Profile of serum microRNAs in heart failure with reduced and preserved ejection fraction: Correlation with myocardial remodeling

Background and aims

Cardiomyocyte hypertrophy and interstitial fibrosis are key components of myocardial remodeling in Heart Failure (HF) with preserved (HFpEF) or reduced ejection fraction (HFrEF). MicroRNAs (miRNAs) are non-coding, evolutionarily conserved RNA molecules that may offer novel insights into myocardial remodeling. This study aimed to characterize miRNA expression in HFpEF (LVEF ≥  45%) and HFrEF (LVEF < 45%) and its association with myocardial remodeling.

Methods

Prospectively enrolled symptomatic HF patients (HFpEF:n = 36; HFrEF:n = 31) and controls (n = 23) underwent cardiac magnetic resonance imaging with T1-mapping and circulating miRNA expression (OpenArray system).

Results

13 of 188 miRNAs were differentially expressed between HF groups (11 downregulated in HFpEF). Myocardial extracellular volume (ECV) was increased in both HF groups (HFpEF 30 ± 5%; HFrEF 30 ± 3%; controls 26 ± 2%, p < 0.001). miR-128a-3p, linked to cardiac hypertrophy, fibrosis, and dysfunction, correlated positively with ECV in HFpEF (r = 0.60, p = 0.01) and negatively in HFrEF (r = - 0.51, p = 0.04). miR-423-5p overexpression, previously associated HF mortality, was inversely associated with LVEF (r = - 0.29, p = 0.04) and intracellular water lifetime (τ ic) (r = - 0.45, p < 0.05) in both HF groups, and with NT-proBNP in HFpEF (r = - 0.63, p < 0.01).

Conclusions

miRNA expression profiles differed between HF phenotypes. The differential expression and association of miR-128a-3p with ECV may reflect the distinct vascular, interstitial, and cellular etiologies of HF phenotypes.

Prognostic role of renal replacement therapy among hospitalized patients with heart failure in the Brazilian national public health system

Introduction

Data on patients hospitalized with acute heart failure in Brazil scarce.

Methods

We performed a cross-sectional, retrospective, records-based study using data retrieved from a large public database of heart failure admissions to any hospital from the Brazilian National Public Health System (SUS) (SUS Hospital Information System [SIHSUS] registry) to determine the in-hospital all-cause mortality rate, in-hospital renal replacement therapy rate and its association with outcome.

Results

In total, 910,128 hospitalizations due to heart failure were identified in the SIHSUS registry between April 2017 and August 2021, of which 106,383 (11.7%) resulted in in-hospital death. Renal replacement therapy (required by 8,179 non-survivors [7.7%] and 11,496 survivors [1.4%, p < 0.001]) was associated with a 56% increase in the risk of death in the univariate regression model (HR 1.56, 95% CI 1.52 -1.59), a more than threefold increase of the duration of hospitalization, and a 45% or greater increase of cost per day. All forms of renal replacement therapy remained independently associated with in-hospital mortality in multivariable analysis (intermittent hemodialysis: HR 1.64, 95% CI 1.60 -1.69; continuous hemodialysis: HR 1.52, 95% CI 1.42 -1.63; peritoneal dialysis: HR 1.47, 95% CI 1.20 -1.88).

Discussion

The in-hospital mortality rate of 11.7% observed among patients with acute heart failure admitted to Brazilian public hospitals was alarmingly high, exceeding that of patients admitted to North American and European institutions. This is the first report to quantify the rate of renal replacement therapy in patients hospitalized with acute heart failure in Brazil.

Serum potassium levels provide prognostic information in symptomatic heart failure beyond traditional clinical variables

Aims

Despite of recent advances in the pharmacological treatment, heart failure (HF) maintains significant morbidity and mortality rates. While serum potassium disorders are common and associated with adverse outcomes, the exact recommended potassium level for patients with HF are not entirely established. We aimed to investigate the prognostic role of potassium levels on a cohort of patients with symptomatic chronic HF.

