Hemodynamic effects of Vernakalant in cardio-surgical ICU-patients treated for recent-onset postoperative atrial fibrillation.

Postoperative atrial fibrillation (POAF) is one of the most frequent complications after cardiothoracic surgery and a predictor for postoperative mortality and prolonged ICU-stay. Current guidelines suggest the multi-channel inhibitor Vernakalant as a treatment option for rhythm control. However, rare cases of severe hypotension and cardiogenic shock following drug administration have been reported. To elucidate the impact of Vernakalant on hemodynamics, we included ten ICU patients developing POAF after elective cardiac surgery, all of them awake and breathing spontaneously, in this prospective trial. Patients received the recommended dosage of Vernakalant and were clinically observed and monitored (heart rate, invasive blood pressure, pulse oximetry, central venous pressure) in 1-minute-intervals for 20 minutes before- and 120 minutes after the first dose of Vernakalant. The median time from the end of surgery until occurrence of POAF amounted up to 52.8 [45.9-77.4] hours, it took 3.5 [1.2-10.1] hours from occurrence of POAF until the first application of Vernakalant. All patients received catecholamine support with epinephrine that was held steady and not dynamic throughout the observational phase. We noted stable hemodynamic conditions, with a trend towards a reduction in heart rate throughout the 120 minutes after drug administration. In 7 patients (70%), conversion to sustained sinus rhythm (SR) occurred within 8.0 minutes [6.0-9.0]. No serious adverse events (SAEs) were noted during the observation period. In this prospective trial in ICU-patients showing POAF after cardiac surgery, intravenous Vernakalant did not induce clinically relevant negative effects on patients' hemodynamics but resulted in conversion to sustained SR after a median of 8.0 minutes in 7 out of ten patients.

Added value of the DIC score and of D-dimer to predict outcome after successfully resuscitated out-of-hospital cardiac arrest.

BACKGROUND: Recent Korean data suggest a high prevalence of overt disseminated intravascular coagulation (DIC) and a good predictive performance of the ISTH DIC score in successfully resuscitated out-of-hospital cardiac arrest. OBJECTIVES: We hypothesised that in a European cohort of resuscitated out-of-hospital cardiac arrest patients the prevalence of DIC is substantially lower. Furthermore, the determination of D-dimer levels at admission, but not the DIC score, could improve mortality prediction above traditional predictors. PATIENTS/METHODS: Data were extracted from a prospective cardiac arrest registry including patients admitted between 2006 and 2015, who achieved return of spontaneous circulation and had parameters for DIC score calculation available. The primary outcome was the prevalence of overt DIC at admission. Secondary outcomes included the association of overt DIC with 30-day mortality and the contribution of the DIC score and D-dimer levels to 30-day mortality prediction using logistic regression. Three stepwise models were evaluated by receiver-operating-characteristic analysis. RESULTS: Out of 1179 patients 388 were included in the study. Overt DIC was present in 8% of patients and associated with substantial 30-day mortality (83% vs. 39%). The AUC for model 1, including traditional mortality predictors, was 0.83. The inclusion of D-dimer levels significantly improved prognostication above traditional predictors (model 3, AUC 0.89), whereas the inclusion of the DIC Score had no effect on mortality prediction (model 2, AUC 0.83). CONCLUSION: Overt DIC was rare in a European cohort of out-of-hospital cardiac arrest patients. D-dimer levels improved 30-day mortality prediction and provided added value to assess early mortality risk after successful resuscitation.

The recommended dose of idarucizumab may not always be sufficient for sustained reversal of dabigatran.

Essentials Reversal of anticoagulant effects of dabigatran may occur despite application of idarucizumab. Monitoring of dabigatran level after antidote application is crucial to detect rebound. Repeated doses of idarucizumab may be necessary in cases of massive dabigatran accumulation. Combination of antidote application and renal replacement therapy may offer additional benefit. SUMMARY: Idarucizumab is a monoclonal antibody fragment designed for reversing the anticoagulant effects of dabigatran. Administration is recommended as two intravenous boluses of 2.5 g within 15 min of each other or as a single 5 g bolus. However, in certain situations a second dose of the drug could be necessary. We report the case of a 77-year-old man, treated with dabigatran for paroxysmal atrial fibrillation. He presented at our department with acute renal failure, concomitant massive dabigatran accumulation and subsequent acute gastrointestinal bleeding. Fifty minutes after the administration of idarucizumab, the dabigatran plasma concentration decreased from a peak of 1630 ng ml-1 to a level below the detection limit of 30 ng ml-1 and bleeding stopped. Eight hours after administration, the dabigatran plasma level started to increase up to 1560 ng ml-1 (96% of the maximum value obtained), accompanied by a further drop in hemoglobin. Concomitant hemodialysis and hemofiltration led to a continuous decrease in dabigatran plasma levels. However, sepsis and multiorgan failure ensued, which led to death. With this case report we raise the question of whether massive dabigatran accumulation requires repeated doses of idarucizumab, or alternatively, if the combination of antidote with hemodialysis/renal replacement therapy is advisable in order to remove circulating levels of dabigatran.

