Supplemental fibrinogen restores thrombus formation in cardiopulmonary bypass-induced platelet dysfunction ex vivo.

BACKGROUND: Major cardiac surgery related blood loss is associated with increased postoperative morbidity and mortality. Platelet dysfunction is believed to contribute to post-cardiopulmonary bypass (CPB)-induced microvascular bleeding. We hypothesised that moderately hypothermic CPB induces platelet dysfunction and that supplemental fibrinogen can restore in vitro thrombus formation. METHODS: Blood from 18 patients, undergoing first-time elective isolated aortic valve surgery was drawn before CPB, 30 min after initiation of CPB, and after CPB and protamine administration, respectively. Platelet aggregation was quantified by optical aggregometry, platelet activation by flow-cytometric detection of platelet surface expression of P-selectin, annexin V, and activated glycoprotein IIb/IIIa, thrombus formation under flow and effect of supplemental fibrinogen (4 mg ml-1) on in vitro thrombogenesis. RESULTS: Post-CPB adenosine-diphosphate and TRAP-6-induced aggregation decreased by 40% and 10% of pre-CPB levels, respectively (P<0.0001). Although CPB did not change glycoprotein IIb/IIIa receptor expression, it increased the percentage of unstimulated P-selectin (1.2% vs 7%, P<0.01) positive cells and annexin V mean fluorescence intensity (15.5 vs 17.2, P<0.05), but decreased percentage of stimulated P-selectin (52% vs 26%, P<0.01) positive cells and annexin V mean fluorescence intensity (508 vs 325, P<0.05). Thrombus area decreased from 6820 before CPB to 5230 after CPB (P<0.05, arbitrary units [a.u.]). Supplemental fibrinogen increased thrombus formation to 20 324 and 11 367 a.u. before CPB and after CPB, respectively (P<0.001), thereby restoring post-CPB thrombus area to levels comparable with or higher than pre-CPB baseline. CONCLUSIONS: Single valve surgery using moderately hypothermic CPB induces partial platelet dysfunction. Thrombus formation was restored in an experimental study design by ex vivo supplementation of fibrinogen.

Divergent Roles of Ephrin-B2/EphB4 Guidance System in Pulmonary Hypertension.

BACKGROUND: Smooth muscle cell (SMC) expansion is one key morphological hallmark of pathologically altered vasculature and a characteristic feature of pulmonary vascular remodeling in pulmonary hypertension. Normal embryonal vessel maturation requires successful coverage of endothelial tubes with SMC, which is dependent on ephrin-B2 and EphB4 ligand-receptor guidance system. In this study, we investigated the potential role of ephrin-B2 and EphB4 on neomuscularization in adult pulmonary vascular disease. METHODS AND RESULTS: Ephrin-B2 and EphB4 expression is preserved in smooth muscle and endothelial cells of remodeled pulmonary arteries. Chronic hypoxia-induced pulmonary hypertension was not ameliorated in mice with SMC-specific conditional ephrin-B2 knockout. In mice with global inducible ephrin-B2 knockout, pulmonary vascular remodeling and right ventricular hypertrophy upon chronic hypoxia exposure were significantly diminished compared to hypoxic controls, while right ventricular systolic pressure was unaffected. In contrast, EphB4 receptor kinase activity inhibition reduced right ventricular systolic pressure in hypoxia-induced pulmonary hypertension without affecting pulmonary vascular remodeling. Genetic deletion of ephrin-B2 in murine pulmonary artery SMC, and pharmacological inhibition of EphB4 in human pulmonary artery smooth muscle cells, blunted mitogen-induced cell proliferation. Loss of EphB4 signaling additionally reduced RhoA expression and weakened the interaction between human pulmonary artery smooth muscle cells and endothelial cells in a three-dimensional coculture model. CONCLUSIONS: In sum, pulmonary vascular remodeling was dependent on ephrin-B2-induced Eph receptor (erythropoietin-producing hepatocellular carcinoma receptor) forward signaling in SMC, while EphB4 receptor activity was necessary for RhoA expression in SMC, interaction with endothelial cells and vasoconstrictive components of pulmonary hypertension.

