High Levels of Methylarginines Were Associated With Increased Mortality in Patients With Severe Sepsis.

INTRODUCTION: Nitric oxide (NO) likely plays a pivotal role in the pathogenesis of sepsis. Arginine is a substrate for NO, whereas the methylated arginines-asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA)-are endogenous by-products of proteolysis that inhibit NO production.We investigated if high-plasma levels of ADMA, SDMA, and arginine/ADMA ratio were associated with 90-day mortality in patients with severe sepsis or septic shock. METHODS: We included 267 adult patients admitted to intensive care unit with severe sepsis or septic shock. The patients had previously been included in the randomized controlled trial "Scandinavian Starch for Severe Sepsis and Septic Shock (6S)." ADMA, SDMA, and arginine/ADMA ratio were measured in plasma. The risk of death within 90 days was estimated in multivariate Cox regression analyses adjusted for gender, age ≥65 years, major cardiovascular disease, diabetes, hypertension, respiratory failure, vasopressor treatment, highest quartile of creatinine and bilirubin, and lowest quartile of platelet count. In the regression analyses missing values were estimated using multiple imputation. RESULTS: Twenty-five patients had missing data in one or more of the baseline variables and 44 patients had missing methylarginine values. Both ADMA and SDMA were independently associated with 90-day mortality (ADMA: hazard ratio 1.54; 95% CI, 1.00-2.38; P = 0.046, and SDMA: hazard ratio 1.78; 95% CI, 1.14-2.72; P = 0.011). Arginine/ADMA ratio was not associated with 90-day mortality neither in univariate nor in multivariate analyses. The difference in mortality between patients with high and low ADMA was most pronounced in the first week after inclusion. CONCLUSIONS: High levels of ADMA and SDMA in plasma were associated with increased 90-day mortality in patients with severe sepsis or septic shock. Interfering with the methylarginine-NO systems may be a novel target in these patients.

Markers of endothelial damage and coagulation impairment in patients with severe sepsis resuscitated with hydroxyethyl starch 130/0.42 vs Ringer acetate.

PURPOSE: The Scandinavian Starch for Severe Sepsis/Septic Shock (6S) trial showed increased mortality in patients resuscitated with hydroxyethyl starch 130/0.42 (HES) vs Ringer acetate. Different effects of the fluids on the endothelium may have contributed to the observed outcome. We aimed to investigate associations between HES vs Ringer and changes in plasma biomarkers reflecting endothelial damage and coagulation impairment. MATERIALS AND METHODS: Six biomarkers, including soluble thrombomodulin (sTM) and plasminogen activator inhibitor 1 (PAI-1), were assessed in a subgroup of 208 patients from the 6S trial. We analyzed differences in plasma concentration in the 2 intervention groups using linear or logistic regression models. RESULTS: The increase in plasma sTM was lower in the HES group (-1.8 ng/mL; 95% confidence interval, -2.9 to -0.7; P = .002). The change was not statistically significant associated with mortality whereas increase in plasminogen activator inhibitor 1 was (odds ratio for 1-unit increase, 1.04; 95% confidence interval, 1.01-1.08; P = .01). CONCLUSIONS: Resuscitation with HES vs Ringer decreased early endothelial damage. Although this finding should be interpreted with caution, it indicates that the increased mortality observed with HES in the 6S trial may not be explained by endothelial damage and it emphasizes the challenge of using surrogate markers as outcome.

Association between biomarkers of endothelial injury and hypocoagulability in patients with severe sepsis: a prospective study.

INTRODUCTION: Patients with severe sepsis often present with concurrent coagulopathy, microcirculatory failure and evidence of vascular endothelial activation and damage. Given the critical role of the endothelium in balancing hemostasis, we investigated single-point associations between whole blood coagulopathy by thrombelastography (TEG) and plasma/serum markers of endothelial activation and damage in patients with severe sepsis. METHODS: A post-hoc multicenter prospective observational study in a subgroup of 184 patients from the Scandinavian Starch for Severe Sepsis/Septic Shock (6S) Trial. Study patients were admitted to two Danish intensive care units. Inclusion criteria were severe sepsis, pre-intervention whole blood TEG measurement and a plasma/serum research sample available from baseline (pre-intervention) for analysis of endothelial-derived biomarkers. Endothelial-derived biomarkers were measured in plasma/serum by enzyme-linked immunosorbent assay (syndecan-1, thrombomodulin, protein C (PC), tissue-type plasminogen activator and plasminogen activator inhibitor-1). Pre-intervention TEG, functional fibrinogen (FF) and laboratory and clinical data, including mortality, were retrieved from the trial database. RESULTS: Most patients presented with septic shock (86%) and pulmonary (60%) or abdominal (30%) focus of infection. The median (IQR) age was 67 years (59 to 75), and 55% were males. The median SOFA and SAPS II scores were 8 (6 to 10) and 56 (41 to 68), respectively, with 7-, 28- and 90-day mortality rates being 21%, 39% and 53%, respectively. Pre-intervention (before treatment with different fluids), TEG reaction (R)-time, angle and maximum amplitude (MA) and FF MA all correlated with syndecan-1, thrombomodulin and PC levels. By multivariate linear regression analyses, higher syndecan-1 and lower PC were independently associated with TEG and FF hypocoagulability at the same time-point: 100 ng/ml higher syndecan-1 predicted 0.64 minutes higher R-time (SE 0.25), 1.78 mm lower TEG MA (SE 0.87) and 0.84 mm lower FF MA (SE 0.42; all P < 0.05), and 10% lower protein C predicted 1.24 mm lower TEG MA (SE 0.31). CONCLUSIONS: In our cohort of patients with severe sepsis, higher circulating levels of biomarkers of mainly endothelial damage were independently associated with hypocoagulability assessed by TEG and FF. Endothelial damage is intimately linked to coagulopathy in severe sepsis. TRIAL REGISTRATION: Clinicaltrials.gov number: NCT00962156. Registered 13 July 2009.