Renal function impairment predicts mortality in patients with chronic heart failure treated with resynchronization therapy

Cardiac Device Therapy in Patients with Chronic Kidney Disease: An Update

Cardiovascular diseases (CVDs) and chronic kidney disease (CKD) are frequently interconnected and their association leads to an exponential increase in the risk of both fatal and non-fatal events. In addition, the burden of arrhythmias in CKD patients is increased. On the other hand, the presence of CKD is an important factor that influences the decision to pursue cardiac device therapy. Data on CKD patients with device therapy are scarce and mostly derives from observational studies and case reports. Cardiac resynchronization therapy (CRT) is associated with decreased mortality, reduced heart failure symptoms, and improved renal function in early stages of CKD. Implantable cardioverter defibrillators (ICDs) are associated with a significant reduction in the mortality of CKD patients only for the secondary prevention of sudden cardiac death. Cardiac resynchronization therapy with defibrillator (CRT-D) is preferred in patients who meet the established criteria. The need for cardiac pacing is increased three-fold in dialysis patients. CKD is an independent risk factor for infections associated with cardiac devices.

Glucose Metabolism in the Kidney: Neurohormonal Activation and Heart Failure Development

The liver is not the exclusive site of glucose production in humans in the postabsorptive state. Robust data support that the kidney is capable of gluconeogenesis and studies have demonstrated that renal glucose production can increase systemic glucose production. The kidney has a role in maintaining glucose body balance, not only as an organ for gluconeogenesis but by using glucose as a metabolic substrate. The kidneys reabsorb filtered glucose through the sodium‐glucose cotransporters sodium‐glucose cotransporter (SGLT) 1 and SGLT2, which are localized on the brush border membrane of the early proximal tubule with immune detection of their expression in the tubularized Bowman capsule. In patients with diabetes mellitus, the renal maximum glucose reabsorptive capacity, and the threshold for glucose passage into the urine, are higher and contribute to the hyperglycemic state. The administration of SGLT2 inhibitors to patients with diabetes mellitus enhances sodium and glucose excretion, leading to a reduction of the glycosuria threshold and tubular maximal transport of glucose. The net effects of SGLT2 inhibition are to drive a reduction in plasma glucose levels, improving insulin secretion and sensitivity. The benefit of SGLT2 inhibitors goes beyond glycemic control, since inhibition of renal glucose reabsorption affects blood pressure and improves the hemodynamic profile and the tubule glomerular feedback. This action acts to rebalance the dense macula response by restoring adenosine production and restraining renin‐angiotensin‐aldosterone activation. By improving renal and cardiovascular function, we explain the impressive reduction in adverse outcomes associated with heart failure supporting the current clinical perspective.

Precision medicine in distinct heart failure phenotypes: Focus on clinical epigenetics

Heart failure (HF) management is challenging due to high clinical heterogeneity of this disease which makes patients responding differently to evidence-based standard therapy established by the current reductionist approach. Better understanding of the genetic and epigenetic interactions may clarify molecular signatures underlying maladaptive responses in HF, including metabolic shift, myocardial injury, fibrosis, and mitochondrial dysfunction. DNA methylation, histone modifications and micro-RNA (miRNAs) may be major epigenetic players in the pathogenesis of HF. DNA hypermethylation of the kruppel-like factor 15 (KLF15) gene plays a key role in switching the failing heart from oxidative to glycolytic metabolism. Moreover, hypomethylation at H3K9 promoter level of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) genes also leads to reactivation of fetal genes in man. The role of miRNAs has been investigated in HF patients undergoing heart transplantation, for whom miR-10a, miR-155, miR-31, and miR-92 may be putative useful prognostic biomarkers. Recently, higher RNA methylation levels have been observed in ischemic human hearts, opening the era of "epitranscriptome" in the pathogenesis of HF. Currently, hydralazine, statins, apabetalone, and omega-3 polyunsatured fatty acids (PUFA) are being tested in clinical trials to provide epigenetic-driven therapeutic interventions. Moreover, network-oriented analysis could advance current medical practice by focusing on protein-protein interactions (PPIs) perturbing the "cardiac" interactome. In this review, we provide an epigenetic map of maladaptive responses in HF patients. Furthermore, we propose the "EPi-transgeneratIonal network mOdeling for STratificatiOn of heaRt Morbidity" (EPIKO-STORM), a clinical research strategy offering novel opportunities to stratify the natural history of HF.

