Relationship between lipoprotein concentrations and short-term and 1-year mortality in intensive care unit septic patients: results from the HIGHSEPS study.

BACKGROUND: High-density lipoproteins (HDLs), particles characterized by their reverse cholesterol transport function, display pleiotropic properties, including anti-inflammatory and antioxidant functions. Moreover, all lipoproteins (HDLs but also low-density lipoproteins (LDLs)) neutralize lipopolysaccharides, leading to increased bacterial clearance. These two lipoproteins decrease during sepsis, and an association between low lipoprotein levels and poor outcome was reported. The goals of this study were to characterize the lipid profile of septic patients hospitalized in our intensive care unit (ICU) and to determine the relationship with the outcome. METHODS: A prospective observational study was conducted in a university hospital ICU. All consecutive patients admitted for septic shock or sepsis were included. Total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglyceride levels were assessed at admission (day 1), at day 3, and at ICU discharge. When available, a prehospitalization lipid profile collected prior to the patient's hospitalization was compiled. Short-term and 1-year prognostic outcomes were prospectively assessed. RESULTS: A total of 205 patients were included. We found a decrease in HDL-C concentration between previous values and those at admission, followed by an additional decrease at day 3. At ICU discharge, the concentration was higher than that at day 3 but did not reach the concentration measured prior to hospitalization (prior HDL-C = 1.22 (1.04-1.57) mmol/l; day 1 HDL-C = 0.44 (0.29-0.70) mmol/l; day 3 HDL-C = 0.30 (0.25-0.48) mmol/l; and HDL-C at discharge = 0.65 (0.42-0.82) mmol/l). A similar trend was found for LDL-C (prior LDL-C = 2.7 (1.91-3.33) mmol/l; day 1 LDL-C = 1.0 (0.58-1.50) mmol/l; day 3 LDL-C = 1.04 (0.64-1.54) mmol/l; and LDL-C at discharge = 1.69 (1.26-2.21) mmol/l). Mixed models for repeated measures of lipoprotein concentrations showed a significant difference in HDL-C and LDL-C concentrations over time between survivors and nonsurvivors at day 28. An HDL-C concentration at admission of less than 0.4 mmol/l was associated with increased mortality at day 28 (log-rank test, p = 0.034) but not at 1 year (log-rank test, p = 0.24). An LDL-C concentration at admission of less than 0.72 mmol/l was associated with increased mortality at day 28 and at 1 year (log-rank test, p < 0.001 and p = 0.007, respectively). No link was found between prior lipid profile and mortality. CONCLUSIONS: We showed no relationship between the prehospitalization lipid profile and patient outcome, but low lipoprotein levels in the ICU were strongly associated with short-term mortality.

Postoperative Cardiac Troponin I Thresholds Associated With 1-Year Cardiac Mortality After Adult Cardiac Surgery: An Attempt to Link Risk Stratification With Management Stratification in an Observational Study.

OBJECTIVES: Cardiac troponin (cTn) concentrations are measured routinely in some centers after cardiac surgery as part of risk stratification, but there are no data on how increased cTn concentrations could change patients' management. The aim of this study was to estimate relevant cTnI thresholds and identify potential interventions (additional monitoring/therapeutic interventions) that could be part of management changes of patients with cTnI greater than relevant thresholds. DESIGN: Retrospective, single-center, observational study. SETTING: Bichat-Claude Bernard Hospital, Paris, France, between January 1, 2009, and December 31, 2012. PARTICIPANTS: Consecutive adult patients undergoing cardiac surgery. MEASUREMENTS AND MAIN RESULTS: cTnI was measured on the 20th postoperative hour. Causes of death and possible interventions were determined by analysis of individual medical records. cTnI thresholds for 1-year cardiac mortality with a specificity >80% were calculated. For this study, 3,228 procedures were analyzed; 129 deaths occurred (4%), 83 of which (2.6%) were cardiac deaths. Threshold cTnI values were 4.2 µg/L for coronary artery bypass grafting (95% confidence interval [CI] 3.9-4.5) and 10.7 µg/L for non-coronary artery bypass grafting (95% CI 10.0-11.3). In multivariable analysis, the EuroSCORE II (odds ratio 1.1 [95% CI 1.06-1.13]; p < 0.001) and cTnI concentrations greater than the thresholds (odds ratio 5.62 [95% CI 3.37-9.37]; p < 0.001) were associated with significantly increased risk of death. The additive and absolute Net Reclassification Index were 0.288% and 14.1%, respectively, for a logistic model including cTnI and EuroSCORE II (area under the curve C-index 0.82 [95% CI 0.77-0.87]) compared with a model including only EuroSCORE II (area under the curve C-index 0.80 [95% CI 0.75-0.84]). Fifty-three of the 83 patients who experienced cardiac death (64%) had a cTnI concentration greater than the threshold, and an intervention was deemed possible in 47 of those 53 (89%) (mostly patients with mild postoperative cardiac dysfunction). For noncardiac deaths, 28% of patients had a cTnI concentration greater than the threshold and no interventions were deemed possible. CONCLUSIONS: In an attempt to evolve from risk to management stratification, this study's results identified a subgroup of patients with mild cardiac dysfunction and a cTnI concentration greater than the threshold who could be the target for interventions in future validation studies concerning changes in patient management.

