Acute kidney injury (AKI) is a frequent complication after cardiac surgery with cardiopulmonary bypass in infants. Renal near-infrared spectroscopy (NIRS) is used to evaluate regional oximetry in a ...non-invasive continuous real-time fashion, and reflects tissue perfusion. The aim of this study was to evaluate the relationship between renal oximetry and development of AKI in the operative and post-operative setting in infants undergoing cardiopulmonary bypass surgery.
In this prospective study, we enrolled 59 infants undergoing cardiopulmonary bypass surgery for congenital heart disease for univentricular (n = 26) or biventricular (n = 33) repair. Renal NIRS was continuously measured intraoperatively and for at least 24 hours postoperatively and analysed for the intraoperative and first 12 hours, first 24 hours and first 48 hours postoperatively. The renal oximetry values were correlated with the paediatric risk, injury, failure, loss, end (pRIFLE) classification for AKI, renal biomarkers and the postoperative course.
Twenty-eight (48%) infants developed AKI based on pRIFLE classification. Already during intraoperative renal oximetry and further in the first 12 hours, 24 hours and 48 hours postoperatively, significantly lower renal oximetry values in AKI patients compared with patients with normal renal function were recorded (P < 0.05). Of the 28 patients who developed AKI, 3 (11%) needed renal replacement therapy and 2 (7%) died. In the non-AKI group, no deaths occurred. Infants with decreased renal oximetry values developed significantly higher lactate levels 24 hours after surgery. Cystatin C was a late parameter of AKI, and neutrophil gelatinase-associated lipocalin values were not correlated with AKI occurrence.
Our results suggest that prolonged low renal oximetry values during cardiac surgery correlate with the development of AKI and may be superior to conventional biochemical markers. Renal NIRS might be a promising non-invasive tool of multimodal monitoring of kidney function and developing AKI in infants undergoing cardiac surgery with cardiopulmonary bypass.
Deep vein thrombosis (DVT) is a major cause of cardiovascular death. The sequence of events that promote DVT remains obscure, largely as a result of the lack of an appropriate rodent model. We ...describe a novel mouse model of DVT which reproduces a frequent trigger and resembles the time course, histological features, and clinical presentation of DVT in humans. We demonstrate by intravital two-photon and epifluorescence microscopy that blood monocytes and neutrophils crawling along and adhering to the venous endothelium provide the initiating stimulus for DVT development. Using conditional mutants and bone marrow chimeras, we show that intravascular activation of the extrinsic pathway of coagulation via tissue factor (TF) derived from myeloid leukocytes causes the extensive intraluminal fibrin formation characteristic of DVT. We demonstrate that thrombus-resident neutrophils are indispensable for subsequent DVT propagation by binding factor XII (FXII) and by supporting its activation through the release of neutrophil extracellular traps (NETs). Correspondingly, neutropenia, genetic ablation of FXII, or disintegration of NETs each confers protection against DVT amplification. Platelets associate with innate immune cells via glycoprotein Ibα and contribute to DVT progression by promoting leukocyte recruitment and stimulating neutrophil-dependent coagulation. Hence, we identified a cross talk between monocytes, neutrophils, and platelets responsible for the initiation and amplification of DVT and for inducing its unique clinical features.
Blood neutrophils provide the first line of defense against pathogens but have also been implicated in thrombotic processes. This dual function of neutrophils could reflect an evolutionarily ...conserved association between blood coagulation and antimicrobial defense, although the molecular determinants and in vivo significance of this association remain unclear. Here we show that major microbicidal effectors of neutrophils, the serine proteases neutrophil elastase and cathepsin G, together with externalized nucleosomes, promote coagulation and intravascular thrombus growth in vivo. The serine proteases and extracellular nucleosomes enhance tissue factor- and factor XII-dependent coagulation in a process involving local proteolysis of the coagulation suppressor tissue factor pathway inhibitor. During systemic infection, activation of coagulation fosters compartmentalization of bacteria in liver microvessels and reduces bacterial invasion into tissue. In the absence of a pathogen challenge, neutrophil-derived serine proteases and nucleosomes can contribute to large-vessel thrombosis, the main trigger of myocardial infarction and stroke. The ability of coagulation to suppress pathogen dissemination indicates that microvessel thrombosis represents a physiological tool of host defense.
