Janka Franeková

Association of Fibroblast Growth Factor-23 Levels and Angiotensin-Converting Enzyme Inhibition in Chronic Systolic Heart Failure.

OBJECTIVES The aim of this study was to evaluate the association of fibroblast growth factor (FGF)-23 with clinical and laboratory findings, the prognostic value of FGF-23, and the relationship between angiotensin-converting enzyme inhibitor (ACEi) therapy, FGF-23 levels, and outcomes in patients with chronic systolic heart failure (HF). BACKGROUND FGF-23 is a bone-derived hormone regulating mineral metabolism. Higher FGF-23 levels are associated with an increased risk of cardiovascular mortality or HF development. Mechanisms leading to increased FGF-23 and its prognostic value have not been thoroughly studied in HF. METHODS FGF-23 was measured in 369 patients (mean age 59 ± 11 years, 84% male) with systolic HF. Patients were followed for adverse events (e.g., death, urgent heart transplantation, ventricular assist device implantation). RESULTS Tricuspid regurgitation severity, chronic kidney disease (CKD), alkaline phosphatase concentrations, inferior vena cava dilation, and absence of ACEi therapy were independently associated with FGF-23. FGF-23 was independently associated with outcomes in patients without CKD (hazard ratio [HR]: 1.43, 95% confidence interval [CI]: 1.14 to 1.78), but not in CKD patients (HR: 1.12, 95% CI: 0.87 to 1.45). In patients without CKD and with FGF-23 in the highest tertile, ACEi therapy was associated with a lower risk of adverse events (HR: 0.42, 95% CI: 0.21 to 0.81), whereas no association was seen in the remaining patients (HR: 1.18, 95% CI: 0.52 to 2.70). CONCLUSIONS In systolic HF, elevated FGF-23 is an independent predictor of adverse events, particularly in patients with preserved renal function. The association of FGF-23 with adverse events likely reflects early alterations of renal hemodynamics and renin-angiotensin system activation. Increased FGF-23 may identify a subset of HF patients benefiting from ACEi therapy.

Analytical evaluation of the automated galectin-3 assay on the Abbott ARCHITECT immunoassay instruments.

Abstract Background: Galectin-3 is secreted from macrophages and binds and activates fibroblasts forming collagen. Tissue fibrosis is central to the progression of chronic heart failure (CHF). We performed a European multicentered evaluation of the analytical performance of the two-step routine and Short Turn-Around-Time (STAT) galectin-3 immunoassay on the ARCHITECT i1000SR, i2000SR, and i4000SR (Abbott Laboratories). Methods: We evaluated the assay precision and dilution linearity for both routine and STAT assays and compared serum and plasma, and fresh vs. frozen samples. The reference interval and biological variability were also assessed. Measurable samples were compared between ARCHITECT instruments and between the routine and STAT assays and also to a galectin-3 ELISA (BG Medicine). Results: The total assay coefficient of variation (CV%) was 2.3%–6.2% and 1.7%–7.4% for the routine and STAT assays, respectively. Both assays demonstrated linearity up to 120 ng/mL. Galectin-3 concentrations were higher in plasma samples than in serum samples and correlated well between fresh and frozen samples (R=0.997), between the routine and STAT assays, between the ARCHITECT i1000 and i2000 instruments and with the galectin-3 ELISA. The reference interval on 627 apparently healthy individuals (53% male) yielded upper 95th and 97.5th percentiles of 25.2 and 28.4 ng/mL, respectively. Values were significantly lower in subjects younger than 50 years. Conclusions: The galectin-3 routine and STAT assays on the Abbott ARCHITECT instruments demonstrated good analytical performance. Further clinical studies are required to demonstrate the diagnostic and prognostic potential of this novel marker in patients with CHF.

Prolyl-hydroxyproline dipeptide in non-hydrolyzed morning urine and its value in postmenopausal osteoporosis.

Abstract Background: Owing to the high correlation between the level of prolyl-4-hydroxyproline dipeptide in non-hydrolyzed urine and that of 4-hydroxyproline in hydrolyzed urine, we examined whether the dipeptide might function as a valuable marker of bone turnover. Methods: Based on densitometric measurements, 68 postmenopausal women were divided into groups of non-osteopathic, osteopenic and osteoporotic subjects. The dipeptide and current urinary resorption markers were assayed in morning urine, the former using liquid chromatography, the others plus serum formation markers by means of immunoassay procedures. Together with the assay of basal levels, diet-related changes and healing effect of yearly alendronate therapy were assessed. Results: Concentration levels in controls and osteoporotic subjects differed significantly; receiver operating characteristics yielded sensitivity of 0.743, specificity of 0.908, area under curve of 0.903, and cut-off of 10.2 μmol/mmol of creatinine. Spearman rank correlation showed the highest pair coefficient between the dipeptide and osteocalcin. Diet-related changes were not found. Following therapy, a significant decline occurred already within a trimester, whilst with the other resorption markers not until 6 months. Conclusions: The ease of the dipeptide assay in non-hydrolyzed urine surpasses that of hydroxyproline, and the results present the compound as a real competition to other commonly assessed markers in osteopathies. Clin Chem Lab Med 2008;46:1391–7.

