Efficacy and safety of intravenous levosimendan compared with dobutamine in severe low-output heart failure (the LIDO study): a randomised double-blind trial

Strategies to optimize respiratory muscle function in ICU patients

Respiratory muscle dysfunction may develop rapidly in critically ill ventilated patients and is associated with increased morbidity, length of intensive care unit stay, costs, and mortality. This review briefly discusses the pathophysiology of respiratory muscle dysfunction in intensive care unit patients and then focuses on strategies that prevent the development of muscle weakness or, if weakness has developed, how respiratory muscle function may be improved. We propose a simple strategy for how these can be implemented in clinical care.

Effect of baseline characteristics on mortality in the SURVIVE trial on the effect of levosimendan vs dobutamine in acute heart failure: Sub-analysis of the Finnish patients

BACKGROUND

In the SURVIVE trial, including 1327 acute heart failure patients, no statistically significant difference between levosimendan and dobutamine in the 180-day all-cause mortality was seen. Country-specific differences in outcome were, however, present. In the Finnish sub-population in fact, mortality was significantly lower in levosimendan treated patients. We aim to understand the reasons for this disparity.

METHODS

The risk factors for all-cause mortality were identified in the whole study population using multivariate Cox proportional hazards regression analysis. Those factors were evaluated in the 95 patients of the Finnish sub-population.

RESULTS

The treatment by country interaction for mortality in Finland vs. other countries was significant, p=0.029. Levosimendan treated patients had a lower 180-day mortality compared to dobutamine treated (17% vs. 40%, p=0.023) in the Finnish sub-population. Baseline variables predicting survival in the whole SURVIVE trial population included age, systolic blood pressure, heart rate, myocardial infarction during admission, levels of NT-pro-BNP, glucose, creatinine, and alanine transferase, use of ACE inhibitors and β-blockers, oliguria, time from hospital admission to randomization, history of cardiac arrest, and left ventricular ejection fraction. Finnish patients were more frequently treated with β-blockers (88% vs. 52%, p<0.0001), their study treatment was started earlier (mean±SD 41±40h vs. 81±154; p<0.0001), and they had more often acute myocardial infarction at admission (39% vs. 16%, p<0.0001).

CONCLUSION

The lower mortality in the Finnish patients treated with levosimendan was associated with higher use of β-blockers, higher frequency of myocardial infarction at admission, and shorter delay between randomization and start of treatment.

Levosimendan improves hemodynamic status in critically ill patients with severe aortic stenosis and left ventricular dysfunction: an interventional study

AIMS

To study the hemodynamic effect of levosimendan administration in acute heart failure patients with severe aortic stenosis (AS) and reduced left ventricular ejection fraction (LVEF).

METHODS

Hemodynamic response to 24 h intravenous levosimendan infusion (0.1 μg/kg/min without a loading dose) in patients with severe AS (aortic valve area ≤1 cm(2) , time-velocity integral between left ventricular out-flow tract and aortic valve <0.25), reduced LVEF (≤40%), and a depressed cardiac index (CI) <2.2 L/min/m(2) was determined in a sequential group of nine patients aged 76 ± 10 years (5 men).

RESULTS

Baseline mean ejection fraction was 33 ± 0.7%; mean aortic valve area was 0.37 ±0.11 cm(2) /m(2) ; peak and mean gradients of 63.6 ± 20.53 and 36.7 ± 12.62 mmHg, respectively; and mean CI was 1.65 ± 0.20 L/min/m(2) . At 6 and 12 h of levosimendan therapy, mean CI had increased to 2.00 ± 0.41 L/min/m(2) (P = 0.02) and 2.17 ± 0.40 L/min/m(2) (P = 0.01), respectively. At 24 h, mean CI had increased further to 2.37 ± 0.49 L/min/m(2) (P = 0.01). A significant beneficial effect was also observed in pulmonary capillary wedge pressure, pulmonary artery mean pressure, central venous pressure, systemic vascular resistances, pulmonary vascular resistances, stroke volume index, left ventricular stroke work index. NTproBNP levels decreased at 24 h of levosimendan treatment. Levosimendan infusion was also well tolerated. Five patients subsequently underwent aortic valve surgery replacement. One died (of postoperative multiorgan failure). At 30 days, overall survival was 75%.

CONCLUSIONS

Levosimendan administration improves hemodynamic parameters in critically ill patients with severe AS and reduced LVEF. In our study, it provides a safe and effective bridge to aortic-valve replacement or oral vasodilator therapy in surgical contraindicated patients. A controlled study is needed to confirm these preliminary findings.

Successful use of levosimendan as a primary inotrope in pediatric cardiac surgery: An observational study in 110 patients

Context:

Levosimendan is a new generation inotrope with calcium sensitizing properties and proven benefits in adults.

Aims:

This study investigates the use of levosimendan as a first line inotrope in congenital heart surgery.

Settings and Design:

Prospective, observational study in a tertiary care center.

Materials and Methods:

One hundred and ten patients undergoing congenital cardiac surgery received levosimendan at a loading dose of 12 mcg/kg during rewarming on cardiopulmonary bypass followed by continuous infusion of 0.1 mcg/kg/min for 48 h. Hemodynamic parameters were recorded at the time of admission to Intensive Care Unit, and at 3 h, 6 h, 12 h, 24 h, and 48 h thereafter.

Statistical Analysis:

Categorical variables were compared using Chi-square test. Non-normally distributed quantitative variables were compared between groups using Kruskal-Wallis test.

Results:

At discharge from operating room (OR), 36 (32.7%) patients required levosimendan alone to maintain optimum cardiac output, 59 (53.6%) patients required the addition of low-dose adrenaline (<0.1 mcg/kg/min) and 15 (13.6%) patients required either increment in adrenaline to high-dose (≥0.1 mcg/kg/min) or starting another inotrope/vasoactive agent. Overall, there were five mortalities. Hypotension leading to discontinuation of levosimendan was not found in any patient. Arrhythmias were observed in three patients. Fifty-four patients were extubated in the OR.

Conclusions:

Levosimendan-based inotropic regime offers optimized cardiac output with a well-controlled heart rate and a low incidence of arrhythmias in patients undergoing all categories of congenital heart surgeries.