Objectives The aim of this prospective trial was to assess whether platelet reactivity to clopidogrel assessed with multiple electrode platelet aggregometry (MEA) correlates with the risk of early ...drug-eluting stent thrombosis (ST). Background Studies using light transmission aggregometry (LTA) have shown that insufficient suppression of platelet reactivity to adenosine diphosphate (ADP) after clopidogrel treatment is associated with an increased risk of adverse cardiovascular events after percutaneous coronary intervention (PCI). However, LTA is time- and labor-intensive and inconvenient for the routine. A point-of-care assay with similar predictive power would be of great value. Methods Between February 2007 and April 2008, a total of 1,608 consecutive patients with coronary artery disease and planned drug-eluting stent implantation were enrolled. Before PCI, all patients received 600 mg clopidogrel. Blood was obtained directly before PCI. The ADP-induced platelet aggregation was assessed in whole blood with MEA on a Multiplate analyzer (Dynabyte, Munich, Germany). The primary end point was definite ST at 30 days. Results The upper quintile of patients according to MEA measurements (n = 323) was defined as clopidogrel low responders. Compared with normal responders (n = 1,285), low responders had a significantly higher risk of definite ST within 30 days (2.2% vs. 0.2%; odds ratio OR: 9.4; 95% confidence interval CI: 3.1 to 28.4; p < 0.0001). Mortality rates were 1.2% in low versus 0.4% in normal responders (OR: 3.2; 95% CI: 0.9 to 11.1; p = 0.07). The composite of death or ST was higher in low versus normal responders (3.1% vs. 0.6%; OR: 5.1; 95% CI: 2.2 to 11.6; p < 0.001). Conclusions Low response to clopidogrel assessed with MEA is significantly associated with an increased risk of ST. Further studies are warranted to evaluate the ability of MEA to guide antiplatelet therapy in patients undergoing PCI.
Patients receiving dual antiplatelet treatment with aspirin and clopidogrel are commonly treated with proton pump inhibitors (PPIs). Attenuating effects on platelet response to clopidogrel have been ...reported solely for the PPI omeprazole. PPIs differ in their metabolisation properties as well as their potential for drug-drug interactions. The aim of this study was to investigate the impact of different PPIs (pantoprazole, omeprazole, esomeprazole) on platelet response to clopidogrel in patients with previous coronary stent placement under chronic clopidogrel treatment. In a cross-sectional observational study, consecutive patients under clopidogrel maintenance treatment (n = 1,000) scheduled for a control coronary angiography were enrolled. Adenosine diphosphate (ADP)-induced platelet aggregation (in AU*min) was measured with multiple electrode platelet aggregometry (MEA). From the entire study population, 268 (26.8%) patients were under PPI treatment at the time point of platelet function testing (pantoprazole, n = 162; omeprazole, n = 64; esomeprazole, n = 42). Platelet aggregation (median interquartile range) was significantly higher in patients with omeprazole treatment (295.5 193.5-571.2 AU*min) compared to patients without PPI treatment (220.0 143.8-388.8 AU*min; p = 0.001). Platelet aggregation was similar in patients with pantoprazole (226.0 150.0-401.5 AU*min) or esomeprazole (209.0 134.8-384.8 AU*min) treatment compared to patients without PPI treatment (p = 0.69 and p = 0.88, respectively). Attenuating effects of concomitant PPI treatment on platelet response to clopidogrel were restricted to the use of omeprazole. No attenuating effects on platelet response to clopidogrel were observed for pantoprazole or esomeprazole. Specifically designed and randomized clinical studies are needed to define the impact of concomitant PPI treatment on adverse events after percutaneous coronary intervention.
