Predictive Value of Point-of-Care Proenkephalin for Worsening Renal Function and Mortality in Patients Presenting to Emergency Department with Acute Heart Failure.

Enkephalins are endogenous opioid peptides that modulate cardiovascular and renal function and are overexpressed in patients with acute heart failure (AHF). Although biologically active enkephalins lack a favorable biomarker profile, their stable surrogate proenkephalin 119-159 (PENK) appears to display prognostic value in AHF settings. The aim of the present study was to evaluate the role of point-of-care (POC) PENK in predicting mortality and worsening renal function (WRF) in patients presenting to the emergency department (ED) with AHF. In this single-center observational study, 107 patients presenting to the ED with AHF were prospectively enrolled. We measured PENK levels upon ED presentation with a commercially available POC immunoassay and investigated their association with WRF within 48 h and all-cause mortality during a 1-year follow-up. The patients had a mean age of 72 ± 13 years, and 58% were men. Moreover, 62% had acutely decompensated chronic heart failure (HF), 24% had pulmonary edema, 9% had cardiogenic shock, and 5% had right HF. The median PENK levels were 111 [60-193] pmol/L. PENK was independently associated with WRF (adjusted OR, 95% CI: 15.4 [2.0-120.2]; = 0.009), with levels of ≥90.5 pmol/L identified as the optimal cut-off for predicting WRF (AUC: 0.690; < 0.001). PENK was also an independent predictor of short- and long-term all-cause mortality, with an optimal cut-off of ≥95.8 pmol/L (AUC for 30-day, 90-day, and 1-year mortality: 0.717, 0.723, and 0.724, respectively; all < 0.001). In patients presenting to the ED with AHF, POC PENK may serve as an early prognostic marker of WRF and short- and long-term mortality.