[Moderate cardiac failure: oxygen consumption during exercise predicts ultrafiltration results]

Abstract

Extracorporeal ultrafiltration (UF) can improve the clinical condition, as assessed by cardiopulmonary exercise evaluation, of patients with moderate heart failure (HF); the pre-UF level of physical performance above which UF does not induce clinical benefits, is not defined. For this purpose, we studied 29 patients with stable HF in functional class II-III (NYHA), who underwent UF (veno-venous bypass, removal of 1,830 +/- 550 ml of plasma water), regardless their baseline oxygen consumption at peak exercise (VO2p) and at anaerobic threshold (VO2AT). All patients experienced cardiopulmonary exercise tests (cycloergometer, increasing workloads of 25 W every 3 min) before (pre-UF), and 4 days and 3 months following UF. According to VO2 changes following UF 2 groups of patients were identified: in Group I (9 patients) no differences in VO2p and VO2AT were observed, while in Group II (18 patients) VO2p rose by 2.7 ml/min/kg (p < 0.001) at 4 days and 4.5 ml/min/kg (p = 0.04) at 3 months, and VO2AT rose by 1.2 ml/min/kg (p < 0.001) at 4 days and 2.8 ml/min/kg (p = 0.03) at 3 months. In unresponsive patients baseline values of VO2p > or = 18 ml/min/kg and VO2AT +/- 13 ml/min/kg were detected. Pre-UF VO2p inversely correlated with the shift of VO2p (delta VO2p) both at 4 days (r = -0.62, p < 0.001) and at 3 months (r = -0.53, p = 0.005), and pre-UF VO2AT inversely correlated with delta VO2AT at 4 days (r = -0.71, p < 0.001) and at 3 months (r = -0.63, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)