SESSION TITLE: Monday Abstract Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: 10/21/2019 02:30 PM - 03:15 PM PURPOSE: Acute pulmonary embolism (PE) is a leading cause of cardiovascular mortality. PE is risk stratified utilizing the pulmonary embolism severity index, vital signs, and markers of right ventricular dysfunction. We sought to investigate the utility of the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) to predict all-cause mortality in PE patients. METHODS: Three hundred acute PE patients between March 2016 and December 2018 were retrospectively analyzed. Demographic information, vitals, co-morbidities, echocardiographic findings, and complete blood count with differential at the time of diagnosis were documented. Patients with sepsis, infection, chronic inflammatory conditions, and active cancer were excluded from further analysis. Furthermore, patients who did not have a complete blood count with differential at the time of PE diagnosis were also excluded. NLR and PLR were calculated by dividing absolute granulocyte count and platelet count by absolute lymphocyte count, respectively. Correlation analysis was performed by calculating the Spearman rank-order correlation coefficient. Receiver operating characteristic curve was constructed to illustrate the sensitivity and specificity of NLR and PLR to predict all-cause mortality. RESULTS: We identified 192 patients who met the study selection criteria. Twenty-eight patients died during follow-up. No significant difference in NLR and PLR was observed between patients with low risk, submassive, and massive PE (p = 0.895 | p = 0.345). Elevated NLR and PLR was associated with all-cause mortality (p = 0.017 | p = 0.021). NLR strongly correlated with PLR (p < 0.001; R = 0.736). PLR correlated with right/left ventricular ratio (p = 0.002, R = -0.232). Both NLR and PLR correlated with PESI score (p < 0.001; R = 0.269 | p = 0.019; R = 0.169). Neither NLR nor PLR correlated with BNP, lactate, or troponin (p = 0.832; p = 0.881; p = 0.799 | p = 0.745; p = 0.577; p = 0.079). NLR of 5.46 was associated with all-cause mortality with sensitivity of 75.0% and specificity of 67.1% (AUC: 0.692; p = 0.001). PLR of 256.6 was associated with all-cause mortality with sensitivity of 53.6% and specificity of 82.3% (AUC: 0.692; p = 0.001). CONCLUSIONS: Elevated NLR and PLR were associated with all-cause mortality in acute PE. The elevation of NLR and PLR may reflect the presence of systemic inflammation. Further studies are needed to ascertain the pathophysiologic process that underlies the associations with all-cause mortality. CLINICAL IMPLICATIONS: NLR and PLR are simple biomarkers that are readily available from routine laboratory values and may be useful components of risk prediction models. DISCLOSURES: No relevant relationships by Yevgeniy Brailovsky, source=Web Response No relevant relationships by Amir Darki, source=Web Response No relevant relationships by Jawed Fareed, source=Web Response No relevant relationships by Debra Hoppensteadt, source=Web Response No relevant relationships by Omer Iqbal, source=Web Response No relevant relationships by Trung Phan, source=Web Response