Background: During cardiopulmonary exercise test, the isocapnic buffering period ranges between anaerobic threshold (AT) and respiratory compensation point (RCP). We investigated whether oxygen uptake (VO 2 ) increase during the isocapnic buffering period (ΔVO 2 AT-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 ΔVO 2 AT-RCP (below and above the median of ΔVO 2 AT-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 VO 2 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 ΔVO 2 AT-RCP (3.85 mL/min per kg (25–75th interquartile range = 2.69–5.46)). ΔVO 2 AT-RCP correlated with several parameters associated to heart failure prognosis, such as peak VO 2 , VE/VCO 2 slope, brain natriuretic peptide and left ventricular ejection fraction. The ΔVO 2 AT-RCP value was associated with prognosis at univariate but not at multivariable analysis, where only VE/VCO 2 slope endured. Conclusion: ΔVO 2 AT-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 / C. Carriere, U. Corrà, M. Piepoli, A. Bonomi, E. Salvioni, S. Binno, A. Magini, S. Sciomer, B. Pezzuto, P. Gentile, M. Schina, G. Sinagra, P. Agostoni. - In: EUROPEAN JOURNAL OF PREVENTIVE CARDIOLOGY. - ISSN 2047-4873. - (2019). [Epub ahead of print] [10.1177/2047487319829950]

Isocapnic buffering period: From physiology to clinics

P. Agostoni
Ultimo
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 (VO 2 ) increase during the isocapnic buffering period (ΔVO 2 AT-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 ΔVO 2 AT-RCP (below and above the median of ΔVO 2 AT-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 VO 2 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 ΔVO 2 AT-RCP (3.85 mL/min per kg (25–75th interquartile range = 2.69–5.46)). ΔVO 2 AT-RCP correlated with several parameters associated to heart failure prognosis, such as peak VO 2 , VE/VCO 2 slope, brain natriuretic peptide and left ventricular ejection fraction. The ΔVO 2 AT-RCP value was associated with prognosis at univariate but not at multivariable analysis, where only VE/VCO 2 slope endured. Conclusion: ΔVO 2 AT-RCP correlates with several parameters linked to heart failure severity. Isocapnic buffering period stratifies heart failure patients, but not more than other prognostic indices.
anaerobic threshold; exercise; Heart failure; isocapnic buffering period; Epidemiology; Cardiology and Cardiovascular Medicine
Settore MED/11 - Malattie dell'Apparato Cardiovascolare
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2434/630287
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