Massive pulmonary embolism leading to cardiac arrest is associated with consumptive coagulopathy presenting as disseminated intravascular coagulation.

SUMMARY BACKGROUND: A consumptive coagulopathy resembling disseminated intravascular coagulation (DIC) has been seen in patients with massive pulmonary embolism (PE). We hypothesized that a DIC-like condition is relevant in patients whose pulmonary embolism leads to cardiopulmonary arrest and cardiopulmonary resuscitation (CPR). METHODS: This hypothesis was tested by the use of a database consisting of all cases of PE diagnosed at the Department of Emergency Medicine from June 1993 to October 2007. Out of 1018 cases with PE, 113 patients underwent CPR. In this cohort study, the resuscitated patients were compared with those with PE but without CPR. RESULTS: Patients with PE and CPR had 3-fold higher D-dimer, prolonged prothrombin time (PT), reduced platelet counts and lower fibrinogen and antithrombin (AT) levels compared with PE patients without cardiac arrest (P < 0.001 for all). Among patients with PE and CPR, D-dimer was abnormal in 100%, PT in 44%, AT in 53%, fibrinogen in 19% and platelets in 25%. In comparison, PE without CPR was associated with abnormal D-dimer in 99%, abnormal PT in 15%, low AT in 6%, low fibrinogen in 1% and low platelets in 2%. Nine per cent of the resuscitated patients had a DIC score >or= 5, indicating overt DIC. The DIC score highly correlated with 1-year and in-hospital mortality. CONCLUSIONS: Massive PE leading to CPR is associated with consumptive coagulopathy and overt DIC. In resuscitated patients, DIC markers may indicate pulmonary embolism as the underlying cause of arrest.

Influence of the Duffy antigen on pharmacokinetics and pharmacodynamics of recombinant monocyte chemoattractant protein (MCP-1, CCL-2) in vivo.

Monocyte chemoattractant protein-1 (MCP-1, CCL-2) binds to the Duffy antigen (DARC) on red blood cells, which act as a sink for several chemokines including MCP-1. In this study it is hypothesized that DARC may alter the pharmacokinetics of infused recombinant human MCP-1 (rhMCP-1). The primary aim of this first in man trial is to compare the pharmacokinetics of rhMCP-1 in Duffy positive and negative individuals. A randomized, double-blinded, placebo-controlled dose escalation trial was conducted on 36 healthy volunteers. Subjects received infusions of 0.02-2.0 microg/kg rhMCP-1 or placebo for one hour. RhMCP-1 displayed linear pharmacokinetics. Duffy negative individuals reached maximal plasma levels significantly earlier, but overall plasma concentration profiles were not altered. rhMCP-1 markedly increased monocyte counts, and estimated EC50 values were 10-fold higher in Duffy positive than in Duffy negative subjects. Increased monocyte counts were associated with decreased surface expression of intercellular adhesion molecule 1 (ICAM-1, CD54). In contrast, neither CCR-2 or CD11b expression, nor markers of platelet or endothelial activation, inflammation and coagulation were altered. RhMCP-1 is a highly selective chemoattractant for monocytes in humans. The Duffy antigen only minimally alters the pharmacokinetics of rhMCP-1 for doses up to 2 microg/kg.

Racial differences in endotoxin-induced tissue factor-triggered coagulation.

