Randomised trial of high-dose isosorbide dinitrate plus low-dose furosemide versus high-dose furosemide plus low-dose isosorbide dinitrate in severe pulmonary oedema

New perspectives of nitric oxide donors in cardiac arrest and cardiopulmonary resuscitation treatment

Nitric oxide (NO) is often used to treat heart failure accompanied with pulmonary edema. According to present knowledge, however, NO donors are contraindicated when systolic blood pressure is less than 90 mmHg. Based on recent findings and our own clinical experience, we formulated a hypothesis about the new breakthrough complex lifesaving effects of NO donors in patients with cardiac arrest and cardiopulmonary resuscitation therapy. It includes a direct hemodynamic effect of NO donors mediated through vasodilation of coronary arteries in cooperation with improvement of cardiac function and cardiac output through reversible inhibition of mitochondrial complex I and mitochondrial NO synthase, followed by reduction in reactive oxygen species and correction of myocardial stunning. Simultaneously, an increase in vascular sensitivity to sympathetic stimulation could lead to an increase in diastolic blood pressure. Confirmation of this hypothesis in clinical practice would mean a milestone in the treatment for cardiac arrest and cardiopulmonary resuscitation.

Short-term intravenous sodium nitrite infusion improves cardiac and pulmonary hemodynamics in heart failure patients

BACKGROUND

Nitrite exhibits hypoxia-dependent vasodilator properties, selectively dilating capacitance vessels in healthy subjects. Unlike organic nitrates, it seems not to be subject to the development of tolerance. Currently, therapeutic options for decompensated heart failure (HF) are limited. We hypothesized that by preferentially dilating systemic capacitance and pulmonary resistance vessels although only marginally dilating resistance vessels, sodium nitrite (NaNO2) infusion would increase cardiac output but reduce systemic arterial blood pressure only modestly. We therefore undertook a first-in-human HF proof of concept/safety study, evaluating the hemodynamic effects of short-term NaNO2 infusion.

METHODS AND RESULTS

Twenty-five patients with severe chronic HF were recruited. Eight received short-term (5 minutes) intravenous NaNO2 at 10 μg/kg/min and 17 received 50 μg/kg/min with measurement of cardiac hemodynamics. During infusion of 50 μg/kg/min, left ventricular stroke volume increased (from 43.22±21.5 to 51.84±23.6 mL; P=0.003), with marked falls in pulmonary vascular resistance (by 29%; P=0.03) and right atrial pressure (by 40%; P=0.007), but with only modest falls in mean arterial blood pressure (by 4 mm Hg; P=0.004). The increase in stroke volume correlated with the increase in estimated trans-septal gradient (=pulmonary capillary wedge pressure-right atrial pressure; r=0.67; P=0.003), suggesting relief of diastolic ventricular interaction as a contributory mechanism. Directionally similar effects were observed for the above hemodynamic parameters with 10 μg/kg/min; this was significant only for stroke volume, not for other parameters.

CONCLUSIONS

This first-in-human HF efficacy/safety study demonstrates an attractive profile during short-term systemic NaNO2 infusion that may be beneficial in decompensated HF and warrants further evaluation with longer infusion regimens.

Patient characteristics and outcomes associated with nitrovasodilator use in the treatment of acute heart failure

Nitrovasodilators (NVs) are commonly recommended for the treatment of acute heart failure (AHF); however, registries suggest their use is not common. The objectives of this study were to determine patient characteristics associated with NV use and to explore the association between NV use and outcomes [length of stay (LoS) and inpatient mortality] in patients with AHF. A survey of US physicians (n = 426) who treat at least 5 AHF patients per month with NV provided a patient sample (n = 812 treated with NV and n = 322 not-NV) derived from chart review. Factors associated with NV use as well as patient characteristics and outcomes associated with NV use were explored using bivariate analysis, logistic regression, and negative binomial regression as appropriate. NV-treated patients were more likely to be female, have a higher systolic blood pressure, higher B-type natriuretic peptide and troponin, and stay in the intensive care unit while hospitalized, but less likely to be hyponatremic or hospitalized once previously. Overall, average LoS was 5.10 days (SD = 4.52) with 5.21 days (SD = 0.15) for the NV group and 4.94 days (SD = 0.31) for the non-NV group. The overall inpatient mortality rate was 2.1%. Among physicians who frequently use NV to treat AHF patients, there are distinct patient characteristics between NV treated and nontreated patients, suggesting a phenotype-driven approach. However, no differences in LoS or mortality were observed.

