Pathophysiological and diagnostic importance of fatty acid-binding protein 1 in heart failure with preserved ejection fraction

Identification of Novel Biomarkers Using Serum and Urinary Proteomics for Early Detection of Hypoxic Ischemic Encephalopathy

Hypoxic-ischemic encephalopathy (HIE) is a severe birth complication affecting neonates. Around 40-60% of affected neonates die by two years of age or have severe disabilities and neurodevelopmental delays. The early assessments of brain injury using traditional clinical and biochemical indicators do not always align with its severity and recovery. This delays identifying neonates who may benefit from adjuvant therapeutic strategies and monitoring therapy response. Our aim was to identify specific proteins using proteomic approach to predict the severity of neonatal asphyxia so that its outcome can also be prevented. To achieve this goal a case-control study was conducted on 38 neonates, and serum and urine samples were collected within 24 h of life. Clinical findings, biochemical parameters, and outcomes of the neonates were recorded. A tandem mass spectrometry-based quantitative proteomics approach was used to identify proteins in the serum and urine of HIE neonates. Bioinformatics analyses were performed to assess the potential features and competence of the identified differentially expressed proteins. This resulted in identification of 51 differentially expressed proteins which were found common to both serum and urine proteomic data. Some of the promising biomarkers found were APOD, ORM1, SOD1, and FABP1. These proteins were associated with the pathways like Amyloid fiber formation, diseases of programmed cell death, detoxification of reactive oxygen species, and neurodegenerative diseases. This study will pave the way for identifying the biomarkers (proteins) that can screen neonates for brain injury and monitor the disease progression, which may reduce mortality and neurodevelopmental impairment.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12291-023-01143-2.

Utility of E/e' Ratio During Low-Level Exercise to Diagnose Heart Failure With Preserved Ejection Fraction

BACKGROUND

E/e' ratio during exercise is the key parameter in identifying elevated pulmonary capillary wedge pressure (PCWP), and thus heart failure with preserved ejection fraction (HFpEF). However, its diagnostic value is limited when mitral inflow or tissue velocities are fused during elevated heart rate.

OBJECTIVES

The authors hypothesized that E/e' ratio during low-level (20 W) exercise (E/e'20W) can help diagnose HFpEF.

METHODS

Ergometric exercise stress echocardiography was performed in 215 dyspneic patients with an EF ≥50%. The authors determined the feasibility of E/e' ratio at each stage (frequency of patients who had measurable E/e' without E-A fusion among 215 participants) and examined whether E/e'20W could predict normal E/e' ratio during peak exercise (E/e'peak ≤15). The authors also evaluated whether E/e'20W could predict normal PCWP during exercise (PCWP <25 mm Hg) in a subset of participants (n = 45) who underwent exercise right heart catheterization.

RESULTS

The feasibility of the E/e' ratio decreased from 100% at rest to 96.3% during 20-W exercise and 74.9% during peak exercise caused by E-A fusion. In patients with E/e'peak >15, there was an increase in E/e' ratio from rest to 20-W exercise (11.2 ± 2.1 to 16.3 ± 3.5; P < 0.0001), but it did not change significantly from 20-W exercise to peak exercise (P = 0.12). E/e'20W predicted E/e'peak ≤15 (AUC: 0.91; P < 0.0001) with the cutoff value of ≤12.4 showing high specificity (94%) and positive predictive value (98%). During 20-W exercise, 93% of the HFpEF patients developed PCWP ≥25 mm Hg. E/e'20W predicted normal PCWP during exercise (AUC: 0.77; P = 0.01) with the cutoff value of ≤12.4 showing high specificity (83%).

CONCLUSIONS

E/e' ratio during low-level exercise is highly feasible and predicts normal E/e' ratio or PCWP during peak exercise with high specificity. These data suggest that E/e'20W could be used as an alternative to the peak exercise value to rule out HFpEF in patients with dyspnea.

Diastolic Filling Time, Chronotropic Response, and Exercise Capacity in Heart Failure and Preserved Ejection Fraction With Sinus Rhythm

Background

Exercise‐induced high heart rate may impair exercise tolerance by reducing diastolic filling time and ventricular filling in heart failure with preserved ejection fraction (HFpEF). Given the importance of chronotropic response, we hypothesized that reduction in diastolic filling time because of exercise‐induced increased heart rate would not impair cardiac output reserve and exercise capacity. We sought to determine the association between heart rate, diastolic filling time, hemodynamics, and exercise capacity in HFpEF.

Methods and Results

Patients with HFpEF (n=66) and controls without HF (n=107) underwent bicycle exercise echocardiography with simultaneous expired gas analysis to measure oxygen consumption. Diastolic filling time was assessed by the overlap time between mitral E‐ and A‐waves (longer overlap time indicates shorter diastolic filling duration). Overlap time increased (ie, diastolic filling time shortened) in HFpEF and controls as heart rate increased with exercise, and the relationship was similar between the groups. Greater heart rate response correlated with higher cardiac output (r=0.51, P<0.0001) and oxygen consumption (r=0.50, P<0.0001) during peak exercise. Shorter diastolic filling time, as assessed by longer overlap time, was correlated with higher cardiac output (r=0.47, P<0.0001) and peak oxygen consumption (r=0.38, P=0.007), not with E/e′ or right ventricular‐pulmonary artery uncoupling. Longer overlap time was associated with mitral A velocity (r=0.53, P<0.0001) and left atrial booster pump strain (r=0.42, P<0.0001).

Conclusions

Shortening of diastolic filling interval in tandem with increased heart rate during exercise does not limit cardiac output reserve or exercise capacity in HFpEF.

Association of body mass index and prognosis in patients with HFpEF: A dose-response meta-analysis

BACKGROUND

Although agreements regarding the negative effects of obesity on the development of heart failure with preserved ejection fraction (HFpEF) have been reached, the relationship between body mass index (BMI) and adverse outcomes in HFpEF patients are still debatable. Therefore, we conducted the dose-response meta-analysis to investigate this relationship.

METHODS

We searched the PubMed and Embase databases up to February 2022 for studies that evaluated the association between BMI and prognostic outcomes in patients with HFpEF. A cubic spline random-effects model was used to fit the potential dose-response curve. The effect estimates were expressed as adjusted hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

A total of 11 studies involving 69,273 patients with HFpEF were included. The summary HR for all-cause mortality was 0.90 (95% CI, 0.84-0.95) per 5 units increase in BMI, but the association was U-shaped (P_nonlinear < 0.01) with the nadir of risk at a BMI of 32-34 kg/m². The summary HR for HF hospitalization was 1.12 (95% CI, 1.05-1.19) with a significant positive linear association (P_nonlinear = 0.54).

CONCLUSIONS

For patients with HFpEF, there was a positive linear association of BMI with HF hospitalization, while a U-shaped relationship between BMI and all-cause mortality was observed with the lowest event rate at a BMI of 32-34 kg/m².