Overview of emerging pharmacologic agents for acute heart failure syndromes

Treatment of refractory vasospastic angina complicated by acute pulmonary oedema with levosimendan: a case report

BACKGROUND

Vasospastic angina (VA) is an important cause of chest pain and patients often have 3- to 6-month clusters of recurrent attacks, separated by relatively asymptomatic periods. During these episodes the resulting myocardial ischaemia can lead to clinical complications of different severity, including acute myocardial infarction, acute heart failure, and cardiogenic shock. The management of severe and recurrent VA attacks is challenging, and no specific recommendations exist in recent cardiologic guidelines on the pharmacological strategy (inotropic/vasopressor agents) to adopt for this acute clinical setting.

CASE SUMMARY

We present a case of recurrent episodes of VA complicated by acute pulmonary oedema and cardiogenic shock despite maximal tolerated therapy (intravenous calcium antagonist and nitrates) that was successfully treated with levosimendan.

DISCUSSION

Levosimendan rapidly reverted cardiogenic shock, acute pulmonary oedema, and mitral regurgitation caused by a refractory coronary spasm, contributing to persistent clinical stabilization. Further evidence and a longer follow-up are needed to support our observation on the efficacy of levosimendan in this specific clinical setting.

Intravenous nicorandil for treatment of the urgent phase acute heart failure syndromes: A randomized, controlled trial

BACKGROUND

Vasodilators, such as nitroglycerin, have long been first-line treatments for acute heart failure syndromes (AHFS). Nicorandil is a vasodilator with dual potassium channel opening and nitrate properties. However, there are no randomized controlled studies of intravenous nicorandil safety and efficacy in the urgent phase AHFS. We examined the symptomatic, hemodynamic, and echocardiographic effects and safety, and 60-day clinical outcomes of intravenous nicorandil, in addition to standard therapy, in patients with AHFS in the urgent phase.

METHODS

In this prospective, randomized controlled trial, 106 AHFS patients were randomized within one hour of arrival to receive either standard therapy (control group, n=56) or standard therapy plus simultaneous intravenous nicorandil (0.2 mg/kg bolus followed by 0.2 mg/kg/h for 24 h; nicorandil group, n=50). Outcomes were assessed at 60 days.

RESULTS

Patients in the nicorandil group exhibited greater improvement of dyspnea as measured by change in a five-point Likert scale compared to those in the control group (after 1 h infusion: p=0.006, 6 h; p<0.001). The nicorandil group also showed significantly improved E/e', an estimate of left ventricular filling pressure, at 1 and 24 h ( p=0.001 and p=0.004, respectively). In addition, intravenous nicorandil therapy was safe and did not cause side effects such as excessive hypotension or reflex tachycardia. However, it did not reduce all-cause mortality and readmission rates at 60 days.

CONCLUSIONS

Addition of intravenous nicorandil to standard therapy for urgent phase AHFS improved dyspnea and left ventricular diastolic function but not 60-day outcome.

Heart failure: novel therapeutic approaches

Heart failure (HF) is a complex clinical syndrome that can result from any structural or functional cardiac disorders that impairs the ability of the ventricle to fill with or eject blood. Despite effective medical interventions, mortality and morbidity remain substantial. There have been significant advances in the therapy of HF in recent decades, such as the introduction of beta-blockers and antagonists of the renin-angiotensin system but still there is a major unmet need for better therapies for HF. In the present era, pathophysiology of HF has been explored. Various novel pathways, molecular sites have been identified, which contribute to the progression of the disease. By targeting these sites, newer pharmacological agents have been developed, which can play a promising role in the treatment of HF. This article focuses on recent advancements in pharmacotherapy of HF, which include agents targeting myocardial contractility, cytokines and inflammation, fibrosis and remodeling, myocardial metabolism, oxidative stress, and other newly defined pathways.