Methods and results

Patients with symptomatic chronic HF were identified at the referral to 6 min walking test (6MWT) and were prospectively followed up for cardiovascular events. Clinical and laboratorial data were retrospectively obtained. The primary endpoint was the composite of cardiovascular death, hospitalization due to HF, and heart transplantation. The cohort included 178 patients with HF with the mean age of 51 ± 12.76 years, 39% were female, 85% of non‐ischaemic cardiomyopathy, and 38% had New York Heart Association Class III with a relatively high Meta‐Analysis Global Group in Chronic Heart Failure (MAGGIC) score (12.91 ± 6.6). The mean left ventricular ejection fraction was 39.98 ± 15.79%, and the mean 6MWT distance was 353 ± 136 m. After a median follow‐up of 516 days, there were 22 major cardiovascular events (4 cardiovascular deaths, 13 HF admissions, and 5 heart transplants). Patients were stratified according to cut‐point level of serum potassium of 4.7 mmol/L to predict combined cardiac events based on receiver operating characteristic analysis. Individuals with higher potassium levels had worse renal function (glomerular filtration rate, K ≤ 4.7: 102.8 ± 32.2 mL/min/1.73 m² vs. K > 4.7: 85.42 ± 36.2 mL/min/1.73 m², P = 0.004), higher proportion of New York Heart Association Class III patients (K ≤ 4.7: 28% vs. K > 4.7: 48%, P = 0.0029), and also higher MAGGIC score (K ≤ 4.7: 12.08 ± 5.7 vs. K > 4.7: 14.9 ± 7.9, P = 0.0089), without significant differences on the baseline pharmacological HF treatment. Both potassium levels [hazard ratio (HR) 4.26, 95% confidence interval (CI) 1.59–11.421, P = 0.003] and 6MWT distance (HR 0.99, 95% CI 0.993–0.999, P = 0.01) were independently associated with the primary outcome. After adjustments for MAGGIC score and 6MWT distance, potassium levels > 4.7 mmol/L maintained a significant association with outcomes (HR 3.57, 95% CI 1.305–9.807, P = 0.013). Patients with K > 4.7 mmol/L were more likely to present clinical events during the follow‐up (log rank = 0.005). Adding potassium levels to the model including 6MWT and MAGGIC significantly improved the prediction of events over 2 years (integrated discrimination index 0.105, 95% CI 0.018–0.281, P = 0.012 and net reclassification index 0.447, 95% CI 0.077–0.703, P = 0.028).

Conclusions

Potassium levels were independently associated with worse outcomes in patients with chronic symptomatic HF, also improving the accuracy model for prognostic prediction when added to MAGGIC score and 6MWT distance. The potassium levels above 4.7 mmol/L might identify those patients at an increased risk of cardiovascular events.

Cardiac resynchronization therapy restores muscular metaboreflex control

INTRODUCTION

The muscular metaboreflex, whose activation regulates blood flow during isometric and aerobic exercise, is blunted in patients with heart failure (HF), and cardiac resynchronization therapy (CRT) may restore this regulatory reflex.

OBJECTIVE

To evaluate metaboreflex responses after CRT.

METHODS

Thirteen HF patients and 12 age-matched healthy control subjects underwent the following evaluations (pre- and post-CRT implantation in the patient group): (a) heart rate, blood pressure, and forearm blood flow measurements; (b) muscle sympathetic nerve activity (MSNA) evaluation; and (c) peak oxygen consumption (VO_2peak ). Examinations were performed at rest, during moderate isometric exercise (IE), and during forearm ischemia (metaboreflex activation). The primary outcome was the increment in MSNA during limb ischemia compared to the rest moment (ΔMSNA rest to metaboreflex activation).