Initial Observations of the Effects of Calcium Chloride Infusions in Pediatric Patients with Low Cardiac Output

Myocardial contractility and relaxation are highly dependent on calcium homeostasis. Immature myocardium, as in pediatric patients, is thought to be more dependent on extracellular calcium for optimal function. For this reason, intravenous calcium chloride infusions may improve myocardial function in the pediatric patient. The objectives of this study were to report the hemodynamic changes seen after administration of continuous calcium chloride to critically ill children. We retrospectively identified pediatric patients (newborn to 17 years old) with hemodynamic instability admitted to the cardiac ICU between May 2011 and May 2012 who received a continuous infusion of calcium chloride. The primary outcome was improvement in cardiac output, assessed by arterial-mixed venous oxygen saturation (A-V) difference. Sixty-eight patients, mean age 0.87 ± 2.67 years, received a total of 116 calcium infusions. Calcium chloride infusions resulted in significant improvements in primary and secondary measures of cardiac output at 2 and 6 h. Six hours after calcium initiation, A-V oxygen saturation difference decreased by 7.4 % (32.6 ± 2.1 to 25.2 ± 2.0 %, p < 0.001), rSO2 increased by 5.5 % (63.1 vs 68.6 %, p < 0.001), and serum lactate decreased by 0.9 mmol/l (3.3 vs 2.4 mmol/l, p < 0.001) with no change in HR (149.1 vs 145.6 bpm p = 0.07). Urine output increased 0.66 ml/kg/h in the 8-h period after calcium initiation when compared to pre-initiation (p = 0.003). Neonates had the strongest evidence of effectiveness with other age groups trending toward significance. Calcium chloride infusions improve markers of cardiac output in a heterogenous group of pediatric patients in a cardiac ICU. Neonates appear to derive the most benefit from utilization of these infusions.

Pediatric Cardiac Intensive Care Society 2014 Consensus Statement: Pharmacotherapies in Cardiac Critical Care Treatment of Acute Heart Failure

OBJECTIVES

To provide an evidence-based review of pharmacotherapies to treat acute heart failure. To accomplish this objective, we will discuss circulatory physiology, vasoactive agents, and their indications in the management of acute heart failure.

DATA SOURCE

A MEDLINE-baseline review of the literature.

CONCLUSIONS

The optimal selection of vasoactive agents requires a consideration of circulatory physiology and the tailored application of pharmacotherapies to treat patients with acute heart failure.

Efficacy and Safety of 1-Hour Infusion of Recombinant Human Atrial Natriuretic Peptide in Patients With Acute Decompensated Heart Failure: A Phase III, Randomized, Double-Blind, Placebo-Controlled, Multicenter Trial

The aim of the study was to evaluate the efficacy and safety of 1-h infusion of recombinant human atrial natriuretic peptide (rhANP) in combination with standard therapy in patients with acute decompensated heart failure (ADHF). This was a phase III, randomized, double-blind, placebo-controlled, multicenter trial. Eligible patients with ADHF were randomized to receive a 1-h infusion of either rhANP or placebo at a ratio of 3:1 in combination with standard therapy. The primary endpoint was dyspnea improvement (a decrease of at least 2 grades of dyspnea severity at 12 h from baseline). Reduction in pulmonary capillary wedge pressure (PCWP) 1 h after infusion was the co-primary endpoint for catheterized patients. Overall, 477 patients were randomized: 358 (93 catheterized) patients received rhANP and 118 (28 catheterized) received placebo. The percentage of patients with dyspnea improvement at 12 h was higher, although not statistically significant, in the rhANP group than in the placebo group (32.0% vs 25.4%, odds ratio=1.382, 95% confidence interval [CI]: 0.863-2.212, P = 0.17). Reduction in PCWP at 1 h was significantly greater in patients treated with rhANP than in patients treated with placebo (-7.74 ± 5.95 vs -1.82 ± 4.47 mm Hg, P < 0.001). The frequencies of adverse events and renal impairment within 3 days of treatment were similar between the 2 groups. Mortality at 1 month was 3.1% in the rhANP group vs 2.5% in the placebo group (hazard ratio = 1.21, 95% CI: 0.34-4.26; P > 0.99). 1-h rhANP infusion appears to result in prompt, transient hemodynamic improvement with a small, nonsignificant, effect on dyspnea in ADHF patients receiving standard therapy. The safety of 1-h infusion of rhANP seems to be acceptable. (WHO International Clinical Trials Registry Platform [ICTRP] number, ChiCTR-IPR-14005719.).

Pediatric Cardiac Intensive Care Society 2014 Consensus Statement: Pharmacotherapies in Cardiac Critical Care Chronic Heart Failure

OBJECTIVE

Heart failure is a serious complication that can occur in patients with a variety of congenital and acquired disorders including congenital heart disease, cardiomyopathy, and myocarditis. Furthermore, heart failure patients comprise an increasing number of ICU admissions. Thus, it is important for those caring for patients with critical cardiovascular disease to have a thorough understanding of the medications used for the treatment of heart failure. The aim of this review is to provide an overview, rationale, indications, and adverse effects of medications used in the treatment of chronic heart failure.

DATA SOURCES

PubMed, Medline, Cochrane Database of Systemic Reviews.

STUDY SELECTION

Studies were selected on their relevance for pediatric heart failure. When limited data on pediatric heart failure were available, studies in adult patients were selected.

DATA EXTRACTION

Relevant findings from studies were selected by the authors.

DATA SYNTHESIS

The rationale for the efficacy of most heart failure medications used in pediatric patients is extrapolated from studies in adult heart failure. Commonly used medications for chronic heart failure include β-receptor antagonists (e.g., carvedilol and metoprolol), and medications aimed at blocking the renin-angiotensin-aldosterone system (e.g., angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, aldosterone receptor antagonists). In addition, diuretics are useful for symptoms of fluid overload. For patients with impaired perfusion, inotropic agents are useful acutely, but may be associated with worse outcomes when used chronically. Newer medications that have been recently approved in adults (e.g., serelaxin, ivabradine, and neprilysin inhibitor [angiotensin receptor blocker]) may prove to be important in pediatric heart failure.

CONCLUSIONS

Heart failure patients are in an important population of critically ill children. The pharmacologic approach to these patients is aimed at treating symptoms of congestion and/or poor perfusion and improving long-term outcomes.

Organ protection possibilities in acute heart failure

Unlike chronic heart failure (HF), the treatment for acute HF has not changed over the last decade. The drugs employed have shown their ability to control symptoms but have not achieved organ protection or managed to reduce medium to long-term morbidity and mortality. Advances in our understanding of the pathophysiology of acute HF suggest that treatment should be directed not only towards correcting the haemodynamic disorders and achieving symptomatic relief but also towards preventing organ damage, thereby counteracting myocardial remodelling and cardiac and extracardiac disorders. Compounds that exert vasodilatory and anti-inflammatory action in the acute phase of HF and can stop cell death, thereby boosting repair mechanisms, could have an essential role in organ protection.

Current and Potential Therapeutic Strategies for Hemodynamic Cardiorenal Syndrome

BACKGROUND

Cardiorenal syndrome (CRS) encompasses conditions in which cardiac and renal disorders co-exist and are pathophysiologically related. The newest classification of CRS into seven etiologically and clinically distinct types for direct patient management purposes includes hemodynamic, uremic, vascular, neurohumoral, anemia- and/or iron metabolism-related, mineral metabolism-related and protein-energy wasting-related CRS. This classification also emphasizes the pathophysiologic pathways. The leading CRS category remains hemodynamic CRS, which is the most commonly encountered type in patient care settings and in which acute or chronic heart failure leads to renal impairment.

