The subset of patients with acute heart failure able to secrete relaxin-2 at pregnancy concentrations could have a longer survival: a pilot study

<p><b>Objective:</b> 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.</p> <p><b>Methods:</b> 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.</p> <p><b>Results</b>: 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 [OR_adjusted = 0.17 (0.05–0.5), <i>p</i> = 0.003].</p> <p><b>Conclusions:</b> The small proportion of AHF patients achieving relaxin-2 concentrations similar to those observed in pregnancy may survive longer.