BACKGROUND: Racial differences in coagulation are poorly understood. While some studies suggest a 'prothrombotic' coagulation profile in blacks compared with whites, others report an increased bleeding risk for blacks in various clinical settings. Moreover, preclinical data suggest a link between the Duffy antigen (=DARC, Duffy antigen receptor of chemokines) and coagulation. OBJECTIVES: Based on our previous research in Duffy antigen negative Africans, we hypothesized that Africans have an attenuated procoagulant response compared with Caucasians in a model of lipopolysaccharide (LPS)-induced, tissue factor (TF)-triggered coagulation activation. PATIENTS/METHODS: Healthy male volunteers (16 Duffy-negative Africans, 16 Duffy-positive Caucasians) received 2 ng kg(-1) LPS, and outcome parameters were measured using enzyme immunoassays and real-time polymerase chain reaction (RT-PCR, Taqman). RESULTS: LPS increased microparticle (MP)-associated TF procoagulant activity (PCA) less in Africans than Caucasians. Africans had reduced in vivo thrombin formation compared with Caucasians: they generated less thrombin-antithrombin (TAT) complexes (10.4 pg mL(-1) vs. 23.0 pg mL(-1), P<0.0001) and less prothrombin fragments (F1+2) (337 pmol mL(-1) vs. 819 pmol mL(-1), P<0.0001). Consistently, Africans also had decreased fibrin formation (D-dimer: 0.3 pg mL(-1) vs. 0.5 pg mL(-1), P=0.02). CONCLUSION: Duffy-negative subjects of African descent have a markedly reduced procoagulant response in a model of LPS-induced, TF-triggered coagulation activation compared with Duffy-positive healthy Caucasians.

The pharmacokinetics and pharmacodynamics of a new sustained-release leuprolide acetate depot compared to market references.

OBJECTIVE: The aim of this study was to compare the efficacy of Lutrate 3.75 and 7.5 mg depot to marketed references Lucrin 3.75 mg and Procrin 7.5 mg depot. METHODS: 20 healthy male volunteers were randomly assigned to receive 1 of 4 active single dose treatments in this double-blind, parallel-group pilot study. Leuprolide acetate and testosterone levels were quantified by radioimmunoassays. RESULTS: The pharmacokinetic profile of leuprolide could be well-described by a 4-step release curve. Leuprolide levels were detectable 14 days longer after injection of the test formulations as compared to the reference products. The total AUC observed with 3.75 and 7.5 mg of the test product were approximately 1.5- and 2.2-fold higher, compared to the reference products, respectively. After the expected testosterone "flare-up" effect, castration was achieved in 4 of 4 subjects with the test formulations, 4 of 5 subjects with Procrin and 2 of 5 subjects with Lucrin. On average, castration lasted more than 1 month with both test formulations compared to 2 weeks with the reference products. CONCLUSION: Sustained release of leuprolide from this new depot formulation suppressed testosterone levels at least as effectively and for a longer period of time than the reference products.

Effects of low dose endotoxemia on endothelial progenitor cells in humans.

BACKGROUND: Endothelial progenitor cells (EPCs) are a specific subtype of hematopoietic stem cells that migrate from the bone marrow to the peripheral circulation where they contribute to the repair of injured endothelium and to the formation of new blood vessels. Levels of circulating EPCs have been investigated in different inflammatory disease states. However, data on circulating EPC levels and systemic inflammation remain scarce and contradictory. OBJECTIVE: We investigated a putative relationship of low grade experimental endotoxemia to changes in circulating EPC levels. METHODS: Randomized, double-blind, placebo-controlled parallel group trial in 36 healthy male volunteers. Thirty-two volunteers received 2 ng/kg LPS intravenously, the remaining four an equal volume of physiologic saline solution as placebo. RESULTS: Endothelial progenitor cells showed a significant decrease over the observation period among the 32 subjects challenged with LPS (P<0.0001) and reached their nadir at 6 h, with a median decrease of 62% (interquartile range: 48-81%) compared with baseline levels. Circulating EPCs returned to values comparable to baseline 24 h after LPS challenge. CONCLUSION: Infusion of 2 ng/kg LPS led to a significant decrease in peripheral EPCs. These results suggest that the early phase of acute inflammation is associated with a decrease in peripheral EPCs.

Pharmacokinetics and pharmacodynamics of the dual FII/FX inhibitor BIBT 986 in endotoxin-induced coagulation.

