Unloading therapy by intravenous diuretic in chronic heart failure: a double-edged weapon?

Vasopressin Receptor Antagonists for the Correction of Hyponatremia in Chronic Heart Failure: An Underutilized Therapeutic Option in Current Clinical Practice?

In the congestive heart failure (CHF) setting, chronic hyponatremia is very common. The present review aims at addressing topics relevant to the pathophysiology of hyponatremia in the course of CHF as well as its optimal treatment, including the main advantages and the limitations resulting from the use of the available dietary and pharmacological measures approved for the treatment of this electrolytic trouble. A narrative review is carried out in order to represent the main modalities of therapy for chronic hyponatremia that frequently complicates CHF. The limits of usual therapies implemented for CHF-related chronic hyponatremia are outlined, while an original analysis of the main advancements achieved with the use of vasopressin receptor antagonists (VRAs) is also executed. The European regulatory restrictions that currently limit the use of VRAs in the management of CHF are substantially caused by financial concerns, i.e., the high costs of VRA therapy. A thoughtful reworking of current restrictions would be warranted in order to enable VRAs to be usefully associated to loop diuretics for decongestive treatment of CHF patients with hyponatremia.

Vasopressin receptor antagonists in patients with chronic heart failure

In this brief review, the pathophysiology of hyponatremia and its clinical significance in the course of chronic heart failure (CHF) are illustrated. Moreover, issues concerning the optimal treatment for hyponatremia during CHF are addressed and discussed. In addition, advantages and limitations resulting from the use of vasopressin receptor antagonists, drugs that have recently emerged as the best available resource against hyponatremia, are highlighted.

Effects of limiting fluid intake on clinical and laboratory outcomes in patients with heart failure. Results of a meta-analysis of randomized controlled trials

BACKGROUND

The guidelines of the Scientific Societies of Cardiology recommend limiting fluid intake as a nonpharmacological measure for the management of chronic heart failure (HF). However, many patients with HF may suffer from severe thirst. A meta-analysis was performed to evaluate the effect of limiting fluid consumption based on various clinical and laboratory outcomes in patients with chronic HF.

METHODS

Only randomized controlled trials comparing liberal and restricted fluid oral intake in patients with HF were included. Primary outcomes were HF hospitalizations and all-cause mortality. Secondary outcomes were the sensation of thirst, the duration of therapy with intravenous diuretics, and the serum levels of creatinine, sodium, and B-type natriuretic peptide (BNP).

RESULTS

Six studies met the inclusion criteria. Significant heterogeneity was detected for the majority of outcomes. In 5 studies, patients with restricted fluid intake compared to patients with free consumption of beverages had similar rehospitalization and mortality rates. There were no differences regarding patients' sense of thirst (4 studies), duration of intravenous diuretic treatment (2 studies), serum creatinine levels (5 studies), and serum sodium levels (5 studies). Serum BNP levels were significantly higher in the group with free fluid intake (4 studies).

CONCLUSION

In patients with HF, liberal fluid consumption does not seem to exert an unfavorable impact on HF rehospitalizations or all-cause mortality. Further randomized controlled trials are warranted to definitively confirm the present findings.

Comparison of three diuretic treatment strategies for patients with acute decompensated heart failure

BACKGROUND

There are few prospective data available for establishing a standard diuretic administration regimen for patients with acute decompensated heart failure (ADHF). We aimed to assess the safety and efficacy of three regimens of furosemide administration in patients with ADHF with regard to diuresis, renal functions, and in-hospital outcomes.

METHODS

A total of 43 patients who presented with ADHF were randomized into three groups: (a) continuous infusion (cIV) of 160 mg furosemide for 16 h/day (n = 15); (b) bolus injections (bI) of 80 mg furosemide twice a day (n = 14); (c) and administration of 160 mg furosemide plus hypertonic saline solution (HSS) as an infusion for 30 min once a day (n = 14). All regimens were continued for 48 h. Study endpoints were negative fluid balance assessed by loss of body weight, change in the serum creatinine (baseline to 48 h and baseline to compensated state), and length of hospitalization.

