title: Plasma immature form of surfactant protein type B correlates with prognosis in patients with chronic heart failure. A pilot single-center prospective study.
abstract: BACKGROUND
  Gas exchange abnormalities are part of the heart failure (HF) syndrome and growing interest raised on possible biomarkers of alveolar-capillary unit damage. The present pilot single-center study sought to investigate the prognostic values of circulating surfactant protein type B (SP-B) in a cohort of systolic HF patients.
  
  
  METHODS
  One hundred and fifty-one HF stable outpatients and 37 healthy subjects underwent a full clinical assessment, including pulmonary function and lung diffusion for carbon monoxide (DLco), maximal cardiopulmonary exercise test and measurements for both circulating immature and mature forms of SP-B. Study end-points were hospitalization due to HF worsening and cardiovascular mortality.
  
  
  RESULTS
  Immature SP-B, but not the mature form, was significantly higher in HF patients than in controls and was independently related to DLco, peak oxygen uptake and ventilatory efficiency. During the follow-up (median: 995 days; interquartile range: 739-1247 days), 97 patients experimented at least one HF hospitalization and 9 died for cardiovascular causes. At univariate analysis immature SP-B levels were significantly related to both cardiovascular death (p=0.033) and HF hospitalization (p<0.001). At multivariate analysis, immature SP-B levels remained independently associated to HF hospitalization (hazard ratio: 2.304; 95% confidence interval 1.858-3.019; p<0.001).
  
  
  CONCLUSIONS
  Present data confirm a strong relationship between circulating immature SP-B levels, gas exchange abnormalities and exercise limitations in stable HF as well as they are consistent with the use of immature SP-B in HF clinical risk assessment. Larger prospective studies are needed to confirm its prognostic role as well as to evaluate whether immature SP-B plasma concentration varies in response to specific treatment.
authors: Department of Clinical and Molecular Medicine, University "La Sapienza", Rome, Italy.
authors: Damiano
authors: D
authors: Magrì
authors: Centro Cardiologico Monzino, IRCCS, University of Milan, Italy.
authors: Cristina
authors: C
authors: Banfi
authors: Southampton Statistical Sciences Research Institute, School of Mathematics, University of Southampton, United Kingdom; Department of Public Institutions, Economy and Society, University "Roma Tre", Rome, Italy.
authors: Antonello
authors: A
authors: Maruotti
authors: Centro Cardiologico Monzino, IRCCS, University of Milan, Italy.
authors: Stefania
authors: S
authors: Farina
authors: Centro Cardiologico Monzino, IRCCS, University of Milan, Italy.
authors: Carlo
authors: C
authors: Vignati
authors: Centro Cardiologico Monzino, IRCCS, University of Milan, Italy.
authors: Elisabetta
authors: E
authors: Salvioni
authors: Centro Cardiologico Monzino, IRCCS, University of Milan, Italy; Cardiovascular Dept., "Ospedali Riuniti", Trieste, Postgraduate School of Cardiovascular Sciences, University of Trieste, Italy.
authors: Marco
authors: M
authors: Morosin
authors: Centro Cardiologico Monzino, IRCCS, University of Milan, Italy.
authors: Maura
authors: M
authors: Brioschi
authors: Centro Cardiologico Monzino, IRCCS, University of Milan, Italy.
authors: Stefania
authors: S
authors: Ghilardi
authors: Centro Cardiologico Monzino, IRCCS, University of Milan, Italy.
authors: Elena
authors: E
authors: Tremoli
authors: Centro Cardiologico Monzino, IRCCS, University of Milan, Italy; Department of Clinical Sciences and Community Health, University of Milan, Italy. Electronic address: piergiuseppe.agostoni@unimi.it.
authors: Piergiuseppe
authors: P
authors: Agostoni
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D002908:Chronic Disease; D015444:Exercise / Q000502:physiology; D005080:Exercise Test / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D054143:Heart Failure, Systolic / Q000097:blood* / Q000188:drug therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood*; D011510:Proteolipids / Q000097:blood*; D011659:Pulmonary Gas Exchange / Q000502:physiology; D012129:Respiratory Function Tests / Q000379:methods
chemical_list: D015415:Biomarkers; D011498:Protein Precursors; D011510:Proteolipids; C105511:surfactant protein B propeptide
keywords: Alveolar–capillary unit; Cardiopulmonary exercise test; Heart failure; Lung diffusion; Prognosis; Surfactant protein type B