Multi-centre evaluation of recent troponin assays for the diagnosis of NSTEMI.

OBJECTIVES: We aimed to compare the use of nine different cardiac troponin (cTn) assays (2 cTnT and 7 cTnI) for the diagnosis of NSTEMI in a single multi-centre population. DESIGN AND METHODS: One hundred and fifty-eight patients were included (mean age 60 years, SD 17 years), including 23 patients (14%) with NSTEMI. RESULTS: The analytical comparison highlighted a large heterogeneity of cTn assays, as reflected by percentages of patients with detectable cTn, correlation coefficients, Passing-Bablok comparisons and concordance coefficients. Correlations within cTnI assays were good and correlation within cTnT assays was excellent. Diagnostic performances demonstrated that each cTn assay has specific threshold values. Furthermore, some assays (HS-cTnI and T, cTnI-Pathfast and cTnI-Centaur) indicated high sensitivity and negative predictive value using the limit of detection (LoD) diagnostic strategy. For the latter assays, a significant increase in specificity was found when using the 99th percentile or the H0-H3 strategies, in comparison to the LoD strategy. When applying the European Society of Cardiology H0-H3 algorithm, comparable diagnostic performances were obtained. CONCLUSION: All 9 cTn assays indicated overall good diagnostic performances for the diagnosis of NSTEMI in emergency departments when the recommended algorithm based on the variation of cTn value between two measurements at admission and 3 h later was used.

Macrophage Polarization Favors Epithelial Repair During Acute Respiratory Distress Syndrome.

OBJECTIVES: Alveolar macrophage polarization and role on alveolar repair during human acute respiratory distress syndrome remain unclear. This study aimed to determine during human acute respiratory distress syndrome: the alveolar macrophage polarization, the effect of alveolar environment on macrophage polarization, and the role of polarized macrophages on epithelial repair. DESIGN: Experimental ex vivo and in vitro investigations. SETTING: Four ICUs in three teaching hospitals. PATIENTS: Thirty-three patients with early moderate-to-severe acute respiratory distress syndrome were enrolled for assessment of the polarization of alveolar macrophages. INTERVENTIONS: Polarization of acute respiratory distress syndrome macrophages was studied by flow cytometry and quantitative polymerase chain reaction. Modulation of macrophage polarization was studied in vitro using phenotypic and functional readouts. Macrophage effect on repair was studied using alveolar epithelial cells in wound healing models. MEASUREMENTS AND MAIN RESULTS: Ex vivo, alveolar macrophages from early acute respiratory distress syndrome patients exhibited anti-inflammatory characteristics with high CD163 expression and interleukin-10 production. Accordingly, early acute respiratory distress syndrome-bronchoalveolar lavage fluid drives an acute respiratory distress syndrome-specific anti-inflammatory macrophage polarization in vitro, close to that induced by recombinant interleukin-10. Culture supernatants from macrophages polarized in vitro with acute respiratory distress syndrome-bronchoalveolar lavage fluid or interleukin-10 and ex vivo acute respiratory distress syndrome alveolar macrophages specifically promoted lung epithelial repair. Inhibition of the hepatocyte growth factor pathway in epithelial cells and hepatocyte growth factor production in macrophages both reversed this effect. Finally, hepatocyte growth factor and soluble form of CD163 concentrations expressed relatively to macrophage count were higher in bronchoalveolar lavage fluid from acute respiratory distress syndrome survivors. CONCLUSIONS: Early acute respiratory distress syndrome alveolar environment drives an anti-inflammatory macrophage polarization favoring epithelial repair through activation of the hepatocyte growth factor pathway. These results suggest that macrophage polarization may be an important step for epithelial repair and acute respiratory distress syndrome recovery.