Prophylactic levosimendan in patients with low ejection fraction undergoing coronary artery bypass grafting: A pooled analysis of two multicentre randomised controlled trials.

OBJECTIVES: To assess the effect of preoperative levosimendan on mortality at day 90 in patients with left ventricular ejection fraction (LVEF) ≤ 40%, and to investigate a possible differential effect between patients undergoing isolated coronary artery bypass grafting (CABG) versus CABG combined with valve replacement surgery. DESIGN: Pooled analysis of two multicentre randomised controlled trials (RCT) investigating prophylactic levosimendan versus placebo prior to CABG surgery on mortality at day 90 in patients with LVEF ≤ 40%. A meta-analysis of all RCT investigating the same issue was also conducted. RESULTS: A cohort of 1084 patients (809 isolated CABG, and 275 combined surgery) resulted from the merging of LEVO-CTS and LICORN databases. Seventy-two patients were dead at day 90. The mortality at day 90 was not different between levosimendan and placebo (Hazard Ratio (HR): 0.73, 95% CI: 0.41-1.28, p = 0.27). However, there was a significant interaction between the type of surgery and the study drug (p = 0.004). We observed a decrease in mortality at day 90 in the isolated CABG subgroup (HR: 0.39, 95% CI: 0.19-0.82, p = 0.013), but not in the combined surgery subgroup (HR: 1.73, 95% CI: 0.77-3.92, p = 0.19). The meta-analysis of 6 RCT involving 1441 patients confirmed the differential effect on mortality at day 30 between the 2 subgroups. CONCLUSIONS: Preoperative levosimendan did not reduce mortality in a mixed surgical population with LV dysfunction. However, the subgroup of patients undergoing isolated CABG had a reduction in mortality at day 90, whereas there was no significant effect in combined surgery patients. This finding requires confirmation with a specific prospective trial.

An update on levosimendan in acute cardiac care: applications and recommendations for optimal efficacy and safety.

Introduction: In the 20 years since its introduction to the palette of intravenous hemodynamic therapies, the inodilator levosimendan has established itself as a valuable asset for the management of acute decompensated heart failure. Its pharmacology is notable for delivering inotropy via calcium sensitization without an increase in myocardial oxygen consumption.Areas covered: Experience with levosimendan has led to its applications expanding into perioperative hemodynamic support and various critical care settings, as well as an array of situations associated with acutely decompensated heart failure, such as right ventricular failure, cardiogenic shock with multi-organ dysfunction, and cardio-renal syndrome. Evidence suggests that levosimendan may be preferable to milrinone for patients in cardiogenic shock after cardiac surgery or for weaning from extracorporeal life support and may be superior to dobutamine in terms of short-term survival, especially in patients on beta-blockers. Positive effects on kidney function have been noted, further differentiating levosimendan from catecholamines and phosphodiesterase inhibitors.Expert opinion:Levosimendan can be a valuable resource in the treatment of acute cardiac dysfunction, especially in the presence of beta-blockers or ischemic cardiomyopathy. When attention is given to avoiding or correcting hypovolemia and hypokalemia, an early use of the drug in the treatment algorithm is preferred.

How Do Type of Preoperative P2Y12 Receptor Inhibitor and Withdrawal Time Affect Bleeding?

