Acute Pulmonary Embolism:  Comment on “Time Trends in Pulmonary Embolism in the United States”

Wiener and colleagues have characterized time trends in PE in the United States in the pre–and post-CTPA angiography (CTA) eras. Using the NIS and Multiple Causes-of-Death databases, they have determined that the introduction of this diagnostic technology has been associated with a substantially increased incidence of acute PE, but with minimal change in PE mortality and a substantially improved case fatality rate. Their findings suggest the phenomenon of overdiagnosis, ie, the detection of an abnormality that will “never” cause symptoms or death. Furthermore, there was an increase in presumed complications resulting from anticoagulation. The authors have done a thorough job of outlining the potential limitations of using these databases, as well as limitations of death certificate diagnoses, how trends may be confounded, and how such issues were addressed. While the data are compelling, the authors are not trying to say that all small and/or asymptomatic pulmonary emboli are necessarily clinically insignificant, nor should they. The incidence of fatal PE recurrence without treatment has been suggested to be as high as 5%¹ to 35%,² although these data come from small studies with methodologic flaws and a different era. Smaller and/or asymptomatic emboli would logically appear to be associated with low mortality, but the catch remains in identifying the patients at high risk for recurrent PE or propagation of residual deep venous thrombosis (DVT) or more long-term sequelae including chronic thromboembolic pulmonary hypertension or postthrombotic syndrome. Such long-term complications may be more difficult to track.