Prognostic significance of different measures of the ventilation-carbon dioxide relation in patients with suspected heart failure

    loading  Checking for direct PDF access through Ovid


AimsWe studied the prognostic significance of the ventilatory equivalent of carbon dioxide production (VEqCO2) at different time-points of a maximal cardiopulmonary exercise test (CPET) in patients with suspected heart failure (HF).Methods and resultsThe VEqCO2 was calculated at three different time-points; VEqCO2 (rest) was calculated following 30 s of resting data immediately prior to the start of exercise; VEqCO2 (nadir) was the lowest 30-s average over the duration of the test; VEqCO2 (peak) was calculated using the mean value of the final 30 s of exercise. We included a healthy control group who had no evidence of cardiorespiratory disease. Four hundred and twenty-three patients with suspected HF (mean age 63 ± 12 years; 80% males; left ventricular ejection fraction 36 ± 6 %; peak oxygen uptake 22.3 ± 8.1 mL kg−1 min−1; VE/VCO2 slope 34 ± 8) were included in the study. Seventy-eight healthy participants (62% males; age 61 ± 11 years) were recruited as controls. One hundred and eighteen patients died during follow-up with a median follow-up of 8.6 ± 2.1 years in survivors. The strongest univariable predictors of all-cause mortality were VEqCO2 (nadir) (χ2 = 47.9), peak oxygen uptake (χ2 = 53.0), and the VE/VCO2 slope (χ2 = 31.7). In a Cox multivariable proportional hazards model, VEqCO2 (nadir) (χ2 = 8.8), peak systolic blood pressure (χ2 = 6.0), and age (χ2 = 6.6) were the most potent independent predictors of all-cause mortality.ConclusionThe VEqCO2 (nadir) provides greater prognostic value than other related ventilatory variables in patients with suspected HF. Further work in other populations is required to confirm our conclusions.

    loading  Loading Related Articles