Fibroblast growth factor 23 in patients with acute dyspnea: Data from the Akershus Cardiac Examination (ACE) 2 Study

Circulating MicroRNA-210 Concentrations in Patients with Acute Heart Failure: Data from the Akershus Cardiac Examination 2 Study

BACKGROUND

MicroRNA (miR)-210 expression is induced by acute and chronic hypoxia and provides prognostic information in patients with aortic stenosis and acute coronary syndrome. We hypothesized that circulating miR-210 concentrations could provide diagnostic and prognostic information in patients with acute heart failure (HF).

METHODS

We measured miR-210 concentrations in serum samples on admission from 314 patients hospitalized for acute dyspnea and 9 healthy control subjects. The diagnostic and prognostic properties of miR-210 were tested in patients after adjudication of all diagnoses and with median follow-up of 464 days.

RESULTS

All patients and control subjects had miR-210 concentrations within the range of detection, and the analytical variation was low as the coefficient of variation of synthetic spike-in RNA was 4%. Circulating miR-210 concentrations were increased in patients with HF compared to healthy control subjects, but miR-210 concentrations did not separate patients with acute HF (n = 143) from patients with non-HF-related dyspnea (n = 171): the area under the curve was 0.50 (95% CI 0.43-0.57). Circulating miR-210 concentrations were associated with mortality (n = 114) after adjustment for clinical risk factors (hazard ratio 1.65 [95% CI 1.03-2.62] per unit miR-210 increase), but this association was attenuated and not significant after adjustment for established cardiac protein biomarkers.

CONCLUSIONS

Circulating miR-210 concentrations are associated with mortality, but do not add to established protein biomarkers for diagnosis or prognosis in patients with acute dyspnea.

FGF23: Clinical usefulness and analytical evolution

Fibroblast Growth Factor 23 (FGF23) is a key hormone for the regulation of phosphate homeostasis. Over the past decades, FGF23 was the subject of intense research in the fields of nephrology and the cardiology. It presents a remarkable correlation with well-established biomarkers of cardiovascular disorders in both chronic kidney disease (CKD) and heart failure (HF) patients. The interest of FGF23 lies in its early-onset in the primary course of CKD as well as in the incremental prognosis information it conveys in both CKD and HF. Different types of assays of FGF-23 testing exist, those targeting the intact form (iFGF23), the other one detecting terminal fragments (cFGF23). The issue is still pending which assay suits best for clinical use. Recently, the implementation of this biomarker on multianalyzer platforms, on which other markers of phospho-calcic balance are set up, allows a rapid turn-around-time and a potential financial gain. However, despite the good analytical performances of the automated methods, there is a poor harmonization between assays. The introduction of an international certified reference material should standardize the measurement and improve the harmonization of results from different laboratories. A deeper understanding of physio-pathological mechanisms and processing of FGF-23 should reinforce its clinical indications and might also identify new therapeutic targets for the treatment of CKD and HF.

Incremental value of intact fibroblast growth factor 23 to natriuretic peptides for long-term risk estimation of heart failure patients

Fibroblast growth factor 23 (FGF-23), a key hormone for the regulation of the phosphorus homeostasis, has also several direct effects on cardiac function. In heart failure (HF), the increase of FGF-23 participates to cardiac hypertrophy and remodeling. Measurement of the intact, biologically active hormone is now available. We determined intact FGF-23 in HF patients with reduced ejection fraction and assess its prognosis value for cardiovascular death over a long-term follow-up. We observed that intact FGF-23 is an independent predictor of cardiovascular death in HF patients and provides added value to the standard of care, natriuretic peptide, for risk estimation.