BIBT986 is a dual inhibitor of factors Xa and IIa. The aim of this study was to compare with placebo the effect of three doses of BIBT986 on coagulation, platelet activation, and inflammation. This was a prospective, randomized, double-blind, placebo-controlled, parallel-group dose escalation trial in 48 healthy male volunteers. Participants received one of three doses of BIBT986 or placebo intravenously together with a bolus infusion of 2 ng/kg lipopolysaccharide (LPS). BIBT986 dose-dependently changed global coagulation parameters and in vivo markers of thrombin generation and action: BIBT986 doses, which prolonged activated partial thromboplastin time by 100%, completely suppressed the LPS-induced increases in prothrombin fragment, thrombin-antithrombin complexes, and D-dimer, which were 6.1-, 14.5, and 3.5-fold in the placebo group, respectively. BIBT986 did not influence inflammation, fibrinolysis, or platelet activation. Therefore, BIBT986 is a potent anticoagulant in the human endotoxemia model.

Reparixin, a specific interleukin-8 inhibitor, has no effects on inflammation during endotoxemia.

Reparixin antagonizes interleukin-8 (IL-8) on the level of signal transduction in vitro. We hypothesized that IL-8 mediates some of the reactions occurring during acute inflammation and specifically that IL-8 may be a mediator of endotoxin induced neutrophilia. We therefore tested the effects of reparixin on humoral and cellular parameters in LPS-induced acute systemic inflammation. The study is a randomized (3:2 active:placebo), double-blind, placebo-controlled parallel group trial. Twenty healthy male volunteers randomly received either reparixin (12) or placebo (8) intravenously. One hour after the start of reparixin/placebo infusion a bolus of 2 ng/kg endotoxin was infused over 1-2 min. Blood samples were obtained over 24 h. Reparixin, being metabolized to ibuprofen, suppressed serum thromboxane B2 levels by 78 percent compared to baseline and control at 8 h. LPS-induced neutrophilia was not significantly affected by reparixin in human volunteers. Consistently, reparixin did not alter the lymphocyte or monocyte counts and had no effect on LPS-induced systemic inflammation as measured by tumor necrosis factor alpha (TNF-alpha) or interleukin-6 (IL-6) release. Regulation of IL-8 receptors CXCR1 and 2 and the degranulation marker CD11b showed the expected kinetics. Reparixin had no effect on thrombin formation as measured by prothrombin fragment (F1+2). In conclusion, our study showed that reparixin was safe but had no impact on endotoxin induced inflammation. In contrast to previous studies with its metabolite ibuprofen, reparixin does not enhance inflammation in this model.

Validation of rotation thrombelastography in a model of systemic activation of fibrinolysis and coagulation in humans.

BACKGROUND: Thrombelastography (TEG) is a whole blood assay to evaluate the viscoelastic properties during blood clot formation and clot lysis. Rotation thrombelastography (e.g. ROTEM) has overcome some of the limitations of classical TEG and is used as a point-of-care device in several clinical settings of coagulation disorders. Endotoxemia leads to systemic activation of the coagulation system and fibrinolysis in humans. OBJECTIVES: We validated whether ROTEM is sensitive to endotoxin induced, tissue factor-triggered coagulation and fibrinolysis and if its measures correlate with biohumoral markers of coagulation and fibrinolysis. PATIENTS AND METHODS: Twenty healthy male volunteers participated in this randomized placebo-controlled trial. Volunteers received either 2 ng kg(-1) National Reference Endotoxin or saline. RESULTS: Endotoxemia significantly shortened ROTEM clotting time (CT) by 36% (CI 0.26-0.46; P < 0.05) with a strong inverse correlation with the peak plasma levels of prothrombin fragments (F(1 + 2)) (r = -0.83, P < 0.05). Additionally, endotoxin infusion enhanced maximal lysis (ML) 3.9-fold (CI: 2.5-5.2) compared with placebo or baseline after 2 h (P < 0.05). Peak ML and peak tissue plasminogen activator (t-PA) values correlated excellently (r = 0.82, P < 0.05). ROTEM parameters clot formation time and maximal clot firmness were not affected by LPS infusion, whereas platelet function analyzer (PFA-100) closure times decreased. CONCLUSIONS: Rotation thrombelastography (ROTEM) detects systemic changes of in vivo coagulation activation, and importantly it is a point of care device, which is sensitive to changes in fibrinolysis in humans. The ex vivo measures CT and ML correlate very well with established in vivo markers of coagulation activation (F(1 + 2)) and fibrinolysis (t-PA), respectively.