Abstract Background The prognostic value of high-sensitivity troponin T (hs-TnT) elevation after elective percutaneous coronary intervention (PCI) in patients with or without raised baseline hs-TnT ...levels is unclear. Objectives The goal of this study was to assess whether the prognostic value of post-procedural hs-TnT level after elective PCI depends on the baseline hs-TnT level. Methods This study included 5,626 patients undergoing elective PCI who had baseline and peak post-procedural hs-TnT measurements available. The primary outcome was 3-year mortality (with risk estimates calculated per SD increase of the log hs-TnT scale). Results Patients were divided into 4 groups: nonelevated baseline and post-procedural hs-TnT levels (hs-TnT ≤0.014 μg/l; n = 742); nonelevated baseline but elevated post-procedural hs-TnT levels (peak post-procedural hs-TnT >0.014 μg/l; n = 2,721); elevated baseline hs-TnT levels (hs-TnT >0.014 μg/l) with no further rise post-procedure (n = 516); and elevated baseline hs-TnT levels with a further rise post-procedure (n = 1,647). A total of 265 deaths occurred: 6 (1.6%) in patients with nonelevated baseline and post-procedural hs-TnT levels; 54 (3.8%) in patients with nonelevated baseline but elevated post-procedural hs-TnT levels; 50 (16.0%) in patients with elevated baseline hs-TnT levels with no further rise post-procedure; and 155 (18.2%) in patients with elevated baseline hs-TnT levels with a further rise post-procedure (p < 0.001). After adjustment, baseline hs-TnT levels (hazard ratio HR: 1.22; 95% confidence interval CI: 1.09 to 1.38; p < 0.001) but not peak post-procedural hs-TnT levels (HR: 1.04; 95% CI: 0.85 to 1.28; p = 0.679) were associated with an increased risk of mortality. Peak post-procedural hs-TnT findings were not associated with mortality in patients with nonelevated (HR: 0.93; 95% CI: 0.69 to 1.25; p = 0.653) or elevated (HR: 1.24; 95% CI: 0.91 to 1.69; p = 0.165) baseline hs-TnT levels. Conclusions In patients with coronary artery disease undergoing elective PCI, an increase in post-procedural hs-TnT level did not offer prognostic information beyond that provided by the baseline level of the biomarker.
The level of platelet aggregation, measured with light transmission aggregometry (LTA) in platelet rich plasma (PRP), has been shown to predict outcomes after percutaneous coronary intervention ...(PCI). However, measuring parameters of platelet function with LTA is time consuming and weakly standardized. Thus, a fast and standardized method to assess platelet function after clopidogrel treatment would be of great value for clinical practice. A new method, multiple electrode platelet aggregometry (MEA), to rapidly measure platelet aggregation in whole blood has recently been developed. The aim of this study was to assess parameters of platelet function with MEA and LTA before and after administration of 600 mg clopidogrel. Blood samples from 149 patients scheduled for coronary angiography were taken after clopidogrel treatment; in addition, in 60 of the patients samples were available before clopidogrel treatment. ADP-induced platelet aggregation was measured with LTA and simultaneously in whole blood with MEA on the Multiplate analyzer. Platelet aggregation measured with MEA decreased significantly after clopidogrel treatment (P < 0.0001). ADP-induced platelet aggregation assessed with MEA and LTA correlated significantly (Spearman rank correlation coefficient = 0.71; P < 0.0001). The results of MEA, a fast and standardized method to assess the platelet response to ADP prior to and after clopidogrel treatment, correlate well with LTA.