Validation of the Fautrel classification criteria for adult-onset Still's disease.

OBJECTIVES: To validate the Fautrel classification criteria for adult-onset Still's disease (AOSD) and to compare the discriminative performance to that of the Yamaguchi criteria. METHODS: We retrospectively reviewed the medical charts of 426 patients who had serum ferritin level and percentage glycosylated ferritin assayed at the biochemistry laboratory of Bichat Hospital. Medical data were extracted by use of a standardized form. All clinical, biological, and imaging features were collected, as well, evidence favoring an alternative diagnosis, specifically symptoms suggestive of other immune-mediated inflammatory diseases (IMID) or active infections. Patients were classified as AOSD patients or controls according to a predefined procedure, including consultation with a multidisciplinary expert group. Algorithms corresponding to the Fautrel and Yamaguchi classification criteria were applied for each patient. RESULTS: In all, 54 AOSD and 278 control patients were included. For the Fautrel criteria, the sensitivity was 87.0%, specificity 97.8%, and positive and negative predictive values 88.7% and 97.5%, respectively. For the standard Yamaguchi set-without strict application of exclusion criteria-the sensitivity was 96.3%, specificity 98.9%, and positive and negative predictive values 94.5% and 99.3%, respectively. If we applied a stricter definition of exclusion criteria, the sensitivity of the Yamaguchi set decreased to 31.5%. As wall, 37 AOSD diagnoses were missed. CONCLUSION: This study validates the Fautrel classification criteria with a cohort independent of that used for the original publication. This criteria set demonstrates good sensitivity and specificity, overcomes exclusion criteria, and includes glycosylated ferritin level. It also confirms the high discriminative power of the Yamaguchi criteria, albeit substantially affected by how exclusion criteria are interpreted.

Reference change values of plasma and urine NGAL in cardiac surgery with cardiopulmonary bypass.

OBJECTIVE: As with any biomarker, interpretation of changes of NGAL concentration must consider its variability in a specific clinical setting. The aim of this study was to calculate the reference change value (RCV) and the index of individuality (II) of plasma and urine NGAL in the context of coronary artery bypass graft surgery with cardiopulmonary bypass, in patients without postoperative acute kidney injury. METHODS: This prospective single-center observational study included patients with a preoperative glomerular filtration rate of >30mlmin-1 1.73m-2, scheduled for elective coronary artery bypass graft with cardiopulmonary bypass and free from postoperative renal injury according to KDIGO criteria during hospital stay or a plasma creatinine Δ<0 (Δ=day1-induction). Plasma and urine NGAL were measured at anesthesia induction, 4h after intensive care admission and on the first and 2nd postoperative day and normalized to plasma proteins or urine creatinine. The RCV was given by the formula: 1.96×√2×√(CVa2+CVi2), were CVi is the intra-individual variability and CVa the reported analytical coefficient of variation of 5%. The II was calculated using the formula II=CVi/CVg for the four previous parameters, where CVg is the inter-individual variability. RESULTS: Of the 100 patients enrolled in the study, 73 or 25 were considered free from acute kidney injury (KDIGO and Δ creatinine criteria, respectively) and included in the analysis. The RCV was 104% and 109% for plasma NGAL and 321% and 608% for urine NGAL. The II was <0.6 for both plasma and urine NGAL. CONCLUSIONS: In patients who underwent coronary artery bypass grafting with normal post-operative kidney function, two-fold change in plasma NGAL and three to six-fold change in urine NGAL occur. In this specific clinical context, pathological variations must consider this biological "noise" for correct interpretation.

High-sensitivity cardiac troponin T is a biomarker for atherosclerosis in systemic lupus erythematous patients: a cross-sectional controlled study.

