Impairment of ventilatory efficiency in heart failure: prognostic impact

Item Type:	Article
Title:	Impairment of ventilatory efficiency in heart failure: prognostic impact
Creators Name:	Kleber, F.X. and Vietzke, G. and Wernecke, K.D. and Bauer, U. and Opitz, C. and Wensel, R. and Sperfeld, A. and Glaeser, S.
Abstract:	BACKGROUND: Impairment of ventilatory efficiency in congestive heart failure (CHF) correlates well with symptomatology and contributes importantly to dyspnea. METHODS AND RESULTS: We investigated 142 CHF patients (mean NYHA class, 2.6; mean maximum oxygen consumption [VO(2)max], 15.3 mL O(2) x kg(-1) x min(-1); mean left ventricular ejection fraction [LVEF], 27%). Patients were compared with 101 healthy control subjects. Cardiopulmonary exercise testing was performed, and ventilatory efficiency was defined as the slope of the linear relationship of V(CO(2)) and ventilation (VE). Results are presented in percent of age- and sex-adjusted mean values. Forty-four events (37 deaths and 7 instances of heart transplantation, cardiomyoplasty, or left ventricular assist device implantation) occurred. Among VO(2)max, NYHA class, LVEF, total lung capacity, and age, the most powerful predictor of event-free survival was the VE versus V(CO(2)) slope; patients with a slope </=130% of age- and sex-adjusted normal values had a significantly better 1-year event-free survival (88.3%) than patients with a slope >130% (54.7%; P<0.001). CONCLUSIONS: The VE versus V(CO(2)) slope is an excellent prognostic parameter. It is easier to obtain than parameters of maximal exercise capacity and is of higher prognostic importance than VO(2)max.
Keywords:	Exercise Test, Follow-Up Studies, Heart Failure, Lung, Multivariate Analysis, Oxygen, Physical Endurance, Prognosis, Proportional Hazards Models, Respiration, Survival Analysis
Source:	Circulation
ISSN:	0009-7322
Publisher:	American Heart Association
Volume:	101
Number:	24
Page Range:	2803-2809
Date:	20 June 2000
Official Publication:	http://circ.ahajournals.org/cgi/content/abstract/101/24/2803
PubMed:	View item in PubMed

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