Plasma Levels of Preβ1-HDL Are Significantly Elevated in Non-Dialyzed Patients with Advanced Stages of Chronic Kidney Disease

In chronic kidney disease (CKD), the level of high-density lipoprotein (HDL) decreases markedly, but there is no strong inverse relationship between HDL-cholesterol (HDL-C) and cardiovascular diseases. This indicates that not only the HDL-C level, but also the other quantitative changes in the HDL particles can influence the protective functionality of these particles, and can play a key role in the increase of cardiovascular risk in CKD patients. The aim of the present study was the evaluation of the parameters that may give additional information about the HDL particles in the course of progressing CKD. For this purpose, we analyzed the concentrations of HDL containing apolipoprotein A-I without apolipoprotein A-II (LpA-I), preβ1-HDL, and myeloperoxidase (MPO), and the activity of paraoxonase-1 (PON-1) in 68 patients at various stages of CKD. The concentration of HDL cholesterol, MPO, PON-1, and lecithin-cholesterol acyltransferase (LCAT) activity were similar in all of the analyzed stages of CKD. We did not notice significant changes in the LpA-I concentrations in the following stages of CKD (3a CKD stage: 57 ± 19; 3b CKD stage: 54 ± 15; 4 CKD stage: 52 ± 14; p = 0.49). We found, however, that the preβ1-HDL concentration and preβ1-HDL/LpA-I ratio increased along with the progress of CKD, and were inversely correlated with the estimated glomerular filtration rate (eGFR), even after adjusting for age, gender, triacylglycerols (TAG), HDL cholesterol, and statin therapy (β = −0.41, p < 0.001; β = −0.33, p = 0.001, respectively). Our results support the earlier hypothesis that kidney disease leads to the modification of HDL particles, and show that the preβ1-HDL concentration is significantly elevated in non-dialyzed patients with advanced stages of CKD.

Impact of baseline renal function on all-cause mortality in patients who underwent cardiac resynchronization therapy: A systematic review and meta-analysis

BACKGROUND

Cardiac resynchronization therapy (CRT) improves both morbidity and mortality in selected patients with heart failure and increased QRS duration. However, chronic kidney disease (CKD) may have an adverse effect on patient outcome. The aim of this systematic review was to analyze the existing data regarding the impact of baseline renal function on all-cause mortality in patients who underwent CRT.

METHODS

Medline database was searched systematically, and studies evaluating the effect of baseline renal function on all-cause mortality in patients who underwent CRT were retrieved. We performed three separate analyses according to the comparison groups included in each study. Data were analyzed using Review Manager software (RevMan version 5.3; Oxford, UK).

RESULTS

We included 16 relevant studies in our analysis. Specifically, 13 studies showed a statistically significant higher risk of all-cause mortality in patients with impaired baseline renal function who underwent CRT. The remaining three studies did not show a statistically significant result. The quantitative synthesis of five studies showed a 19% decrease in all-cause mortality per 10-unit increment in estimated glomerular filtration rate (eGFR) [HR: 0.81, 95% CI (0.73-0.90), p<0.01, 86% I²]. Additionally, we demonstrated that patients with an eGFR<60 mL/min/1.73 m² had an all-cause mortality rate of 66% [HR: 1.66, 95% CI (1.37-2.02), p<0.01, 0% I²], which was higher than in those with an eGFR≥60 mL/min/1.73 m².

CONCLUSION

Baseline renal dysfunction has an adverse effect on-all cause mortality in patients who underwent CRT.

The Prognostic Importance of Changes in Renal Function during Treatment for Acute Heart Failure Depends on Admission Renal Function

Background

Worsening and improving renal function during acute heart failure have been associated with adverse outcomes but few studies have considered the admission level of renal function upon which these changes are superimposed.

Objectives

The objective of this study was to evaluate definitions that incorporate both admission renal function and change in renal function.

Methods

696 patients with acute heart failure with calculable eGFR were classified by admission renal function (Reduced [R, eGFR<45 ml/min] or Preserved [P, eGFR≥45 ml/min]) and change over hospital admission (worsening [WRF]: eGFR ≥20% decline; stable [SRF]; and improving [IRF]: eGFR ≥20% increase). The primary outcome was all-cause mortality. The prevalence of Pres and Red renal function was 47.8% and 52.2%. The frequency of R-WRF, R-SRF, and R-IRF was 11.4%, 28.7%, and 12.1%, respectively; the incidence of P-WRF, P-SRF, and P-IRF was 5.7%, 35.3%, and 6.8%, respectively. Survival was shorter for patients with R-WRF compared to R-IRF (median survival times 13.9 months (95%CI 7.7–24.9) and 32.5 months (95%CI 18.8–56.1), respectively), resulting in an acceleration factor of 2.3 (p = 0.016). Thus, an increase compared with a decrease in renal function was associated with greater than two times longer survival among patients with Reduced renal function.