BACKGROUND: Cardiovascular disease (CVD) is the main cause of death in systemic lupus erythematous (SLE) patients. The Framingham score underestimates the risk for CVD in this population. Our study aimed to determine whether serum high-sensitivity cardiac troponin T (HS-cTnT) might help to identify SLE patients at risk for CVD. METHODS: The presence of carotid plaques was prospectively assessed by ultrasound in 63 consecutive SLE patients asymptomatic for CVD and 18 controls. Serum HS-cTnT concentration was measured using the electrochemiluminescence method. Factors associated with carotid plaques were identified and multivariate analysis was performed. RESULTS: Framingham score was low in both SLE patients (median 1 (range 1-18%)) and controls (1 (1-13%)). Nevertheless, 23 (36.5%) SLE patients, but only 2 (11.1%) controls (p = 0.039), had carotid plaque detected by vascular ultrasound. In the multivariate analysis, only age (p = 0.006) and SLE status (p = 0.017) were independently associated with carotid plaques. Serum HS-cTnT concentration was detectable (i.e. >3 ng/L) in 37 (58.7%) SLE patients and 6 (33.3%) controls (p = 0.057). Interestingly, 87% of SLE patients with carotid plaques, but only 42.5% of SLE patients without plaques (p < 0.001), had detectable HS-cTnT. Conversely, 54.5% of SLE patients with detectable HS-cTnT, but only 11.5% with undetectable HS-cTnT (p < 0.001), had a carotid plaque. In the multivariate analysis, only body mass index (p = 0.006) and HS-cTnT (p = 0.033) were statistically associated with carotid plaques in SLE patients. Overall, the risk of having a carotid plaque was increased by 9 (odds ratio 9.26, 95% confidence interval 1.55-90.07) in SLE patients in whom HS-cTnT was detectable in serum. CONCLUSION: Serum HS-cTnT level is high and associated with carotid plaques in SLE patients who are at an apparently low risk for CVD according to the Framingham score. HS-cTnT may be a useful biomarker for SLE-associated atherosclerosis.

Determinants and prognostic value of B-type natriuretic peptide in patients with aortic valve stenosis.

BACKGROUND: The prognostic value of N-terminal fragment of pro B-type natriuretic peptide (Nt-proBNP) in aortic stenosis (AS) is still being debated. We sought to evaluate the determinants of Nt-proBNP in AS and its prognostic value in asymptomatic patients. METHODS: Patients with pure isolated at least mild degenerative AS enrolled in our prospective cohort (2006-2013) constituted our population. Clinical and biological measurements as well as echocardiographic evaluations were performed at study entry for all patients. Severe AS was defined by a valve area <1cm2. Asymptomatic patients were contacted every six months and seen every year. The occurrence of AS-related events (sudden death, congestive heart failure or new onset of symptoms) within two years was recorded prospectively. RESULTS: We enrolled 809 patients. Nt-proBNP increased with AS severity (p<0.0001) and symptomatic status (p<0.0001) but there was a wide overlap between groups of AS severity or symptomatic status. Nt-proBNP was the result of complex interactions between multiple determinants, including AS severity and symptomatic status but also age (p=0.0008), history of coronary artery disease (p=0.03), rhythm (p=0.007) and diastolic function (p<0.0001). Consequently, in asymptomatic patients with moderate/severe AS, normal ejection fraction and in sinus rhythm, Nt-proBNP was associated with AS-related events in univariate analysis (p=0.009) but not after adjustment for AS severity (p=0.12). Repeated Nt-proBNP measurements at one year did not improve their predictive value (p=0.43). CONCLUSION: This study highlights the limitations of Nt-proBNP in AS and raises caution regarding its use, at least as a single factor, in the decision-making process regarding asymptomatic patients with AS.

Serum Amyloid P Contained in Alveolar Fluid From Patients With Acute Respiratory Distress Syndrome Mediates the Inhibition of Monocyte Differentiation into Fibrocyte.