Background:B-type natriuretic peptide (BNP) is an established marker for heart failure assessment, but the prognostic quality of BNP after atrial switch operation (ASO) has not yet been ...elucidated.Methods and Results:In 89 patients (median age, 24 years; range, 15–35 years) after ASO, BNP was measured. During a 48-months follow-up we focused on critical cardiac events, defined as decompensation, sudden cardiac death or need for heart transplantation. BNP was considerably lower in 81 patients in functional class (FC) I/II (median, 35 pg/ml; range, 3–586 pg/ml) than in 6 patients in FC III/IV (median, 246 pg/ml; range, 14–1,150 pg/ml, P≤0.073). BNP was significantly higher after Mustard than after Senning procedure (P≤0.030). There was no significant difference in BNP between simple or complex transposition of the great arteries (TGA) (P≤0.44). Eleven subjects (13%, 95% CI: 7–22%) had a critical cardiac event within 48 months. On ROC analysis BNP had a high predictive value regarding discrimination of patients with and without critical events (area under the ROC curve, 0.90; 95% CI: 0.76 to >0.99, P<0.001). The cut-off was 85 pg/ml (sensitivity, 88%; specificity, 85%). Additionally, estimated event-free-survival was longer after Senning than after Mustard procedure (P≤0.017). There was no significant difference in outcome between patients with simple or complex TGA with regard to occurrence of critical events.Conclusions:BNP is a sensitive and specific prognostic marker for critical cardiac events after ASO. (Circ J 2015; 79: 2677–2681)
Abstract Background The amyloid beta peptide is the major protein constituent of neuritic plaques in Alzheimer disease and appears to play a central role in vascular inflammation pathophysiology. ...Objectives This study sought to determine the clinical value of amyloid-beta 1-40 (Abeta40) measurement in predicting cardiovascular (CV) mortality in patients with coronary heart disease (CHD) and arterial stiffness progression in young healthy subjects. Methods Abeta40 was retrospectively measured in blood samples collected from 3 independent prospective cohorts and 2 case-control cohorts (total N = 1,464). Major adverse cardiac events (MACE) were assessed in the 2 prospective cohorts (n = 877) followed for a median of 4.4 years. To look at effects on subclinical disease, arterial stiffness was evaluated at baseline and after 5-year follow-up (n = 107) in young healthy subjects. The primary endpoint was the predictive value of Abeta40 for CV mortality and outcomes in patients with CHD. Results In Cox proportional hazards models adjusted for age, sex, estimated glomerular filtration rate, left ventricular ejection fraction, high-sensitivity C-reactive protein, and high-sensitivity troponin T, Abeta40 independently predicted CV death and MACE in patients with CHD (p < 0.05 for all). After multivariate adjustment, Abeta40 levels conferred a substantial enhancement of net reclassification index and integrated discrimination improvement of individuals at risk in the total combined CHD cohort over the best predictive model. Further cohort-based analysis revealed that Abeta40 levels were significantly and independently associated with arterial stiffness progression, incident subclinical atherosclerosis, and incident CHD. Conclusions Measuring blood levels of Abeta40 identified patients at high risk for CV death.
Objectives To evaluate the in vitro effects of high concentrations of heparin and its reversal with protamine on routine laboratory parameters as well as on modified thromboelastogram (ROTEM; TEM ...International, Munich, Germany) and impedance aggregometry (MULTIPLATE; Dynabyte, Munich, Germany). Design An observational, nonrandomized in vitro study. Setting A single-center, university hospital. Participants Ten healthy volunteers. Interventions Heparinization of whole blood to levels of 2, 4, 6, and 8 IU/mL of heparin and reversal with protamine. For MULTIPLATE measurements, heparin levels up to 20 IU/mL were tested. Measurements and Main Results The present results show that the prothrombin time (PT) and fibrinogen measurements are altered significantly by heparin concentrations above 2 IU/mL. Protamine reversal also affected coagulation tests except for the fibrinogen. The INTEM test using the ROTEM system was influenced significantly by heparin concentrations of 2 IU/mL or higher, whereas EXTEM measurements remained stable up to 4 IU/mL. The findings for the FIBTEM test were stable up to 6 IU/mL but then declined to values less than 50% of baseline at 8 IU/mL. HEPTEM results remained valid under all concentrations of heparin tested. The effect of protamine on ROTEM was seen mainly in the INTEM and HEPTEM measurements. Heparin concentrations up to a level of 20 U/mL had no effect on MULTIPLATE measurements. Effects of protamine on MULTIPLATE became significant at heparin-to-protamine ratios below 1:1 and were more pronounced for adenosine diphosphate than for thrombin receptor-activated protein testing. Conclusions Neither fibrinogen (Clauss) nor derived fibrinogen or FIBTEM testing is valid in the setting of high concentrations of heparin unless antagonized by heparinase. Reversal of heparin with protamine worsens platelet function at all ratios as detected by aggregometry (MULTIPLATE) and thromboelastography (ROTEM), starting at a 1:1 ratio. Therefore, appropriate coagulation testing under cardiopulmonary bypass conditions should be selected carefully according to heparin levels. In particular, fibrinogen values are falsely low at heparin levels of 2 IU/mL and above. Therefore, newer algorithms promoting the correction of fibrinogen levels on cardiopulmonary bypass should be based on appropriate testing.
PDF
