Diuretic Resistance in Acute Decompensated Heart Failure: A Challenging Clinical Conundrum

Acetazolamide as an Adjunctive Diuretic Therapy for Patients with Acute Decompensated Heart Failure: A Systematic Review and Meta-Analysis

BACKGROUND

Recent evidence suggests that acetazolamide may be beneficial as an adjunctive diuretic therapy in patients with acute decompensated heart failure (HF). We aim to pool all the studies conducted until now and provide updated evidence regarding the role of acetazolamide as adjunctive diuretic in patients with acute decompensated HF.

METHODS

PubMed/Medline, Cochrane Library, and Scopus were searched from inception until July 2023, for randomized and nonrandomized studies evaluating acetazolamide as add-on diuretic in patients with acute decompensated HF. Data about natriuresis, urine output, decongestion, and the clinical signs of congestion were extracted, pooled, and analyzed. Data were pooled using a random effects model. Results were presented as risk ratios (RRs), odds ratios (ORs), or weighted mean differences (WMD) with 95% confidence intervals (95% CIs). Certainty of evidence was assessed using the grading of recommendation, assessment, development, and evaluation (GRADE) approach. A P value of < 0.05 was considered significant in all cases.

RESULTS

A total of 5 studies (n = 684 patients) were included with a median follow-up time of 3 months. Pooled analysis demonstrated significantly increased natriuresis (MD 55.07, 95% CI 35.1-77.04, P < 0.00001; I2 = 54%; moderate certainty), urine output (MD 1.04, 95% CI 0.10-1.97, P = 0.03; I2 = 79%; moderate certainty) and decongestion [odds ratio (OR) 1.62, 95% CI 1.14-2.31, P = 0.007; I2 = 0%; high certainty] in the acetazolamide group, as compared with controls. There was no significant difference in ascites (RR 0.56, 95% CI 0.23-1.36, P = 0.20; I2 = 0%; low certainty), edema (RR 1.02, 95% CI 0.52-2.0, P = 0.95; I2 = 45%; very low certainty), raised jugular venous pressure (JVP) (RR 0.86, 95% CI 0.63-1.17, P = 0.35; I2 = 0%; low certainty), and pulmonary rales (RR 0.82, 95% CI 0.44-1.51, P = 0.52; I2 = 25%; low certainty) between the two groups.

CONCLUSIONS

Acetazolamide as an adjunctive diuretic significantly improves global surrogate endpoints for decongestion therapy but not all individual signs and symptoms of volume overload.

SYSTEMATIC REVIEW REGISTRATION

This systematic review was prospectively registered on the PROSPERO ( https://www.crd.york.ac.uk/PROSPERO/ ), registration number CRD498330.

Diuretic-resistant heart failure and the role of ultrafiltration: A proposed protocol

Acute heart failure (HF) decompensation generally manifests with signs and symptoms of congestion that strongly predict poor poor patient outcome. Loop diuretics are the cornerstone of therapy to counteract fluid overload and are widely used for acute management and chronic stabilization of HF. However, a diminished response to loop diuretics is a common problem, affecting the patient's clinical course and potentially prolonging hospitalization. Diuretic resistance is defined as failure to decongest despite appropriate and escalating loop diuretic therapy. We propose a protocol for the management of diuretic resistance. The initial approach should include an assessment of causes of pseudo-diuretic resistance. Adjustments to loop diuretic therapy, such as increasing doses and frequency of administration and sequential nephron blockade, may be successful. For hospitalized patients with progressive disease there are more invasive methods for fluid removal. Switching from oral to intravenous loop diuretics is essential to avoid variable absorption and for symptomatic relief. Extracorporeal ultrafiltration is also an option since this technique is highly effective at removing plasma fluid from blood. While extracorporeal ultrafiltration is an invasive solution, peritoneal dialysis is a home-based, intermittent therapeutic option that can enable efficient management of fluid overload, preventing HF-related hospital admission, and improving quality of life. As a last resort for fluid removal, a peritoneal dialysis regimen should fully exploit its decongestive properties and should be tailored to the patient's characteristics and clinical needs.

