Metabolomic analysis of 92 pulmonary embolism patients from a nested case-control study identifies metabolites associated with adverse clinical outcomes.

Essentials Risk-stratification often fails to predict clinical deterioration in pulmonary embolism (PE). First-ever high-throughput metabolomics analysis of risk-stratified PE patients. Changes in circulating metabolites reflect a compromised energy metabolism in PE. Metabolites play a key role in the pathophysiology and risk stratification of PE. SUMMARY: Background Patients with acute pulmonary embolism (PE) exhibit wide variation in clinical presentation and outcomes. Our understanding of the pathophysiologic mechanisms differentiating low-risk and high-risk PE is limited, so current risk-stratification efforts often fail to predict clinical deterioration and are insufficient to guide management. Objectives To improve our understanding of the physiology differentiating low-risk from high-risk PE, we conducted the first-ever high-throughput metabolomics analysis (843 named metabolites) comparing PE patients across risk strata within a nested case-control study. Patients/methods We enrolled 92 patients diagnosed with acute PE and collected plasma within 24 h of PE diagnosis. We used linear regression and pathway analysis to identify metabolites and pathways associated with PE risk-strata. Results When we compared 46 low-risk with 46 intermediate/high-risk PEs, 50 metabolites were significantly different after multiple testing correction. These metabolites were enriched in the following pathways: tricarboxylic acid (TCA) cycle, fatty acid metabolism (acyl carnitine) and purine metabolism, (hypo)xanthine/inosine containing. Additionally, energy, nucleotide and amino acid pathways were downregulated in intermediate/high-risk PE patients. When we compared 28 intermediate-risk with 18 high-risk PE patients, 41 metabolites differed at a nominal P-value level. These metabolites were enriched in fatty acid metabolism (acyl cholines), and hemoglobin and porphyrin metabolism. Conclusion Our results suggest that high-throughput metabolomics can provide insight into the pathophysiology of PE. Specifically, changes in circulating metabolites reflect compromised energy metabolism in intermediate/high-risk PE patients. These findings demonstrate the important role metabolites play in the pathophysiology of PE and highlight metabolomics as a potential tool for risk stratification of PE.

Dose-associated pulmonary complication rates after fresh frozen plasma administration for warfarin reversal.

UNLABELLED: ESSENTIALS: Fresh frozen plasma (FFP) may be associated with a dose-based risk of pulmonary complications. Patients received FFP for warfarin reversal at a large academic hospital over a 3-year period. Almost 20% developed pulmonary complications, and the risk was highest after > 3 units of FFP. The risk of pulmonary complications remained significant in multivariable analysis. BACKGROUND: Fresh frozen plasma (FFP) is often administered to reverse warfarin anticoagulation. Administration has been associated with pulmonary complications, but it is unclear whether this risk is dose-related. Aims We sought to characterize the incidence and dose relationship of pulmonary complications, including transfusion-associated circulatory overload (TACO) and transfusion-related acute lung injury (TRALI), after FFP administration for warfarin reversal. METHODS: We performed a structured retrospective review of patients who received FFP for warfarin reversal in the emergency department (ED) of an academic tertiary-care hospital over a 3-year period. Logistic regression was used to explore the relationship between FFP dose and risk of pulmonary events. RESULTS: Two hundred and fifty-one patients met the inclusion criteria. Overall, 49 patients (20%) developed pulmonary complications, including 30 (12%) with TACO, two (1%) with TRALI, and 17 (7%) with pulmonary edema not meeting the criteria for TACO. Pulmonary complications were significantly more frequent in those who received > 3 units of FFP (34.0% versus 15.6%, 95% confidence interval for risk difference 7.9%-8.9%). After stratification by subtype of complication, only the risk of TACO was statistically significant (28.3% versus 7.6%, 95% confidence interval for risk difference 8.2%-16.6%). In multivariable analysis controlling for age, sex, initial systolic blood pressure, and intravenous fluids given in the ED, > 3 units of FFP remained a significant risk factor for pulmonary complications (odds ratio 2.49, 95% confidence interval 1.21-5.13). CONCLUSIONS: Almost 20% of patients who received FFP for warfarin reversal developed pulmonary complications, primarily TACO, and this risk increased with > 3 units of FFP. Clinicians should be aware of and prepared to manage these complications.