Association between serum soluble urokinase-type plasminogen activator receptor and atrial fibrillation

Fibroblast growth factor 5 as a target for atrial fibrillation treatment: Evidence from mendelian randomization

BACKGROUND

Previous studies have found that inflammatory proteins are involved in the pathogenesis of atrial fibrillation (AF). We used mendelian randomization to explore the potential pathogenic inflammatory proteins of AF.

METHODS

This study adopts a Mendelian randomization design to primarily assess causal associations using the Wald ratio and the inverse variance weighting method. It leverages protein quantitative trait locus (pQTL) data encompassing 91 types of inflammatory proteins from 14,824 participants of European ancestry. The primary analysis phase utilizes AF GWAS data from 55,106 participants, with an additional 237,690 participants included in the validation stage. Sensitivity analyses, including reverse causality analysis, Bayesian colocalization analysis, and phenotype scanning, were conducted. Finally, the study explores potential targeted drugs.

RESULTS

The findings highlight a causal link between 7 inflammatory proteins and AF, with 2 showing positive correlations and 5 exhibiting negative correlations. Among these, fibroblast growth factor 5 (FGF5) emerges as particularly robust in sensitivity analysis. Colocalization analysis indicates a shared genetic variation between FGF5 and AF, supporting its potential as a targeted therapy for AF. Importantly, this causal relationship remains unaffected by reverse causality. Furthermore, significant pleiotropic effects were observed in phenotype scanning. Finally, the causal association between FGF5 and AF was successfully replicated during the validation phase.

CONCLUSION

FGF5 may become an intervention target for AF targeted therapy.

The Association between Coagulation and Atrial Fibrillation

The existing literature highlights the presence of numerous coagulation factors and markers. Elevated levels of coagulation factors are associated with both existing and newly diagnosed cases of atrial fibrillation (AF). However, this article summarizes the role of coagulation in the pathogenesis of AF, which includes fibrinogen and fibrin, prothrombin, thrombomodulin, soluble urokinase plasminogen activator receptor, von Willebrand factor, P-selectin, D-dimer, plasminogen activator inhibitor-1, and platelet activation. Coagulation irregularities play a significant role in the pathogenesis of AF.

Soluble Urokinase Plasminogen Activator Receptor as a Diagnostic and Prognostic Biomarker in Cardiac Disease

This review summarizes the published literature referring to the use and validity of the biomarker soluble urokinase plasminogen activator receptor (suPAR) when used for the assessment of patients with cardiac diseases. It is measured by enzyme-linked immunosorbent assay (ELISA) in plasma samples. In cardiology a cut-off value range of 3.5 - 4.5 ng/mL has been commonly utilized. Different cut-off values may be applied based on the measuring kit used, the patient population and the clinical setting. A PubMed/Medline search was conducted aiming to identify all publications relevant to the use of suPAR in patients with cardiac diseases. A total of 39 studies were included in this review. suPAR as a marker of inflammation has been used more extensively in recent years, alone or in combination with other biomarkers of inflammation and cardiac pathology in the assessment of patients with acute and chronic cardiac diseases. suPAR is closely related to the pathophysiology of cardiac disease, and a number of publications encourages its use as a valuable biomarker in the assessment of patients presenting to the cardiology service. It may be most valuable in the risk assessment of patients with acute coronary syndromes and congestive heart failure, as suPAR elevation may be an independent predictor of mortality in these conditions. In conclusion, among several biomarkers used for clinical entities with underlying inflammatory pathophysiology including cardiac diseases, suPAR is a novel attractive index for the prognostic risk stratification of cardiac patients. More research is warranted to confirm its diagnostic and prognostic validity, alone or combined with other cardiac and inflammatory biomarkers.

Preoperative Levels of the Soluble Urokinase-Type Plasminogen Activator Receptor as Predictor for New Episodes of Atrial Fibrillation After Vascular Surgery

INTRODUCTION

The soluble urokinase-type plasminogen activator receptor (suPAR) in uPAR soluble form is produced when the uPAR is cleaved from the cell membrane during the inflammatory process. Postoperative atrial fibrillation (AF) is the most common perioperative cardiac arrhythmia. It is speculated that elevated suPAR has a role in the development of AF. The aim of our study was to investigate the predictive role of preoperative suPAR in the occurrence of AF during the first 6 months after major vascular surgery.