The role of timely measurement of galectin-3, NT-proBNP, cystatin C and hsTnT in predicting prognosis and heart function after heart transplantation.

Abstract Background: Changes of biomarkers measured soon after heart transplantation (HTx) can reflect different processes: cardiomyocyte necrosis (troponins, high-sensitivity cardiac TnT and TnI), heart function (natriuretic peptides, BNP and NT-proBNP), fibrosis (galectin-3 and ST2), and global cardiorenal risk (cystatin C). We assessed the prognostic role of hsTnT, NT-proBNP, galectin-3 and cystatin C during the early post-transplant period. Methods: A total of 121 consecutive post-HTx patients were assessed. The main outcomes were survival, left ventricular ejection fraction (LVEF) and rejection periods. Survival was assessed after intermediate (12 months) and long periods (total follow-up during study, median of survival 763 days, IR 527–1038 days). LVEF was assessed 12 months after HTx. Rejection was evaluated during follow-up. We report biomarker concentrations measured 10 days and 12 months after HTx. Results: Ten days after HTx, cystatin C and hsTnT predicted death both under univariable and multivariable analysis. These two biomarkers along with galectin-3 were increased in patients with decreased LVEF measured 1 year after HTx. NT-proBNP did not show early prognostic power. None of the measured biomarkers predicted rejection, but hsTnT and NT-proBNP were increased significantly 12 months after HTx in patients with at least one rejection. Conclusions: Cystatin C and hsTnT measured 10 days after HTx can provide prognostic information on survival and galectin-3 measured at the same time may display a relationship to heart function assessed 1 year after HTx. Further study should be carried out in a large cohort of patients.

Comparison of Cystatin C and NGAL in Early Diagnosis of Acute Kidney Injury After Heart Transplantation

BACKGROUND Acute kidney injury (AKI) is a risk factor for adverse hospital outcomes in recipients of a heart transplantation (HTx). Timely recognition of AKI is crucial for the initiation of proper treatment. We hypothesized that serum or urine biomarkers can predict AKI. MATERIAL AND METHODS In this prospective study we evaluated 117 consecutive patients after HTx. AKI was defined as an increase of the serum creatinine level by ≥50% or a worsening of the renal function requiring renal replacement therapy during the first post-HTx week. We serially sampled serum cystatin C (S-cystatin C) as a marker of glomerular filtration and urinary neutrophil gelatinase-associated lipocalin (U-NGAL) as a marker of tubular damage. RESULTS A cohort of 30 patients (25.6%) fulfilled the criteria of AKI. S-cystatin C allowed the earliest separation between the AKI and non-AKI groups, with a significant difference present as soon as 3 h after surgery and it persisted on days 7, 10, and 30. The increase in S-cystatin C preceded the serum creatinine elevation by 4 days. In a multivariate analysis, S-cystatin C >1.6 mg/L at 3 h after HTx predicted AKI with OR 4.3 (95% CI: 1.6-11.5). U-NGAL was significantly higher at day 3 in the AKI group (p=0.003) and elevated S-cystatin C (≥2.54 mg/L on day 7) could predict 1-year mortality in these HTx recipients. CONCLUSIONS Our study showed that the measurement of S-cystatin C at 3 h after surgery may help to identify patients with high risk for renal complications. A persistent elevation of S-cystatin C also predicts 1-year mortality.

A Novel Biomarker‐Based Approach for the Detection of Asymptomatic Brain Injury During Catheter Ablation of Atrial Fibrillation

Diffusion‐weighted magnetic resonance imaging (DW‐MRI) is a widely used method for studying of asymptomatic brain injury during catheter ablation of atrial fibrillation (AF). However, this technique lacks sensitivity for subtle or diffuse brain lesions. We investigated whether detection of the ablation‐related brain injury can improve by assessment of a biomarker of brain damage—protein S100B.

Free light chain and intact immunoglobulin abnormalities in heart transplant recipients: Two year follow-up timelines and clinical correlations

OBJECTIVES To assess the timelines of serum free light chain (sFLC) concentrations and the kappa/lambda light chain (K/L) ratio in heart transplant (HTX) recipients. To analyze the performance of serum protein electrophoresis (SPE), serum immunofixation (sIFE) and sFLC measurements for gammopathy detection following a HTX. METHODS A total of 96 patients who underwent a HTX were analyzed during a two-year follow-up period. The relevant clinical data were obtained from patient medical records. SPE, sIFE and sFLC methods were used for the detection of free light chain and intact immunoglobulin gammopathies at 4 time points after HTX. RESULTS A statistically significant decrease in sFLC K and L (a decrease of 39.1% and 27.6%, respectively, when compared to pretransplant values) was found 9months after the HTX (p<0.001, Friedman test). We detected SPE or sIFE abnormalities in 23 (8.4%) samples, and sFLC K/L ratio abnormalities in 34 (12.4%) samples. All of the K/L ratio abnormalities had normal SPE/sIFE values, and 19% of the findings were persistent. CONCLUSIONS A significant and consistent dynamics in the sFLC concentration was found in the HTX patients during a 2-year follow-up period, which reflected changes in the immunosuppressant dosage. A remarkable number of monoclonal and polyclonal gammopathies was identified with some persistent abnormalities, using the SPE/sIFE and sFLC methods. Some of the detected abnormalities, which might possess a higher risk for PTLD if interpreted according to common practice in nonTX patients can only be detected by sFLC methods.

