Diuretika bei Herzinsuffizienz

Diuretics are useful and inevitable in acute congestive heart failure with pulmonary congestion and edema. The use of low-dose thiazide diuretics is well established in arterial hypertension. In acute heart failure, diuretics are recommended for the treatment of fluid overload and pulmonary edema. No evidence is available so far regarding any benefit of diuretics on the outcome of patients with chronic heart failure, whereas evidence-based blockade of the renin-angiotensin system and sympathetic nervous system reduces the risk of congestion and improves survival. Several types of diuretics are relevant: loop diuretics, thiazides, and potassium-sparing diuretics. All diuretics have significant side effects, mainly electrolyte disorders, metabolic acidosis/alkalosis, insulin resistance, and ototoxicity. Diuretics have no benefit in acute or acute-on-chronic renal failure; moreover, they even increase mortality and reduce the chance of renal recovery in these patients. Increased mortality with the use of diuretics also seems to be associated with a higher risk of lethal arrhythmias. Sequential tubular blockade may be useful for the short term in potentiating the natriuresis in renocardiac syndromes. Furthermore, ultrafiltration or renal replacement therapy may have an additional beneficial effect in these patients, although controlled trials are still lacking.     

Evolving Treatment Strategies for Management of Cardiorenal Syndrome

The treatment of acute decompensated heart failure in the presence of progressive renal dysfunction is a commonly encountered dilemma in clinical practice. Also known as cardiorenal syndrome, this complex disease state has forced researchers and clinicians to develop new treatment strategies to relieve the symptomatic congestion of heart failure while preserving renal function. Loop diuretics remain the standard of pharmacologic treatment of acute heart failure, but their effects on renal function have been called into question. The DOSE trial set out to determine optimal diuretic dosing strategies but no clear regimen was firmly established. Initial studies with vasopressin antagonists showed promise in their ability to increase urine output, provide short-term symptom relief, and correct hyponatremia while maintaining renal function. Unfortunately, the EVEREST trial did not demonstrate any benefit on long-term clinical outcomes. Adenosine antagonists also appeared to be an emerging therapeutic option, but the recently completed PROTECT trial failed to establish their role in the treatment of cardiorenal syndrome. Both nesiritide and low-dose dopamine have endured years of trials with mixed results. Most recently, findings from the ASCEND-HF trial showed that nesiritide was safe with no adverse effects on renal function or mortality and was associated with a modest improvement in dyspnea. The ongoing ROSE study, sponsored by the National Institutes of Health Heart Failure Research Network, will attempt to confirm the safety and efficacy profiles of low-dose nesiritide and dopamine, as well as clarify their roles within acute heart failure management. Despite its inherent complexities, ultrafiltration has demonstrated potential benefit in several clinical outcomes compared to traditional pharmacotherapy. The results of the CARRESS-HF trial will reveal how the use of ultrafiltration specifically applies to patients with cardiorenal syndrome. The most exciting aspects about our evolving understanding of the cardiorenal system are the innovative treatments that have emerged as a result. The creation of chimeric natriuretic peptides, targeted intra-renal pharmacotherapy, the novel use of phosphodiesterase inhibitors, and combination treatment strategies demonstrate that despite our varied success in treating cardiorenal syndrome in the past, there are highly encouraging translational therapies rapidly developing in the pipeline.     

The Acute Cardiorenal Syndrome Type I: Considerations on Physiology,Epidemiology, and Therapy

Acute cardiorenal syndrome, also known as cardiorenal syndrome type 1, is defined as an abrupt worsening of cardiac function that occurs in at least 30 % of patients with acute decompensated heart failure and can lead to the development of acute kidney injury. The changes in renal function that occur in this setting have variable prognostic implications, as both poorer and better outcomes have been reported when renal function worsens during treatment of heart failure decompensation. Furthermore, it remains unclear when worsening renal function is actually a manifestation of true acute kidney injury or simply an indicator of hemoconcentration. Given these gaps in the understanding of the significance of renal function changes in the setting of decompensated heart failure, it is not surprising that studies on the effects of available therapies, including diuretics, vasoactive drugs, and mechanical fluid removal have yielded inconsistent results. The purpose of this review is to analyze critically the current knowledge on the pathophysiology, epidemiology, prognosis, and treatment of acute cardiorenal syndrome.     

