title: Relaxin serum levels in acute heart failure are associated with pulmonary hypertension and right heart overload.
abstract: Despite the promising results of serelaxin as a new potential acute heart failure (HF) therapy, its clinical use preceded the understanding of the endogenous relaxin system in HF. We aimed to evaluate relaxin circulating levels in a population of acute HF and their association with clinical and echocardiographic parameters.
  
  
  
  We included 117 patients from a registry of acute HF. Admission serum relaxin was measured using an enzyme-linked immunosorbent assay (ELISA) kit. Clinical, analytical, and echocardiographic parameters were compared between patients with relaxin levels above and below the median. Median age was 82 years [interquartile range (IQR) 72-87], 41% of the patients were male, and 63% had systolic dysfunction. Median serum relaxin was 31.4 pg/mL (IQR 0.6-89.8). Patients with relaxin levels above the median had more peripheral oedema (89.8% vs. 68.4%, P = 0.004) and a significantly higher sodium retention score (mean 4.8 ± 1.5 vs. 3.6 ± 2.0, P < 0.001). These patients also had significantly higher systolic pulmonary arterial pressure [median 47.0 (IQR 36.0-61.0) vs. 34.5 (IQR 25.0-51.0) mmHg, P = 0.002], higher prevalence of right ventricular (RV) systolic dysfunction (28.1% vs. 10.3%, P = 0.02), RV dilation (31.0% vs. 5.3%, P < 0.001), and right atrial dilation (66.1% vs. 36.5%, P = 0.002), and less inferior vena cava diameter variability (40% vs. 60%, P = 0.009). No differences were noted regarding admission blood pressure, left chamber dimensions, or LV function.
  
  
  
  In our population of acute HF patients, admission relaxin serum levels were associated with clinical and echocardiographic markers of pulmonary hypertension, RV dysfunction, and overload, suggesting a role for circulating relaxin as a biomarker in this setting.
authors.affiliation: Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine, University of Porto, Portugal.|Internal Medicine Department, São João Hospital Centre, Porto, Portugal.|Cardiovascular Research Centre, Portugal.
authors.forename: Mariana
authors.initials: M
authors.lastname: Pintalhao
authors.affiliation: Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine, University of Porto, Portugal.|Internal Medicine Department, São João Hospital Centre, Porto, Portugal.|Cardiovascular Research Centre, Portugal.
authors.forename: Paulo
authors.initials: P
authors.lastname: Castro-Chaves
authors.affiliation: Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine, University of Porto, Portugal.|Internal Medicine Department, São João Hospital Centre, Porto, Portugal.|Cardiovascular Research Centre, Portugal.
authors.forename: Francisco
authors.initials: F
authors.lastname: Vasques-Novoa
authors.affiliation: Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine, University of Porto, Portugal.
authors.forename: Francisco
authors.initials: F
authors.lastname: Gonçalves
authors.affiliation: Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine, University of Porto, Portugal.|Cardiovascular Research Centre, Portugal.
authors.forename: Luís
authors.initials: L
authors.lastname: Mendonça
authors.affiliation: Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine, University of Porto, Portugal.|Cardiovascular Research Centre, Portugal.|Cardiology Department, Gaia Hospital Centre, Gaia, Portugal.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Fontes-Carvalho
authors.affiliation: Internal Medicine Department, São João Hospital Centre, Porto, Portugal.|Cardiovascular Research Centre, Portugal.
authors.forename: Patrícia
authors.initials: P
authors.lastname: Lourenço
authors.affiliation: Cardiology Department, São João Hospital Centre, Porto, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Almeida
authors.affiliation: Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine, University of Porto, Portugal.|Cardiovascular Research Centre, Portugal.|Cardiothoracic Surgery Department, São João Hospital Centre, Porto, Portugal.
authors.forename: Adelino
authors.initials: A
authors.lastname: Leite-Moreira
authors.affiliation: Internal Medicine Department, São João Hospital Centre, Porto, Portugal.|Cardiovascular Research Centre, Portugal.|Department of Medicine, Faculty of Medicine, University of Porto, Portugal.
authors.forename: Paulo
authors.initials: P
authors.lastname: Bettencourt
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D004452:Echocardiography; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006333:Heart Failure / Q000097:blood* / Q000150:complications; D006801:Humans; D006976:Hypertension, Pulmonary / Q000097:blood* / Q000150:complications; D008297:Male; D012042:Registries; D012065:Relaxin / Q000097:blood*; D018497:Ventricular Dysfunction, Right / Q000097:blood* / Q000150:complications
chemical_list: C095067:RLN1 protein, human; C095068:RLN2 protein, human; C480238:RLN3 protein, human; D012065:Relaxin
keywords: Acute heart failure; Circulating biomarker; Pulmonary hypertension; Relaxin; Right ventricular dysfunction