Lack of evidence for intravenous vasodilators in ED patients with acute heart failure: a systematic review

There are nearly 700,000 annual US emergency department (ED) visits for acute heart failure (AHF). Although blood pressure is elevated on most of these visits, acute therapy remains focused on preload and not afterload reduction. Data from recent prospective studies suggest that patients with AHF with concomitant acute hypertension benefit from intravenous (IV) vasodilators. To better understand the use of vasodilators for such patients, we conducted a systematic review of (1) currently available intravenous vasodilators for ED patients with AHF, or (2) intravenous vasodilators that are not yet available, but have completed phase III clinical trials in AHF, and may be available for ED use in the future. We used multiterm search queries to retrieve research involving nitroglycerin, nitroprusside, enalaprilat, hydralazine, relaxin, and nesiritide. A total of 2001 unique citations were identified from 3 databases: PubMed, EMBASE, and CINAHL. Of these, 1966 were excluded on the basis of established review criteria, leaving 35 published articles for inclusion. Our primary finding was that intravenous nitrovasodilators, when used in the treatment of AHF in ED and ED-like settings, do improve short-term symptoms and appear safe to administer. There are no data suggesting that they impact mortality. Other commonly used vasodilators such as hydralazine and enalaprilat have very little published data about their safety and efficacy. Of note, few studies enrolled patients early in their course of treatment. Thus, to assess the specific impact of vasodilator therapy on both short- and long-term outcomes, future research efforts should focus on patient recruitment in the ED setting.

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.

Early management of patients with acute heart failure: state of the art and future directions. A consensus document from the society for academic emergency medicine/heart failure society of America acute heart failure working group

Heart failure (HF) afflicts nearly 6 million Americans, resulting in one million emergency department (ED) visits and over one million annual hospital discharges. An aging population and improved survival from cardiovascular diseases is expected to further increase HF prevalence. Emergency providers play a significant role in the management of patients with acute heart failure (AHF). It is crucial that emergency physicians and other providers involved in early management understand the latest developments in diagnostic testing, therapeutics and alternatives to hospitalization. Further, clinical trials must be conducted in the ED in order to improve the evidence base and drive optimal initial therapy for AHF. Should ongoing and future studies suggest early phenotype-driven therapy improves in-hospital and post-discharge outcomes, ED treatment decisions will need to evolve accordingly. The potential impact of future studies which incorporate risk-stratification into ED disposition decisions cannot be underestimated. Predictive instruments that identify a cohort of patients safe for ED discharge, while simultaneously addressing barriers to successful outpatient management, have the potential to significantly impact quality of life and resource expenditures.

Early management of patients with acute heart failure: state of the art and future directions--a consensus document from the SAEM/HFSA acute heart failure working group

Heart failure (HF) afflicts nearly 6 million Americans, resulting in 1 million emergency department (ED) visits and over 1 million annual hospital discharges. The majority of inpatient admissions originate in the ED; thus, it is crucial that emergency physicians and other providers involved in early management understand the latest developments in diagnostic testing, therapeutics, and alternatives to hospitalization. This article discusses contemporary ED management as well as the necessary next steps for ED-based acute HF research.