Pulmonary Oedema-Therapeutic Targets

Pulmonary oedema (PO) is a common manifestation of acute heart failure (AHF) and is associated with a high-acuity presentation and with poor in-hospital outcomes. The clinical picture of PO is dominated by signs of pulmonary congestion, and its pathogenesis has been attributed predominantly to an imbalance in Starling forces across the alveolar-capillary barrier. However, recent studies have demonstrated that PO formation and resolution is critically regulated by active endothelial and alveolar signalling. PO represents a medical emergency and treatment should be individually tailored to the urgency of the presentation and acute haemodynamic characteristics. Although, the majority of patients admitted with PO rapidly improve as result of conventional intravenous (IV) therapies, treatment of PO remains largely opinion based as there is a general lack of good evidence to guide therapy. Furthermore, none of these therapies showed simultaneous benefit for symptomatic relief, haemodynamic improvement, increased survival and end-organ protection. Future research is required to develop innovative pharmacotherapies capable of relieving congestion while simultaneously preventing end-organ damage.

Protective effect of resveratrol against pressure overload-induced heart failure

Transverse aortic constriction (TAC)-induced pressure overload (PO) causes adverse cardiac remodeling and dysfunction that progresses to heart failure (HF). The purpose of this study was to determine whether the potent antioxidant, resveratrol, significantly attenuates PO-induced HF in wild-type mice. Male C57BL6 mice were subjected to either sham or TAC surgery. One group of TAC mice was given daily resveratrol treatment. Echocardiographic, biometric, and immunohistological analyses were performed on the three groups of mice. All echocardiographic parameters demonstrated significantly greater adverse cardiac remodeling and dysfunction in the TAC compared to the sham mice. Increases in the ratios of heart weight (HW)/body weight (BW) and lung weight (LW)/BW and a sharp decline in the percentage of ejection fraction and fractional shortening were found in TAC relative to sham mice. Likewise, the TAC protocol increased markers of oxidative stress, cardiac hypertrophy, inflammation, fibrosis, hypoxia, and apoptosis. These pathological changes were significantly attenuated by resveratrol treatment. Resveratrol treatment significantly attenuates the adverse cardiac remodeling and dysfunction produced by the TAC protocol in C57/BL6 mice and this activity is mediated, at least in part, by the inhibition of oxidative stress and inflammation indicating a therapeutic potential of resveratrol in HF.

Current management and future directions for the treatment of patients hospitalized for heart failure with low blood pressure

Although patients hospitalized with heart failure have relatively low in-hospital mortality, the post-discharge rehospitalization and mortality rates remain high despite advances in treatment. Most patients admitted for heart failure have normal or high blood pressure, but 15-25 % have low systolic blood pressure with or without signs and/or symptoms of hypoperfusion. All pharmacological agents known to improve the prognosis of patients with heart failure also reduce blood pressure, and this limits their use in patients with heart failure and low blood pressure (HF-LBP). However, patients with HF-LBP have much higher in-hospital and post-discharge mortality. In these patients, a conceptually important therapeutic target is to improve cardiac output in order to alleviate signs of hypoperfusion. Accordingly, the majority of these patients will require an inotrope as cardiac dysfunction is the cause of their low cardiac output. However, the short-term use of currently available inotropes has been associated with further decreases in blood pressure and increases in heart rate, myocardial oxygen consumption and arrhythmias. Agents that improve cardiac contractility without this undesirable effects should be developed. To the best of our knowledge, the epidemiology, pathophysiology and therapy of patients with HF-LBP have not been addressed thoroughly. In June 2010, a workshop that included scientists and clinicians was held in Rome, Italy. The objectives of this meeting were to (1) develop a working definition for HF-LBP, (2) describe its clinical characteristics and pathophysiology, (3) review current therapies and their limitations, (4) discuss novel agents in development and (5) create a framework for the design and conduct of future clinical trials.

Chronic istaroxime improves cardiac function and heart rate variability in cardiomyopathic hamsters

PURPOSE

Istaroxime is a new luso-inotropic compound. It exerts inotropic action by reducing Na+/K+-ATPase activity, and simultaneously it stimulates sarcoplasmic reticulum Ca(2+)-ATPase function, thus also inducing lusitropic action. The aim of present study is to assess the effect of chronic istaroxime treatment on cardiac function and heart rate variability in Bio TO.2 Syrian hamster model of progressive heart failure.

