Prognostic accuracy of Whole Lung Perfusion Blood Volume as a predictor of 28-day Mortality in Acute Pulmonary Thromboembolism - A prospective study.

BACKGROUND

The estimated incidence of pulmonary embolism (PE) is around 60-70 cases per 100,000 people annually. The overall mortality rate for massive PE is substantial, ranging from 18% to 65%. We can utilise changes in lung perfusion to stratify patients with PE acutely based on risk, highlighting its diagnostic and prognostic value.

OBJECTIVES

To calculate the whole-lung perfused blood volume (PBV) and right-to-left ventricular diameter ratio from dual-energy computed tomography thorax in patients with acute PE and find its association with 28-day all-cause mortality.

METHODS

This was a prospective diagnostic accuracy study at the Jawaharlal Institute of Post-Graduate Medical Education and Research. We included suspected acute PE patients. A dual-energy chest CT was performed on all these patients, and iodine maps were generated using the Syngo dual-energy workstation. Whole-lung PBVs were then calculated. Patients were followed up for 28 days, and all-cause mortality data were collected. The prognostic accuracy of PBVs in predicting mortality among acute PE patients was analysed using the ROC curve using SPSS version 19.0.

RESULTS

The area under the curve (AUC) was 0.696, indicating a moderate discriminatory power in distinguishing between patients who experienced mortality and those who did not. An empirical cut-off value of 0.945 corresponds to a sensitivity of 63.2% and a specificity of 67.6%.

CONCLUSION

The prognostic accuracy of total perfused lung volume/total lung volume revealed a moderate discriminatory power, indicating 70% accuracy in predicting 28-day mortality based on standardised total PBVs.