BACKGROUND: Despite recommendations for standardized preoperative waiting of at least 3, 5, and 7 days for ticagrelor, clopidogrel, and prasugrel, respectively, there is still substantial interinstitutional variation in preoperative discontinuation of dual antiplatelet therapy in patients needing coronary artery bypass grafting (CABG). METHODS: In 299 patients undergoing CABG with or without valve intervention less than 7 days after last P2Y12 receptor inhibition, this study evaluated calculated red blood cell loss and Bleeding Academic Research Consortium type 4 (BARC-4) bleeding. RESULTS: A total of 83% of patients underwent CABG less than 48 hours after last drug intake. Calculated blood loss was lower in patients taking clopidogrel as compared with prasugrel or ticagrelor (1063 mL [690 to 1394 mL] vs 1351 mL [876 to 1829 mL] vs 1330 mL [994 to 1691 mL]; P < .001). Overall, 135 (45%) patients sustained BARC-4 bleeding; the incidence differed among the groups (P = .015) and was significantly higher in prasugrel-treated patients, as compared with clopidogrel-treated patients. In multivariable linear regression analysis, European System for Cardiac Operative Risk Evaluation II (EuroSCORE II), aspirin dose, cardiopulmonary bypass time, drug withdrawal time, and type of P2Y12 receptor inhibitor were significantly associated with red blood cell loss. Compared with 0 to 24 hours, a period of more than 48 hours of preoperative discontinuation substantially reduced calculated blood loss by 37% to 48% and BARC-4 bleeding by 58% to 71%, depending on the P2Y12 receptor inhibitor. CONCLUSIONS: Exposure to prasugrel and ticagrelor 24 hours or less before CABG increases both calculated blood loss and BARC-4 bleeding as compared with clopidogrel. Although discontinuation for longer than 48 hours substantially reduced calculated blood loss and BARC-4 bleeding across all P2Y12 receptor inhibitors, our single-center data further support strict adherence to the 2017 guidelines whenever justified by stable hemodynamics and nonjeopardized myocardium.

Levosimendan Efficacy and Safety: 20 Years of SIMDAX in Clinical Use.

Levosimendan was first approved for clinical use in 2000, when authorization was granted by Swedish regulatory authorities for the hemodynamic stabilization of patients with acutely decompensated chronic heart failure (HF). In the ensuing 20 years, this distinctive inodilator, which enhances cardiac contractility through calcium sensitization and promotes vasodilatation through the opening of adenosine triphosphate-dependent potassium channels on vascular smooth muscle cells, has been approved in more than 60 jurisdictions, including most of the countries of the European Union and Latin America. Areas of clinical application have expanded considerably and now include cardiogenic shock, takotsubo cardiomyopathy, advanced HF, right ventricular failure, pulmonary hypertension, cardiac surgery, critical care, and emergency medicine. Levosimendan is currently in active clinical evaluation in the United States. Levosimendan in IV formulation is being used as a research tool in the exploration of a wide range of cardiac and noncardiac disease states. A levosimendan oral form is at present under evaluation in the management of amyotrophic lateral sclerosis. To mark the 20 years since the advent of levosimendan in clinical use, 51 experts from 23 European countries (Austria, Belgium, Croatia, Cyprus, Czech Republic, Estonia, Finland, France, Germany, Greece, Hungary, Italy, the Netherlands, Norway, Poland, Portugal, Russia, Slovenia, Spain, Sweden, Switzerland, the United Kingdom, and Ukraine) contributed to this essay, which evaluates one of the relatively few drugs to have been successfully introduced into the acute HF arena in recent times and charts a possible development trajectory for the next 20 years.

Levosimendan Efficacy and Safety: 20 years of SIMDAX in Clinical Use.

