Aims In chronic heart failure (CHF) patients, the ventilation (VE) needed to eliminate metabolically produced CO2 during exercise (i.e. the VE/VCO2 slope) is a strong prognosticator. VE/Vco(2) slope determinants are the dead space-tidal volume (VD/VT) ratio and the arterial CO2 partial pressure (Paco(2)). We aimed at defining the respective prognostic role of these two variables. Methods and results One hundred and twenty-eight stable CHIF patients (average left ventricular ejection fraction 34 &PLUSMN; 10%) underwent cardiopulmonary exercise testing and blood gas analysis. The prognostic relevance of the VE/Vco(2) slope, VD/VT, and Paco(2) at peak exercise was evaluated by the Kaptan-Meier approach with Log-rank testing and by multivariate Cox regression analysis, During a mean period of 31.3 &PLUSMN; 20 months, 24 patients died from cardiac causes. In univariate analysis, predictors of death included the use of anti-aldosterone drugs, low peak Vo(2), peak Ve/Vo(2), peak Paco(2) and high VE/VCO2 slope, and peak VD/VT. Multivariate analysis identified a low peak Paco(2) (< 35 mmHg) as the strongest independent prognostic indicator [hazard ratio 4.65, 95% confidence interval (CI) (1.695 12.751), P = 0.003] that primarily accounts for the VE/Vco(2) slope prognostic power. Conclusion These findings imply that regulatory mechanisms involved in the tight control of ventilatory command and blood gas tension, rather than lung function abnormalities, play a critical pathophysiological. rote in the exercise ventilation inefficiency of CHF patients.

Exercise ventilation inefficiency and cardiovascular mortality in heart failure : the critical independent prognostic value of the arterial CO2 partial pressure / M. Guazzi, G. Reina, G. Tumminello, M.D. Guazzi. - In: EUROPEAN HEART JOURNAL. - ISSN 0195-668X. - 26:5(2005), pp. 472-480.

Exercise ventilation inefficiency and cardiovascular mortality in heart failure : the critical independent prognostic value of the arterial CO2 partial pressure

M. Guazzi
Primo
;
G. Reina
Secondo
;
M.D. Guazzi
Primo
2005

Abstract

Aims In chronic heart failure (CHF) patients, the ventilation (VE) needed to eliminate metabolically produced CO2 during exercise (i.e. the VE/VCO2 slope) is a strong prognosticator. VE/Vco(2) slope determinants are the dead space-tidal volume (VD/VT) ratio and the arterial CO2 partial pressure (Paco(2)). We aimed at defining the respective prognostic role of these two variables. Methods and results One hundred and twenty-eight stable CHIF patients (average left ventricular ejection fraction 34 &PLUSMN; 10%) underwent cardiopulmonary exercise testing and blood gas analysis. The prognostic relevance of the VE/Vco(2) slope, VD/VT, and Paco(2) at peak exercise was evaluated by the Kaptan-Meier approach with Log-rank testing and by multivariate Cox regression analysis, During a mean period of 31.3 &PLUSMN; 20 months, 24 patients died from cardiac causes. In univariate analysis, predictors of death included the use of anti-aldosterone drugs, low peak Vo(2), peak Ve/Vo(2), peak Paco(2) and high VE/VCO2 slope, and peak VD/VT. Multivariate analysis identified a low peak Paco(2) (< 35 mmHg) as the strongest independent prognostic indicator [hazard ratio 4.65, 95% confidence interval (CI) (1.695 12.751), P = 0.003] that primarily accounts for the VE/Vco(2) slope prognostic power. Conclusion These findings imply that regulatory mechanisms involved in the tight control of ventilatory command and blood gas tension, rather than lung function abnormalities, play a critical pathophysiological. rote in the exercise ventilation inefficiency of CHF patients.
Heart failure; PaCO2; Prognosis; Ventilation
Settore MED/01 - Statistica Medica
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/2434/12248
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