Managing acute renal failure in patients with acute decompensated heart failure: The cardiorenal syndrome

In patients with acute decompensated heart failure, worsening renal function during conventional decongestive therapy (cardiorenal syndrome) affects prognosis and the initiation of therapies with known benefit in chronic heart failure. Potential strategies for decongestion in patients who develop cardiorenal syndrome include invasive hemodynamic monitoring to guide therapy, use of continuous diuretic infusions, ultrafiltration, or novel therapy with adenosine or vasopressin receptor antagonists. Clinical trials by the National Heart, Lung, and Blood Institute’s Heart Failure Network are currently underway to validate such therapies in patients with acute decompensated heart failure with worsening renal function and to establish novel biomarkers for the early identification of patients who develop cardiorenal syndrome.     

Dialyse- und Ultrafiltrationsverfahren bei kardiorenalem Syndrom

Renal failure is common in patients with severe heart failure and this complex pathophysiological interaction is classified as cardiorenal syndrome. In these patients hydropic decompensation is the main reason for hospitalization. In patients with refractory heart failure characterized by diuretic resistance and congestion due to volume overload, ultrafiltration has to be considered. In cases of acute decompensated heart failure with deterioration of renal function, extracorporeal ultrafiltration is the preferred treatment modality. On the other hand, patients suffering from chronic decompensated heart failure, particularly patients with ascites, will profit from the treatment-specific advantages of peritoneal ultrafiltration. A prerequisite for an optimized care of patients with cardiorenal syndrome is the close collaboration between intensive care physicians, cardiologists and nephrologists.     

Novel strategies: challenge loop diuretics and sodium management in heart failure--Part I

This is the first of a 2-part series. This article reviews the relationships among diuretics, neurohormonal activation, renal function, fluid and Na management, the cardiorenal syndrome, and heart failure. Part II will describe novel therapies based on these relationships, focusing particularly on vasopressin antagonists and treatment using hypertonic saline solution with high-dose loop diuretics. Heart failure (HF) is a complex hemodynamic disorder characterized by chronic and progressive pump failure and fluid accumulation. Diuretics are a vital component of symptomatic management, and enhancing diuretic response in the setting of diuretic resistance is therefore pivotal. In HF patients treated with diuretics, compensatory pathophysiologic mechanisms to maintain vascular resistance, such as nonosmotic stimulation of vasopressin secretion and activation of the renin-angiotensin-aldosterone system and sympathetic nervous system, promote renal Na and water reabsorption. Thus, there remains a need to develop novel therapies for HF patients who are refractory to conventional medical treatment. The conflicting results of diuretic treatments in HF and the importance of Na management in the context of the cardiorenal syndrome and neurohormonal activation have suggested novel and counterintuitive strategies, focusing primarily on the use of vasopressin antagonists and hypertonic saline solution with high doses of loop diuretics and neurohormonal interference. The authors review the current evidence for these therapies and suggest hypothetical bases for their efficacy.     

心肾综合征的临床研究进展

心肾综合征一词已广泛用于进行性充血性心力衰竭引起的肾功能下降。为了概括心脏与肾脏之间复杂的因果关系,心肾综合征分为5种临床亚型:Ⅰ型:急性心肾综合征;Ⅱ型:慢性心肾综合征;Ⅲ型:急性肾心综合征;Ⅳ型:慢性肾心综合征;Ⅴ型:继发性心肾综合征。心肾综合征是慢性肾功能不全和慢性心力衰竭中治疗的难题,现就心肾综合征近年来临床研究进展进行综述。     

Decompensated Heart Failure and Renal Failure: What Is the Current Evidence?