Levosimendan was first approved for clinic use in 2000, when authorisation was granted by Swedish regulatory authorities for the haemodynamic stabilisation of patients with acutely decompensated chronic heart failure. In the ensuing 20 years, this distinctive inodilator, which enhances cardiac contractility through calcium sensitisation and promotes vasodilatation through the opening of adenosine triphosphate-dependent potassium channels on vascular smooth muscle cells, has been approved in more than 60 jurisdictions, including most of the countries of the European Union and Latin America. Areas of clinical application have expanded considerably and now include cardiogenic shock, takotsubo cardiomyopathy, advanced heart failure, right ventricular failure and pulmonary hypertension, cardiac surgery, critical care and emergency medicine. Levosimendan is currently in active clinical evaluation in the US. Levosimendan in IV formulation is being used as a research tool in the exploration of a wide range of cardiac and non-cardiac disease states. A levosimendan oral form is at present under evaluation in the management of amyotrophic lateral sclerosis. To mark the 20 years since the advent of levosimendan in clinical use, 51 experts from 23 European countries (Austria, Belgium, Croatia, Cyprus, Czech Republic, Estonia, Finland, France, Germany, Greece, Hungary, Italy, the Netherlands, Norway, Poland, Portugal, Russia, Slovenia, Spain, Sweden, Switzerland, UK and Ukraine) contributed to this essay, which evaluates one of the relatively few drugs to have been successfully introduced into the acute heart failure arena in recent times and charts a possible development trajectory for the next 20 years.

Levosimendan in patients with reduced left ventricular function undergoing isolated coronary or valve surgery.

OBJECTIVE: In the Levosimendan in Patients with Left Ventricular Systolic Dysfunction Undergoing Cardiac Surgery Requiring Cardiopulmonary Bypass (LEVO-CTS) trial, no differences in clinical outcomes were observed between levosimendan and placebo in a broad population of patients undergoing cardiac surgery. In previous studies, the benefits of levosimendan were most clearly evident in patients undergoing isolated coronary artery bypass grafting (CABG) surgery. In a prespecified analysis of LEVO-CTS, we compared treatment-related outcomes and costs across types of cardiac surgical procedures. METHODS: Overall, 563 (66.4%) patients underwent isolated CABG, 97 (11.4%) isolated valve, and 188 (22.2%) combined CABG/valve surgery. Outcomes included the co-primary 4-component composite (30-day mortality, 30-day renal replacement, 5-day myocardial infarction, or 5-day mechanical circulatory support), the 2-component composite (30-day mortality or 5-day mechanical circulatory support), 90-day mortality, low cardiac output syndrome (LCOS), and 30-day medical costs. RESULTS: The 4- and 2-component outcomes were not significantly different with levosimendan and placebo in patients undergoing CABG (15.2% vs 19.3% and 7.8% vs 10.4%), valve (49.0% vs 33.3% and 22.4% vs 2.1%), or combined procedures (39.6% vs 35.9% and 24.0% vs 19.6%). Ninety-day mortality was lower with levosimendan in isolated CABG (2.1% vs 7.9%; hazard ratio [HR], 0.26; 95% confidence interval [CI], 0.11-0.64), but not significantly different in valve (8.3% vs 2.0%; HR, 4.10; 95% CI, 0.46-36.72) or combined procedures (10.4% vs 7.6%; HR, 1.39; 95% CI, 0.53-3.64; interaction P = .011). LCOS (12.0% vs 22.1%; odds ratio, 0.48; 95% CI, 0.30-0.76; interaction P = .118) was significantly lower in levosimendan-treated patients undergoing isolated CABG. Excluding study drug costs, median and mean 30-day costs were $53,707 and $65,852 for levosimendan and $54,636 and $67,122 for placebo, with a 30-day mean difference (levosimendan - placebo) of -$1270 (bootstrap 95% CI, -$8722 to $6165). CONCLUSIONS: Levosimendan was associated with lower 90-day mortality and LCOS in patients undergoing isolated CABG, but not in those undergoing isolated valve or combined CABG/valve procedures.

A prolonged run-in period of standard subcutaneous microdialysis ameliorates quality of interstitial glucose signal in patients after major cardiac surgery.

