Pharmacological management of cardiorenal syndromes

[Cardiorenal syndrome in geriatric patients]

The unfavorable mutual influence of the kidney and heart functions in acute or chronic kidney and/or heart failure has defined the cardiorenal syndrome (CRS) since a consensus conference in 2004. The pathophysiological considerations and the subsequent treatment approaches determine the classification into five types. The syndrome has a high prevalence in geriatric patients. The interactions of medications on one or the other organ system require an interaction of treatment modalities in order to improve the prognosis and prevent acute deterioration. Exact knowledge of the respective indications, differential treatment approaches and specifics in dealing with CRS can improve the current undertreatment due to concerns about side effects.

Association between central haemodynamics and renal function in advanced heart failure: a nationwide study from Sweden

AIMS

Renal dysfunction in patients with heart failure (HF) has traditionally been attributed to declining cardiac output and renal hypoperfusion. However, other central haemodynamic aberrations may contribute to impaired kidney function. This study assessed the relationship between invasive central haemodynamic measurements from right-heart catheterizations and measured glomerular filtration rate (mGFR) in advanced HF.

METHODS AND RESULTS

All patients referred for heart transplantation work-up in Sweden between 1988 and 2019 were identified through the Scandiatransplant organ-exchange organization database. Invasive haemodynamic variables and mGFR were retrieved retrospectively. A total of 1001 subjects (49 ± 13 years; 24% female) were eligible for the study. Analysis of covariance adjusted for age, sex, and centre revealed that higher right atrial pressure (RAP) displayed the strongest relationship with impaired GFR [β coefficient -0.59; 95% confidence interval (CI) -0.69 to -0.48; P < 0.001], followed by lower mean arterial pressure (MAP) (β coefficient 0.29; 95% CI 0.14-0.37; P < 0.001), and finally reduced cardiac index (β coefficient 3.51; 95% CI 2.14-4.84; P < 0.003). A combination of high RAP and low MAP was associated with markedly worse mGFR than any other RAP/MAP profile, and high renal perfusion pressure (RPP, MAP minus RAP) was associated with superior renal function irrespective of the degree of cardiac output.

CONCLUSIONS

In patients with advanced HF, high RAP contributed more to impaired GFR than low MAP. A higher RPP was more closely related to GFR than was high cardiac index.

In Silico Integrative Approach Revealed Key MicroRNAs and Associated Target Genes in Cardiorenal Syndrome

Cardiorenal syndromes constellate primary dysfunction of either heart or kidney whereby one organ dysfunction leads to the dysfunction of another. The role of several microRNAs (miRNAs) has been implicated in number of diseases, including hypertension, heart failure, and kidney diseases. Wide range of miRNAs has been identified as ideal candidate biomarkers due to their stable expression. Current study was aimed to identify crucial miRNAs and their target genes associated with cardiorenal syndrome and to explore their interaction analysis. Three differentially expressed microRNAs (DEMs), namely, hsa-miR-4476, hsa-miR-345-3p, and hsa-miR-371a-5p, were obtained from GSE89699 and GSE87885 microRNA data sets, using R/GEO2R tools. Furthermore, literature mining resulted in the retrieval of 15 miRNAs from scientific research and review articles. The miRNAs-gene networks were constructed using miRNet (a Web platform of miRNA-centric network visual analytics). CytoHubba (Cytoscape plugin) was adopted to identify the modules and the top-ranked nodes in the network based on Degree centrality, Closeness centrality, Betweenness centrality, and Stress centrality. The overlapped miRNAs were further used in pathway enrichment analysis. We found that hsa-miR-21-5p was common in 8 pathways out of the top 10. Based on the degree, 5 miRNAs, namely, hsa-mir-122-5p, hsa-mir-222-3p, hsa-mir-21-5p, hsa-mir-146a-5p, and hsa-mir-29b-3p, are considered as key influencing nodes in a network. We suggest that the identified miRNAs and their target genes may have pathological relevance in cardiorenal syndrome (CRS) and may emerge as potential diagnostic biomarkers.

Pathophysiology of Cardiorenal Syndrome and Use of Diuretics and Ultrafiltration as Volume Control

Acute deterioration in kidney function in the setting of decompensated heart failure, known as cardiorenal syndrome, results from venous congestion. Although diuretics or ultrafiltration are effective measures in decreasing venous congestion and improving symptoms in patients with cardiorenal syndrome, the impact of decongestive therapy on kidney function or mortality remains uncertain. A precise assessment of venous congestion is required to assess the adequacy of patients' response to decongestive therapy and to guide therapeutic decision making.

Acute or chronic dysfunction of the heart or kidneys can cause dysfunction of other organs. This interaction between the heart and kidneys is characterized as cardiorenal syndrome (CRS). Recently, a preponderance of data indicated that venous congestion plays an important role in the combination of renal and cardiac diseases. This review aims to focus on the pathophysiology of venous congestion that leads to renal impairment in heart failure and the use of diuretics or ultrafiltration as decongestive therapy in CRS. We found that although clinical studies have confirmed that decongestive therapy has a definite role in decreasing volume overload and the consequent symptom improvement in patients with CRS, the impact of diuretics or ultrafiltration on the improvement of kidney function or mortality remains uncertain. A precise assessment of volume status is required to determine the adequacy of decongestion. Objective measures of renal venous congestion may be a future metric to assess the adequacy of the diuretic response in patients and guide therapeutic decision making.