METHODS

We included 119 male and 63 female patients with an average age of 67.19 ± 6.02 years, without permanent/persistent AF. Basic predictive model (BASIC) included traditional risk factors for AF: age, gender, body mass index-BMI, smoking status, presence of arterial hypertension, diabetes mellitus and dyslipidemia.

RESULTS

Over the 6-month period, 19 (10.4%) patients had one new episode of atrial fibrillation and 2 patients (1.1%) had 2 episodes of paroxysmal atrial fibrillation. Paroxysms of AF were significantly more frequent in patients who had a resection of an abdominal aneurysm than in patients with other types of major vascular surgery. BASIC had good discriminatory ability in the prediction of AF paroxysms during the first 6 months after surgery (AUC = 0.715, 95%CI 0.590-0.840). Adding suPAR to the basic model significantly improved the discriminative ability of the predictive model for AF episodes (ΔAUC = 0.238, p < 0.001). The predictive performance of the model BASIC+CRP+suPAR, measured using AUC, NRI and IDI statistics, was very similar to the model BASIC+suPAR.

CONCLUSION

AF is a common complication in surgical patients with high mortality and morbidity. suPAR could improve the ability of traditional risk factors to predict its occurrence up to 6 months after major vascular surgery.

Prognostic Value of Soluble Urokinase-Type Plasminogen Activator Receptor and High-Sensitivity C-Reactive Protein on Postoperative Mortality in Patients Undergoing Elective On-Pump Cardiac Surgery

OBJECTIVES

Elevated soluble urokinase-type plasminogen activator receptor (suPAR) and high-sensitivity C-reactive protein (hsCRP) have been associated with increased mortality in patients with cardiovascular disease. The aim of the present study was to explore the relationship between suPAR and hsCRP values and associated mortality after elective cardiac surgery. A secondary aim was to assess whether a combined risk model of European System for Cardiac Operative Risk Evaluation (EuroSCORE II), suPAR, and/or hsCRP would improve the prognostic accuracy compared with EuroSCORE II alone.

DESIGN

Retrospective observational study.

SETTING

Single-center, university hospital.

PARTICIPANTS

Adult patients admitted for elective on-pump cardiac surgery were included. Biobank blood samples were obtained from previous research projects at a tertiary heart center from 2012 to 2018.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 931 patients were included. Kaplan-Meier and Cox proportional hazard analyses were used to explore a potential association between preoperative suPAR and hsCRP values and all-cause mortality up to one year after surgery. Thirty-day mortality was predicted from suPAR, hsCRP, and EuroSCORE II by logistic regression and compared using area under the receiver operating characteristics curve and Brier scores. After adjustment for known confounders, a doubling of suPAR and hsCRP corresponded to a hazard ratio for all-cause mortality of 2.27 (95% confidence interval 1.65-3.11; p < 0.001) and 1.26 (95% confidence interval 1.07-1.49; p = 0.005), respectively. However, adding the biomarkers to EuroSCORE II did not improve prediction/discrimination with respect to 30-day mortality.

CONCLUSIONS

Elevated preoperative levels of suPAR and hsCRP were associated with all-cause mortality in elective cardiac surgery patients. However, inclusion of biomarkers did not improve the prognostic accuracy of EuroSCORE II.

N-Terminal Pro B-Type Natriuretic Peptide's Usefulness for Paroxysmal Atrial Fibrillation Detection Among Populations Carrying Cardiovascular Risk Factors

