[Thoracic fluid content - a possible determinant of ventilatory efficiency in patients with heart failure].

Ventilatory efficiency, evaluated by cardiopulmonary exercise testing (CPET), has considerable prognostic value in patients with chronic heart failure (CHF) due to left ventricular systolic dysfunction (LVSD). Its determinants nevertheless remain controversial. To investigate the possible correlation between parameters of ventilatory efficiency obtained by CPET and thoracic fluid content (TFC), assessed by thoracic electrical bioimpedance (TEB), in patients with CHF due to LVSD. We studied 120 patients with LVSD and CHF, referred to our laboratory for CPET: 76% male, age 52.1 ± 12.1 years, 37% of ischemic etiology, left ventricular ejection fraction 27.6 ± 7.9%, 83% in sinus rhythm, 96% receiving ACEIs and/or ARBs and 79% beta-blockers, and 20% treated with a cardiac resynchronization device. TEB studies were performed after 15 minutes of rest, prior to symptom-limited treadmill CPET, using the modified Bruce protocol. CPET-derived peak oxygen consumption (pVO(2)), the slope of the relationship between minute ventilation (VE) and carbon dioxide production (VCO(2)), VE/VCO(2) at the anaerobic threshold (AT), and TFC assessed by TEB were considered for analysis. TFC ranged between 20.6 and 45.8kOhm-1, mean 32.2, SD=5.7, median 32.7, pVO(2) 8.9-40.6 ml/kg/min, mean 21.0, SD 6.2, median 20.2, VE/VCO(2) slope 19.8-60.7, mean 30.7, SD 7.9, median 29.1 and VE/VCO(2) at AT 21-62, mean 33.1, SD 7.5, median 31.5. By linear regression, TFC did not correlate with pVO(2) (r=0.05, p=0.58), but showed correlation with parameters of ventilatory efficiency: r=0.20, p=0.032, r(2)=0.04 for VE/VCO(2) slope and r=0.25, p=0.009, r(2)=0.06 for VE/VCO(2) at AT. TFC correlates with CPET parameters of ventilatory efficiency in patients with CHF due to LVSD, suggesting that it may be one of its determinants.

Tereno Valente B ，Feliciano J ，Soares R ，Toste A ，Ferreira F ，Hamad H ，Santos N ，Silva S ，Abreu A ，Ferreira R ... -  《Revista Portuguesa de Cardiologia》

Prognostic value of a new cardiopulmonary exercise testing parameter in chronic heart failure: oxygen uptake efficiency at peak exercise - comparison with oxygen uptake efficiency slope.

A growing body of evidence shows the prognostic value of oxygen uptake efficiency slope (OUES), a cardiopulmonary exercise test (CPET) parameter derived from the logarithmic relationship between O(2) consumption (VO(2)) and minute ventilation (VE) in patients with chronic heart failure (CHF). To evaluate the prognostic value of a new CPET parameter - peak oxygen uptake efficiency (POUE) - and to compare it with OUES in patients with CHF. We prospectively studied 206 consecutive patients with stable CHF due to dilated cardiomyopathy - 153 male, aged 53.3±13.0 years, 35.4% of ischemic etiology, left ventricular ejection fraction 27.7±8.0%, 81.1% in sinus rhythm, 97.1% receiving ACE-Is or ARBs, 78.2% beta-blockers and 60.2% spironolactone - who performed a first maximal symptom-limited treadmill CPET, using the modified Bruce protocol. In 33% of patients an cardioverter-defibrillator (ICD) or cardiac resynchronization therapy device (CRT-D) was implanted during follow-up. Peak VO(2), percentage of predicted peak VO(2), VE/VCO(2) slope, OUES and POUE were analyzed. OUES was calculated using the formula VO(2) (l/min) = OUES (log(10)VE) + b. POUE was calculated as pVO(2) (l/min) / log(10)peakVE (l/min). Correlation coefficients between the studied parameters were obtained. The prognosis of each variable adjusted for age was evaluated through Cox proportional hazard models and R2 percent (R2%) and V index (V6) were used as measures of the predictive accuracy of events of each of these variables. Receiver operating characteristic (ROC) curves from logistic regression models were used to determine the cut-offs for OUES and POUE. pVO(2): 20.5±5.9; percentage of predicted peak VO(2): 68.6±18.2; VE/VCO(2) slope: 30.6±8.3; OUES: 1.85±0.61; POUE: 0.88±0.27. During a mean follow-up of 33.1±14.8 months, 45 (21.8%) patients died, 10 (4.9%) underwent urgent heart transplantation and in three patients (1.5%) a left ventricular assist device was implanted. All variables proved to be independent predictors of this combined event; however, VE/VCO2 slope was most strongly associated with events (HR 11.14). In this population, POUE was associated with a higher risk of events than OUES (HR 9.61 vs. 7.01), and was also a better predictor of events (R2: 28.91 vs. 22.37). POUE was more strongly associated with death, urgent heart transplantation and implantation of a left ventricular assist device and proved to be a better predictor of events than OUES. These results suggest that this new parameter can increase the prognostic value of CPET in patients with CHF.

Toste A ，Soares R ，Feliciano J ，Andreozzi V ，Silva S ，Abreu A ，Ramos R ，Santos N ，Ferreira L ，Ferreira RC ... -  《Revista Portuguesa de Cardiologia》

The role of exercise ventilation in clinical evaluation and risk stratification in patients with chronic heart failure.

Jankowska EA ，Pietruk-Kowalczyk J ，Zymliński R ，Witkowski T ，Ponikowska B ，Sebzda T ，Rzeczuch K ，Borodulin-Nadzieja L ，Hańczycowa H ，Banasiak W ，Ponikowski P ... -  《Kardiologia Polska》

[Reduced cardiopulmonary exercise capacity in patients with chronic heart failure: impact of left ventricular systolic dysfunction].

Shen YQ ，Wang LM ，Che L ，Song HM ，Zhang QP ... -  《-》

Cardiopulmonary exercise testing and prognosis in heart failure due to systolic left ventricular dysfunction: a validation study of the European Society of Cardiology Guidelines and Recommendations (2008) and further developments.

Corrà U ，Giordano A ，Mezzani A ，Gnemmi M ，Pistono M ，Caruso R ，Giannuzzi P ... -  《-》