We evaluated a standard subcutaneous microdialysis technique for glucose monitoring in two critically ill patient populations and tested whether a prolonged run-in period improves the quality of the interstitial glucose signal. 20 surgical patients after major cardiac surgery (APACHE II score: 10.1 ± 3.2) and 10 medical patients with severe sepsis (APACHE II score: 31.1 ± 4.3) were included in this investigation. A microdialysis catheter was inserted in the subcutaneous adipose tissue of the abdominal region. Interstitial fluid and arterial blood were sampled in hourly intervals to analyse glucose concentrations. Subcutaneous adipose tissue glucose was prospectively calibrated to reference arterial blood either at hour 1 or at hour 6. Median absolute relative difference of glucose (MARD), calibrated at hour 6 (6.2 (2.6; 12.4) %) versus hour 1 (9.9 (4.2; 17.9) %) after catheter insertion indicated a significant improvement in signal quality in patients after major cardiac surgery (p < 0.001). Prolonged run-in period revealed no significant improvement in patients with severe sepsis, but the number of extreme deviations from the blood plasma values could be reduced. Improved concurrence of glucose readings via a 6-hour run-in period could only be achieved in patients after major cardiac surgery.

Tranexamic acid for treatment and prophylaxis of bleeding and hyperfibrinolysis.

Uncontrolled massive bleeding with subsequent derangement of the coagulation system is a major challenge in the management of both surgical and seriously injured patients. Under physiological conditions activators and inhibitors of coagulation regulate the sensitive balance between clot formation and fibrinolysis. In some cases, excessive and diffuse bleeding is caused by systemic activation of fibrinolysis, i. e. hyperfibrinolysis (HF). Uncontrolled HF is associated with a high mortality. Polytrauma patients and those undergoing surgical procedures involving organs rich in plasminogen proactivators (e. g. liver, kidney, pancreas, uterus and prostate gland) are at a high risk for HF. Antifibrinolytics, such as tranexamic acid (TXA) are used for prophylaxis and treatment of bleeding caused by a local or generalized HF as well as other hemorrhagic conditions. TXA is a synthetic lysine analogue that has been available in Austria since 1966. TXA is of utmost importance in the prevention and treatment of traumatic and perioperative bleeding due to the resulting reduction in perioperative blood loss and blood transfusion requirements. The following article presents the different fields of application of TXA with particular respect to indications and dosages, based on a literature search and on current guidelines.

Levosimendan in Patients with Left Ventricular Dysfunction Undergoing Cardiac Surgery.

BACKGROUND: Levosimendan is an inotropic agent that has been shown in small studies to prevent or treat the low cardiac output syndrome after cardiac surgery. METHODS: In a multicenter, randomized, placebo-controlled, phase 3 trial, we evaluated the efficacy and safety of levosimendan in patients with a left ventricular ejection fraction of 35% or less who were undergoing cardiac surgery with the use of cardiopulmonary bypass. Patients were randomly assigned to receive either intravenous levosimendan (at a dose of 0.2 µg per kilogram of body weight per minute for 1 hour, followed by a dose of 0.1 µg per kilogram per minute for 23 hours) or placebo, with the infusion started before surgery. The two primary end points were a four-component composite of death through day 30, renal-replacement therapy through day 30, perioperative myocardial infarction through day 5, or use of a mechanical cardiac assist device through day 5; and a two-component composite of death through day 30 or use of a mechanical cardiac assist device through day 5. RESULTS: A total of 882 patients underwent randomization, 849 of whom received levosimendan or placebo and were included in the modified intention-to-treat population. The four-component primary end point occurred in 105 of 428 patients (24.5%) assigned to receive levosimendan and in 103 of 421 (24.5%) assigned to receive placebo (adjusted odds ratio, 1.00; 99% confidence interval [CI], 0.66 to 1.54; P=0.98). The two-component primary end point occurred in 56 patients (13.1%) assigned to receive levosimendan and in 48 (11.4%) assigned to receive placebo (adjusted odds ratio, 1.18; 96% CI, 0.76 to 1.82; P=0.45). The rate of adverse events did not differ significantly between the two groups. CONCLUSIONS: Prophylactic levosimendan did not result in a rate of the short-term composite end point of death, renal-replacement therapy, perioperative myocardial infarction, or use of a mechanical cardiac assist device that was lower than the rate with placebo among patients with a reduced left ventricular ejection fraction who were undergoing cardiac surgery with the use of cardiopulmonary bypass. (Funded by Tenax Therapeutics; LEVO-CTS ClinicalTrials.gov number, NCT02025621 .).