RESULTS

After CRT, rest MSNA decreased in the HF participants: 50.4 ± 9.2 bursts/min pre-CRT vs 34.0 ± 14.4 bursts/min post-CRT, P = .001, accompanied by an improvement in systolic blood pressure and in rate-pressure product. MSNA during limb ischemia decreased: 56.6 ± 11.5 bursts/min pre-CRT vs 43.6 ± 12.7 bursts/min post-CRT, P = .001, and the ΔMSNA rest to metaboreflex activation increased: 0% (interquartile range [IQR)], -7 to 9) vs 13% (IQR, 5-30), P = .03. An augmentation of mean blood pressure during limb ischemia post-CRT was noticed: 94 mmHg (IQR, 81-104) vs 110 mmHg (IQR, 100-117), P = .04. CRT improved VO_2peak , and this improvement was correlated with diminution in ΔMSNA pre- to post-CRT at rest moment (r_s = -0.74, P = .006).

CONCLUSION

CRT provides metaboreflex sensitization and MSNA enhancement. The restoration of sympathetic responsiveness correlates with the improvement in functional capacity.

Noninvasive imaging assessment of rehabilitation therapy in heart failure with preserved and reduced left ventricular ejection fraction (IMAGING-REHAB-HF): design and rationale

Background:

Studies have shown significant benefits of exercise therapy in heart failure (HF) with a reduced ejection fraction (HFrEF) and HF with a preserved ejection fraction (HFpEF). The mechanisms responsible for the beneficial effect of exercise in HFrEF and HFpEF are still unclear. We hypothesized that the effect of exercise on myocardial remodeling may explain its beneficial effect.

Methods:

IMAGING-REHAB-HF is a single-center, randomized, controlled clinical trial using cardiac magnetic resonance imaging, vasomotor endothelial function, cardiac sympathetic activity imaging and serum biomarkers to compare the effect of exercise therapy in HFpEF (LVEF ≥ 45%) and HFrEF (LVEF < 45%). Subjects will be assessed at baseline and after 4 months. The exercise program will consist of three 60-min exercise sessions/week. The primary endpoints are the effect of exercise on myocardial extracellular volume (ECV), left ventricular (LV) systolic function, LV mass, LV mass-to-volume and LV cardiomyocyte volume. Secondary endpoints include the effect of exercise on vasomotor endothelial function, cardiac sympathetic activity and plasmatic biomarkers. Patients will be allocated in a 2:1 fashion to supervised exercise program or usual care. A total sample size of 90 patients, divided into two groups according to LVEF:HFpEF group (45 patients:30 in the intervention arm and 15 in the control arm) and HFrEF group (45 patients:30 in the intervention arm and 15 in the control arm) – will be necessary to achieve adequate power.

Conclusion:

This will be the first study to evaluate the benefits of a rehabilitation program on cardiac remodeling in HF patients. The unique design of our study may provide unique data to further elucidate the mechanisms involved in reverse cardiac remodeling after exercise in HFpEF and HFrEF patients.

High levels of C-reactive protein are associated with reduced vagal modulation and low physical activity in young adults

The purpose of this study was to examine the relationship between cardiac autonomic control derived from heart rate variability (HRV), high-sensitivity C-reactive protein (hs-CRP) and physical activity (PA) levels measured using accelerometers. A total of 80 healthy university students volunteered to participate in this study (20.56 ± 0.82 years, 1.36 ± 1.5 mg/L of hs-CRP). The participants were divided into groups based on tertiles of hs-CRP. Analysis of covariance adjusted to PA was used to assess group differences in HRV. Associations between hs-CRP, HRV indices and PA were analyzed using Pearson's correlation. The participants at the highest tertile of hs-CRP (tertile 3) had lower cardiac vagal modulation (SDNN, tertile 1=78.05 ± 5.9,tertile 2=82.43 ± 5.9,tertile 3=56.03 ± 6.1; SD1, tertile 1=61.27 ± 5.3, tertile 2=62.93 ± 5.4, tertile 3=40.03 ± 5.5). In addition, vagal indices were inversely correlated with hs-CRP but positively correlated with PA (SDNN r=-0.320, SD1 r=-0.377; SDNN r=0.304, SD1 r=0.299; P<0.05). Furthermore, the most physically active subjects had lower levels of hs-CRP and the highest levels of vagal modulation.