Editor's Choice-Recent therapeutic trials on fluid removal and vasodilation in acute heart failure

Recent therapeutic trials regarding the management of acute heart failure (AHF) failed to demonstrate the efficacy of newer therapeutic modalities and agents. Low- versus high-dose and continuous administration of furosemide were shown not to matter. Ultrafiltration was not found to be more efficacious than sophisticated diuretic therapy including dose-adjusted intravenous furosemide and metolazone. Dopamine and nesiritide were not shown to be superior to current therapy. Tezosentan and tovalptan had no effect on mortality. The development of rolofylline was terminated due to adverse effect (seizures). Lastly, preliminary experience with serelaxin indicates a mortality improvement at six months that remains to be confirmed. The disappointing findings of these recent trials may reflect the lack of efficacy of newer therapeutic modalities and agents. Alternatively the disappointing findings of these recent trials may be in part due to methodological issues. The AHF syndrome is complex with many clinical phenotypes. Failure to match clinical phenotypes and therapeutic modalities is likely to be partly responsible for the disappointing findings of recent AHF trials.

New insights into combinational drug therapy to manage congestion in heart failure

Congestion is the most important contributor to morbidity and mortality in heart failure. In patients without congestion, maintaining a neutral sodium balance is imperative to prevent evolving volume overload. Adequate use of neurohumoral blockers, in combination with dietary sodium restriction, is essential and may preclude the need for maintenance diuretic therapy. If volume overload still prevails, loop diuretics remain the mainstay treatment to reduce excessive extracellular volume. However, combinational drug therapy might offer a more attractive alternative to achieve a balanced natriuresis, instead of further uptitration of loop diuretics. Importantly, elevated cardiac filling pressures may be caused by volume misdistribution and impaired venous capacitance, rather than absolute volume overload. Vasodilator therapy to unload the heart, increase venous capacitance, and lower arterial impedance might be interesting in such cases. This review offers a practical approach into current and potential future pharmacologic therapies for managing congestion, focusing on combinational and targeted therapy.

Impact of chronic congestive heart failure on pharmacokinetics and vasomotor effects of infused nitrite

BACKGROUND AND PURPOSE

Nitrite (NO₂⁻) has recently been shown to represent a potential source of NO, in particular under hypoxic conditions. The aim of the current study was to compare the haemodynamic effects of NO₂⁻ in healthy volunteers and patients with stable congestive heart failure (CHF).

EXPERIMENTAL APPROACH

The acute haemodynamic effects of brachial artery infusion of NO₂⁻ (0.31 to 7.8 μmol·min⁻¹) was assessed in normal subjects (n = 20) and CHF patients (n = 21).

KEY RESULTS

NO₂⁻ infusion was well tolerated in all subjects. Forearm blood flow (FBF) increased markedly in CHF patients at NO₂⁻ infusion rates which induced no changes in normal subjects (ANOVA: F = 5.5; P = 0.02). Unstressed venous volume (UVV) increased even with the lowest NO₂⁻ infusion rate in all subjects (indicating venodilation), with CHF patients being relatively hyporesponsive compared with normal subjects (ANOVA: F = 6.2; P = 0.01). There were no differences in venous blood pH or oxygen concentration between groups or during NO₂⁻ infusion. Venous plasma NO₂⁻ concentrations were lower in CHF patients at baseline, and rose substantially less with NO₂⁻ infusion, without incremental oxidative generation of nitrate, consistent with accelerated clearance in these patients. Plasma protein-bound NO concentrations were lower in CHF patients than normal subjects at baseline. This difference was attenuated during NO₂⁻ infusion. Prolonged NO₂⁻ exposure in vivo did not induce oxidative stress, nor did it induce tolerance in vitro.

CONCLUSIONS AND IMPLICATIONS

The findings of arterial hyper-responsiveness to infused NO₂⁻ in CHF patients, with evidence of accelerated transvascular NO₂⁻ clearance (presumably with concomitant NO release) suggests that NO₂⁻ effects may be accentuated in such patients. These findings provide a stimulus for the clinical exploration of NO₂⁻ as a therapeutic modality in CHF.

Is addition of vasodilators to loop diuretics of value in the care of hospitalized acute heart failure patients? Real-world evidence from a retrospective analysis of a large United States hospital database

BACKGROUND

Current guidelines recommend the use of intravenous (IV) vasodilators in addition to IV loop diuretics for the treatment of acute heart failure (AHF) patients without hypotension. The evidence basis for these recommendations is limited.