Levosimendan in patients with left ventricular systolic dysfunction undergoing cardiac surgery on cardiopulmonary bypass: Rationale and study design of the Levosimendan in Patients with Left Ventricular Systolic Dysfunction Undergoing Cardiac Surgery Requiring Cardiopulmonary Bypass (LEVO-CTS) trial.

BACKGROUND: Low cardiac output syndrome is associated with increased mortality and occurs in 3% to 14% of patients undergoing cardiac surgery on cardiopulmonary bypass (CPB). Levosimendan, a novel calcium sensitizer and KATP channel activator with inotropic, vasodilatory, and cardioprotective properties, has shown significant promise in reducing the incidence of low cardiac output syndrome and related adverse outcomes in patients undergoing cardiac surgery on CPB. METHODS: LEVO-CTS is a phase 3 randomized, controlled, multicenter study evaluating the efficacy, safety, and cost-effectiveness of levosimendan in reducing morbidity and mortality in high-risk patients with reduced left ventricular ejection fraction (≤35%) undergoing cardiac surgery on CPB. Patients will be randomly assigned to receive either intravenous levosimendan (0.2 µg kg-1 min-1 for the first hour followed by 0.1 µg/kg for 23hours) or matching placebo initiated within 8hours of surgery. The co-primary end points are (1) the composite of death or renal replacement therapy through day 30 or perioperative myocardial infarction, or mechanical assist device use through day 5 (quad end point tested at α<.01), and (2) the composite of death through postoperative day 30 or mechanical assist device use through day 5 (dual end point tested at α<.04). Safety end points include new atrial fibrillation and death through 90days. In addition, an economic analysis will address the cost-effectiveness of levosimendan compared with placebo in high-risk patients undergoing cardiac surgery on CPB. Approximately 880 patients will be enrolled at approximately 60 sites in the United States and Canada between July 2014 and September 2016, with results anticipated in January 2017. CONCLUSION: LEVO-CTS, a large randomized multicenter clinical trial, will evaluate the efficacy, safety, and cost-effectiveness of levosimendan in reducing adverse outcomes in high-risk patients undergoing cardiac surgery on CPB. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov (NCT02025621).

Does Platelet Reactivity Predict Bleeding in Patients Needing Urgent Coronary Artery Bypass Grafting During Dual Antiplatelet Therapy?

BACKGROUND: Up to 15% of patients require coronary artery bypass grafting (CABG) during dual antiplatelet therapy. Available evidence suggests an association between platelet reactivity and CABG-related bleeding. However, platelet reactivity cutoffs for bleeding remain elusive. We sought to explore the association between platelet reactivity and bleeding. METHODS: Patients on aspirin and a P2Y12 receptor inhibitor within 48 hours before isolated CABG (n = 149) were enrolled in this prospective study. Blood was drawn 2 to 4 hours preoperatively and platelet reactivity assessed by light transmittance aggregometry (LTA), vasodilator-stimulated phosphoprotein (VASP) assay, Multiplate analyzer and Innovance PFA2Y. The primary endpoint was calculated red blood cell loss computed as follows: (blood volume × preoperative hematocrit × 0.91) - (blood volume × hematocrit × 0.91 on postoperative day 5) + (mL of transfused red blood cells × 0.59). RESULTS: Preoperative platelet reactivity was low [median (interquartile range): LTA: 20 (9-28)%; VASP-PRI: 39 (15-73)%; Multiplate adenosine phosphate test: 16 (12-22) U∗min]. Innovance PFA2Y ≥300 seconds, 72%. Median (IQR) red blood cell loss in patients in first the LTA tertile was 1,449 (1,020 to 1,754) mL compared with 1,107 (858 to 1,512) mL and 1,075 (811 to 1,269) mL in those in the second and third tertiles, respectively (p < 0.004). Bleeding Academic Research Consortium (BARC)-4 bleeding differed between tertiles (62% versus 46% versus 36%; p = 0.037). In a multivariable linear regression model, aspirin dose ≥300 mg, cardiopulmonary bypass time, EuroSCORE, and tertile distribution of platelet reactivity were significantly associated with red blood cell loss. CONCLUSIONS: A gradual decrease in red blood cell loss and BARC-4 bleeding occurs with increasing platelet reactivity in patients on antiplatelet therapy undergoing CABG. Our findings support current guidelines to determine time of surgery based on an objective measurement of platelet function (Platelet Inhibition and Bleeding in Patients Undergoing Emergent Cardiac Surgery; clinicaltrials.gov NCT01468597).