Purpose of Review

Acute decompensated heart failure (ADHF) is one of the biggest challenges in the management of chronic heart failure. Despite several advances in medical and device therapy, high readmission and mortality rates continue to be a burden on healthcare systems worldwide. The aim of the current review is to provide an overview on current as well as future approaches in cardiorenal interactions in patients with ADHF.

Recent Findings

One of the strongest predictors of adverse outcomes in ADHF is renal dysfunction, referred to as cardiorenal syndromes (CRS) or cardiorenal interactions. Patients with ADHF frequently develop worsening of renal function (WRF) and/or acute kidney injury (AKI). Recent studies brought new information about biomarkers in diagnosing and predicting prognosis of CRS. Among others, dry weight at hospital discharge is considered a surrogate marker of successful treatment in ADHF patients with/without renal dysfunction.

Summary

The etiology of WRF appears to be an important factor for determining risk related to WRF as well as clinical management. The hypertonic saline used as adjunctive therapy for intravenous loop diuretics and/or induction of aquaresis (e.g., using tolvaptan) may be promising and efficient approaches in the future.

     

Cardiorenal Syndrome and the Role of Ultrafiltration in Heart Failure

Acute decompensated heart failure (ADHF) with associated volume overload is the most common cause of hospitalization in heart failure patients. When accompanied by worsening renal function, it is described as a cardiorenal syndrome and is a therapeutic challenge. Initial treatment commonly encompasses intravenous diuretics however, suboptimal results and high rehospitalization rates have led experts to search for alternative therapeutic strategies. Recent technological advances in extracorporeal therapies have made ultrafiltration a feasible option for treatment of hypervolemia in ADHF. Recent large randomized trials have compared the efficacy and safety of ultrafiltration with diuretics. Additionally, the benefits of novel pharmacologic approaches, including combining hypertonic saline with diuretics, have recently been studied. The aim of this review is to discuss the developments in both pharmacologic and extracorporeal methods for treating hypervolemia in ADHF and acute cardiorenal syndrome.     

Value of aldosterone receptor blockade in diuretic therapy of patients with chronic heart failure

PATHOGENESIS: All forms of chronic heart failure (high-output and low-output failure) are accompanied by an "arterial underfilling" inducing the activation of various neurohumoral systems (renin-angiotensin-aldosterone system, sympathic nervous system, non-osmotic stimulation of vasopressin). Elevated levels of those neurohormones detrimentally modulate renal function. Subsequently, renal salt and volume retention occurs leading to the main symptoms of heart failure, edema formation and dyspnea. DIURETIC THERAPY: Diuretics, which have been discovered more than 40 years ago, beneficially influence renal salt- and volume retention by their effects on tubular sodium reabsorption. While thiazides are recommended in mild forms, loop diuretics are used in severe stages of congestive heart failure. The clinician has to consider the changed pharmacokinetic and -dynamic properties during the application of diuretics in patients with chronic heart failure. In addition, increased sodium reabsorption occurs immediately after cessation of diuretic action often nullifying the preceding diuresis. Thus, salt- and volume restriction should be guaranteed, and a regular application of loop diuretics during the day should be preferred due to the short-acting nature of currently available loop diuretics. Sometimes, diuresis does not longer occur during the treatment with one substance (diuretic resistance), although the therapeutic goals of water excretion have not been achieved. After ruling out factors reducing the actions of diuretics (non-compliance, hyponatremia, etc.), a sequential nephron blockade should be initiated (combination of loop diuretics and a thiazide or an aldosterone-receptor antagonist) to increase diuresis and to elevate symptoms of volume overload. SIDE EFFECTS: Loop diuretics and thiazides often induce mild hypokalemia, which has been demonstrated to be not as benign as thought before. Chronic treatment with oral potassium supplements has several drawbacks, as urine excretion of potassium is subsequently increased and supplementation is not as effective as believed. Diuretic-induced hypokalemia seems to be aldosterone dependent. As aldosterone levels increase during diuretic therapy even during chronic treatment with an angiotensin-converting enzyme (aldosterone-escape) a combined treatment including an aldosterone-receptor antagonist has been suggested. Beneficial effects of aldosterone-receptor blockade on mortality (RALES trial) appear to be mediated be extrarenal and renal mechanisms. The suggested beneficial renal mechanisms of aldosterone receptor blockade are discussed in detail in the review. CONCLUSION: In conclusion, diuretic therapy of patients with congestive heart failure is effective to relieve symptoms and, presumably, to prolong life. As renal function and pharmacokinetics and -dynamics of diuretics are changed in heart failure, diuretic treatment has to be adapted to provide optimal treatment. Increased levels of aldosterone appear to play an important role in diuretic-induced hypokalemia, and in the progression of heart and renal failure. Thus, aldosterone receptor antagonists should be used in the treatment of heart failure more frequently.     

