Factors Influencing Anti-Xa Assays: A Multicenter Prospective Study in Critically Ill and Noncritically Ill Patients Receiving Unfractionated Heparin.

BACKGROUND: The presence of dextran sulfate (DS) in reagents and the type of blood collection tube (citrate/citrated-theophylline-adenosine-dipyridamole [CTAD]) can lead to discrepancies between unfractionated heparin (UFH) anti-Xa levels. OBJECTIVES: To evaluate the extent of the effect (1) of different reagents containing or not containing DS and (2) of the blood collection tubes, on UFH anti-Xa levels, in various clinical situations (NCT04700670). METHODS: We prospectively included patients from eight centers: group (G)1, cardiopulmonary bypass (CPB) after heparin neutralization (n = 39); G2, cardiothoracic intensive care unit (ICU) after CPB (n = 35); G3, medical ICU (n = 53); G4, other medical inpatients (n = 38). Blood was collected into citrated and CTAD tubes. Chromogenic anti-Xa assays were centrally performed, using seven reagent/analyzer combinations including two without DS. The association between anti-Xa levels and covariates was tested using a linear mixed-effects model. RESULTS: We analyzed 4,546 anti-Xa values from 165 patients. Median anti-Xa levels were systematically higher with reagents containing DS, whatever the patient group, with the greatest effect observed in G1 (0.32 vs. 0.05 IU/mL). Anti-Xa levels were slightly higher in CTAD than in citrate samples, irrespective of the assay. The model showed: (1) a significant dextran-patient group interaction (p < 0.0001), the effect of DS on anti-Xa levels varying from 30.9% in G4 to 296% in G1, and (2) a significant effect of CTAD, varying between patient groups (p = 0.0302). CONCLUSION: The variability of anti-Xa levels with a great overestimation of the values, using a reagent containing DS, can lead to different treatment decisions, especially after heparin neutralization by protamine. Clinical consequences of these differences remain to be demonstrated.

Central venous-to-arterial PCO2 difference, arteriovenous oxygen content and outcome after adult cardiac surgery with cardiopulmonary bypass: A prospective observational study.

BACKGROUND: Rapid identification and treatment of tissue hypoxia reaching anaerobiosis (dysoxia) may reduce organ failure and the occurrence of major postoperative complications (MPC) after cardiac surgery. The predictive ability of PCO2-based dysoxia biomarkers, central venous-to-arterial PCO2 difference (ΔPCO2) and ΔPCO2 to arteriovenous oxygen content difference ratio, is poorly studied in this setting. OBJECTIVES: We evaluated the ability of PCO2-based tissue dysoxia biomarkers, blood lactate concentration and central venous oxygen saturation measured 2 h after admission to the ICU as predictors of MPC. DESIGN: A prospective, observational cohort study. SETTING: Single-centre, academic hospital cardiovascular ICU. PATIENTS: We included adult patients undergoing cardiac surgery with cardiopulmonary bypass and measured dysoxia biomarkers at ICU admission, and after 2, 6 and 24 h. MAIN OUTCOME MEASURES: The primary endpoint was MPC, a composite of cardiac and noncardiac MPC evaluated in the 48 h following surgery. After univariate analysis of MPC covariates including dysoxia biomarkers measured at 2 h, multivariate logistic regression analyses were performed to identify the association of these biomarkers with MPC for confounders. Areas under the receiver operating characteristic curves were determined for biomarkers which remained independently associated with MPC. RESULTS: MPC occurred in 56.5% of the 308 patients analysed. ΔPCO2, blood lactate concentration and central venous oxygen saturation measured at 2 h, but not ΔPCO2 to arteriovenous oxygen content difference ratio, were significantly associated with MPC. However, only ΔPCO2 was independently associated with MPC after multivariate analysis. The areas under the receiver operating characteristic curves of ΔPCO2 measured at 2 h for MPC prediction was 0.64 (95% CI 0.57 to 0.70, P < 0.001). CONCLUSION: After cardiac surgery with cardiopulmonary bypass, ΔPCO2 measured 2 h after ICU admission was the only dysoxia biomarker independently associated with MPC, but with limited performance. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03107572.

Impact of antimicrobial therapy on prognosis of patients requiring valve surgery during active infective endocarditis.

OBJECTIVES: We examined the characteristics and outcomes of patients requiring valve surgery during active infective endocarditis (IE), focusing on the impact of antimicrobial therapy. METHODS: In this retrospective study, medical charts of all consecutive patients admitted to our cardiovascular surgery department from January 1998 to December 2010, with a diagnosis of IE requiring surgical management, were reviewed. Adult patients were enrolled in the study if they had definite or possible active IE and if the antimicrobial treatment was evaluable. RESULTS: After initial screening of medical records, we selected 173 surgically treated patients (135 men; mean age, 55.8 years). Native valves were involved in 150 (87%) patients. IE mainly involved the aortic valve (n = 113) and then mitral (n = 83), tricuspid (n = 13), and pulmonary (n = 3) valves. The most common causative pathogens were streptococci (n = 70), staphylococci (n = 60), and enterococci (n = 29). Operative mortality was 15%. Multivariate logistic regression analysis demonstrated that adequacy of the overall antimicrobial treatment (adjusted odds ratio, 0.292; 95% confidence interval, 0.117-0.726; P = .008) and temperature greater than 38°C at the time of diagnosis (adjusted odds ratio, 0.288; 95% confidence interval, 0.115-0.724; P = .008) were independently associated with a lower risk of mortality. Conversely, age greater than 60 years (adjusted odds ratio, 4.42; 95% confidence interval, 1.57-12.4; P = .005) was associated with a greater risk of operative mortality. CONCLUSIONS: Surgery for active IE is still associated with a high mortality rate, but its prognosis is significantly improved by adequate antimicrobial therapy.

Characteristics and prognosis of patients requiring valve surgery during active infective endocarditis.

BACKGROUND AND AIM OF THE STUDY: The study aim was to describe the characteristics and operative mortality of patients requiring valve surgery during active infective endocarditis (IE). METHODS: This retrospective analysis involved 141 surgically treated patients with active IE. All cardiac operations were performed by the same surgical team between January 1998 and July 2009. All patients had definite (n = 128) or possible (n = 13) endocarditis according to modified Duke criteria. The IE was considered active if surgery was required before completion of a standard course of antimicrobial therapy. Operative mortality included any death occurring within the same hospital admission as surgery. RESULTS: Among the patients (108 males, 33 females; mean age 56.3 +/- 14.9 years), native valve endocarditis was present in 122 cases (87%). Multiple valve involvement was observed in 27 patients. The infected valves were the aortic (n = 81), mitral (n = 70), tricuspid (n = 15), or pulmonary (n = 2). The most common pathogens were staphylococci (n = 49), streptococci (n = 46) and enterococci (n = 27). The operative mortality was 16%. In univariate analysis, factors linked to operative mortality were age, prosthetic valve endocarditis (PVE) and inadequate antimicrobial therapy. In multivariate analysis, only PVE was an independent adverse predictor (adjusted Odds Ratio = 4.16; 95% confidence intervals 1.14-12.2; p = 0.01). CONCLUSION: Surgery for active IE is associated with a high mortality rate. The prognosis is impaired in patients with PVE, but might be improved by adequate antimicrobial therapy.