METHODS

Bio TO.2 hamsters were daily treated, from 12 to 28 weeks of age, with 30 mg/kg/day oral istaroxime. Age-matched Bio TO.2 and Bio F1B hamsters were treated with vehicle and used as diseased and healthy controls. At the end of treatment, hearts function and autonomic cardiac control were evaluated.

RESULTS

Hearts from vehicle-treated Bio TO.2 when compared with hearts from Bio F1B showed higher heart/body weight ratio, and lower left ventricular systolic pressure (LVSP), positive and negative derivative of LV pressure (dP/dT), coronary flow rate (CFR). Hearts from istaroxime-treated when compared with those of vehicle-treated hamsters, showed the reduction of heart/body weight ratio, and the increase of LVSP, of both positive and negative dP/dT, and of CFR. Autonomic cardiac control, evaluated by HRV analysis, indicated in vehicle-treated Bio TO.2 hamsters, when compared to healthy, a shift towards increased sympathetic and decreased parasympathetic activities. Istaroxime-treatment preserved parasympathetic activity.

CONCLUSIONS

Chronic istaroxime improves cardiac function and heart rate variability in Bio TO.2 Syrian hamster model of progressive heart failure.

Gene-disease network analysis reveals functional modules in mendelian, complex and environmental diseases

Background

Scientists have been trying to understand the molecular mechanisms of diseases to design preventive and therapeutic strategies for a long time. For some diseases, it has become evident that it is not enough to obtain a catalogue of the disease-related genes but to uncover how disruptions of molecular networks in the cell give rise to disease phenotypes. Moreover, with the unprecedented wealth of information available, even obtaining such catalogue is extremely difficult.

Principal Findings

We developed a comprehensive gene-disease association database by integrating associations from several sources that cover different biomedical aspects of diseases. In particular, we focus on the current knowledge of human genetic diseases including mendelian, complex and environmental diseases. To assess the concept of modularity of human diseases, we performed a systematic study of the emergent properties of human gene-disease networks by means of network topology and functional annotation analysis. The results indicate a highly shared genetic origin of human diseases and show that for most diseases, including mendelian, complex and environmental diseases, functional modules exist. Moreover, a core set of biological pathways is found to be associated with most human diseases. We obtained similar results when studying clusters of diseases, suggesting that related diseases might arise due to dysfunction of common biological processes in the cell.

Conclusions

For the first time, we include mendelian, complex and environmental diseases in an integrated gene-disease association database and show that the concept of modularity applies for all of them. We furthermore provide a functional analysis of disease-related modules providing important new biological insights, which might not be discovered when considering each of the gene-disease association repositories independently. Hence, we present a suitable framework for the study of how genetic and environmental factors, such as drugs, contribute to diseases.

Availability

The gene-disease networks used in this study and part of the analysis are available at http://ibi.imim.es/DisGeNET/DisGeNETweb.html#Download.

Development and physico-chemical characterization of a liposomal formulation of istaroxime

Istaroxime, an investigational new drug that targets defective Ca(2+) cycling without compromising cardiac efficiency, may represent a promising and safe treatment of both acute and chronic heart failure. Even though the compound demonstrated good tolerability in a phase I/II safety study, symptoms related to the gastro-intestinal tract and pain at the injection site were reported as the most frequent side effects. The aim of this study was to encapsulate istaroxime in a drug delivery system (DDS) that could minimize the pain perceived upon administration. The DDS was designed to be quickly destabilized in plasma, in order to minimize alteration of the pharmacokinetic profile of istaroxime. To meet those requirements, a balance between the encapsulation efficiency and the release rate was sought. Transmembrane pH-gradient liposomes formulated with different phosphatidylcholines were investigated as vehicles for an efficient active drug loading. Poly(ethylene glycol)-660-hydroxystearate (PEG-HS) was chosen as excipient to modulate the bilayer fluidity and the release properties of the liposomes. A fast and efficient encapsulation was obtained by modulating the drug-to-lipid ratio, the amount of PEG-HS, and the incubation temperature. High encapsulation efficiency was achieved by incubating the drug with liposomal dispersions at room temperature for 10 min. Almost complete release was obtained in physiological conditions in less than 10 min, suggesting a model formulation potentially useful for drugs presenting similar features and side effects.

