BACKGROUND: During cardiopulmonary exercise test, the isocapnic buffering period ranges between anaerobic threshold (AT) and respiratory compensation point (RCP). We investigated whether oxygen uptake (VO2) increase during the isocapnic buffering period (ΔVO2AT-RCP) is related to heart failure severity and prognosis. METHODS: We retrospectively analysed reduced ejection fraction heart failure patients who attained RCP at cardiopulmonary exercise test. The study endpoint was the composite of cardiovascular mortality and urgent heart transplantation/left ventricular assist device implantation. Hazard ratio was assessed to identify the increase of risk associated with ΔVO2AT-RCP (below and above the median of ΔVO2AT-RCP). RESULTS: AT and RCP were both identified in 782 (39.2%) out of 1995 reduced ejection fraction heart failure cases. Left ventricular ejection fraction and peak VO2 were 33 ± 9% and 16.5 ± 4.5 mL/kg per min (61 ± 16% of predicted value), suggesting moderate heart failure. At five years, endpoint did not vary between patients below and above the median ΔVO2AT-RCP (3.85 mL/min per kg (25-75th interquartile range = 2.69-5.46)). ΔVO2AT-RCP correlated with several parameters associated to heart failure prognosis, such as peak VO2, VE/VCO2 slope, brain natriuretic peptide and left ventricular ejection fraction. The ΔVO2AT-RCP value was associated with prognosis at univariate but not at multivariable analysis, where only VE/VCO2 slope endured. CONCLUSION: ΔVO2AT-RCP correlates with several parameters linked to heart failure severity. Isocapnic buffering period stratifies heart failure patients, but not more than other prognostic indices.

Isocapnic buffering period: from physiology to clinics

Carriere, Cosimo;Gentile, Piero;Sinagra, Gianfranco;
2019

Abstract

BACKGROUND: During cardiopulmonary exercise test, the isocapnic buffering period ranges between anaerobic threshold (AT) and respiratory compensation point (RCP). We investigated whether oxygen uptake (VO2) increase during the isocapnic buffering period (ΔVO2AT-RCP) is related to heart failure severity and prognosis. METHODS: We retrospectively analysed reduced ejection fraction heart failure patients who attained RCP at cardiopulmonary exercise test. The study endpoint was the composite of cardiovascular mortality and urgent heart transplantation/left ventricular assist device implantation. Hazard ratio was assessed to identify the increase of risk associated with ΔVO2AT-RCP (below and above the median of ΔVO2AT-RCP). RESULTS: AT and RCP were both identified in 782 (39.2%) out of 1995 reduced ejection fraction heart failure cases. Left ventricular ejection fraction and peak VO2 were 33 ± 9% and 16.5 ± 4.5 mL/kg per min (61 ± 16% of predicted value), suggesting moderate heart failure. At five years, endpoint did not vary between patients below and above the median ΔVO2AT-RCP (3.85 mL/min per kg (25-75th interquartile range = 2.69-5.46)). ΔVO2AT-RCP correlated with several parameters associated to heart failure prognosis, such as peak VO2, VE/VCO2 slope, brain natriuretic peptide and left ventricular ejection fraction. The ΔVO2AT-RCP value was associated with prognosis at univariate but not at multivariable analysis, where only VE/VCO2 slope endured. CONCLUSION: ΔVO2AT-RCP correlates with several parameters linked to heart failure severity. Isocapnic buffering period stratifies heart failure patients, but not more than other prognostic indices.
12-feb-2019
Pubblicato
https://journals.sagepub.com/doi/abs/10.1177/2047487319829950?rfr_dat=cr_pub=pubmed&url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&journalCode=cprc
File in questo prodotto:
File Dimensione Formato  
Isocapnic buffering period-2-9.pdf

non disponibili

Tipologia: Documento in Versione Editoriale
Licenza: Copyright Editore
Dimensione 3.74 MB
Formato Adobe PDF
3.74 MB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11368/2935907
Citazioni
  • ???jsp.display-item.citation.pmc??? 5
  • Scopus 9
  • ???jsp.display-item.citation.isi??? 9
social impact