Clinical review: practical recommendations on the management of perioperative heart failure in cardiac surgery.

Acute cardiovascular dysfunction occurs perioperatively in more than 20% of cardiosurgical patients, yet current acute heart failure (HF) classification is not applicable to this period. Indicators of major perioperative risk include unstable coronary syndromes, decompensated HF, significant arrhythmias and valvular disease. Clinical risk factors include history of heart disease, compensated HF, cerebrovascular disease, presence of diabetes mellitus, renal insufficiency and high-risk surgery. EuroSCORE reliably predicts perioperative cardiovascular alteration in patients aged less than 80 years. Preoperative B-type natriuretic peptide level is an additional risk stratification factor. Aggressively preserving heart function during cardiosurgery is a major goal. Volatile anaesthetics and levosimendan seem to be promising cardioprotective agents, but large trials are still needed to assess the best cardioprotective agent(s) and optimal protocol(s). The aim of monitoring is early detection and assessment of mechanisms of perioperative cardiovascular dysfunction. Ideally, volume status should be assessed by 'dynamic' measurement of haemodynamic parameters. Assess heart function first by echocardiography, then using a pulmonary artery catheter (especially in right heart dysfunction). If volaemia and heart function are in the normal range, cardiovascular dysfunction is very likely related to vascular dysfunction. In treating myocardial dysfunction, consider the following options, either alone or in combination: low-to-moderate doses of dobutamine and epinephrine, milrinone or levosimendan. In vasoplegia-induced hypotension, use norepinephrine to maintain adequate perfusion pressure. Exclude hypovolaemia in patients under vasopressors, through repeated volume assessments. Optimal perioperative use of inotropes/vasopressors in cardiosurgery remains controversial, and further large multinational studies are needed. Cardiosurgical perioperative classification of cardiac impairment should be based on time of occurrence (precardiotomy, failure to wean, postcardiotomy) and haemodynamic severity of the patient's condition (crash and burn, deteriorating fast, stable but inotrope dependent). In heart dysfunction with suspected coronary hypoperfusion, an intra-aortic balloon pump is highly recommended. A ventricular assist device should be considered before end organ dysfunction becomes evident. Extra-corporeal membrane oxygenation is an elegant solution as a bridge to recovery and/or decision making. This paper offers practical recommendations for management of perioperative HF in cardiosurgery based on European experts' opinion. It also emphasizes the need for large surveys and studies to assess the optimal way to manage perioperative HF in cardiac surgery.

N-terminal pro-brain natriuretic peptide identifies patients at high risk for adverse cardiac outcome after vascular surgery.