RESULTS

There was no significant difference in the mean change in serum creatinine level at the end of 48 h between groups (p = 0.08). There was also no significant difference among groups regarding loss of body weight (p = 0.66). A significantly shorter hospitalization was observed in patients treated with HSS compared with the other groups (cIV group 6.6 ± 3.4 days vs. bI group 7.9 ± 4.1 days vs. HSS group 3.7 ± 1.3 days; p < 0.01).

CONCLUSION

All three furosemide regimens have similar renal safety and efficacy measures. However, administration of furosemide plus HSS may be the preferred diuretic strategy because of its shorter hospital stay.

Cardiorenal syndrome type 2: from diagnosis to optimal management

The deterioration of renal function, which is linked to chronic heart failure by a chronological and causal relationship (ie, the so-called cardiorenal syndrome [CRS] type 2), has recently become a matter of growing debate. This debate has concerned the efficacy, safety, and cost effectiveness of the therapies that have been implemented thus far for this syndrome (for example, the intravenous [IV] loop diuretics, such as repeated IV boluses or slow IV infusions, as well as mechanical fluid removal, particularly by means of isolated ultrafiltration [IUF]). Further controversies have also emerged concerning the optimal dosage and timing of some evidence-based drugs, such as angiotensin-converting-enzyme inhibitors. The present review summarizes the currently used diagnostic tools for detecting renal damage in CRS type 2. Subsequently, the meaning of worsening renal function is outlined, as well as the sometimes inconsistent therapeutic schemes that have been implemented in order to prevent or counteract worsening renal function. The need to elaborate upon more detailed and comprehensive scientific recommendations for targeted prevention and/or therapy of CRS type 2 is also underlined. The measures usually adopted (such as the more accurate modulation of loop diuretic dose, combined with the exploitation of other diuretics that are able to achieve a sequential blockade of the nephron, as well as the use of IV administration for loop diuretics) are briefly presented. The concept of diuretic resistance is illustrated, along with the paramount operational principles of IUF in diuretic-resistant patients. Some controversies regarding the comparison of IUF with stepped diuretic therapy in patients with CRS type 2 are also addressed.

Effect of diuretic use on 30-day postdialysis mortality in critically ill patients receiving acute dialysis

BACKGROUND

The impact of diuretic usage and dosage on the mortality of critically ill patients with acute kidney injury is still unclear.

METHODS AND RESULTS

In this prospective, multicenter, observational study, 572 patients with postsurgical acute kidney injury receiving hemodialysis were recruited and followed daily. Thirty-day postdialysis mortality was analyzed using Cox's proportional hazards model with time-dependent covariates. The mean age of the 572 patients was 60.8±16.6 years. Patients with lower serum creatinine (p = 0.031) and blood lactate (p = 0.033) at ICU admission, lower predialysis urine output (p = 0.001) and PaO(2)/FiO(2) (p = 0.039), as well as diabetes (p = 0.037) and heart failure (p = 0.049) were more likely to receive diuretics. A total of 280 (49.0%) patients died within 30 days after acute dialysis initiation. The analysis of 30-day postdialysis mortality by fitting propensity score-adjusted Cox's proportional hazards models with time-dependent covariates showed that higher 3-day accumulated diuretic doses after dialysis initiation (HR = 1.449, p = 0.021) could increase the hazard rate of death. Moreover, higher time-varying 3-day accumulative diuretic doses were associated with hypotension (p<0.001) and less intense hemodialysis (p<0.001) during the acute dialysis period.

BACKGROUND AND SIGNIFICANCE

Higher time-varying 3-day accumulative diuretic dose predicts mortality in postsurgical critically ill patients requiring acute dialysis. Higher diuretic doses are associated with hypotension and a lower intensity of dialysis. Caution should be employed before loop diuretics are administered to postsurgical patients during the acute dialysis period.