Association of computed tomography pulmonary angiography findings with clinical outcome in patients with acute pulmonary embolism

Context: Acute pulmonary embolism (PE) is one of the common and potentially fatal medical emergencies. The short-term mortality of PE ranges from less than 1% in hemodynamically stable patients to over 90% in patients presenting with cardiopulmonary arrest.[1] Patients presenting with PE have a high risk of mortality in the first 30 days.[2],[3],[4],[5] Echocardiography is routinely done in cases of PE for knowing cardiac status but echo being highly operator dependent, Computed Tomography (CT) pulmonary angiography (CTPA) can provide an alternative with lesser operator dependence. The main purpose of this study is to assess the prognostic value of different parameters measured by multi-detector CT pulmonary angiography (CTPA) in evaluating the clinical outcome of acute PE patients. Aim and Objectives: To study association of left atrium (LA) volume, LA volume index, RVV/LVV ratio, IVC reflux, interventricular septal bowing with clinical outcome. Methods and Materials: The prospective study was conducted in the Department of Radio-Diagnosis, Sri Venkateswara Institute of Medical Sciences (SVIMS), Tirupati in the time frame of March 2018 to June 2019. A total of 46 cases that were confirmed to have acute pulmonary thromboembolism on CTPA meeting the study criteria were studied for location of emboli, LA volume, LA volume index, RVV/LVV ratio, IVC reflux, interventricular septal bowing. The parameters were compared with adverse clinical outcomes which were defined as death within 30 days or escalation of therapy, according to the MAPPET-3 ( Management Strategies and Prognosis in Pulmonary Embolism Trial-3) study criteria.[7] Statistical Analysis Used: Chi-square test was used for comparisons of categorical variables, and Student t-test was used for comparisons in the distributions of continuous variables by using IBM SPSS statistics 20. A P value <0.05 was considered significant. Results: Our study included 46 patients belonging to age range of 18 to 83 years with evidence of pulmonary thromboembolism on CTPA study. Out of these, 18 (39%) patients had adverse events, where 17 (37%) patients died within 30 days, and 1 (2%) had a cardiac arrest where he was revived after cardiopulmonary resuscitation within 30 days from diagnosis of acute PE. There was no difference in the distribution of age, sex or other comorbidities between the patients who had adverse events and those who did not. In our study, patients with centrally lodged thrombi showed higher mortality and other adverse events than patients with more peripherally lodged PE (p value = 0.022). There was no evidence of any statistically significant association between the IVC reflux, septal bowing, cardiac volume parameters with adverse events within 30 days of diagnosis of acute PE. Conclusion: In our study, we found the location of thrombus on CTPA to be a significant factor in predicting the adverse outcome. Other parameters like LA volume, LA volume index, RVV/LVV ratio, IVC reflux interventricular septal bowing did not demonstrate a significant relationship with 30-day adverse outcomes. The use of cardiac volumes in predicting the clinical outcome did not show any significant relationship, and this could be due to underlying conditions like hypertension, smoking, systemic diseases. The use of cardiac chamber volumes in predicting clinical outcome needs to be studied on a larger sample size to look for the role of other systemic factors affecting its volume.