Relationship between markers of inflammation and hemodynamic stress and death in patients with out-of-hospital cardiac arrest.

Biomarkers that reflect hemodynamic stress, inflammation, extracellular matrix remodeling, angiogenesis, and endothelial dysfunction may improve risk stratification and add valuable pathobiological insight in patients with out-of-hospital cardiac arrest (OHCA). In total, 120 patients with OHCA who survived at least 48 h after return of spontaneous circulation were consecutively included in the present analysis. Concentrations of 30 biomarkers were measured simultaneously using a multi-panel biomarker assay. Cox regression models were adjusted for age, sex, estimated glomerular filtration rate, lactate concentration, bystander resuscitation, initial cardiac rhythm, and type of targeted temperature management. Overall, 57 patients (47.5%) had a favorable neurological outcome (Cerebral Performance Category ≤ 2) at 30 days, while palliative care was initiated in 49 patients (40.8%), and 52 patients (43.3%) died. After correction for multiple testing with Bonferroni-Holm, 8 biomarkers (including Angiopoietin-2, Procalcitonin, Resistin, IL-4Rα, MMP-8, TNFα, Renin, and IL-1α) were significantly associated with all-cause death. After multivariable adjustment, only angiopoietin-2 (Adjusted (Adj) hazard ratio (HR) per 1-unit increase in standardized biomarker concentrations 1.52 (95% CI 1.16-1.99)) and renin (Adj HR 1.32 (95% CI 1.06-1.65) remained independently associated with an increased risk of death. The discriminatory performance indicated good performance for angiopoietin-2 (area under the curve (AUC): 0.75 (95% CI 0.66-0.75) and was significantly higher (P = 0.011) as compared with renin (AUC: 0.60, 95% CI 0.50-0.60). In conclusion, angiopoietin-2 was significantly associated with all-cause mortality in patients with OHCA who survived the first 48 h and may prove to be useful for risk stratification of these patients.

Atherosclerosis is aggravated by iron overload and ameliorated by dietary and pharmacological iron restriction.

AIMS: Whether and how iron affects the progression of atherosclerosis remains highly debated. Here, we investigate susceptibility to atherosclerosis in a mouse model (ApoE-/- FPNwt/C326S), which develops the disease in the context of elevated non-transferrin bound serum iron (NTBI). METHODS AND RESULTS: Compared with normo-ferremic ApoE-/- mice, atherosclerosis is profoundly aggravated in iron-loaded ApoE-/- FPNwt/C326S mice, suggesting a pro-atherogenic role for iron. Iron heavily deposits in the arterial media layer, which correlates with plaque formation, vascular oxidative stress and dysfunction. Atherosclerosis is exacerbated by iron-triggered lipid profile alterations, vascular permeabilization, sustained endothelial activation, elevated pro-atherogenic inflammatory mediators, and reduced nitric oxide availability. NTBI causes iron overload, induces reactive oxygen species production and apoptosis in cultured vascular cells, and stimulates massive MCP-1-mediated monocyte recruitment, well-established mechanisms contributing to atherosclerosis. NTBI-mediated toxicity is prevented by transferrin- or chelator-mediated iron scavenging. Consistently, a low-iron diet and iron chelation therapy strongly improved the course of the disease in ApoE-/- FPNwt/C326S mice. Our results are corroborated by analyses of serum samples of haemochromatosis patients, which show an inverse correlation between the degree of iron depletion and hallmarks of endothelial dysfunction and inflammation. CONCLUSION: Our data demonstrate that NTBI-triggered iron overload aggravates atherosclerosis and unravel a causal link between NTBI and the progression of atherosclerotic lesions. Our findings support clinical applications of iron restriction in iron-loaded individuals to counteract iron-aggravated vascular dysfunction and atherosclerosis.

Serum neprilysin and the risk of death in patients with out-of-hospital cardiac arrest of non-traumatic origin.

BACKGROUND: Early risk stratification remains an unmet clinical need in patients with in out-of-hospital cardiac arrest. We hypothesised that soluble neprilysin may represent a promising biomarker in patients with out-of-hospital cardiac arrest of non-traumatic origin and provide new pathobiological insight. METHODS: This pilot study was a biomarker analysis from the Heidelberg Resuscitation Registry. Serum soluble neprilysin levels on admission were measured in 144 patients with successful return of spontaneous circulation after out-of-hospital cardiac arrest of non-traumatic origin. The primary endpoint was time to all-cause mortality. KM Event Rates are reported. Cox models were adjusted for age, bystander resuscitation, initial ECG rhythm, baseline estimated glomerular filtration rate, baseline lactate, left ventricular function at baseline, and targeted temperature management. RESULTS: In total, 90 (62.5%) patients died over a follow-up of at least 30 days. Soluble neprilysin correlated weakly with high-sensitivity troponin T (r=0.18, P=0.032) but did not correlate significantly with estimated glomerular filtration rate (r=-0.12) or lactate (r=0.11). Patients with elevated soluble neprilysin levels on admission were at significantly higher risk of all-cause mortality (Q4 69.1% vs. Q1 48.4%). After multivariable adjustment, soluble neprilysin in the top quartile (Q4) was significantly associated with all-cause mortality (Q4 vs. Q1: adjusted hazard ratio 2.48 (1.20-5.12)). In an adjusted multimarker model including high-sensitivity troponin T and high-sensitivity C-reactive protein, soluble neprilysin and high-sensitivity troponin T remained independently associated with all-cause mortality (soluble neprilysin: adjusted hazard ratio 2.27 (1.08-4.78); high-sensitivity troponin T: adjusted hazard ratio 3.40 (1.63-7.09)). CONCLUSION: Soluble neprilysin, measured as early as on hospital admission, was independently associated with all-cause mortality in patients with out-of-hospital cardiac arrest of non-traumatic origin and may prove to be useful in the estimation of risk in these patients.