OBJECTIVE: Alveolar fibrocytes are monocyte-derived mesenchymal cells associated with poor prognosis in patients with acute respiratory distress syndrome. Our aims were to determine the following: 1) the ability of monocytes from acute respiratory distress syndrome patients to differentiate into fibrocytes; 2) the influence of the acute respiratory distress syndrome alveolar environment on fibrocyte differentiation; and 3) mediators involved in this modulation, focusing on serum amyloid P. DESIGN: Experimental in vitro investigation. SETTING: Two ICUs of a teaching hospital. PATIENTS: Twenty-five patients (19 mild-to-severe acute respiratory distress syndrome and six matched ventilated controls without acute respiratory distress syndrome) were enrolled. Six healthy volunteers served as non-ventilated controls. INTERVENTIONS: Peripheral blood mononuclear cells were isolated from acute respiratory distress syndrome, ventilated controls, and non-ventilated controls blood and cultured in vitro. Fibrocytes were counted at basal condition and after culture with broncho-alveolar lavage fluid. Plasma and broncho-alveolar lavage fluid serum amyloid P contents were determined by western blot and enzyme-linked immunosorbent assay. Serum amyloid P was located in normal and acute respiratory distress syndrome lung by immunohistochemistry. MEASUREMENTS AND MAIN RESULTS: Acute respiratory distress syndrome peripheral blood mononuclear cells had a three-fold increased ability to differentiate into fibrocytes compared to ventilated controls or non-ventilated controls. Acute respiratory distress syndrome broncho-alveolar lavage fluid inhibited by 71% (55-94) fibrocyte differentiation compared to saline control. Ventilated controls' broncho-alveolar lavage fluid was a less potent inhibitor (51% [23-66%] of inhibition), whereas non-ventilated controls' broncho-alveolar lavage fluid had no effect on fibrocyte differentiation. Serum amyloid P concentration was decreased in plasma and dramatically increased in broncho-alveolar lavage fluid during acute respiratory distress syndrome. Alveolar serum amyloid P originated, in part, from the release of serum amyloid P associated with lung connective tissue during acute respiratory distress syndrome. Serum amyloid P depletion decreased the inhibitory effect of acute respiratory distress syndrome broncho-alveolar lavage fluid by 60%, whereas serum amyloid P replenishment of serum amyloid P-depleted acute respiratory distress syndrome broncho-alveolar lavage fluid restored their full inhibitory effect. CONCLUSIONS: The presence of fibrocytes in the lung during acute respiratory distress syndrome could result in a balance between higher ability of monocytes to differentiate into fibrocytes and the inhibitory effect of the alveolar environment, mainly dependent on serum amyloid P.

Obstructive Sleep Apnoea Modulates Airway Inflammation and Remodelling in Severe Asthma.

BACKGROUND: Obstructive sleep apnoea (OSA) is frequently observed in severe asthma but the causal link between the 2 diseases remains hypothetical. The role of OSA-related systemic and airway neutrophilic inflammation in asthma bronchial inflammation or remodelling has been rarely investigated. The aim of this study was to compare hallmarks of inflammation in induced sputum and features of airway remodelling in bronchial biopsies from adult patients with severe asthma with and without OSA. MATERIALS AND METHODS: An overnight polygraphy was performed in 55 patients referred for difficult-to-treat asthma, who complained of nocturnal respiratory symptoms, poor sleep quality or fatigue. We compared sputum analysis, reticular basement membrane (RBM) thickness, smooth muscle area, vascular density and inflammatory cell infiltration in bronchial biopsies. RESULTS: In total, 27/55 patients (49%) had OSA diagnosed by overnight polygraphy. Despite a moderate increase in apnoea-hypopnoea index (AHI; 14.2 ± 1.6 event/h [5-35]), the proportion of sputum neutrophils was higher and that of macrophages lower in OSA than non-OSA patients, with higher levels of interleukin 8 and matrix metalloproteinase 9. The RBM was significantly thinner in OSA than non-OSA patients (5.8 ± 0.4 vs. 7.8 ± 0.4 µm, p<0.05). RBM thickness and OSA severity assessed by the AHI were negatively correlated (rho = -0.65, p<0.05). OSA and non-OSA patients did not differ in age, sex, BMI, lung function, asthma control findings or treatment. CONCLUSION: Mild OSA in patients with severe asthma is associated with increased proportion of neutrophils in sputum and changes in airway remodelling.

Determinants and prognostic value of Galectin-3 in patients with aortic valve stenosis.

