Are circulating relaxin levels related to pulmonary hypertension in patients with heart failure?

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“…This patient selection criterion may, on one hand, have hindered the establishment of differences in pulmonary and right heart pressures between groups. However, on the other hand, it supports our hypothesis of increased relaxin secretion to circulation in states of PH as relaxin levels in these patients (median: 82.3 pg/mL) were higher than have been described in most previous studies addressing relaxin levels in HF, including our own. The lack of relaxin levels below the detection limit of the assay, unlike in our study in which levels were undetectable in about 25% of patients, also strengthens this hypothesis.…”

“…We read with great interest the research letter from Emmens et al . and thank the authors for their comments on our recently published paper in this journal .…”

“…Emmens et al . evaluated relaxin circulating levels in a cohort of patients with heart failure (HF) with preserved ejection fraction (HFpEF) and pulmonary hypertension (PH) and found no association between relaxin groups and echocardiographically or invasively determined intracardiac pressures …”

“…These patients were heterogeneous with respect to the degree of volume overload, volume distribution and echocardiographic parameters of chamber dimensions and function, which allowed us to establish different patterns of pulmonary pressures and right heart overload among relaxin groups . In the study by Emmens et al ., all patients had chronic HFpEF with established PH. This patient selection criterion may, on one hand, have hindered the establishment of differences in pulmonary and right heart pressures between groups.…”

Relaxin-2 as a Potential Biomarker in Cardiovascular Diseases

“…The uncovering that serum relaxin-2 concentration is not increased in HFpEF patients is consonant with previous studies from shear stress and pressure models applied to pulmonary artery endothelial cells (a model of HFpEF), in which relaxin-2 levels remained unaltered [ 107 ]. In another study with chronic HFpEF patients, Emmens et al (2017) could not determine an association between circulant relaxin-2 levels and pulmonary artery pressure (PAP) and right-sided heart function, although relaxin-2 plasma levels were detectable in all patients and showed higher levels (median 82.3 pg/mL) than previous studies ( Table 2 ), suggesting an increase in circulant relaxin-2 levels during pulmonary hypertension [ 104 ]. Relaxin-2 is considered a functional antagonist of the vasoconstrictor effect of endothelin-1 due to its ability to inhibit endothelin-1 secretion when administered in a flow-chamber model of bovine pulmonary endothelial cells [ 70 , 108 ].…”