Abstract 16055: Ongoing Prothrombotic State in the Early Phase of Pneumonia
Introduction: Respiratory tract infections are associated with an increased risk of acute cardiovascular and cerebrovascular events. Of note, pneumonia may be associated with arterial and venous thrombosis but the underlying pathophysiological mechanisms are still unclear.
Hypothesis: Our aim was to investigate if in patients with community-acquired pneumonia (CAP) a pro-thrombotic state does exist and its relationship with plasma levels of endotoxin.
Methods: One hundred-four consecutive patients with CAP, admitted to the University-Hospital Policlinico Umberto I of Rome, Italy, were prospectively recruited and followed up until discharge. At admission and at discharge endotoxin and systemic markers of clotting activation including protein C activity (aPC) and F1+2 were analyzed. Hospitalized patients matched for sex, age, atherosclerotic risk factors but without any type of infections were used as controls.
Results: At admission CAP patients showed higher plasma levels of F1+2 (237 [164, 388] vs. 163 [136-313] pmol/L; p=0.023) and lower levels of aPC (36.3 [19.7, 52.4] vs.49.8 [43.7-56.0] pmol/L, p<0.001) compared to controls. Moreover, CAP patients disclosed lower aPc/F1+2 ratio (0.13 [0.07, 0.26] vs.0.28 [0.16-0.37; p<0.001), a global marker of imbalance between thrombin generation and the anticoagulation system. At discharge aPC plasma levels and aPC/F1+2 significantly increased, while F1+2 significantly decreased (p<0.001). Baseline LPS were significantly higher in patients than controls (230±34 vs 27±22 pg/ml; p<0.001); in patients a significant decrease of serum LPS was detected at discharge. Serum LPS values were correlated directly to F1+2 (Rs= 0.402, p<0.001) and inversely to aPC/F1+2 (Rs=-0.303; p<0.002). In a multivariable regression analysis CURB65 (β=-0.410 p<0.001) and LPS (β=-0.261 p<0.001) were significantly associated to aPC/F1+2.
Conclusion: CAP patients disclose a significant increase of thrombin generation rate along with a reduced Protein C activity. Changes of clotting activation are significantly associated with LPS suggesting endotoxemia as a key factor in determining enhanced thrombin generation in CAP patients.
Author Disclosures: R. Cangemi: None. C. Calvieri: None. R. Carnevale: None. M. Falcone: None. C. Nocella: None. P. Ferroni: None. P. Pignatelli: None. G. Taliani: None. A. D'Angelo: None. F. Violi: None.
- © 2015 by American Heart Association, Inc.