OBJECTIVE: Myocardial fibrosis has been proposed as an outcome predictor in asymptomatic patients with severe aortic stenosis (AS) that may lead to consider prophylactic surgery. It can be detected using MRI but its widespread use is limited and development of substitute biomarkers is highly desirable. We analysed the determinants and prognostic value of galectin-3, one promising biomarker linked to myocardial fibrosis. METHODS: Patients with at least mild degenerative AS enrolled between 2006 and 2013 in two ongoing studies, COFRASA/GENERAC (COhorte Française de Rétrécissement Aortique du Sujet Agé/GENEtique du Rétrécissement Aortique), aiming at assessing the determinants of AS occurrence and progression, constituted our population. RESULTS: We prospectively enrolled 583 patients. The mean galectin-3 value was 14.3±5.6 ng/mL. There was no association between galectin-3 and functional status (p=0.55) or AS severity (p=0.58). Independent determinants of galectin-3 were age (p=0.0008), female gender (p=0.04), hypertension (p=0.002), diabetes (p=0.02), reduced left ventricular ejection fraction (p=0.01), diastolic dysfunction (E/e', p=0.02) and creatinine clearance (p<0.0001). Among 330 asymptomatic patients at baseline, galectin-3 was neither predictive of outcome in univariate analysis (p=0.73), nor after adjustment for age, gender, rhythm, creatinine clearance and AS severity (p=0.66). CONCLUSIONS: In a prospective cohort of patients with a wide range of AS severity, galectin-3 was not associated with AS severity or functional status. Main determinants of galectin-3 were age, hypertension and renal function. Galectin-3 did not provide prognostic information on the occurrence of AS-related events. Our results do not support the use of galectin-3 in the decision-making process of asymptomatic patients with AS. TRIAL REGISTRATION NUMBER: COFRASA NCT00338676 and GENERAC CT00647088.

Head-to-head comparison of 10 natriuretic peptide assays.

BACKGROUND: The aim of the study was to compare NT-proBNP and BNP levels in fresh samples from heart failure (HF) patients measured using 10 immunoassays and to assess their agreement. METHODS: NT-proBNP (CobasH232(®), Elecsys(®), Vidas(®), Vista(®), XPand(®), Vitros(®)) and BNP (Triage(®), Access(®), CentaurXP(®), Architect(®)) levels were measured in 39 heparin and 19 EDTA samples, respectively. RESULTS: The Pearson correlation coefficient ranged between 0.929 (Triage(®-)Centaur(®)) and 0.994 (Access(®)-Architect(®)) for BNP assays and between 0.972 (Vidas(®)-Cobas H232(®)) and 0.999 (Vitros(®)-Vidas(®)) for NT-proBNP assays. Passing Bablok regression analyses showed a significant difference in the slopes [0.80 (Centaur(®)-Triage(®)) to 1.84 (Architect(®)-Centaur(®))] and intercepts [-55 ng/L (Architect(®)-Centaur(®)) to 48 ng/L (Access(®)-Triage®)] for BNP assays, and a lower heterogeneity between NT-proBNP assays [0.83 (Vidas(®)-Elecsys(®)) to 1.20 (Vitros(®)-Vidas(®)) and -97 ng/L (XPand(®)-CobasH232(®)) to 51 ng/L (CobasH232(®)-Elecsys(®)) for slopes and intercepts, respectively]. The concordance correlation coefficient revealed a poor (ρc<0.90) to moderate (ρc=0.90-0.95) agreement in 4/6 pairs of BNP assays and an almost perfect (ρc>0.99) agreement in 5/15 pairs of NT-proBNP assays. The acceptable difference limit reflecting the number of individual discrepant results between two assays, ranged between 15.1% (Access(®)-CentaurXP(®)) and 34.5% (Architect(®)-Triage(®)) for BNP assays, and between 10.9% (Vidas(®)-Vitros(®)) and 55% (CobasH232(®)-Xpand(®)) for NT-proBNP assays. CONCLUSIONS: This study stresses the lack of transferability of the results obtained using different techniques to measure BNP and NT-proBNP levels in fresh samples. Individual reference ranges and HF diagnostic cut-offs should be assessed for each commercial NP immunoassay. We recommend to systematically monitoring HF patients using the same assay (BNP or NT-proBNP) over the time.

Cardiovascular Changes After Gastric Bypass Surgery: Involvement of Increased Secretions of Glucagon-Like Peptide-1 and Brain Natriuretic Peptide.

