Renal function, N-terminal Pro-B-Type natriuretic peptide, propeptide big-endothelin and patients with heart failure and preserved ejection fraction

The Diabetic Cardiorenal Nexus

The end-stage of the clinical combination of heart failure and kidney disease has become known as cardiorenal syndrome. Adverse consequences related to diabetes, hyperlipidemia, obesity, hypertension and renal impairment on cardiovascular function, morbidity and mortality are well known. Guidelines for the treatment of these risk factors have led to the improved prognosis of patients with coronary artery disease and reduced ejection fraction. Heart failure hospital admissions and readmission often occur, however, in the presence of metabolic, renal dysfunction and relatively preserved systolic function. In this domain, few advances have been described. Diabetes, kidney and cardiac dysfunction act synergistically to magnify healthcare costs. Current therapy relies on improving hemodynamic factors destructive to both the heart and kidney. We consider that additional hemodynamic solutions may be limited without the use of animal models focusing on the cardiomyocyte, nephron and extracellular matrices. We review herein potential common pathophysiologic targets for treatment to prevent and ameliorate this syndrome.

Biomarkers in Heart Failure with Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous disorder developing from multiple aetiologies with overlapping pathophysiological mechanisms. HFpEF diagnosis may be challenging, as neither cardiac imaging nor physical examination are sensitive in this situation. Here, we review biomarkers of HFpEF, of which the best supported are related to myocardial stretch and injury, including natriuretic peptides and cardiac troponins. An overview of biomarkers of inflammation, extracellular matrix derangements and fibrosis, senescence, vascular dysfunction, anaemia/iron deficiency and obesity is also provided. Finally, novel biomarkers from -omics technologies, including plasma metabolites and circulating microRNAs, are outlined briefly. A cardiac-centred approach to HFpEF diagnosis using natriuretic peptides seems reasonable at present in clinical practice. A holistic approach including biomarkers that provide information on the non-cardiac components of the HFpEF syndrome may enrich our understanding of the disease and may be useful in classifying HFpEF phenotypes or endotypes that may guide patient selection in HFpEF trials.

Alternative Echocardiographic Algorithm for Left Ventricular Filling Pressure in Patients With Heart Failure With Preserved Ejection Fraction

The American Society of Echocardiography and/or the European Association of Cardiovascular Imaging recommend a conventional algorithm for estimating left ventricular (LV) filling pressure in heart failure. However, several patients are classed as "indeterminate" due to their LV filling pressures being impossible to calculate. We investigated whether our new echocardiographic algorithm can predict clinical outcomes in patients with heart failure with preserved ejection fraction (HFpEF). We enrolled 754 consecutive patients from the PURSUIT-HFpEF registry. We used the new algorithm to divide them into 2 groups; a normal LV filling pressure group (N group) and a high LV filling pressure group (H group). The H group consisted of 342 patients. Over a mean follow-up of 342 days, 185 patients reached the primary composite end point (157 readmissions for worsening heart failure and 43 cardiovascular deaths). In a multivariable Cox analysis, being in the H group was significantly associated with an increased rate of cardiac events compared with the N group (hazard ratio: 1.71; 95% confidence interval: 1.17 to 2.50, p = 0.006). There were 56 patients (7%) who were assigned to "indeterminate" with the conventional algorithm. Using the new algorithm, we reclassified 16 patients (29%) into the H group and 40 patients (71%) into the N group. The Kaplan-Meier curves showed the reclassified H group had a significantly higher incidence of cardiac events than those assigned to the N group (p < 0.01). In conclusion, the present study demonstrated LV filling pressure assessed by our algorithm can predict clinical outcomes in patients with HFpEF.

Do Natriuretic Peptide Measurements Provide Insights into Management of End-Stage Renal Disease Patients Undergoing Dialysis?

PURPOSE OF REVIEW

Impaired renal function may affect natriuretic peptide levels through a variety of factors and mechanisms, such as high prevalence of concomitant vascular and myocardial diseases, reduced clearance, increased risk of volume overload, and different types and solute removal techniques in the setting of dialysis. Nevertheless, accumulating evidence suggests that natriuretic peptide testing may provide insights into management of patients with chronic kidney disease (CKD) and end-stage kidney disease (ESRD) on dialysis, as they have been shown to be independently associated with morbidity and mortality.