Glucose Homeostasis, Pancreatic Endocrine Function, and Outcomes in Advanced Heart Failure

Background The mechanisms and relevance of impaired glucose homeostasis in advanced heart failure (HF) are poorly understood. The study goals were to examine glucose regulation, pancreatic endocrine function, and metabolic factors related to prognosis in patients with nondiabetic advanced HF. Methods and Results In total, 140 advanced HF patients without known diabetes mellitus and 21 sex‐, age‐, and body mass index–matched controls underwent body composition assessment, oral glucose tolerance testing, and measurement of glucose‐regulating hormones to model pancreatic β‐cell secretory response. Compared with controls, HF patients had similar fasting glucose and insulin levels but higher levels after oral glucose tolerance testing. Insulin secretion was not impaired, but with increasing HF severity, there was a reduction in glucose, insulin, and insulin/glucagon ratio—a signature of starvation. The insulin/C‐peptide ratio was decreased in HF, indicating enhanced insulin clearance, and this was correlated with lower cardiac output, hepatic insufficiency, right ventricular dysfunction, and body wasting. After a median of 449 days, 41% of patients experienced an adverse event (death, urgent transplant, or assist device). Increased glucagon and, paradoxically, low fasting plasma glucose displayed the strongest relations to outcome (P=0.01). Patients in the lowest quartile of fasting plasma glucose (3.8–5.1 mmol·L−1, 68–101 mg·dL−1) had 3‐times higher event risk than in the top quartile (6.0–7.9 mmol·L−1, 108–142 mg·dL−1; relative risk: 3.05 [95% confidence interval, 1.46–6.77]; P=0.002). Conclusions Low fasting plasma glucose and increased glucagon are robust metabolic predictors of adverse events in advanced HF. Pancreatic insulin secretion is preserved in advanced HF, but levels decrease with increasing HF severity due to enhanced insulin clearance that is coupled with right heart failure and cardiac cachexia.

Procalcitonin Dynamics After Long-Term Ventricular Assist Device Implantation

BACKGROUND Infectious complications (IC) are one of the main causes of worsening prognosis after long-term ventricular assist device (LVAD) implantation. Procalcitonin (PCT) is widely used for diagnosis of a bacterial infection. The objective of this study was to assess PCT dynamics after LVAD surgery and their relationship to the infectious complications. METHODS A total of 25 consecutive patients indicated for LVAD implantation as a bridge to heart transplant were included. Procalcitonin levels were prospectively assessed before surgery and during the postoperative period (day 1, 2, 14 and 30). Values were compared according to the presence of IC. RESULTS Procalcitonin levels were low before surgery, raised significantly within 1st and 2nd day after operation and decreased in the 14th and 30th days back to the baseline. There was no significant difference in PCT values between patients with or without IC as well as with or without right ventricle assist device (RVAD). Acute renal failure (ARF) increased PCT significantly only 14 days after LVAD implantation. In patients with ARF and/or RVAD we observed significantly higher PCT values in the 2nd, 14th and 30th day after operation. In subjects with IC and/or ARF and/or RVAD we also observed significantly elevated PCT concentrations 2 and 14 days after surgery. CONCLUSIONS Our data show that the ability of PCT to detect IC in patients after LVAD implantation is limited and its concentrations more likely correlate with postoperative complications in general.

Serial measurement of presepsin, procalcitonin, and C-reactive protein in the early postoperative period and the response to antithymocyte globulin administration after heart transplantation

Differentiation between systemic inflammatory response syndrome and sepsis in surgical patients is of crucial significance. Procalcitonin (PCT) and C‐reactive protein (CRP) are widely used biomarkers, but PCT becomes compromised after antithymocyte globulin (ATG) administration, and CRP exhibits limited specificity. Presepsin has been suggested as an alternative biomarker of sepsis. This study aimed to demonstrate the role of presepsin in patients after heart transplantation (HTx). Plasma presepsin, PCT, and CRP were measured in 107 patients serially for up to 10 days following HTx. Time responses of biomarkers were evaluated for both noninfected (n=91) and infected (n=16) patients. Areas under the concentration curve differed in the two groups of patients for presepsin (P<.001), PCT (P<.005), and CRP (P<.001). The effect of time and infection was significant for all three biomarkers (P<.05 all). In contrast to PCT, presepsin was not influenced by ATG administration. More than 25% of noninfected patients had PCT above 42 μg/L on the first day, and the peak concentration of CRP in infected patients was reached on the third post‐transplant day (median 135 mg/L). Presepsin seems to be as valuable a biomarker as PCT or CRP in the evaluation of infectious complications in patients after HTx.