SUMMARY

This review focuses on selected therapeutic strategies for the clinical management of hemodynamic CRS. This is often characterized by an exceptionally high ratio of serum urea to creatinine concentrations. Loop diuretics, positive inotropic agents including dopamine and dobutamine, vasopressin antagonists including vasopressin receptor antagonists such as tolvaptan, nesiritide and angiotensin-neprilysin inhibitors are among the pharmacologic agents used. Additional therapies include ultrafiltration (UF) via hemofiltration or dialysis. The beneficial versus unfavorable effects of these therapies on cardiac decongestion versus renal blood flow may act in opposite directions. Some of the most interesting options for the outpatient setting that deserve revisiting include portable continuous dobutamine infusion, peritoneal dialysis and outpatient UF via hemodialysis or hemofiltration.

KEY MESSAGES

The new clinically oriented CRS classification system is helpful in identifying therapeutic targets and offers a systematic approach to an optimal management algorithm with better understanding of etiologies. Most interventions including UF have not shown a favorable impact on outcomes. Outpatient portable dobutamine infusion is underutilized and not well studied. Revisiting traditional and novel strategies for outpatient management of CRS warrants clinical trials.

Emerging Therapies for Acute and Chronic Heart Failure

Although the period from 1953 to 2001 resulted in the approval of more than 30 medications currently used to treat heart failure (HF), few novel drugs have been approved in the last decade. However, the investigational pipeline for HF medications once again appears promising. In patients with chronic heart failure with reduced ejection fraction (HFrEF), ivabradine and valsartan/sucubitril (LCZ696) were recently approved by the US Food and Drug Administration. Both agents have been shown to reduce the risk of cardiovascular death and HF hospitalization. In the treatment of acute HF, serelaxin and ularitide are the farthest along in development. Both agents have demonstrated favorable effects on surrogate end points and preliminary data suggest a possible mortality benefit with serelaxin. Consequently, phase 3 trials are ongoing to evaluate the effect of serelaxin and ularitide on clinical outcomes. Given the poor history of recent investigational acute HF drugs that have advanced to phase 3/4 studies, enthusiasm for both serelaxin and ularitide must be tempered until these trials are completed.

Shock Management for Cardio-surgical Intensive Care Unit Patient: The Silver Days

Shock in cardio-surgical intensive care unit (ICU) patients requires prompt identification of the underlying condition and timely therapeutic interventions. Management during the first 6 hours, also referred to as "the golden hours", is of paramount importance to reverse the shock state and improve the patient's outcome. The authors have previously described a state-of-the-art diagnostic work-up and discussed how to optimise preload, vascular tone, contractility, heart rate and oxygen delivery during this phase. Ideally, shock can be reversed during this initial period. However, some patients might have developed multiple organ dysfunction, which persists beyond the first 6 hours despite the early haemodynamic treatment goals having been accomplished. This period, also referred to as "the silver days", is the focus of this review. The authors discuss how to reduce vasopressor load and how to minimise adrenergic stress by using alternative inotropes, extracorporeal life-support and short acting beta-blockers. The review incorporates data on fluid weaning, safe ventilation, daily interruption of sedation, delirium management and early rehabilitation. It includes practical recommendations in areas where the evidence is scarce or controversial. Although the focus is on cardio-surgery ICU patients, most of the considerations apply to critical ill patients in general.

Omecamtiv mecarbil: a new cardiac myosin activator for the treatment of heart failure

INTRODUCTION

Current available inotropic agents increase cardiac contractility, but are associated with myocardial ischemia, arrhythmias, and mortality. A novel selective cardiac myosin activator, omecamtiv mecarbil (CK-1827452/ AMG-423) is a small molecule that activates the sarcomere proteins directly, resulting in prolonged systolic ejection time and increased cardiac contractility.

AREAS COVERED

This paper discusses the chemistry, pharmacokinetics, clinical efficacy and safety of omecamtiv mecarbil. Omecamtiv mecarbil represents a novel therapeutic approach to directly improve cardiac function and is therefore proposed as a potential new treatment of patients with systolic heart failure. The authors review results of previous studies investigating the effect of omecamtiv mecarbil in heart failure animal models, healthy volunteers, and patients with acute and chronic systolic heart failure.

EXPERT OPINION

Results of phase I and phase II studies demonstrate that omecamtiv mecarbil is safe and well tolerated both as an intravenous and oral formulation. In healthy volunteers and chronic systolic heart failure patients, administration of omecamtiv mecarbil resulted in a concentration-dependent increase of left ventricular ejection time, ejection fraction, fractional shortening, and stroke volume. The first results of a double-blind, randomized, placebo-controlled phase IIb dose-finding study with the oral formulation of omecamtiv mecarbil demonstrated beneficial effects on cardiac function and N-terminal pro-brain natriuretic peptide levels. This study will provide essential dosing information for the requisite phase III trials which will investigate whether the beneficial effects of omecamtiv mecarbil translate into improved clinical outcomes.

Use of Inotropic Agents in Treatment of Systolic Heart Failure

The most common use of inotropes is among hospitalized patients with acute decompensated heart failure, with reduced left ventricular ejection fraction and with signs of end-organ dysfunction in the setting of a low cardiac output. Inotropes can be used in patients with severe systolic heart failure awaiting heart transplant to maintain hemodynamic stability or as a bridge to decision. In cases where patients are unable to be weaned off inotropes, these agents can be used until a definite or escalated supportive therapy is planned, which can include coronary revascularization or mechanical circulatory support (intra-aortic balloon pump, extracorporeal membrane oxygenation, impella, left ventricular assist device, etc.). Use of inotropic drugs is associated with risks and adverse events. This review will discuss the use of the inotropes digoxin, dopamine, dobutamine, norepinephrine, milrinone, levosimendan, and omecamtiv mecarbil. Long-term inotropic therapy should be offered in selected patients. A detailed conversation with the patient and family shall be held, including a discussion on the risks and benefits of use of inotropes. Chronic heart failure patients awaiting heart transplants are candidates for intravenous inotropic support until the donor heart becomes available. This helps to maintain hemodynamic stability and keep the fluid status and pulmonary pressures optimized prior to the surgery. On the other hand, in patients with severe heart failure who are not candidates for advanced heart failure therapies, such as transplant and mechanical circulatory support, inotropic agents can be used for palliative therapy. Inotropes can help reduce frequency of hospitalizations and improve symptoms in these patients.

