagnostic magic bullet. They long for a test that would rule in or rule out the diagnosis of venous thromboembolism with a high degree of certainty. Ideally, such a test would be rapid, non-invasive, and widely available.

The search for a reliable test has continued because the clinical diagnosis of thromboembolism is neither sensitive nor specific. Neither symptoms nor examination of the legs are reliable; nor can clinical signs or symptoms define the presence or absence of pulmonary embolism. Clinical signs and symptoms can only suggest these diagnoses—and asymptomatic venous thrombosis and pulmonary embolism are both fairly common.

Not surprisingly, then, over the years a succession of simple, relatively non-invasive tests has been explored. Blood tests have included measurement of the “diagnostic” triad of lactic dehydrogenase, bilirubin, and glutamic oxaloacetic transaminase; immunoglobulin E1; …