Acute Heart Failure: Acute Cardiorenal Syndrome and Role of Aggressive Decongestion

Congestion and acute renal dysfunction are at the center of acute heart failure (HF) syndromes. Acute cardiorenal syndrome, which refers to worsening of renal function in a patient with acute HF syndrome, is partly related to venous congestion and high renal afterload. Aggressive decongestion improves renal and myocardial flow and ventricular loading conditions, potentially resulting in reduced HF progression, rehospitalization, and mortality. High‐dose diuretic therapy remains the mainstay therapy. Ultrafiltration and inotropic therapy are useful in the subgroup of patients with a low‐output state and diuretic resistance.     

Diuretic resistance in heart failure

The use of diuretics for the treatment of heart failure (HF) is ubiquitous in any basic HF medical regimen. Although initially these drugs clearly show benefit by relieving symptomatic episodes of decompensated HF, long-term use of these drugs can lead to a ‘diuretic-resistant’ state and is associated with an increased risk of morbidity and mortality. A number of factors may be responsible for this, including dietary noncompliance, inadequate diuretic dosing or methods of administration, and concomitant use of certain medications. Diuretics themselves may set in motion an iatrogenic cardiorenal syndrome leading to worsening renal function and diuretic resistance. The methods for overcoming this resistance are varied and require a focused approach with emphasis on relieving the congestive symptoms related to HF while attempting to preserve renal function and minimize any untoward systemic effects.     

Soluble Guanylate Cyclase Stimulators: a Novel Treatment Option for Heart Failure Associated with Cardiorenal Syndromes?

Heart failure in the setting of chronic kidney disease (CKD) is an increasingly common scenario and carries a poor prognosis. Clinicians lack tools for primary or secondary heart failure prevention in patients with cardiorenal syndromes. In patients without CKD, angiotensin-converting enzyme inhibitors (ACE-I) or angiotensin receptor blockers (ARB) and statins mitigate cardiovascular risk in large part due to salutary effects on the endothelium. In the setting of CKD, use of these therapies is limited by adverse effects of hyperkalemia in pre-dialysis CKD (ACE-I/ARB), or potential increased risk of stroke in end-stage renal disease (statins). The soluble guanylate cyclase (sGC) stimulators are a novel class of medications that promote endothelial and myocardial function with no known risk of hyperkalemia or stroke. In this review, we discuss the evidence emerging from recent clinical trials of sGC stimulators in pulmonary hypertension and heart failure, the diseased pathways involved in cardiorenal syndromes likely to be restored by sGC stimulators, and several strategies for designing future clinical trials of cardiorenal syndromes that might shorten the timeline for discovery and approval of effective cardiovascular therapies in these high-risk patients.     