Levosimendan for Prevention of Acute Kidney Injury After Cardiac Surgery: A Meta-analysis of Randomized Controlled Trials

BACKGROUND

Levosimendan has been shown to confer direct renoprotection in renal endotoxemic and ischemia-reperfusion injury and could increase renal blood flow in patients with low-cardiac-output heart failure. Results from clinical trials of levosimendan on acute kidney injury (AKI) following cardiac surgery are controversial.

STUDY DESIGN

A random-effect meta-analysis was conducted based on evidence from PubMed, EMBASE, and Cochrane Library.

SETTINGS & POPULATION

Adult patients undergoing cardiac surgery.

SELECTION CRITERIA FOR STUDIES

Randomized controlled trials comparing the renal effect of levosimendan versus placebo or other inotropic drugs during cardiac surgery.

INTERVENTION

Perioperative levosimendan continuous infusion at a rate of 0.1 to 0.2μg/kg/min following a loading dose (6-24μg/kg) for 24 hours or only 1 loading dose (24μg/kg) within 1 hour.

OUTCOMES

AKI, need for renal replacement therapy, mechanical ventilation duration, intensive care unit stay during hospitalization, and postoperative mortality (in-hospital or within 30 days).

RESULTS

13 trials with a total of 1,345 study patients were selected. Compared with controls, levosimendan reduced the incidence of postoperative AKI (40/460 vs 78/499; OR, 0.51; 95% CI, 0.34-0.76; P=0.001; I(2)=0.0%), renal replacement therapy (22/492 vs 49/491; OR, 0.43; 95% CI, 0.25-0.76; P=0.002; I(2)=0.0%), postoperative mortality (35/658 vs 94/657; OR, 0.41; 95% CI, 0.27-0.62; P<0.001; I(2)=0.0%), mechanical ventilation duration (in days; n=235; weighted mean difference, -0.34; 95% CI, -0.58 to -0.09; P=0.007], and intensive care unit stay (in days; n=500; weighted mean difference, -2.2; 95% CI, -4.21 to -0.13; P=0.04).

LIMITATIONS

Different definitions for AKI among studies. Small sample size for some trials.

CONCLUSIONS

Perioperative administration of levosimendan in patients undergoing cardiac surgery may reduce complications. Future trials are needed to determine the dose effect of levosimendan in improving outcomes, especially in patients with decreased baseline kidney function.

New medical therapies for heart failure

Heart failure (HF) can rightfully be called the epidemic of the 21(st) century. Historically, the only available medical treatment options for HF have been diuretics and digoxin, but the capacity of these agents to alter outcomes has been brought into question by the scrutiny of modern clinical trials. In the past 4 decades, neurohormonal blockers have been introduced into clinical practice, leading to marked reductions in morbidity and mortality in chronic HF with reduced left ventricular ejection fraction (LVEF). Despite these major advances in pharmacotherapy, our understanding of the underlying disease mechanisms of HF from epidemiological, clinical, pathophysiological, molecular, and genetic standpoints remains incomplete. This knowledge gap is particularly evident with respect to acute decompensated HF and HF with normal (preserved) LVEF. For these clinical phenotypes, no drug has been shown to reduce long-term clinical event rates substantially. Ongoing developments in the pharmacotherapy of HF are likely to challenge our current best-practice algorithms. Novel agents for HF therapy include dual-acting neurohormonal modulators, contractility-enhancing agents, vasoactive and anti-inflammatory peptides, and myocardial protectants. These novel compounds have the potential to enhance our armamentarium of HF therapeutics.

Evaluation of myocardial contractility determination with tissue tracking echocardiography after levosimendan infusion in patients with poor left ventricular function and hemodynamics

BACKGROUND

The aim of this study was to assess the effect of conventional inotropic drugs compared to levosimendan using tissue tracking echocardiography in the early postoperative period for patients with low ejection fraction undergoing coronary artery bypass graft (CABG) surgery.

METHODS

We prospectively analyzed 115 patients (69 male, 46 female) who planned for elective coronary artery bypass surgery with low ejection fraction, ≤% 30, from September 2012 to December 2013. Patients were divided into two groups. Levosimendan was used at a loading dose of 15 μg/kg/min for the first twenty minutes, and continued at a maintenance dose of 0.2 μg/kg/min six hours before the anesthetic induction in group I (n = 47, 23 male, mean age 67.16 ± 4.72 years). Dopamine at 10 μg/kg/min and/or dobutamine at 10 μg/kg/min were used at the time of weaning from cardiopulmonary bypass in group II (n = 68, 47 male, mean age 65.43 ± 6.12 years). The patients were evaluated preoperatively and on the fifth postoperative day by transthoracic echocardiography. Patients were also evaluated just before the cardiopulmonary bypass and at the 12th and 24th hours on the first postoperative day by transesophageal echocardiography. Student t test and χ2 test were used for statistical analyses.

RESULTS

There were no significant differences in demographics and preoperative hemodynamic parameters between groups I and II. Hemodynamic and echocardiographic parameters were significantly better in group I receiving levosimendan, compared to group II.

CONCLUSION

Levosimendan enhances functional myocardial tissue mass and ensures positive hemodynamic effect in the early postoperative period in patients with low ejection fraction undergoing elective CABG.

Anesthetic management of the patient with low ejection fraction

The number of patients with heart failure presenting for surgery continues to rise, and anesthesiologists are increasingly being called upon to provide quality, safe care in the operating room for patients with low ejection fraction (EF). Perioperative goals in the management of these patients include maintaining forward flow, promoting inotropy without inducing or exacerbating ischemia, and returning patients to their preoperative level of function after surgery. Oftentimes, these goals can be met with pharmacologic support, including the use of calcium channel blockers, phosphodiesterase inhibitors, and novel agents, such as nesiritide and levosimendan. Many patients with diminished EF have implantable cardioverter-defibrillators (ICDs) in place. These devices can be complex to manage, and concern often arises regarding electromagnetic interference from monopolar cautery. Although simply placing a magnet on the device will often disable the antitachycardia interventions of an ICD, this is not always the case. The safest way to manage an ICD in the perioperative period is to interrogate and reprogram the device before and after surgery. Another helpful device in dealing with patients with low EF, particularly those in acute cardiogenic shock, is the intra-aortic balloon pump. These devices can serve a critical role in managing patients who have inadequate responses to pharmacologic therapy or in whom vasopressor and inotropic support are suboptimal because of concerns for increasing myocardial work. With full understanding of available pharmacologic agents, and an appreciation of the capabilities of ICDs and intra-aortic balloon pumps, anesthesiologists will be better equipped to meet the perioperative needs of the patient with low EF.

Levosimendan improves exercise performance in patients with advanced chronic heart failure

AIMS

Cardiopulmonary exercise test (CPET) provides parameters such as peak VO2 and ventilation/CO2 production (VE/VCO2) slope, which are strong prognostic predictors in patients with stable advanced chronic heart failure (ADHF). The study aim was to evaluate the effects of the inodilator levosimendan on CPET in patients with ADHF under stable clinical conditions.

