title: The alveolar to arterial oxygen partial pressure difference is associated with pulmonary diffusing capacity in heart failure patients.
abstract: In chronic heart failure (HF), the alveolar-capillary membrane undergoes a remodeling process that negatively affects gas exchange. In case of alveolar-capillary gas diffusion impairment, arterial desaturation (SaO2) is rarely observed in HF patients. At play are 3 factors: overall pulmonary diffusing capacity (assessed as lung diffusion for CO, DLCO), global O2consumption (VO2) and alveolar (A) to arterial (a) pO2gradient (AaDO2). In 100 consecutive stable HF patients, DLCO, resting respiratory gases and arterial blood gases were measured to determine VO2,paO2, pAO2and AaDO2. DLCO was poorly but significantly related to AaDO2. The correlation improved after correcting AaDO2for VO2(p<0.001, r=0.49). Both VO2and AaDO2were independently associated with DLCO (p<0.001). Patients with reduced DLCO showed no differences as regards paO2and pAO2. AaDO2/VO2showed a higher gradient in patients with lower DLCO. AaDO2increase and VO2reduction allow preventing low SaO2in HF patients with reduced DLCO. Accordingly, we suggest considering AaDO2and VO2combined and reporting AaDO2/VO2.
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy; Cardiovascular Dept. "Ospedali Riuniti" Trieste and Postgraduate School Cardiovascular Sciences, University of Trieste, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Morosin
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Vignati
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Novi
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Salvioni
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Veglia
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: Alimento
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy.
authors.forename: Guido
authors.initials: G
authors.lastname: Merli
authors.affiliation: Dipartimento di Scienze Cardiovascolari e Respiratorie, "Sapienza", Rome University, Rome, Italy.
authors.forename: Susanna
authors.initials: S
authors.lastname: Sciomer
authors.affiliation: Cardiovascular Dept. "Ospedali Riuniti" Trieste and Postgraduate School Cardiovascular Sciences, University of Trieste, Italy.
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Sinagra
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy; Dept. of Clinical Sciences and Community Health, Cardiovascular Section, University of Milano, Milano, Italy. Electronic address: piergiuseppe.agostoni@unimi.it.
authors.forename: Piergiuseppe
authors.initials: P
authors.lastname: Agostoni
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001784:Blood Gas Analysis; D015331:Cohort Studies; D005080:Exercise Test; D005260:Female; D006333:Heart Failure / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption / Q000502:physiology; D010313:Partial Pressure; D011650:Pulmonary Alveoli / Q000503:physiopathology*; D011653:Pulmonary Diffusing Capacity / Q000502:physiology*; D011659:Pulmonary Gas Exchange; D012044:Regression Analysis; D014797:Vital Capacity / Q000502:physiology
chemical_list: D010100:Oxygen
keywords: Arterial-alveolar oxygen gradient; Cardiopulmonary exercise testing; Diffusing capacity for carbon monoxide; Heart failure; Peak VO(2)