BACKGROUND: Preoperative N-terminal pro-BNP (NT-proBNP) is independently associated with adverse cardiac outcome but does not anticipate the dynamic consequences of anesthesia and surgery. The authors hypothesized that a single postoperative NT-proBNP level provides additional prognostic information for in-hospital and late cardiac events. METHODS: Two hundred eighteen patients scheduled to undergo vascular surgery were enrolled and followed up for 24-30 months. Logistic regression and Cox proportional hazards model were performed to evaluate predictors of in-hospital and long-term cardiac outcome. The optimal discriminatory level of preoperative and postoperative NT-proBNP was determined by receiver operating characteristic analysis. RESULTS: During a median follow-up of 826 days, 44 patients (20%) experienced 51 cardiac events. Perioperatively, median NT-proBNP increased from 215 to 557 pg/ml (interquartile range, 83/457 to 221/1178 pg/ml; P<0.001). The optimum discriminate threshold for preoperative and postoperative NT-proBNP was 280 pg/ml (95% confidence interval, 123-400) and 860 pg/ml (95% confidence interval, 556-1,054), respectively. Adjusted for age, previous myocardial infarction, preoperative fibrinogen, creatinine, high-sensitivity C-reactive protein, type, duration, and surgical complications, only postoperative NT-proBNP remained significantly associated with in-hospital (adjusted hazard ratio, 19.8; 95% confidence interval, 3.4-115) and long-term cardiac outcome (adjusted hazard ratio, 4.88; 95% confidence interval, 2.43-9.81). CONCLUSION: A single postoperative NT-proBNP determination provides important additional prognostic information to preoperative levels and may support therapeutic decisions to prevent subsequent structural myocardial damage.

Clinical evaluation of alternative-site glucose measurements in patients after major cardiac surgery.

OBJECTIVE: Tight glycemic control improves outcome in critically ill patients but requires frequent glucose measurements. Subcutaneous adipose tissue (SAT) has been characterized as promising for glucose monitoring in diabetes, but it remains unknown whether it can also be used as an alternative site in critically ill patients. The present study was performed to clinically evaluate the relation of glucose in SAT compared with arterial blood in patients after major cardiac surgery. RESEARCH DESIGN AND METHODS: Forty critically ill patients were investigated at two clinical centers after major cardiac surgery. Arterial blood and SAT microdialysis samples were taken in hourly intervals for a period of up to 48 h. The glucose concentration in dialysate was calibrated using a two-step approach, first using the ionic reference technique to calculate the SAT glucose concentration (SATg) and second using a one-point calibration procedure to obtain a glucose profile comparable to SAT-derived blood glucose (BgSAT). Clinical validation of the data was performed by introducing data analysis based on an insulin titration algorithm. RESULTS: Correlation between dialysate glucose and blood glucose (median 0.80 [interquartile range 0.68-0.88]) was significantly improved using the ionic reference calibration technique (SATg vs.blood glucose 0.90 [0.83-0.94]; P < 0.001). Clinical evaluation of the data indicated that 96.1% of glucose readings from SAT would allow acceptable treatment according to a well-established insulin titration protocol. CONCLUSIONS: The results indicate good correlation between SATg and blood glucose in patients after major cardiac surgery. Clinical evaluation of the data suggests that with minor limitations, glucose from SAT can be used to establish tight glycemic control in this patient group.

Levosimendan, a new inotropic and vasodilator agent.

Several clinical studies suggest substantial limitations of currently available positive inotropic substances, including beta1-adrenoceptor agonists and phosphodiesterase III inhibitors in the short- and long-term treatment of heart failure. The reasons for these detrimental effects are related to the mechanism of action of these drugs, including increases in intracellular Ca2+ with subsequent increases in myocardial oxygen demand and arrhythmogenesis. Levosimendan, a myofilament Ca2+ sensitizer with inotropic effects, increases myocardial performance without substantial changes in oxygen consumption and with neutral effects on heart rhythm. In addition, levosimendan has vasodilatory effects that are achieved by stimulation of adenosine triphosphate-dependent potassium channels. This action may be of specific interest in the setting of myocardial ischemia. To date, levosimendan is approved in 31 countries worldwide, and more patients with heart failure have participated in randomized controlled trials with levosimendan than with any other intravenous inotropic agent.