Early dyspnoea relief in acute heart failure: prevalence, association with mortality, and effect of rolofylline in the PROTECT Study

AIMS

Dyspnoea and pulmonary and/or peripheral congestion are the most frequent manifestations of acute heart failure (AHF) and are important targets for therapy. We have assessed changes in dyspnoea, their relationship with mortality, and the effects of the adenosine A1 receptor antagonist rolofylline on these endpoints in patients enrolled in the PROTECT trial.

METHODS AND RESULTS

PROTECT was a prospective, double-blind, placebo-controlled study assessing the effect of rolofylline in patients hospitalized for AHF with dyspnoea, fluid overload, increased plasma natriuretic peptides, and mild-to-moderate renal dysfunction. Early dyspnoea relief, prospectively defined as moderately or markedly better dyspnoea at both 24 and 48 h after the start of study drug administration, occurred in 49.8% of the patients. Early dyspnoea relief was associated with greater weight loss and with reduced mortality at Days 14 and 30 [hazard ratio (HR) 0.28, 95% confidence interval (CI): 0.15, 0.50; and 0.35, 95% CI: 0.22, 0.55, respectively]. Rolofylline administration was associated with an increase in the proportion of patients showing early dyspnoea relief (HR 1.30; 95% CI: 1.08, 1.57) and with a numerically lower mortality at 14 and 30 days, largely driven by the mortality due to HF [at 30 days, HR (95% CI, P-value): 0.65 (0.38-1.10, P= 0.107)]. Rolofylline did not reduce episodes of in-hospital worsening HF or post-discharge re-admissions, nor did it improve survival at 60 or 180 days.

CONCLUSION

The present analysis from PROTECT demonstrated that more weight loss was associated with early dyspnoea relief and reduced short-term mortality.

Role and mechanism of subcellular Ca2+ distribution in the action of two inotropic agents with different toxicity

Pro-arrhythmic risk strongly limits the therapeutic value of current inotropic interventions. Istaroxime (previously PST2744) is a novel inotropic agent, significantly less pro-arrhythmic than digoxin that, in addition to block Na(+)/K(+) pump, stimulates sarcoplasmic reticulum (SR) Ca(2+) ATPase (SERCA2). Here we compare istaroxime and digoxin effects to further address the role of SR modulation in reducing the toxicity associated with Na(+)/K(+) pump blockade. In murine ventricular myocytes both compounds increased cell twitch (inotropy) in a concentration-dependent fashion. At high concentrations digoxin, but not istaroxime, induced unstimulated contractions, a sign of pro-arrhythmic toxicity. To evaluate the mechanism of this difference, we compared the two drugs at concentrations exerting equal inotropy but different toxicity. At these concentrations: (1) the two drugs equally inhibited the Na(+)/K(+) pump; (2) digoxin induced larger increases in resting Ca(2+) and in diastolic Ca(2+) during pacing; (3) neither drug affected the relationship between RyR-mediated SR Ca(2+) leak and Ca(2+) content; (4) istaroxime, but not digoxin, enhanced SR Ca(2+) reuptake rate. In conclusion, digoxin toxicity was associated to larger accumulation of cytosolic Ca(2+), which did not result from RyR facilitation, but which might ultimately induce it to promote unstimulated Ca(2+) release. The lower toxicity of Na(+)/K(+) pump blockade by istaroxime may thus reflect improved Ca(2+) confinement within the SR, likely to result from concomitant SERCA2 stimulation.

Inotropes in cardiac patients: update 2011

PURPOSE OF REVIEW

ICU patients frequently develop low output syndromes due to cardiac dysfunction, myocardial injury, and inflammatory activation. Conventional inotropic agents seem to be useful in restoring hemodynamic parameters and improving peripheral organ perfusion, but can increase short-term and long-term mortality in these patients. Novel inotropes may be promising in the management of ICU patients, having no serious adverse effects. This review summarizes all the current knowledge about the use of conventional and new inotropic agents in various clinical entities of critically ill patients.