METHODS AND RESULTS

We enrolled patients with ADHF (peak VO2 < 12 mL/min/kg) in a double-blind, placebo-controlled protocol. Patients were randomly assigned to i.v. infusion of placebo (500 mL 5% glucose; n = 19) or levosimendan (in 500 mL 5% glucose; n = 23). Before and 24 h after the end of the infusion, patients underwent determination of New York Heart Association class, B-type natriuretic peptide (BNP), haemoglobin, serum creatinine, and blood urea nitrogen levels, as well as CPET, standard spirometry, and alveolar capillary gas diffusion. BNP showed no change with placebo (1042 ± 811 to 1043 ± 867 pg/mL), but it was decreased with levosimendan (1163 ± 897 to 509 ± 543 pg/mL, P < 0.001). No changes were observed for haemoglobin, creatinine, and blood urea nitrogen in either group. With levosimendan, a minor improvement was observed in spirometry measurements, but not in alveolar capillary gas diffusion. Peak VO2 showed a small, non-significant increase with placebo (9.5 ± 1.7 to 10.0 ± 2.1 mL/kg/min, P = 0.12), and a greater increase with levosimendan (9.8 ± 1.7 to 11.0 ± 1.9 mL/kg/min, P < 0.005). The VE/VCO2 slope showed no change (44.0 ± 11 vs. 43.4 ± 10.3, P = 0.44), and a decrease (41.9 ± 10 vs. 36.6 ± 6.4, P < 0.001) in the placebo and in the levosimendan group, respectively.

CONCLUSION

Levosimendan treatment significantly improves peak VO2 and reduces VE/VCO2 slope and BNP in patients with ADHF.

Ularitide: a natriuretic peptide candidate for the treatment of acutely decompensated heart failure

Treatment for acutely decompensated heart failure (ADHF) has not changed much in the last two decades. Currently available therapies have variable efficacy and can be associated with adverse outcomes. Natriuretic peptides properties include diuresis, natriuresis, vasorelaxation, inhibition of renin-angiotensin-aldosterone system, and are thus chosen in the treatment of ADHF. Two forms of natriuretic peptides are currently available for the treatment of ADHF. Urodilatin (INN: ularitide) represents another member of the natriuretic peptide family with a unique molecular structure that may provide distinct benefits in the treatment of ADHF. Early clinical exploratory and Phase II studies have demonstrated that ularitide has potential cardiovascular and renal benefits. Ularitide is currently being tested in the Phase III TRUE-AHF clinical study. TRUE-AHF has features that may be different when compared with other recent outcome studies in ADHF. These distinct differences aim to maximize clinical effects and minimize potential adverse events of ularitide. However, whether this rationale translates into a better outcome needs to be awaited.

When sepsis affects the heart: A case report and literature review

A 59-year-old nursing home patient with Down syndrome was brought to the internal medicine department of our hospital due to fever, cough without expectorate, and dyspnea. A thoracic computed tomography revealed the presence of bilateral basal parenchymal opacities. Her condition deteriorated after admission and troponin reached a peak serum concentration of 16.9 ng/mL. The patient was in cardiogenic shock. In addition to fluid resuscitation, vaso-active amine infusion was administered to achieve hemodynamic stabilization. The differential diagnosis investigated possible pulmonary embolism, myocardial infarction, and myocarditis. Furthermore, a second transthoracic echocardiogram suggested Tako-Tsubo syndrome. This is a septic patient. The purpose of this manuscript is to review studies which formerly examined the possible association between high levels of troponin and mortality to see if it can be considered a positive predictive factor of fatal prognosis as the case of thrombocytopenia, already a positive independent predictive factor of multiple organ failure syndrome, and generally to characterize risk profile in a septic patient.

Inhibition of phosphodiesterase-3 by levosimendan is sufficient to account for its inotropic effect in failing human heart

BACKGROUND AND PURPOSE

Levosimendan is known as a calcium sensitizer, although it is also known to inhibit PDE3. We aimed to isolate each component and estimate their contribution to the increased cardiac contractility induced by levosimendan.

EXPERIMENTAL APPROACH

Contractile force was measured in electrically stimulated ventricular strips from explanted failing human hearts and left ventricular strips from normal male Wistar rats. PDE activity was measured in a two-step PDE activity assay on failing human ventricle.

KEY RESULTS

Levosimendan exerted a positive inotropic effect (PIE) reaching maximum at 10(-5)  M in ventricular strips from failing human hearts. In the presence of the selective PDE3 inhibitor cilostamide, the PIE of levosimendan was abolished. During treatment with a PDE4 inhibitor and a supra-threshold concentration of isoprenaline, levosimendan generated an amplified inotropic response. This effect was reversed by β-adrenoceptor blockade and undetectable in strips pretreated with cilostamide. Levosimendan (10(-6)  M) increased the potency of β-adrenoceptor agonists by 0.5 log units in failing human myocardium, but not in the presence of cilostamide. Every inotropic response to levosimendan was associated with a lusitropic response. Levosimendan did not affect the concentration-response curve to calcium in rat ventricular strips, in contrast to the effects of a known calcium sensitizer, EMD57033 [5-(1-(3,4-dimethoxybenzoyl)-1,2,3,4-tetrahydroquinolin-6-yl)-6-methyl-3,6-dihydro-2H-1,3,4-thiadiazin-2-one]. PDE activity assays confirmed that levosimendan inhibited PDE3 as effectively as cilostamide.

CONCLUSIONS AND IMPLICATIONS

Our results indicate that the PDE3-inhibitory property of levosimendan was enough to account for its inotropic effect, leaving a minor, if any, effect to a calcium-sensitizing component.

Assessment and prevalence of pulmonary oedema in contemporary acute heart failure trials: a systematic review

AIMS

Pulmonary oedema is a common and important finding in acute heart failure (AHF). We conducted a systematic review to describe the methods used to assess pulmonary oedema in recent randomized AHF trials and report its prevalence in these trials.

METHODS AND RESULTS

Of 23 AHF trials published between 2002 and 2013, six were excluded because they were very small or not randomized, or missing full-length publications. Of the remaining 17 (n = 200-7141) trials, six enrolled patients with HF and reduced ejection fraction (HF-REF) and 11, patients with both HF-REF and HF with preserved ejection fraction (HF-PEF). Pulmonary oedema was an essential inclusion criterion, in most trials, based upon findings on physical examination ('rales'), radiographic criteria ('signs of congestion'), or both. The prevalence of pulmonary oedema in HF-REF trials ranged from 75% to 83% and in combined HF-REF and HF-PEF trials from 51% to 100%. Five trials did not report the prevalence or extent of pulmonary oedema assessed by either clinical examination or chest x-ray. Improvement of pulmonary congestion with treatment was inconsistently reported and commonly grouped with other signs of congestion into a score. One trial suggested that patients with rales over >2/3 of the lung fields on admission were at higher risk of adverse outcomes than those without.