BACKGROUND: Obesity induces cardiovascular alterations, including cardiac hypertrophy, impaired relaxation, and heart rate variability (HRV), which are associated with increased mortality. Gastric bypass surgery (GBP) reduces cardiovascular mortality, but the mechanisms involved are not clearly established. To date, the implication of postsurgical hormonal changes has not been tested. Our aim was to study the relationships between the evolution of cardiovascular functions after GBP and changes in metabolic and hormonal parameters, including glucagon-like peptide-1 (GLP-1) and brain natriuretic peptide (N-terminal pro-brain natriuretic peptide (NT-proBNP)). METHODS: Echocardiographic parameters, 24-h rhythmic Holter recording, plasma concentrations of GLP-1 before and after a test meal, and fasting NT-proBNP were assessed in 34 patients (M/F 2/32, age 36 ± 11 years, BMI 46 ± 6 kg/m(2)), before and 1 year after GBP. RESULTS: After GBP, excess weight loss was 79 ± 20%. Blood pressure (BP), heart rate, and left ventricular mass decreased, while HRV and diastolic function (E/A ratio) improved. Plasma concentrations of NT-proBNP and postprandial (PP) GLP-1 increased. Changes in cardiovascular parameters were related to BMI and insulin sensitivity. Furthermore, the decrease in BP was independently associated with the increase of PP GLP-1 level and HRV was positively associated with NT-proBNP concentration after surgery. CONCLUSIONS: The increase in endogenous GLP-1 observed after GBP was associated with decreased BP but not with improvement of other cardiovascular parameters, whereas the increase in NT-proBNP, within the physiological range, was associated with improved HRV.

High-sensitivity cardiac troponin assays: answers to frequently asked questions.

Cardiac troponin (cTn) assays have quickly gained in analytical sensitivity to become what are termed 'high-sensitivity cardiac troponin' (hs-cTn) assays, bringing a flurry of dense yet incomplete literature data. The net result is that cTn assays are not yet standardized and there are still no consensus-built data on how to use and interpret cTn assay results. To address these issues, the authors take cues and clues from multiple disciplines to bring responses to frequently asked questions. In brief, the effective use of hs-cTn hinges on knowing: specific assay characteristics, particularly precision at the 99th percentile of a reference population; factors of variation at the 99th percentile value; and the high-individuality of hs-cTn assays, for which the notion of individual kinetics is more informative than straight reference to 'normal' values. The significance of patterns of change between two assay measurements has not yet been documented for every hs-cTn assay. Clinicians need to work hand-in-hand with medical biologists to better understand how to use hs-cTn assays in routine practice.

Post-operative kinetics of procalcitonin after lung transplantation.

BACKGROUND: Post-operative infections are a major complication after lung transplantation (LT). Early bacterial pneumonia worsens the prognosis of LT. Procalcitonin (PCT) has been proposed as an early and rapid laboratory marker of infection and sepsis. PCT could be a useful biomarker of pulmonary infection after LT, but the early kinetics of PCT in this setting are unknown. We evaluated the kinetics of PCT and the impact of respiratory tract infection on PCT concentrations. METHODS: Over a 12-month period, PCT concentrations were determined daily in each patient admitted to our ICU for LT. Epidemiologic, clinical, laboratory and outcome data were obtained. A diagnosis of respiratory tract infection was suspected on clinical examination and confirmed by microbiologic culture. RESULTS: Twenty-six consecutive patients were included and 397 blood samples were obtained (13 [range 4 to 66] samples per patient). Plasma PCT reached a peak in the first 24 hours post-transplantation (5.72 [0.11 to 93.8] ng/ml), with a progressive decline over the first 7 post-operative days. Doubling of plasma PCT levels after an initial decrease was significantly associated with respiratory tract infection in transplanted patients (RR = 4.2 95% CI [1.95 to 9.03]). CONCLUSIONS: A non-specific increase in PCT values was observed during the first week post-LT. In combination with microbiologic cultures, PCT assays may be useful after the first post-operative week as an aid in the diagnosis of bacterial pulmonary infection.

Repeated nitrogen dioxide exposures and eosinophilic airway inflammation in asthmatics: a randomized crossover study.

BACKGROUND: Nitrogen dioxide (NO2), a ubiquitous atmospheric pollutant, may enhance the asthmatic response to allergens through eosinophilic activation in the airways. However, the effect of NO2 on inflammation without allergen exposure is poorly studied. OBJECTIVES: We investigated whether repeated peaks of NO2, at various realistic concentrations, induce changes in airway inflammation in asthmatics. METHODS: Nineteen nonsmokers with asthma were exposed at rest in a double-blind, crossover study, in randomized order, to 200 ppb NO2, 600 ppb NO2, or clean air once for 30 min on day 1 and twice for 30 min on day 2. The three series of exposures were separated by 2 weeks. The inflammatory response in sputum was measured 6 hr (day 1), 32 hr (day 2), and 48 hr (day 3) after the first exposure, and compared with baseline values measured twice 10-30 days before the first exposure. RESULTS: Compared with baseline measurements, the percentage of eosinophils in sputum increased by 57% after exposure to 600 ppb NO2 (p = 0.003) but did not change significantly after exposure to 200 ppb. The slope of the association between the percentage of eosinophils and NO2 exposure level was significant (p = 0.04). Eosinophil cationic protein in sputum was highly correlated with eosinophil count and increased significantly after exposure to 600 ppb NO2 (p = 0.001). Lung function, which was assessed daily, was not affected by NO2 exposure. CONCLUSIONS: We observed that repeated peak exposures of NO2 performed without allergen exposure were associated with airway eosinophilic inflammation in asthmatics in a dose-related manner.