METHODS AND RESULTS

Hospital billing records for 82,808 AHF patients in the United States were analyzed. Patients receiving IV loop diuretics alone were paired with patients receiving IV loop diuretics + IV nitrates or IV nesiritide with the use of propensity score matching, excluding those with hypotension and/or evidence of cardiogenic shock, myocardial infarction, or acute coronary syndrome. Compared with paired patients receiving IV loop diuretics alone, in-hospital mortality was similar among IV loop diuretics + IV nitrates patients (n = 4,401; 1.9% vs 2.0%; P = .88) and marginally higher for IV loop diuretics + IV nesiritide patients (n = 2,254; 2.2% vs 3.1%; P = .05). Compared with paired IV loop diuretics patients, IV loop diuretics + IV nitrates or IV nesiritide had longer lengths of stay (+1.6 and +2.1 days; P < .01) and 57% higher costs (P < .01).

CONCLUSIONS

Among hospitalized AHF patients, the addition of IV vasodilators to IV loop diuretics did not lower inpatient mortality or rehospitalization rates compared with loop diuretics alone, and was associated with longer lengths of stay and higher hospitalization costs. Although the lack of complete clinical, socioeconomic, and post-discharge data may have confounded these results, this analysis questions whether currently available IV vasodilators can improve outcomes in hospitalized AHF patients.

Pharmacology and therapeutic role of inorganic nitrite and nitrate in vasodilatation

Nitrite has emerged as an important bioactive molecule that can be biotransformed to nitric oxide (NO) related metabolites in normoxia and reduced to NO under hypoxic and acidic conditions to exert vasodilatory effects and confer a variety of other benefits to the cardiovascular system. Abundant research is currently underway to understand the mechanisms involved and define the role of nitrite in health and disease. In this review we discuss the impact of nitrite and dietary nitrate on vascular function and the potential therapeutic role of nitrite in acute heart failure.

Treatment of acute heart failure in the emergency department

Millions of patients are hospitalized for acute heart failure (AHF) every year throughout the world. Despite tremendous advances in cardiovascular care, morbidity and mortality for AHF remain high, consuming billions of health care dollars. With the aging of the population, the incidence and prevalence of HF is projected to increase. Yet, initial treatment of AHF today is similar to 40 years ago. Multiple studies have yielded new insights regarding initial management, with regards to both treatment and strategies of care. These advances will be reviewed in the context of initial or early AHF management. There remains, however, an unmet need to improve outcomes for AHF patients.

Vasodilators in Acute Heart Failure: Review of the Latest Studies

Vasodilators play an important role in the management of acute heart failure, particularly when increased afterload is the precipitating cause of decompensation. The time-honored approach to afterload reduction has been largely focused on use of intravenous nitrovasodilators and, when properly dosed, this class of agents does provide substantial symptom relief for patients with acute hypertensive heart failure. Despite this, nitrovasodilators have never been shown to diminish mortality or provide any post-discharge outcome benefit leading to an on-going search for viable and more effective alternatives. While no new vasodilators have been approved for use in acute heart failure since nesiritide more than a decade ago, a number of novel agents have been developed, with some showing significant promise in recent clinical trials. In this review, we summarize the latest study data as it relates to vasodilator therapy and provide a glimpse into the not too distant future state of acute heart failure care.

The kidney in congestive heart failure: 'are natriuresis, sodium, and diuretics really the good, the bad and the ugly?'