Background: Atrial fibrillation (AF) systematic screening studies have not shown a clear usefulness in stroke prevention, as AF might present as paroxysmal and asymptomatic. This study aims to determine the usefulness of some blood-biomarkers to identify paroxysmal atrial fibrillation in the context of a screening programme. Methods: A total of 100 subjects aged 65-75 years with hypertension and diabetes were randomly selected. AF was assessed by conventional electrocardiogram (ECG) and 4 weeks monitoring with a wearable Holter device (Nuubo™). N-terminal pro B-type natriuretic peptide (NT-proBNP), apolipoprotein CIII (ApoC-III), von Willebrand factor (vWF), ADAMTS13, urokinase plasminogen activator surface receptor (uPAR), and urokinase plasminogen activator (uPA) were determined in serum/plasma samples and the levels were compared depending on AF presence and mode of detection. Results: The AF prevalence in the studied population was found to be 20%. In seven subjects, AF was only detected after 1 month of Holter monitoring (hAF group). NT-proBNP levels were higher in subjects with AF compared with subjects with no AF (p < 0.0001), even when only taking into account the hAF group (p = 0.031). No significant differences were found in the other biomarkers. The NT-proBNP >95 pg/ml cut-off showed high sensitivity and specificity to detect AF (95%, 66.2%) or hAF (85.72%, 66.2%) and was found to be an independent predictor of AF and hAF in a logistic regression analysis. NT-proBNP correlated with AF burden (r = 0.597, p = 0.024). Conclusion: NT-proBNP was elevated in AF cases not identified by ECG; thus, it may be used as a screening biomarker in asymptomatic high-risk populations, with a promising cut-off point of 95 pg/ml that requires further validation.

Increased soluble urokinase plasminogen activator receptor (suPAR) levels in neovascular age-related macular degeneration: a role for inflammation in the pathogenesis of the disease?

PURPOSE

To evaluate the plasma concentration of the soluble form of the urokinase-type plasminogen activator receptor ((s)uPAR), an established biomarker of chronic inflammation, in patients affected by neovascular age-related macular degeneration.

METHODS

Forty consecutive patients affected by age-related macular degeneration and 52 subjects with no history of the disease were included in this case-control study. The two groups of individuals considered for the study were matched for age, sex, and class of medications taken. Plasma concentration of suPAR was measured using a specific ELISA assay (suPARnostic, Birkeroed, Denmark).

RESULTS

The case and control groups were similar for age, gender distribution, weight, height, and systolic and diastolic blood pressure, as well as for dyslipidemia and high blood pressure medication (P > 0.28). The plasma concentrations of suPAR were significantly increased in patients with neovascular age-related macular degeneration when compared to controls (6.19 ± 2.2 ng/ml, vs 5.21 ± 1.5, respectively, mean ± SD P = 0.01).

CONCLUSIONS

Patients with neovascular age-related macular degeneration display increased plasma levels of suPAR, suggesting that chronic inflammation may be involved in the pathogenesis of the disease.

Soluble Urokinase Plasminogen Activator Receptor (suPAR) as a Predictor of Incident Atrial Fibrillation

Soluble urokinase plasminogen activator receptor (suPAR) is a biomarker of chronic low-grade inflammation and a potent predictor of cardiovascular events. We hypothesized that plasma suPAR levels would predict new-onset atrial fibrillation (AF) in a large cohort of con-secutively admitted acute medical patients during long-term follow-up. In 14,764 acutely ad-mitted patients without prior or current AF, median suPAR measured upon admission was 2.7 ng/ml (interquartile range (IQR) 1.9-4.0). During a median follow-up of 392 days (IQR 218-577), 349 patients (2.4%) were diagnosed with incident AF. suPAR levels at admission significantly predicted subsequent incident AF (HR per doubling of suPAR: 1.21, 95% CI 1.05-1.41, adjusted for age and sex). After further adjustment for Charlson score, plasma C-reactive protein (CRP), plasma creatinine and blood hemoglobin-levels, the result remained essentially unaltered (HR per doubling of suPAR: 1.20, 95% CI: 1.01-1.42). In multivariate ROC curve analysis, combining age, sex, Charlson score, CRP, creatinine, and hemoglobin (AUC 0.77, 95% CI 0.75-0.79), the addition of suPAR did not improve the prediction of incident AF (AUC 0.77, 95% CI 0.75-0.79, P=0.89). Plasma suPAR is independently associated with subsequent new-onset AF in a population of recently hospitalized patients, but the addition of suPAR to baseline risk markers appears not to improve the prediction of AF.