Management and monitoring of haemodynamic complications in acute heart failure

The pathophysiology of acute heart failure syndromes (AHFS), defined as a change or worsening in heart failure symptoms and signs, is complex. The variety of adverse neurohormonal adaptations includes increased levels of plasma renin, aldosterone and angiotensin II, all responsible for cardio-renal dysfunction. In fact, such alterations result in an array of clinical changes that include abnormal haemodynamics, altered ventricular filling pressures, pathological neurohormonal responses, leading to fluid overload, congestion and ultimately heart failure symptoms. Clinical pictures can be various: in spite of a usual improvement in dyspnoea, little weight change and significant morbidity are generally observed during hospitalization. Short-term outcomes are characterized by a high 60-day re-hospitalization and high mortality rates; apparently, both can be predicted from pre-discharge characteristics. The most frequently used treatments for AHF care include diuretics, inotropic agents, and vasodilator/vasoactive agents; however, the final therapeutic strategy is often individualized. Diuretics are currently the most used agents, but resistance to diuretic therapy is common. In addition, several studies have demonstrated that aggressive diuresis can contribute to reduced renal function, and high doses of diuretics have been associated with increased morbidity and mortality. Many patients with AHFS also suffer from acute or from chronic renal dysfunction (cardio-renal syndromes type 1 and 2, respectively), which further complicate the outcomes and treatment strategies. A personalized patient evaluation of the combined heart and kidney functions is advised to implement the best possible multidisciplinary diagnostic and therapeutic approach.     

Diuretika und extrakorporale Verfahren zur Behandlung des kardiorenalen Syndroms

Acute or chronic heart failure can lead to a reduction in kidney function presenting as cardiorenal syndrome (CRS). A substantial clinical problem in such patients is hypervolemia in combination with deteriorating renal function. The treatment initially consists of diuretics at this clinical stage; however, development of resistance against diuretics often limits successful therapy. The aim of this overview is to provide an overview of extracorporeal treatment options, such as peritoneal dialysis (PD), hemodialysis (HD), and mechanical ultrafiltration alone. In patients with manifest CRS the use of PD can result in improvement in the quality of life and improve cardiac function as well as reduction in the number of hospital stays. The HD is also an option in the treatment of such patients; however, it is often related to unfavorable effects, such as hypotension and a reduction in diuresis. Mechanical ultrafiltration alone does not seem to provide any advantages as compared to diuretic treatment in patients with CRS.     

Einsatz von Diuretika bei der akut dekompensierten Herzinsuffizienz

Patients with acute heart failure usually present with dyspnea and edema secondary to elevated intracardiac filling pressure resulting from volume overload. Despite significant progress in understanding heart failure, the treatment strategy for acute heart failure did not change in the same way. Diuretics, especially loop diuretics, are the most common drugs used in this setting. Intravenous diuretics act acutely by exerting a modest vasodilatory response and chronically by reducing circulating blood volume. Despite a very common use of diuretics in patients hospitalized with acute heart failure, nearly half of these patients are discharged from the hospital without weight loss. This could be due to inadequate diuresis, overdiuresis with subsequent volume replacement and diuretic resistance. Aggressive diuresis carries a significant risk of electrolyte and volume depletion with subsequent arrhythmias, hypotension, and worsening renal function. Actually, little data from randomized clinical trials are available to guide therapeutic treatment with diuretics. Thus, the choice and dosing of diuretic therapy must be individualized based on general knowledge of potency and pharmacokinetic and pharmacodynamic considerations.     

Renal dysfunction in acute congestive heart failure: a common problem for cardiologists and nephrologists

The term acute heart failure (AHF) refers to a clinical syndrome with typical symptoms and signs, in which a structural or functional heart abnormality leads to defective oxygen delivery. The term cardiorenal syndrome has been proposed to outline the strict interplay between cardiac and renal function. In the setting of acute cardiac decompensation, acute kidney injury (AKI) is generally referred to as cardiorenal syndrome type 1. In this review, we summarize the fundamental pathophysiological aspects of both AHF and AHF-related AKI. We also review the latest therapeutic options, including both pharmacological ones, such as loop diuretics, potassium-sparing diuretics and vaptans, and non-pharmacological ones, such as ultrafiltration, and their impact on patients’ outcome. We discuss the pathophysiology of diuretic resistance, a common occurrence in these patients, reviewing the available strategies to treat it and highlighting how a close collaboration between cardiologists and nephrologists is frequently crucial for the management of this complication. Finally, we discuss three new promising non-pharmacological tools for the prevention of AHF recurrence, including two methods that exploit sympathetic denervation and one technique that acts by increasing vagal tone.     