This review discusses renal sodium handling in heart failure. Increased sodium avidity and tendency to extracellular volume overload, i.e. congestion, are hallmark features of the heart failure syndrome. Particularly in the case of concomitant renal dysfunction, the kidneys often fail to elicit potent natriuresis. Yet, assessment of renal function is generally performed by measuring serum creatinine, which has inherent limitations as a biomarker for the glomerular filtration rate (GFR). Moreover, glomerular filtration only represents part of the nephron's function. Alterations in the fractional reabsorptive rate of sodium are at least equally important in emerging therapy-refractory congestion. Indeed, renal blood flow decreases before the GFR is affected in congestive heart failure. The resulting increased filtration fraction changes Starling forces in peritubular capillaries, which drive sodium reabsorption in the proximal tubules. Congestion further stimulates this process by augmenting renal lymph flow. Consequently, fractional sodium reabsorption in the proximal tubules is significantly increased, limiting sodium delivery to the distal nephron. Orthosympathetic activation probably plays a pivotal role in those deranged intrarenal haemodynamics, which ultimately enhance diuretic resistance, stimulate neurohumoral activation with aldosterone breakthrough, and compromise the counter-regulatory function of natriuretic peptides. Recent evidence even suggests that intrinsic renal derangements might impair natriuresis early on, before clinical congestion or neurohumoral activation are evident. This represents a paradigm shift in heart failure pathophysiology, as it suggests that renal dysfunction-although not by conventional GFR measurements-is driving disease progression. In this respect, a better understanding of renal sodium handling in congestive heart failure is crucial to achieve more tailored decongestive therapy, while preserving renal function.

Pharmacological treatment of acute heart failure: current treatment and new targets

Acute heart failure (AHF) is defined as the rapid onset of, or changes in, the symptoms and signs of heart failure (HF). It is a life-threatening situation in which diagnosis and initiation of therapy are crucial. The treatment aims are to stabilize the patient, improve clinical symptoms, and increase long-term survival rates. Few treatments have been investigated in clinical trials. This review summarizes the principles of pharmacologic treatment, the underlying clinical trials, and new pharmacologic targets.

The role of the emergency department in the patient with acute heart failure

The diagnosis and management of the patient with acute decompensated heart failure (ADHF) presents a unique challenge to the emergency medicine (EM) physician. ADHF is one of the most common cardiac emergencies managed in the emergency department (ED). ED presentations for ADHF will grow as survival rates after myocardial infarction continue to increase and thus, the incidence and prevalence of heart failure (HF) increases. There are very little data to aid EM physicians when trying to identify low-risk patients who are safe for ED discharge and observation units are not yet universally utilized. This results in 80% of patients with ADHF getting admitted to the hospital. The aim of this review is to evaluate current strategies for diagnosis, treatment, and disposition of the ADHF patient in the ED while highlighting new approaches for treatment and disposition, and areas in need of additional research.

Rates of ED visits and of intubations for congestive heart failure declined from 1996 to 2008

OBJECTIVE

Many advances have been made recently in the treatment of congestive heart failure (CHF). We hypothesize that this should have resulted in fewer CHF patients presenting to the emergency department (ED) and fewer being intubated.

DESIGN

Retrospective cohort.

SETTING

consecutive patients seen by ED physicians in 4 suburban hospitals in New Jersey and New York from 1996 to 2008.

OBJECTIVE

PROTOCOL

We classified patients as having CHF based on International Classification of Diseases, Ninth Revision, codes. For each year of the study, we determined CHF visit rates (as a percentage of total ED visits) and calculated the percentage of CHF patients intubated. We used the Student t test, calculated 95% confidence intervals (CIs), and performed regression analyses.

RESULTS

Of the 2,374,428 ED visits, 32,036 (1.3%) were for CHF. The mean age of the CHF patients was 76 ± 14 years, and 57% were female. Congestive heart failure visits declined from 1.6% of all ED visits in 1996 to 1.2% in 2008, a 26% relative decrease (95% CI: 21%-30%, P < .001, correlation coefficient R(2) = 0.94, P < .001). Of the CHF patients, 778 (2.4%) were intubated. Intubation rates declined from 3.6% in 1996 to 1.7% in 2008, a 53% (95% CI: 31%-68%, P < .001, R(2) = 0.83, P < .001) relative decrease.

CONCLUSION

The rates of annual ED visits for CHF and intubation rates declined from 1996 to 2008. These decreases are most likely due to better CHF treatments.