RECENT FINDINGS

In recent European Society of Cardiology guidelines, inotropic agents are administered in patients with low output syndrome due to impaired cardiac contractility, and signs and symptoms of congestion. The most recommended inotropes in this condition are levosimendan and dobutamine (both class of recommendation: IIa, level of evidence: B). Recent data indicate that levosimendan may be useful in postmyocardial infarction cardiac dysfunction and septic shock through increasing coronary flow and attenuating inflammatory activation, respectively. Furthermore, calcium sensitizing by levosimendan can be effectively used for weaning of mechanical ventilation in postcardiac surgery patients and has also cardioprotective effect as expressed by the absence of troponin release in this patient population. Finally, new agents, such as istaroxime and cardiac myosin activators may be safe and improve central hemodynamics in experimental models of heart failure and heart failure patients in phase II clinical trials; however, large-scale randomized clinical trials are required.

SUMMARY

In an acute cardiac care setting, short-term use of inotropic agents is crucial for the restoration of arterial blood pressure and peripheral tissue perfusion, as well as weaning of cardiosurgery. New promising agents should be tested in randomized clinical trials.

International variations in the clinical, diagnostic, and treatment characteristics of emergency department patients with acute heart failure syndromes

AIMS

Results from investigations in one area of the world may not translate to another if patient characteristics and practices differ. We examine differences in the presentation and management of emergency department (ED) patients with dyspnoea from acute heart failure syndromes (AHFS) between the USA, Western Europe, and Eastern Europe.

METHODS AND RESULTS

The URGENT Dyspnoea study was a multinational prospective observational study of dyspnoeic ED patients with AHFS from 18 countries. Acute heart failure syndrome patients from the USA and Western and Eastern Europe underwent dyspnoea assessments within 1 h of the first physician evaluation. Patient characteristics, evaluation, and treatments were compared between geographical regions using analysis of variance and χ(2) tests. Four hundred and ninety-three patients with AHFS met the inclusion criteria. Participants in the USA were more frequently non-white, younger, on chronic beta-blocker therapy, and with an ejection fraction ≤40% when compared with Eastern and Western Europe. Patients from Eastern Europe were more likely to present with de novo heart failure and have ischaemic electrocardiogram changes. Pulmonary oedema was more common on chest radiograph in Western Europe, but natriuretic peptide levels were elevated in all three regions. Diuretic use was similar across all the regions. Intravenous nitroglycerin was used more frequently in Eastern (32.8%) and Western Europe (24.4%) compared with the USA (2.5%).

CONCLUSION

International differences in AHFS presentations and management between regions suggest results from clinical trials in one region may not translate directly to another. These differences should be considered when designing trials and interpreting the results from clinical investigations.

Dyspnoea and worsening heart failure in patients with acute heart failure: results from the Pre-RELAX-AHF study

Aims

Although dyspnoea is the most common cause of admission for acute heart failure (AHF), more needs to be known about its clinical course and prognostic significance.

Methods and results

The Pre-RELAX-AHF study randomized 232 subjects with AHF to placebo or four doses of relaxin and evaluated early (6–24 h Likert scale) and persistent [change in visual analogue scale area under the curve (VAS AUC) through Day 5] dyspnoea relief. Worsening heart failure (WHF) was defined as worsening AHF signs and symptoms requiring additional therapy. Patients were followed until Day 180. Early dyspnoea relief was observed in only 25% of all patients, and VAS AUC at 5 days was 45% over baseline values in all patients (32% placebo; 50% all relaxin-treated patients). Worsening heart failure to Day 5 was observed in 16% of all patients (21% placebo; 14% relaxin). Lack of persistent dyspnoea relief and WHF were associated with a longer length of initial hospital stay and worse 60-day outcomes.

Conclusion

Dyspnoea relief in patients admitted with AHF is often incomplete, and many may show WHF after the initial stabilization. Both lack of persistent dyspnoea relief and in-hospital WHF predict a longer length of stay and worse outcome.

