title: Independent and incremental prognostic value of endogenous ouabain in idiopathic dilated cardiomyopathy.
abstract: Increased circulating levels of endogenous ouabain (EO) have been observed in some heart failure patients, but their long term clinical significance is unknown. This study investigated the prognostic value of EO for worsening heart failure among 140 optimally treated patients (age 50+/-14 years; 104 male; NYHA class 1.9+/-0.7) with idiopathic dilated cardiomyopathy. Plasma EO was determined by RIA and by liquid chromatography mass spectrometry, values were linearly correlated (r = 0.89) in regression analysis. During follow-up (13+/-5 months), heart failure progression was defined as worsening clinical condition leading to one or more of the following: sustained increase in conventional therapies, hospitalization, cardiac transplant, or death. NYHA functional class, age, LVEF, peak VO2 and plasma levels of EO were predictive for heart failure progression. Heart failure worsened 1.5 fold (HR: 1.005; 95% CI: 1.001-1.007; p<0.01) for each 100 pmol/L increase in plasma EO. Moreover, those patients with higher plasma EO values had an odds ratio of 5.417 (95% CI: 2.044-14.355; p<0.001) for heart failure progression. Following multivariate analysis, LVEF, NYHA class and plasma EO remained significantly linked with clinical events. This study provides the first evidence that circulating EO is a novel, independent and incremental marker that predicts the progression of heart failure.
authors.affiliation: Institute of Cardiology, University of Bari, Bari, Italy.
authors.forename: Maria Vittoria
authors.initials: MV
authors.lastname: Pitzalis
authors.forename: John M
authors.initials: JM
authors.lastname: Hamlyn
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Messaggio
authors.forename: Massimo
authors.initials: M
authors.lastname: Iacoviello
authors.forename: Cinzia
authors.initials: C
authors.lastname: Forleo
authors.forename: Roberta
authors.initials: R
authors.lastname: Romito
authors.forename: Elisabetta
authors.initials: E
authors.lastname: de Tommasi
authors.forename: Paolo
authors.initials: P
authors.lastname: Rizzon
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Bianchi
authors.forename: Paolo
authors.initials: P
authors.lastname: Manunta
mesh_terms: D000704:Analysis of Variance; D002311:Cardiomyopathy, Dilated / Q000097:blood*; D016022:Case-Control Studies; D018450:Disease Progression; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D008875:Middle Aged; D010042:Ouabain / Q000097:blood*; D010101:Oxygen Consumption; D011379:Prognosis; D011446:Prospective Studies; D011863:Radioimmunoassay; D012044:Regression Analysis; D013318:Stroke Volume
chemical_list: D010042:Ouabain