RECENT FINDINGS

Rising natriuretic peptide levels over time may identify CKD patients more likely to approach ESRD and requiring dialysis initiation. Moreover, serial natriuretic peptide measurements may also be helpful in guiding fluid management in ESRD patients on dialysis. However, since patients with CKD usually have significantly higher and more variable baseline levels of natriuretic peptides than those without CKD, traditional cut-off values may not be applicable, and individualized trajectories should be applied and interpreted in the clinical context. Routine clinical use natriuretic peptide testing in the CKD and ESRD settings still needs to be refined and individualized, yet their diagnostic and prognostic values can provide valuable insights into clinical trajectories and potential treatment responses.

Pathophysiology and significance of natriuretic peptides in patients with end-stage kidney disease

Natriuretic peptides (NP), especially B type (BNP) and its N-terminal pro-B type natriuretic peptide (NT-proBNP), have long been regarded as biomarkers of volume overload and tools to exclude heart failure in the general population. However, their role in end-stage kidney disease (ESKD) is less certain given that BNP and NT-proBNP are excreted by the kidney and so serum concentrations of NPs are nearly universally elevated compared to controls. Nevertheless, the accumulated evidence suggests thatserum concentrations of NPs in patients with ESKD show moderate or strong positive relationships with underlying heart disease, abnormal cardiac structure or function and mortality. Limited evidence also supports the role of BNP including NT-proBNP, ANP in some studies, rather than CNP or DNP in risk stratification among ESKD patients as well as the utility of BNP samplings pre- and post- hemodialysis. However, studies of the cut-off values of NPs have yielded inconsistent results, such that further large-scale studies are needed to clarify these issues. This review summarizes the pathophysiology and significance of NPs in ESKD patients, especially their potential role as risk stratification biomarkers in clinical management.

Association Between the Lipid Profile and Renal Dysfunction in the Heart Failure Patients

BACKGROUND/AIMS

In heart failure patients with high prevalence of chronic renal disease (CKD), hospitalization and mortality, whether the lipid profile was associated with renal dysfunction remained unknown. The present study intended to clarify the association between the lipid profile and renal dysfunction in the heart failure patients.

METHODS

336 hospitalized heart failure patients with left ventricle ejection fraction (LVEF) ≤45% and New York Heart Association (NYHA) class II-IV were enrolled. The estimated glomerular filtration rate (eGFR) < 90 mL/min·1.73 m2 was defined as renal dysfunction. The demographic, clinical data, blood samples and echocardiography were documented. The Pearson simple linear correlation was performed to evaluate the confounding factors correlated with eGFR. The significantly correlated factors were enrolled in Logistic regression as confounding factors to determine the association between the lipid profile and renal dysfunction in the heart failure patients.

RESULTS

182 patients (54.2%) had renal dysfunction and 154 patients (45.8%) did not have renal dysfunction. The waist circumference, platelet counts, platelet distribution width (PDW), high density lipoprotein-cholesterol (HDL-C), apolipoprotein A1 (apoA1), albumin and left ventricular ejection fraction (LVEF) are positively correlated with eGFR (all P< 0.05). Meanwhile, the age, mean platelet volume (MPV), neutrophilic granulocyte percentage (NEUT%), urea nitrogen (BUN), creatinine and total bilirubin (TBIL) are negatively correlated with eGFR (all P< 0.05). The total cholesterol (TC), triglyceride, low density lipoprotein-cholesterol (LDL-C) and apolipoprotein B (apoB) show no correlation with eGFR. After the adjustment of sex, hypertension, diabetes mellitus, age, waist circumference, platelet counts, MPV, PDW, NEUT%, TBIL, albumin and LVEF, HDL-C is the only lipid factor still significantly associated with renal dysfunction in hospitalized heart failure patients (OR=0.119, P=0.003).

CONCLUSION

Among the lipid profile of TC, triglyceride, LDL-C, HDL-C, apo A1 and apo B, the HDL-C is the only lipid factor significantly associated with renal dysfunction in hospitalized heart failure patients.