Resveratrol arrests and regresses the development of pressure overload- but not volume overload-induced cardiac hypertrophy in rats

Cardiac hypertrophy is a compensatory enlargement of the heart due to either volume overload (VO) and/or pressure overload (PO) that develops into heart failure if left untreated. The polyphenol resveratrol has been reported to regress PO-induced cardiac hypertrophy in rats. Our aim in this study was to assess the effectiveness of resveratrol on VO-induced cardiac hypertrophy. Sprague Dawley rats were subjected to aortocaval shunt and abdominal aortic banding surgeries to create VO and PO, respectively; sham-operated rats served as controls. To arrest the development of cardiac hypertrophy, daily resveratrol treatment (2.5 mg/kg body weight) was started 2 d postsurgery for 26 d and assessed by echocardiography at 2, 14, and 28 d postsurgery. Similarly, to regress cardiac hypertrophy resveratrol treatment was started after structural and functional abnormalities developed (14 d postsurgery) for 14 d and assessed by echocardiography at 14 and 28 d postsurgery. VO surgeries induced eccentric hypertrophy characterized by increased left ventricle internal dimensions (LVID) without wall thickening. Conversely, PO induced concentric hypertrophy with increased wall thickness without change in LVID. Lipid peroxidation, a marker for oxidative stress, was significantly elevated in both PO and VO rats. Resveratrol treatment arrested the development and regressed abnormalities in cardiac structure and function in PO but not VO rats. Treatment with resveratrol also significantly reduced oxidative stress in cardiac tissue of PO and VO rats. The results on cardiac structure and function demonstrate a potential for resveratrol in the treatment of cardiac hypertrophy due to PO but not VO.

Systolic blood pressure at admission as a predictor of the response to initial carperitide therapy in patients hospitalized for acute decompensated heart failure with left ventricular systolic dysfunction

PURPOSE

In patients with acute decompensated heart failure (ADHF) and left ventricular systolic dysfunction (LVSD), the role of initial vasodilator therapy remains uncertain. The present study aimed to evaluate the acute efficacy of initial carperitide therapy and to predict its response in ADHF patients with LVSD.

METHODS

Twenty-four consecutive patients with ADHF and LVSD were enrolled. Inclusion criteria were a left ventricular ejection fraction < 40%, systolic blood pressure (BP) > 90 mm Hg, and pulmonary capillary wedge pressure >or=18 mm Hg at baseline. Hemodynamic parameters were evaluated by right heart catheterization before and after carperitide infusion. Responders were defined as a >or=30% reduction of pulmonary capillary wedge pressure (PCWP) or a decrease to < 16 mm Hg within 6 h after carperitide infusion.

RESULTS

Seventeen (71%) of the 24 patients were responders for initial carperitide therapy. The responders had significantly higher systolic BP and cardiac index at baseline compared with nonresponders. The area under the curve (AUC) for systolic BP was 0.93 and a cut-off value of 120 mm Hg had a sensitivity of 94% and specificity of 86% for predicting the efficacy of carperitide. The AUC for the cardiac index was 0.88 and a cut-off value of 2.30 L/min/m(2) had a sensitivity of 65% and a specificity of 100% for predicting the response to carperitide.

CONCLUSIONS

The initial use of carperitide therapy safely reduces PCWP in ADHF patients with LVSD and baseline systolic BP may be useful for predicting the response to initial carperitide therapy for ADHF with LVSD.

Heart failure burden and therapy

Heart failure (HF) is a syndrome with a broad spectrum of heterogeneous symptoms and signs resulting in a wide range of clinical expressions. The prevalence of HF is estimated to be 1-2% in developed countries, increasing with age. Heart failure is the leading cause of hospitalization for patients older than 65 years, raising concerns about the economic burden of this syndrome. This article provides a critical review of epidemiological and clinical aspects for HF; causes, comorbidities, and types of HF are also described. The systolic vs. diastolic, the acute vs. chronic approaches, and the connections between HF and left bundle branch block or atrial fibrillation are further detailed. In addition, a synthesis of the latest results and recommendations concerning the indication and the prescription of pharmacological (such as diuretics or rennin-angiotensin-aldosterone system inhibitors) and non-pharmacological treatments (particularly device therapy) is proposed.