心肾综合征诊治进展

心肾综合征为心脏或肾脏中一个器官对另一个器官的功能损害,不能进行代偿,最终导致心脏和肾脏功能的共同损害。临床呈现心肾衰竭、肾功能恶化及利尿剂抵抗三者之一,或更多表现的进展性心肾功能调控障碍状态。发病机制尚未阐明,可能与肾内血流动力学障碍、神经介质紊乱等有关。失代偿性心力衰竭常规治疗未能奏效的容量超载患者应予超滤治疗。血管加压素受体拮抗剂及选择性腺苷A1受体拮抗剂等新制剂的相关临床试验正在进行中,近期有望在临床应用。     

Cardiorenal Syndrome: Diagnosis,Treatment, and Clinical Outcomes

The pathophysiologic interactions that link the heart and kidney are multiple and complex, and have been grouped under the umbrella term “cardiorenal syndrome.” In the setting of acute decompensated heart failure, worsening renal function has been directly associated with poor clinical prognosis and complicates treatment. However, the pathophysiology underlying acute cardiorenal syndrome remains incompletely understood and treatment options remain limited. Traditionally, the development of worsening renal function in acute decompensated heart failure has been attributed to renal arterial underfilling due to reduced cardiac output or intravascular volume depletion. However, increasing data have expanded our understanding of the roles that venous congestion and intra-abdominal pressure play in driving renal injury, with important implications for therapeutic management and the development of novel renal-sparing therapies.     

How to use diuretics in heart failure

Systemic and pulmonary congestion is a central aspect of both acute and chronic heart failure and directly leads to many of the clinical manifestations of these syndromes. Therefore, diuretic therapy to treat congestion plays a fundamental role in heart failure management. However, although diuretics are the most common drugs prescribed for heart failure, there is limited quality evidence to guide their use. Unlike other components of the heart failure armamentarium, such as β-blockers and angiotensin-converting enzyme inhibitors, diuretics (with the exception of aldosterone antagonists) have not been shown to decrease heart failure progression or improve mortality. Additionally, some observational data suggest that diuretics may actually be harmful in heart failure, contributing to neurohormonal activation, renal dysfunction, and potentially mortality. Despite these concerns, diuretics remain ubiquitous in heart failure management because of the need to address symptoms of congestion and the lack of alternative strategies. Recently, the development of a variety of potential adjuncts or alternatives to diuretic therapy has suggested the need for an active reappraisal of diuretic therapy for heart failure. The main classes of diuretics are the loop diuretics, potassium-sparing diuretics, and thiazides. Loop diuretics, the mainstay of acute and chronic therapy for heart failure, are “threshold drugs”; therefore, an adequate dose to achieve a pharmacodynamic effect (ie, to increase urine output) must be prescribed for effective therapy. The minimum dose to achieve diuresis and manage congestion should be used to minimize adverse effects. For patients refractory to initial dosing of intravenous diuretics, options include dose escalation, use of continuous infusion rather than intermittent boluses, or combination therapy with the addition of a thiazide or thiazide-like diuretic (eg, metolazone). Management of chronic heart failure often includes patient-directed titration of diuretics based on changes in symptoms or body weight in an attempt to decrease hospitalizations, although the efficacy of this strategy has not been tested in well-designed trials. Aldosterone antagonists, which are used primarily as neurohormonal agents rather than for their diuretic effects, are indicated for patients with systolic failure and moderate to severe symptoms, as long as renal function and serum potassium are stable and monitored closely. All diuretic therapy requires careful monitoring of electrolytes and renal function. Whether newer modalities for managing congestion (vasopressin antagonists, adenosine A1 antagonists, and ultrafiltration therapy) will be an improvement over diuretic therapy will be determined by the results of multiple ongoing clinical trials.