Efficacy of Nondiuretic Pharmacotherapy for Improving the Treatment of Congestion in Patients with Acute Heart Failure: A Systematic Review of Randomised Controlled Trials

Diuretic therapy is the mainstay during episodes of acute heart failure (AHF). Diuretic resistance is often encountered and poses a substantial challenge for clinicians. There is a lack of evidence on the optimal strategies to tackle this problem. This review aimed to compare the outcomes associated with congestion management based on a strategy of pharmacological nondiuretic-based regimens. The PubMed, Cochrane Library, Scopus, and ScienceDirect databases were systematically searched for all randomised controlled trials (RCTs) of adjuvant pharmacological treatments used during hospitalisation episodes of AHF patients. Congestion relief constitutes the main target in AHF; hence, only studies with efficacy indicators related to decongestion enhancement were included. The Cochrane risk-of-bias tool was used to evaluate the methodological quality of the included RCTs. Twenty-three studies were included; dyspnea relief constituted the critical efficacy endpoint in most included studies. However, substantial variations in dyspnea measurement were found. Tolvaptan and serelaxin were found to be promising options that might improve decongestion in AHF patients. However, further high-quality RCTs using a standardised approach to diuretic management, including dosing and monitoring strategies, are crucial to provide new insights and recommendations for managing heart failure in acute settings.

Metolazone Add-On Therapy in Heart Failure: A Cohort Study from Persian Registry of Cardiovascular Disease/Heart Failure (PROVE/HF)

Background

One of the strategies for overcoming diuretic resistance among heart failure (HF) patients is adding thiazide-type diuretics. The main aim of this article is to compare the adverse clinical outcomes, including death and re-hospitalization, among individuals suffering from severe acute decompensated HF (ADHF) that consumed furosemide or furosemide plus metolazone.

Methods

This retrospective cohort study was done in the context of the Persian registry of cardiovascular disease (PROVE) from September 2017 to September 2018. One thousand and four hundred thirty-eight individuals (furosemide: 972 and furosemide plus metolazone: 466) with the final diagnosis of severe ADHF (left ventricular ejection fraction < 30%) were selected and followed for 10.3 ± 7.8 months. The association between two groups, as mentioned above, with the incidence of death and re-admission, was evaluated with different models.

Results

The mean age of the study population was 68.19 ± 12.98 years. There was no significant relation in terms of death or re-hospitalization between patients with different diuretic regimens. After adjustment of potential confounders, we found that adding metolazone as an adjuvant HF therapy was not independently associated with death or re-hospitalization (hazard ratio (HR): 0.78,95% confidence interval (CI) = 0.59–1.03, P = 0.085, and odds ratio (OR): 0.80, 95% CI: 0.60–1.07, P = 0.135, respectively).

Conclusion

Our findings revealed that adding metolazone in patients with furosemide resistance is not associated with higher morbidity and mortality. Therefore, usage of these two therapeutic agents could be a helpful strategy for severe HF patients.

Lymphatic Dysregulation in Patients With Heart Failure: JACC Review Topic of the Week

The lymphatic system is an integral part of the circulatory system and plays an important role in the volume homeostasis of the human body. The complex anatomy and physiology paired with a lack of simple diagnostic tools to study the lymphatic system have led to an underappreciation of the contribution of the lymphatic system to acute and chronic heart failure (HF). Herein, we discuss the physiological role of the lymphatic system in volume management and the evidence demonstrating the dysregulation of the lymphatic system in HF. Further, we discuss the opportunity to target the lymphatic system in the management of HF and different potential approaches to accessing the lymphatic system.

Congestion and Diuretic Resistance in Acute or Worsening Heart Failure

Hospitalisation for acute heart failure (AHF) is associated with high mortality and high rehospitalisation rates. In the absence of evidence-based therapy, treatment is aimed at stabilisation and symptom relief. The majority of AHF patients have signs and symptoms of fluid overload, and, therefore, decongestion is the number one treatment goal. Diuretics are the cornerstone of therapy in AHF, but the treatment effect is challenged by diuretic resistance and poor diuretic response throughout the spectrum of chronic to worsening to acute to post-worsening HF. Adequate dosing and monitoring and evaluation of diuretic effect are important for treatment success. Residual congestion at discharge is a strong predictor of worse outcomes. Therefore, achieving euvolaemia is crucial despite transient worsening renal function.

Diuretic Resistance in Heart Failure

Decompensated heart failure accounts for approximately 1 million hospitalizations in the United States annually, and this number is expected to increase significantly in the near future. Diuretics provide the initial management in most patients with fluid overload. However, the development of diuretic resistance remains a significant challenge in the treatment of heart failure. Due to the lack of a standard definition, the prevalence of this phenomenon remains difficult to determine, with some estimates suggesting that 25-30% of patients with heart failure have diuretic resistance. Certain characteristics, including low systolic blood pressures, renal impairment, and atherosclerotic disease, help predict the development of diuretic resistance. The underlying pathophysiology is likely multifactorial, with pharmacokinetic alterations, hormonal dysregulation, and the cardiorenal syndrome having significant roles. The therapeutic approach to this common problem typically involves increases in the diuretic dose and/or frequency, sequential nephron blockade, and mechanical fluid movement removal with ultrafiltration or peritoneal dialysis. Paracentesis is potentially useful in patients with intra-abdominal hypertension.