Overdiagnosis of PEs on CT-angiograms seems likely (Ann Intern Med)
Using the Nationwide Inpatient Sample and the national Multiple Cause-of-Death files, Wiener et al found that since the inception of CT-angiography in 1998, the number of CT-PE scans have risen 11-fold, and age-adjusted incidence of pulmonary embolism rose from 62 to 112 per 100,000 (an 81% increase). Over the same period, the mortality rate (presence of PE on a death certificate as a primary or contributing cause of death) fell minimally from 12.3 to 11.9. Either we're treating PEs dramatically better, which seems implausible, or we're overdiagnosing ones which would never cause death, authors argue. Arch Int Med 2011;171:831-837.
An editorial by Victor Tapson reminds us although these data suggest that many of these PEs are not harmful, some seemingly trivial PEs still might herald future lethal risk, and we don't know how to discriminate between them today. The ACCP's stance is still to anticoagulate virtually all of these (1C recommendation).