CONCLUSION

Although pulmonary oedema is a common finding in AHF, represents a therapeutic target, and may be of prognostic importance, recent trials used inconsistent criteria to define it, and did not consistently report its severity at baseline or its response to treatment. Consistent and ideally quantitative, methods for the assessment of pulmonary oedema in AHF trials are needed.

Pharmaco-economics of levosimendan in cardiology: a European perspective

INTRODUCTION

Heart failure places a significant economic burden on health care. Acute heart failure requires hospitalization and often frequent re-hospitalization in expensive wards where vasoactive rescue therapy is often added on top of standard medications. In these lean times, there is a growing need for cost-effective therapeutic options that supply superior support and in addition shorten the length of stay in hospital and reduce re-hospitalization rates. The inodilator levosimendan represents the latest addition to the vasoactive treatments of acute heart failure patients, and it appears to meet these expectations. Our aim was to answer the question whether the treatment efficacy of levosimendan - when selected as therapy for patients hospitalized for acute heart failure - brings savings to hospitals in various European countries representing different economies.

METHODS AND RESULTS

We took a conservative approach and selected some a fortiori arguments to simplify the calculations. We selected seven European countries to represent different economies: Italy, Spain, Greece, Germany, Sweden, Finland and Israel. Data on the costs of medications and on the cost per day were collected and fed in a simple algorithm to detect savings. These saving varied from country to country, from a minimum of €0.50 in Germany to a maximum of €354.64 in Sweden.

CONCLUSIONS

The use of levosimendan as a therapy for patients hospitalized for acute heart failure provides a net saving to hospitals driven by a reduction in the length of hospital stay. This finding is true in each of the countries considered in this study.

Drug Therapy for Acute Heart Failure

Acute heart failure is globally one of most frequent reasons for hospitalization and still represents a challenge for the choice of the best treatment to improve patient outcome. According to current international guidelines, as soon as patients with acute heart failure arrive at the emergency department, the common therapeutic approach aims to improve their signs and symptoms, correct volume overload, and ameliorate cardiac hemodynamics by increasing vital organ perfusion. Recommended treatment for the early management of acute heart failure is characterized by the use of intravenous diuretics, oxygen, and vasodilators. Although these measures ameliorate the patient's symptoms, they do not favorably impact on short- and long-term mortality. Consequently, there is a pressing need for novel agents in acute heart failure treatment with the result that research in this field is increasing worldwide.

Effect of levosimendan on the contractility of muscle fibers from nemaline myopathy patients with mutations in the nebulin gene

Background

Nemaline myopathy (NM), the most common non-dystrophic congenital myopathy, is characterized by generalized skeletal muscle weakness, often from birth. To date, no therapy exists that enhances the contractile strength of muscles of NM patients. Mutations in NEB, encoding the giant protein nebulin, are the most common cause of NM. The pathophysiology of muscle weakness in NM patients with NEB mutations (NEB-NM) includes a lower calcium-sensitivity of force generation. We propose that the lower calcium-sensitivity of force generation in NEB-NM offers a therapeutic target. Levosimendan is a calcium sensitizer that is approved for use in humans and has been developed to target cardiac muscle fibers. It exerts its effect through binding to slow skeletal/cardiac troponin C. As slow skeletal/cardiac troponin C is also the dominant troponin C isoform in slow-twitch skeletal muscle fibers, we hypothesized that levosimendan improves slow-twitch muscle fiber strength at submaximal levels of activation in patients with NEB-NM.

Methods

To test whether levosimendan affects force production, permeabilized slow-twitch muscle fibers isolated from biopsies of NEB-NM patients and controls were exposed to levosimendan and the force response was measured.

Results

No effect of levosimendan on muscle fiber force in NEB-NM and control skeletal muscle fibers was found, both at a submaximal calcium level using incremental levosimendan concentrations, and at incremental calcium concentrations in the presence of levosimendan. In contrast, levosimendan did significantly increase the calcium-sensitivity of force in human single cardiomyocytes. Protein analysis confirmed that the slow skeletal/cardiac troponin C isoform was present in the skeletal muscle fibers tested.

Conclusions

These findings indicate that levosimendan does not improve the contractility in human skeletal muscle fibers, and do not provide rationale for using levosimendan as a therapeutic to restore muscle weakness in NEB-NM patients. We stress the importance of searching for compounds that improve the calcium-sensitivity of force generation of slow-twitch muscle fibers. Such compounds provide an appealing approach to restore muscle force in patients with NEB-NM, and also in patients with other neuromuscular disorders.

Electronic supplementary material

The online version of this article (doi:10.1186/s13395-015-0037-7) contains supplementary material, which is available to authorized users.

Levosimendan displays anti-inflammatory effects and decreases MPO bioavailability in patients with severe heart failure

Treatment of decompensated heart failure often includes administration of levosimendan. Myeloperoxidase (MPO) is released during polymorphonuclear neutrophil (PMN) degranulation, and mediates dysregulation of vascular tone in heart failure. We evaluated the effects of levosimendan-treatment on MPO in patients with acute decompensation of chronic heart failure over a one week course. Plasma MPO levels were significantly decreased after levosimendan treatment (from 252.1 ± 31.1 pmol/l at baseline to 215.02 ± 27.96 pmol/l at 6 h, p < 0.05). Ex vivo incubation of whole blood with levosimendan decreased MPO release after PMN-stimulation (8.2 ± 1.4-fold increase at baseline vs. 6.0 ± 1.1-fold increase with levosimendan). MPO levels also significantly correlated with diastolic blood pressure over the time course. In a multivariate linear model, the main contributor to systolic, diastolic and mean blood pressure was level of PMN elastase. MPO contributed only in heparin-treated patients, suggesting a more significant role for endothelial-bound MPO than for circulating MPO or elastase with respect to blood pressure regulation. We here provide the first evidence that levosimendan treatment inhibits MPO release by PMNs in decompensated heart failure patients. This mechanism may regulate endothelial function and vascular tone in heart failure patients.

Effects of levosimendan on heart failure in normotensive patients: does loading dose matter?

BACKGROUND

Levosimendan is a calcium sensitizer and K(+)-ATP channel opener with inotropic and vasodilatatory effects irrespective of myocardial oxygen consumption, used for treatment of heart failure (HF). A loading dose is usually given by infusion for 12 h; however, profound lowering of blood pressure often disrupts or prolongs the infusion. The aim of this study was to assess clinical, biochemical and myocardial differences between different regimes of levosimendan therapy, with or without loading dose, and compared to standard therapy in heart failure.

