Abstract
BACKGROUND: Cardiopulmonary exercise testing has been widely used to risk stratify patients with chronic heart failure (CHF). Peak oxygen consumption (peakVO2) was regarded as a powerful predictor of survival, as it is a surrogate for peak cardiac output (CO), which by most is considered the "true" measure of heart failure. Therefore, it is reasonable to hypothesize that CO is an even stronger predictor than peak VO2. The present study is aimed to investigate the prognostic value of peak cardiac power output (peak CPO) in comparison with peakVO2 in Chinese patients with CHF. METHODS: Participants provided written informed consent to participate in this study. Totally 129 patients with CHF underwent symptom-limited cardiopulmonary exercise testing (CPET), with mean age 59.1 ± 11.4 years, 87.6% male, 57.4% ischemic etiology, body mass index (BMI) 24.7 ± 3.7 kg/m(2) and LVEF 38 ± 9%. CO was measured using an inert gas rebreathing method. The primary endpoints are cardiac deaths. RESULTS: Over median 33.7-month follow-up, 19 cardiac deaths were reported. Among peak VO2,VE/VCO2 slope and Peak CPO, their area under ROC were 0.64, 0.67, 0.68, respectively (Ρ<0.05).The optimal thresholds for predicting cardiac deaths were peak VO2 ≤ 13.4 ml.kg(-1).min(-1), and VE/VCO2 slope ≥ 39.3 and peak CPO≤ 1.1 respectively by ROC analysis. Finally, in patients with a peak VO2 ≤ 13.4 ml.kg(-1).min(-1) those with peak CPO>1.1W had better survival than those with peak CPO ≤ 1.1W. However, by multivariate analysis adjusted for age, sex, BMI, resting heart rate, LVMI, LVEF, Peak CPO was not an independent predictor of cardiac deaths (P> 0.05). CONCLUSIONS: Peak CPO was not a predictor of cardiac death in Chinese CHF patients.