Abstract
BACKGROUND: Cardiopulmonary exercise testing measures oxygen uptake at increasing levels of work and predicts cardiopulmonary performance under conditions of stress, such as after abdominal surgery. Dynamic assessment of preoperative exercise capacity may be a useful predictor of postoperative prognosis. This study examined the relationship between preoperative exercise capacity and event-free survival in hepatocellular carcinoma (HCC) patients with chronic liver injury who underwent hepatectomy. METHODS: Sixty-one HCC patients underwent preoperative cardiopulmonary exercise testing to determine their anaerobic threshold (AT). The AT was defined as the break point between carbon dioxide production and oxygen consumption per unit of time (VO₂). Postoperative events including recurrence of HCC, death, liver failure, and complications of cirrhosis were recorded. Univariate and multivariate analyses were performed to evaluate associations between 35 clinical factors and outcomes, and identify independent prognostic indicators of event-free survival and maintenance of Child-Pugh class. RESULTS: Multivariate analyses identified preoperative branched-chain amino acid/tyrosine ratio (BTR) <5, alanine aminotransferase level ≥42 IU/l, and AT VO₂ <11.5 ml/min/kg as independent prognostic indicators of event-free survival. AT VO2 <11.5 ml/min/kg and BTR <5 were identified as independent prognostic indicators of maintenance of Child-Pugh class. CONCLUSIONS: This study identified preoperative exercise capacity as an independent prognostic indicator of event-free survival and maintenance of Child-Pugh class in HCC patients with chronic liver injury undergoing hepatectomy.