1457. Risk Stratification Using Lung Perfusion Blood Volume in Acute Pulmonary Embolism
Authors* Denotes Presenting Author
Kody Kleinrichert *;
Michigan State University College of Human Medicine
Risk stratification of patients presenting with acute pulmonary embolism (PE) helps determine appropriate treatment. The Pulmonary Embolism Severity Index (PESI) and the simplified PESI (sPESI) are validated clinical scoring systems used to predict 30 day mortality in patients with PE. Although they take into account multiple clinical factors, they do not incorporate objective information from CT findings. Dual energy computed tomography (DECT) improves upon traditional CT angiography by generating iodine maps that provide both visual depiction of perfusion defects in the lungs, as well as quantification of the pulmonary perfusion blood volume (PBV). It is our objective to determine if whole lung PBV can be used as a surrogate measure for acute PE severity compared to PESI and simplified PESI (sPESI) clinical risk stratification systems.
Materials and Methods:
We analyzed 144 patients presenting with acute PE and scanned with DECT from August 2020 to February 2021. Retrospective chart review was conducted to calculate the PESI and sPESI scores of each patient. Lung PBV was then quantified using syngo.via (Siemens). Average lung PBV was calculated for each PESI and sPESI class. These average values were compared using a homoscedastic t-test to evaluate for statistically significant differences in average lung PBV between the different PESI and sPESI classes.
Patients in high-risk PESI classes (class III, IV, and V) had a lower average PBV than those in low-risk PESI classes (class I and II), measured at 33.0 +/- 11.0 and 41.6 +/- 14.0, respectively. Furthermore, we found that patients with high-risk sPESI scores also had lower average PBV than their low-risk counterparts at 34.6 +/- 11.5 and 40.5 +/- 15.1, respectively. Both of these differences were determined to be statistically significant (p < 0.05).
There is a statistically significant inverse correlation between PE severity and lung PBV. This indicates that whole lung PBV is indicative of PE severity and has predictive value for mortality. This study suggests that quantification of lung PBV may be used as a metric to guide both prognosis and impact clinical decision making for type and urgency of intervention in patients with acute PE.