Growth differentiation factor-15 levels in the blood around the pulmonary artery is associated with hospitalization for heart failure in patients with pulmonary arterial hypertension

Pathophysiological insights into machine learning-based subphenotypes of acute heart failure with preserved ejection fraction

OBJECTIVE

The heterogeneous pathophysiology of the diverse heart failure with preserved ejection fraction (HFpEF) phenotypes needs to be examined. We aim to assess differences in the biomarkers among the phenotypes of HFpEF and investigate its multifactorial pathophysiology.

METHODS

This study is a retrospective analysis of the PURSUIT-HFpEF Study (N=1231), an ongoing, prospective, multicentre observational study of acute decompensated HFpEF. In this registry, there is a predefined subcohort in which we perform multibiomarker tests (N=212). We applied the previously established machine learning-based clustering model to the subcohort with biomarker measurements to classify them into four phenotypes: phenotype 1 (n=69), phenotype 2 (n=49), phenotype 3 (n=41) and phenotype 4 (n=53). Biomarker characteristics in each phenotype were evaluated.

RESULTS

Phenotype 1 presented the lowest value of N-terminal pro-brain natriuretic peptide (NT-proBNP), high-sensitive C reactive protein, tumour necrosis factor-α, growth differentiation factor (GDF)-15, troponin T and cystatin C, whereas phenotype 2, which is characterised by hypertension and cardiac hypertrophy, showed the highest value of these markers. Phenotype 3 showed the second highest value of GDF-15 and cystatin C. Phenotype 4 presented a low NT-proBNP value and a relatively high GDF-15.

CONCLUSIONS

Distinctive characteristics of biomarkers in HFpEF phenotypes would indicate differential underlying mechanisms to be elucidated. The contribution of inflammation to the pathogenesis varied considerably among different HFpEF phenotypes. Systemic inflammation substantially contributes to the pathophysiology of the classic HFpEF phenotype with cardiac hypertrophy.

TRIAL REGISTRATION NUMBER

UMIN-CTR ID: UMIN000021831.

Transpulmonary Expression of Exosomal microRNAs in Idiopathic and Congenital Heart Disease-Related Pulmonary Arterial Hypertension

BACKGROUND

Pulmonary artery hypertension (PAH) is a fatal disease characterized by a complex pathogenesis. Exosomes containing microRNAs (miRs) have emerged as a novel biomarker. Transpulmonary exosomal miRs offer valuable insights into pulmonary circulation microenvironments. Hereby, we aimed to explore the potentials of transpulmonary exosomal miRs as differentiating factors between idiopathic PAH and congenital heart disease (CHD)-related PAH.

METHODS AND RESULTS

During right heart catheterization, we collected exosomes at pulmonary arteries in 25 patients diagnosed with idiopathic PAH and 20 patients with CHD-related PAH. Next-generation sequencing identified several candidate exosomal miRs. Using quantitative polymerase chain reaction, we validated the expressions of these miRs and revealed significantly elevated expressions of miR-21, miR-139-5p, miR-155-5p, let-7f-5p, miR-328-3p, miR-330-3p, and miR-103a-3p in patients with CHD-related PAH, in contrast to patients with idiopathic PAH. Among these miRs, miR-21 exhibited the highest expression in patients with CHD-related PAH. These findings were further corroborated in an external cohort comprising 10 patients with idiopathic PAH and 8 patients with CHD-related PAH. Using an in vitro flow model simulating the shear stress experienced by pulmonary endothelial cells, we observed a significant upregulation of miR-21. Suppressing miR-21 rescued the shear stress-induced downregulation of the RAS/phosphatidylinositol 3-kinase/protein kinase B pathway, leading to a mitigation of apoptosis.

CONCLUSIONS

Our study identified a pronounced expression of transpulmonary exosomal miR-21, particularly in patients with CHD-related PAH, through next-generation sequencing analysis. Further investigation is warranted to elucidate the regulatory mechanisms involving miR-21 in the pathophysiology of PAH.

