H2 relaxin expression and its effect on clinical outcomes in patients with chronic heart failure

To investigate the expression of H2 Relaxin (H2RLX) in chronic heart failure (CHF) patients and determine whether H2RLX level can predict cardiovascular events in CHF patients within 180 days after discharge. One hundred forty-six patients were selected for examination from July 2012 to January 2014. The CHF group included a total of 115 patients, while the control group comprised a total of 31 patients without CHF. In the early morning on the first day after admission, patients' blood samples were obtained for measuring levels of brain natriuretic peptide (BNP), LDL-cholesterol, haemoglobin, fasting blood glucose, thyroid stimulating hormone, and creatinine clearance rate (Ccr). Enzyme-linked immunosorbent assay was performed to analyse the plasma concentration of H2RLX, collagen I, and collagen III. Echocardiography was used to estimate left ventricular ejection fraction. We followed patients for 6 months to record cardiovascular events (asymptomatic, symptomatic, re-hospitalisation for heart failure, and cardiac death). Plasma H2RLX in CHF patients was significantly higher than that in the control group (0.593 [0.542-0.644] vs. 0.390 [0.355-0.425] pg/mL; P < 0.01). With elevated cardiac dysfunction, plasma concentrations of both collagen I and H2RLX increased in all patients. Moreover, there was a significant correlation between H2RLX and collagen I (r = 0.890, P < 0.001). The area under the receiver operating characteristic (ROC) curve for prognosis was 0.816 (P < 0.01), suggesting that plasma H2RLX level predicts severe cardiovascular events (re-hospitalisation and cardiac death) within 180 days after discharge. Elevated H2RLX levels in CHF patients may be associated with disease severity, and H2RLX level may predict cardiovascular events in CHF patients within 180 days after discharge.