METHODS

Fifty-seven patients (mean age ± SD: 60.9 ± 9.3 years, 45 males) with HF, New York Heart Association (NYHA) III-IV, reduced left ventricular ejection fraction (LVEF) were included. Twenty patients (NB group) were given levosimendan without loading dose, 14 patients (B group) were given levosimendan with loading dose, and 23 patients (C group) were given standard therapy. Clinical, biochemical and echocardiographic characteristics at baseline and one week after treatment were evaluated.

RESULTS

Groups were similar at baseline. After one week NHYA class (P < 0.001), NT pro-BNP (P < 0.001), LVEF (P = 0.045), E/A (P = 0.048) E/e' (P < 0.001), and PAPs (P < 0.001) decreased. DT (P = 0.011) and TAPSE (P = 0.035) increased in all groups.

CONCLUSIONS

Levosimendan, as well as standard therapy, improves myocardial function and symptoms of HF, irrespective of the loading dose administration. Treatment options for patients with end-stage heart failure refractory to conventional medical therapy are limited. Inotropic drugs play an important role in heart failure (HF).

[Catecholamines: pro and contra]

BACKGROUND

Catecholamines with vasopressor and inotropic effects are commonly used in intensive care medicine. The aim of this review is to explain some of the physiologic actions on which a catecholamine therapy is based, but also to elucidate the risks which are associated with an uncritical and excessive use of these drugs.

SIDE EFFECTS

Emphasis is placed on the myocardial damage triggered by adrenergic overstimulation. There is considerable evidence that in conditions of severe heart failure, myocardial ischemia as well as cardiogenic and septic shock especially the use of catecholamines with predominant β-adrenergic effects (epinephrine, dobutamine, dopamine) can have a negative clinical impact. A simple cardiac risk marker might be a tachycardia.

ADMINISTRATION

Vasopressor therapy with norepinephrine, based on individually applied perfusion parameters (e.g., urine output, lactate), however, seems justified in many conditions of shock and hemodynamic instability during deep analgosedation. In terms of a cardioprotective therapy, the administration of catecholamines, however, should always be reevaluated and titrated to the minimum deemed necessary.

Peri-operative Levosimendan in Patients Undergoing Cardiac Surgery: An Overview of the Evidence

Levosimendan, a calcium sensitiser, has recently emerged as a valuable agent in the peri-operative management of cardiac surgery patients. Levosimendan is a calcium-sensitising ionodilator. By binding to cardiac troponin C and reducing its calcium-binding co-efficient, it enhances myofilament responsiveness to calcium and thus enhances myocardial contractility without increasing oxygen demand. Current evidence suggests that levosimendan enhances cardiac function after cardiopulmonary bypass in patients with both normal and reduced left ventricular function. In addition to being used as post-operative rescue therapy for low cardiac output syndrome, a pre-operative levosimendan infusion in high risk patients with poor cardiac function may reduce inotropic requirements, the need for mechanical support, the duration of intensive care admissions as well as post-operative mortality. Indeed, it is these higher-risk patients who may experience a greater degree of benefit. Larger, multicentre randomised trials in cardiac surgery will help to elucidate the full potential of this agent.

Levosimendan Improves Neurological Outcome in a Swine Model of Asphyxial Cardiac Arrest

BACKGROUND

In asphyxial cardiac arrest, the severe hypoxic stress complicates the resuscitation efforts and results in poor neurological outcomes. Our aim was to assess the effects of levosimendan on a swine model of asphyxial cardiac arrest.

METHODS

Asphyxial cardiac arrest was induced in 20 Landrace/Large White piglets, which were subsequently left untreated for four minutes. The animals were randomised to receive adrenaline alone (n=10, Group A) and adrenaline plus levosimendan (n=10, Group B). All animals were resuscitated according to the 2010 European Resuscitation Council guidelines. Haemodynamic variables were measured before arrest, during arrest and resuscitation, and during the first 30 minutes after return of spontaneous circulation (ROSC), while survival and neurologic alertness score were measured 24 hours later.

RESULTS

Return of spontaneous circulation was achieved in six animals (60%) from Group A and nine animals (90%) from Group B (p=0.303). During the first minute of cardiopulmonary resuscitation, coronary perfusion pressure was significantly higher in Group B (p=0.046), but there was no significant difference at subsequent time points until ROSC. Although six animals (60%) from each group survived after 24 hours (p=1.000), neurologic examination was significantly better in the animals of Group B (p<0.01).

CONCLUSIONS

The addition of levosimendan to adrenaline improved coronary perfusion pressure immediately after the onset of cardiopulmonary resuscitation and resulted in better 24-hour neurological outcome.

Management of the cardiorenal syndrome in decompensated heart failure

BACKGROUND

The management of the cardiorenal syndrome (CRS) in decompensated heart failure (HF) is challenging, with high-quality evidence lacking.

SUMMARY

The pathophysiology of CRS in decompensated HF is complex, with glomerular filtration rate (GFR) and urine output representing different aspects of kidney function. GFR depends on structural factors (number of functional nephrons and integrity of the glomerular membrane) versus hemodynamic alterations (volume status, renal perfusion, arterial blood pressure, central venous pressure or intra-abdominal pressure) and neurohumoral activation. In contrast, urine output and volume homeostasis are mainly a function of the renal tubules. Treatment of CRS in decompensated HF patients should be individualized based on the underlying pathophysiological processes.

KEY MESSAGES

Congestion, defined as elevated cardiac filling pressures, is not a surrogate for volume overload. Transient decreases in GFR might be accepted during decongestion, but hypotension must be avoided. Paracentesis and compression therapy are essential to remove fluid overload from third spaces. Increasing the effective circulatory volume improves renal function when cardiac output is depressed. As mechanical support is invasive and inotropes are related to increased mortality, afterload reduction through vasodilator therapy remains the preferred strategy in patients who are normo- or hypertensive. Specific therapies to augment renal perfusion (rolofylline, dopamine or nesiritide) have rendered disappointing results, but recently, serelaxin has been shown to improve renal function, even with a trend towards reduced all-cause mortality in selected patients. Diuretic resistance is associated with worse outcomes, independent of the underlying GFR. Combinational diuretic therapy, with ultrafiltration as a bail-out strategy, is indicated in case of diuretic resistance.

Levosimendan affects oxidative and inflammatory pathways in the diaphragm of ventilated endotoxemic mice

INTRODUCTION

Controlled mechanical ventilation and endotoxemia are associated with diaphragm muscle atrophy and dysfunction. Oxidative stress and activation of inflammatory pathways are involved in the pathogenesis of diaphragmatic dysfunction. Levosimendan, a cardiac inotrope, has been reported to possess anti-oxidative and anti-inflammatory properties. The aim of the present study was to investigate the effects of levosimendan on markers for diaphragm nitrosative and oxidative stress, inflammation and proteolysis in a mouse model of endotoxemia and mechanical ventilation.