Human liver single nuclear RNA sequencing implicates BMPR2, GDF15, arginine, and estrogen in portopulmonary hypertension

Portopulmonary hypertension (PoPH) is a type of pulmonary vascular disease due to portal hypertension that exhibits high morbidity and mortality. The mechanisms driving disease are unknown, and transcriptional characteristics unique to the PoPH liver remain unexplored. Here, we apply single nuclear RNA sequencing to compare cirrhotic livers from patients with and without PoPH. We identify characteristics unique to PoPH in cells surrounding the central hepatic vein, including increased growth differentiation factor signaling, enrichment of the arginine biosynthesis pathway, and differential expression of the bone morphogenic protein type II receptor and estrogen receptor type I genes. These results provide insight into the transcriptomic characteristics of the PoPH liver and mechanisms by which PoPH cellular dysfunction might contribute to pulmonary vascular remodeling.

The diagnostic and prognostic value of growth differentiation factor-15 in systemic lupus erythematosus-associated pulmonary arterial hypertension

Growth-differentiation factor (GDF)-15 is a member of transforming growth factor-β-related cytokine and may respond to right ventricular overload. The objective of this article was to assess the diagnosis and prognostic value of GDF-15 in systemic lupus erythematosus-associated pulmonary arterial hypertension (SLE-PAH). Serum samples were obtained from 65 patients with SLE-PAH, 51 sex and age matched patients of SLE without PAH (SLE-non-PAH), and 32 healthy controls. Serum GDF-15 level was detected by enzyme-linked immunosorbent assay and the optimal cut-off point was determined by receiver operating characteristic curve. The primary end-point was death from any cause and the secondary end-point was target goal achievement (TGA). Cox regression analyses and Kaplan-Meier method were performed to identify the prognostic value of GDF-15. Serum GDF-15 levels were significantly higher in SLE-PAH patients (1112.14 ± 781.80 pg/mL) than SLE-non-PAH patients (810 ± 408 pg/mL) and healthy controls (442 ± 139 pg/mL) at baseline. The optimal cut-off value of GDF-15 in the diagnosis of SLE-PAH was 733 pg/mL (AUC = 0.84). In patients with SLE-PAH, GDF-15 level was associated with 6 min walking distance (ρ = -0.385, p = 0.017) and higher serum N terminal-pro brain natriuretic peptide (NT-proBNP) (ρ = 0.605, p < 0.001). Patients with GDF-15 > 733 pg/mL were more likely to death (adjusted hazard ratio [HR] = 4.01, 95% confidence intervals [CI]: 1.23-6.27, p = 0.041) and less likely to achieve treatment goal (adjusted HR = 0.57, 95% CI: 0.23-0.79, p = 0.028). In addition, patients with simultaneous elevation of GDF-15 and NT-proBNP showed lower proportion of TGA (p = 0.046). In conclusion, GDF-15 is a new and promising biomarker of development and prognosis in SLE-PAH. The combination of GDF-15 and NT-proBNP may provide more accurate prognostic information.

An Overview of Circulating Pulmonary Arterial Hypertension Biomarkers

Pulmonary arterial hypertension (PAH), also known as Group 1 Pulmonary Hypertension (PH), is a PH subset characterized by pulmonary vascular remodeling and pulmonary arterial obstruction. PAH has an estimated incidence of 15-50 people per million in the United States and Europe, and is associated with high mortality and morbidity, with patients' survival time after diagnosis being only 2.8 years. According to current guidelines, right heart catheterization is the gold standard for diagnostic and prognostic evaluation of PAH patients. However, this technique is highly invasive, so it is not used in routine clinical practice or patient follow-up. Thereby, it is essential to find new non-invasive strategies for evaluating disease progression. Biomarkers can be an effective solution for determining PAH patient prognosis and response to therapy, and aiding in diagnostic efforts, so long as their detection is non-invasive, easy, and objective. This review aims to clarify and describe some of the potential new candidates as circulating biomarkers of PAH.