Background: Several approaches have been proposed for the diagnosis of acute pulmonary embolism (PE), but little is known about the strategies effectively used in daily clinical practice.
Methods: Retrospective evaluation of the diagnostic strategy used in our institution in the patients (pts) discharged between January 1st 1995 and December 31st 1996 with diagnostic code 415.1, corresponding to acute PE in the International Classification of Disease.
Results: One-hundred-twenty-seven patients (49 M; 78 F; mean age: 71.5 +/- 15 years; range: 25-95) were identified. Electrocardiogram, chest X-ray, blood gas analysis and plasma D-dimer measurement were performed in 122 (96%), 121 (95%), 114 (90%) and 86 (68%) pts, respectively. Out of the 102 pts surviving the initial phase (early mortality: 20%), 83 (81%) underwent lung scintigraphy, 10 (10%) spiral CT scanning and 2 (2%) pulmonary angiography, while 7 (7%) were treated directly. Thirty of the 83 pts undergoing lung scintigraphy had non-diagnostic results, but only 8 of them underwent further investigation (with spiral CT in 6 cases and pulmonary angiography in 2 cases). Transthoracic echocardiography and ultrasonography of the lower limbs were used in 49 (48%) and 74 (73%) pts respectively, for diagnostic confirmation and to search for the embolic source.
Conclusions: At our institution, where multiple and modern diagnostic facilities are available, ventilation/perfusion lung scanning still represents the most frequently used imaging technique. Spiral CT is employed quite often as an alternative to either lung scintigraphy or pulmonary angiography which, in turn, is used very seldom. Ultrasonography of the lower-limbs is widely utilized (although not in a serial manner and only as a second-line test), while the role of echocardiography appears to be marginal. Spiral CT, pulmonary angiography and lower-limb ultrasonography showed high diagnostic accuracy, while the accuracy of lung scintigraphy and echocardiography was confirmed as being suboptimal. However, due to the retrospective design of our study and the characteristics of our population, these results cannot be extrapolated to pts referred for suspected acute PE, in whom further investigations are thus warranted in order to identify the most cost-effective diagnostic approach.