METHODS

Three groups were studied: (1) unventilated mice (CON, n =8), (2) mechanically ventilated endotoxemic mice (MV LPS, n =17) and (3) mechanically ventilated endotoxemic mice treated with levosimendan (MV LPS + L, n =17). Immediately after anesthesia (CON) or after 8 hours of mechanical ventilation, blood and diaphragm muscle were harvested for biochemical analysis.

RESULTS

Mechanical ventilation and endotoxemia increased expression of inducible nitric oxide synthase (iNOS) mRNA and cytokine levels of interleukin (IL)-1β, IL-6 and keratinocyte-derived chemokine, and decreased IL-10, in the diaphragm; however, they had no effect on protein nitrosylation and 4-hydroxy-2-nonenal protein concentrations. Levosimendan decreased nitrosylated proteins by 10% (P <0.05) and 4-hydroxy-2-nonenal protein concentrations by 13% (P <0.05), but it augmented the rise of iNOS mRNA by 47% (P <0.05). Levosimendan did not affect the inflammatory response in the diaphragm induced by mechanical ventilation and endotoxemia.

CONCLUSIONS

Mechanical ventilation in combination with endotoxemia results in systemic and diaphragmatic inflammation. Levosimendan partly decreased markers of nitrosative and oxidative stress, but did not affect the inflammatory response.

Design and synthesis of new dihydrotestosterone derivative with positive inotropic activity

There are several reports which indicate that some steroid derivatives have inotropic activity; nevertheless, the cellular site and mechanism of action of steroid derivatives at cardiovascular level is very confusing. In order, to clarify these phenomena in this study, two dihydrotestosterone derivatives (compounds 5 and 10) were synthesized with the objective of to evaluate its biological activity on left ventricular pressure and characterize their molecular mechanism. In the first stage, the Langendorff technique was used to measure changes on perfusion pressure and coronary resistance in an isolated rat heart model in absence or presence of the steroid derivatives. Additionally, to characterize the molecular mechanism involved in the inotropic activity induced by the compound 5 was evaluated by measuring left ventricular pressure in absence or presence of following compounds; nifedipine, flutamide, indomethacin, prazosin, isoproterenol, propranolol and metoprolol. The results showed that the compound 5 significantly increased the perfusion pressure and coronary resistance in comparison with dihydrotestosterone, compound 10 and the control conditions. Other data indicate that 5 increase left ventricular pressure in a dose-dependent manner (0.001-100 nM); nevertheless, this phenomenon was significantly inhibited only by propranolol or metoprolol at a dose of 1 nM. These data suggest that positive inotropic activity induced by the compound 5 is through β1-adrenergic receptor however, this effect was independent of cAMP levels. This phenomenon is a particularly interesting because the positive inotropic activity induced by this steroid derivative involves a molecular mechanism different in comparison with other positive inotropic drugs.

Acute effects of levosimendan in experimental models of right ventricular hypertrophy and failure

Pulmonary arterial hypertension (PAH) is a fatal disease, and the ultimate cause of death is right ventricular (RV) failure. In this study, we investigated the acute hemodynamic effects of levosimendan in two rat models of RV hypertrophy and failure. Wistar rats were randomized to receive sham surgery (n = 8), pulmonary trunk banding (PTB; n = 8), or monocrotaline injection (MCT; n = 7). RV function was evaluated at baseline and after injection of placebo and two concentrations of levosimendan (12 and 60 μg/kg) using magnetic resonance imaging, echocardiography, and invasive pressure recordings. PTB and MCT injection caused hypertrophy, dilatation, and failure of the RV compared with sham surgery. Levosimendan increased RV end systolic pressure (sham surgery: 16.0% ± 3.8% [P = 0.0038]; MCT: 9.9% ± 3.1% [P = 0.018]; PTB: 24.5% ± 3.3% [P = 0.0001]; mean ± SEM) compared with placebo. Levosimendan markedly increased RV stroke volume (SV) in the MCT group (29.1% ± 8.3%; P = 0.012), did not change RV SV in the PTB group (0.4% ± 4.5%; P = 0.93), and decreased RV SV in the sham surgery group (-10.9% ± 3.7%; P = 0.020). Nitroprusside, which was used to mimic the systemic arterial vasodilator action of levosimendan, did not influence RV function. These data demonstrate that levosimendan acutely improves the failing right heart in a MCT model of PAH and that the mechanism involves a direct acute positive inotropic effect on the hypertrophic and failing RV of the rat.

The interface between monitoring and physiology at the bedside

Hemodynamic instability as a clinical state represents either a perfusion failure with clinical manifestations of circulatory shock or heart failure or 1 or more out-of-threshold hemodynamic monitoring values, which may not necessarily be pathologic. Different types of causes of circulatory shock require different types of treatment modalities, making these distinctions important. Diagnostic approaches or therapies based on data derived from hemodynamic monitoring assume that specific patterns of derangements reflect specific disease processes, which respond to appropriate interventions. Hemodynamic monitoring at the bedside improves patient outcomes when used to make treatment decisions at the right time for patients experiencing hemodynamic instability.

Prognostic value of noninvasive hemodynamic evaluation of the acute effect of levosimendan in advanced heart failure

AIMS

Optimization of inotropic treatment in worsening heart failure sometimes requires invasive hemodynamic assessment in selected patients. Impedance cardiography (ICG) may be useful for a noninvasive hemodynamic evaluation.

METHODS

ICG was performed in 40 patients (69 ± 8 years; left ventricular ejection fraction 27.5 ± 5.6%; New York Heart Association 3.18 ± 0.34; Interagency Registry for Mechanically Assisted Circulatory Support 5.48 ± 0.96, before and after infusion of Levosimendan (0.1–0.2 µg/kg per min for up to 24 h). Echocardiogram, ICG [measuring cardiac index (CI), total peripheral resistances (TPRs) and thoracic fluid content (TFC)] and plasma levels of brain natriuretic peptide (BNP) were obtained; in nine patients, right heart catheterization was also carried out.

RESULTS

When right catheterization and ICG were performed simultaneously, a significant relationship was observed between values of CI and TPR, and between TFC and pulmonary wedge pressure. ICG detected the Levosimendan-induced recovery of the hemodynamic status, associated with improved systolic and diastolic function and reduction in BNP levels. One-year mortality was 4.4%. At multivariate analysis, independent predictors of mortality were: no improvement in the severity of mitral regurgitation, a persistent restrictive filling pattern (E/E’ > 15), a reduction of BNP levels below 30% and a change below 10% in CI, TPR and TFC. When combined, absence of hemodynamic improvement at ICG could predict 1-year mortality with better sensitivity (86%) and specificity (85%) than the combination of echocardiographic and BNP criteria only (sensitivity 80% and specificity 36%).

CONCLUSION

Noninvasive hemodynamic evaluation of heart failure patients during infusion of inodilator drugs is reliable and may help in their prognostic stratification.