Diagnostic and prognostic value of procalcitonin and C-reactive protein in malnourished children.

BACKGROUND: Early recognition of bacterial infections is crucial for their proper management, but is particularly difficult in children with severe acute malnutrition (SAM). The objectives of this study were to evaluate the accuracy of C-reactive protein (CRP) and procalcitonin (PCT) for diagnosing bacterial infections and assessing the prognosis of hospitalized children with SAM, and to determine the reliability of CRP and PCT rapid tests suitable for remote settings. METHODS: From November 2007 to July 2008, we prospectively recruited 311 children aged 6 to 59 months hospitalized with SAM plus a medical complication in Maradi, Niger. Blood, urine, and stool cultures and chest radiography were performed systematically on admission. CRP and PCT were measured by rapid tests and by reference quantitative methods using frozen serum sent to a reference laboratory. RESULTS: Median CRP and PCT levels were higher in children with bacteremia or pneumonia than in those with no proven bacterial infection (P < .002). However, both markers performed poorly in identifying invasive bacterial infection, with areas under the curve of 0.64 and 0.67 before and after excluding children with malaria, respectively. At a threshold of 40 mg/L, CRP was the best predictor of death (81% sensitivity, 58% specificity). Rapid test results were consistent with those from reference methods. CONCLUSIONS: CRP and PCT are not sufficiently accurate for diagnosing invasive bacterial infections in this population of hospitalized children with complicated SAM. However, a rapid CRP test could be useful in these settings to identify children most at risk for dying.

Circulating markers of endothelial dysfunction and platelet activation in patients with severe symptomatic cerebral small vessel disease.

BACKGROUND: Small deep infarcts (SDI), also called lacunar infarcts, resulting from the occlusion of deep branch arteries, account for 25% of ischemic strokes. The physiopathology of the disease remains largely unknown. However, evidence about the role of endothelial dysfunction has emerged. Whereas chronic platelet activation is of major importance in acute thrombosis of large atherosclerotic arteries, its role in SDI remains unclear. Frequently associated risk factors are hypertension and diabetes mellitus. The aim of this study was to determine platelet and endothelial activation in patients with recent SDI in comparison to population-based control subjects matched for age, sex and vascular risk factors. METHODS: Platelet activation markers (activated glycoprotein IIb/IIIa, P-selectin and platelet microparticles), shear-induced platelet aggregation (SIPA) studied in the SIPAgreg device at 4,000 s(-1), endothelial activation markers [including von Willebrand factor (vWF) antigen and homocysteine] and high-sensitivity C-reactive protein (hsCRP) were measured in 74 consecutive patients with recent SDI, in whom detectable large artery atherosclerosis or cardiac embolism had been ruled out. Blood samples were collected 1 and 3 months after symptom onset. These factors were also measured in 74 population-based controls with no stroke history and matched for age, sex, hypertension and diabetes. RESULTS: One month after symptom onset, the patients had similar levels of platelet activation to matched controls (p > 0.40 for all comparisons). In contrast, endothelial activation parameters were increased in patients in comparison to controls (vWF: p = 0.002 and homocysteinemia/creatinemia: p = 0.025). The level of hsCRP was slightly increased in patients compared to controls (p = 0.059). At 3 months, we observed a significant decrease in vWF and hsCRP levels in patients (median change in vWF = 10%, p = 0.004; median change in hsCRP = 0.4 mg/l, p = 0.02). Homocysteine levels and all platelet parameters remained unchanged at this time compared to at 1 month. CONCLUSIONS: Our results confirm that chronic platelet activation, when compared to controls matched for age, sex and vascular risk factors, did not seem to play a central role in the pathophysiology of lacunar stroke. In contrast, we found markers of endothelial dysfunction, the role of which in the occurrence of lacunar infarction has still to be clarified in further studies.