Objective: To investigate how many patients with acute heart failure (AHF) hypersecrete relaxin-2 concentrations similar to those of pregnant women and determine their long-term outcome.
Methods: In consecutive AHF patients relaxin-2 was quantified by ELISA sandwich method. Patients were divided into pregnancy-like group (PLG, relaxin-2 ≥ 500 pg/mL) and control group (CG, relaxin-2 < 500 pg/mL). The primary outcome was all-cause death during follow-up. Secondary endpoints were prolonged hospitalisation (>10 days), combined endpoint (death, rehospitalisation, ED revisit) 30 days after discharge, and 30-day, one-year and three-year death rates.
Results: We included 814 patients [81 (SD = 9) years; 53.0% women] followed during 1.9 (SD 2.8) years; 517 (63.5%) died. Twenty patients (2.5%) formed the PLG (median relaxin-2 = 1459 pg/mL; IQR = 1722) and 794 the CG (median = 26; IQR = 44). There was no interaction with variables included on adjustment (age, sex, ischaemic cardiomyopathy, NT-proBNP, glycaemia, and sodium). PLG patients did not have better short-term secondary endpoints, but did show a significantly lower three-year mortality [ORadjusted = 0.17 (0.05-0.5), p = 0.003].
Conclusions: The small proportion of AHF patients achieving relaxin-2 concentrations similar to those observed in pregnancy may survive longer.
Keywords: Relaxin-2; acute heart failure; biomarker; emergency department; survival.