Agents with inotropic properties for the management of acute heart failure syndromes. Traditional agents and beyond

Treatment with inotropic agents is one of the most controversial topics in heart failure. Initial enthusiasm, based on strong pathophysiological rationale and apparent empirical efficacy, has been progressively limited by results of controlled trials and registries showing poorer outcomes of the patients on inotropic therapy. The use of these agents remains, however, potentially indicated in a significant proportion of patients with low cardiac output, peripheral hypoperfusion and end-organ dysfunction caused by heart failure. Limitations of inotropic therapy seem to be mainly related to their mechanisms of action entailing arrhythmogenesis, peripheral vasodilation, myocardial ischemia and damage, and possibly due to their use in patients without a clear indication, rather than to the general principle of inotropic therapy itself. This review will discuss the characteristics of the patients with a potential indication for inotropic therapy, the main data from registries and controlled trials, the mechanism of the untoward effects of these agents on outcomes and, lastly, perspectives with new agents with novel mechanisms of action.

Ca2+: is there something new for the cardiovascular anesthesiologist?

PURPOSE OF REVIEW

Anesthesiologists are frequently called upon to treat abnormalities of heart rhythm or pumping ability. Intracellular Ca is crucial for normal excitation-contraction coupling in the heart and plays a major role in the sequence of events that starts with an electrical signal generated in the atria and ends with myocardial contraction.

RECENT FINDINGS

From controlled diffusion within the cell to a potential role as a biological clock, intracellular Ca is receiving a great deal of attention. For example, the pacemaking electrical signal is known to originate in the sinoatrial node myocyte, but exactly what role Ca plays is controversial despite the fact that the sinoatrial node was discovered over 100 years ago. Basic mechanisms involved in disease processes such as atrial fibrillation and new interventions for heart rate control are beginning to emerge. New discoveries in ventricular myocytes are also stimulating the development of promising therapeutic interventions to safely increase the pumping ability of the heart.

SUMMARY

As our understanding of cardiac physiology and pharmacology progresses at the subcellular and molecular levels, new therapies will continue to emerge and the practice of anesthesia will benefit greatly.

Update on ventricular assist device management in the ICU

PURPOSE OF REVIEW

Mechanical circulatory support has a progressively increasing impact in the treatment of heart failure. The results of mechanical circulatory support are limited not only by the severity of the disease, which necessitated initiation of support, but also by the serious device-related adverse events. Optimized patient selection, improved patient management, and advanced device technology are interdependent key factors that contributed to the recently improved outcomes. The aim of this article is to summarize the current experience in application of mechanical circulatory support, focusing on the ICU management.

RECENT FINDINGS

Management should aim to prevent rather than treat serious complications and adverse events. Timing of intervention, optimization of the preimplantation patient status, patient and device management to ensure optimal hemodynamics, infection prevention, nutritional support, careful anticoagulation, and vigilance for early recognition and prompt treatment of 'minor' events before progression into major complications are essential elements of successful treatment.

SUMMARY

Critical patient care is a valuable adjunct to successful application of mechanical circulatory support, but it cannot counterbalance a late intervention, neither can it be fruitful in treating irreversible organ damage. Current management includes careful application of treatment protocols adjusted to recent experience, and also individualized care by a specialized team.

The role of correction of anaemia in patients with congestive heart failure: a short review

Many patients with Congestive Heart Failure (CHF) are anaemic. This anaemia is associated with more severe CHF and a higher incidence of mortality, hospitalisation and morbidity. The only way to prove that the anaemia is causing this worsening of CHF is to correct it. We review here some of the published papers about correction of anaemia. Many studies show a positive effect of Erythropoietin (EPO) or its' derivatives when administered in combination with oral or IV iron, with improvements in left and right ventricular systolic and diastolic function, dilation and hypertrophy and renal function. In addition, a reduction in hospitalisations, diuretic dose, pulmonary artery pressure, plasma volume, heart rate, serum Brain Natriuretic Peptide levels, the inflammatory marker Interleukin 6, soluble Fas ligand--a mediator of apoptosis, and improvements in New York Heart Association class, exercise capacity, oxygen utilization, caloric intake, Quality of Life and the activity of Endothelial Progenitor Cells, have been observed. Iron deficiency may also play an important role in this anaemia, since improvements in CHF have also been reported following treatment with IV iron alone. However, until the ongoing large placebo-controlled studies of the EPO derivative darbepoetin or IV iron are completed, we will not know whether these treatments really influence CHF outcome.