Chronic liver disease (CLD) is associated with muscle wasting, reduced exercise tolerance and aerobic capacity (AC). Measures of AC determined using cardiopulmonary exercise testing (CPET) may predict post liver transplant (LT) survival, but relation to non-transplant outcome is uncertain. In patients assessed for LT we examined the relation of CPET AC parameters to severity of liver disease, nutritional state and survival with and without LT.
Patients and Methods:
Patients assessed for elective first LT for who underwent CPET and anthropometric assessment at a single centre were studied. CPET-derived measures of AC evaluated were peak oxygen consumption (VO2 -peak) and Anaerobic Threshold (AT).
399 patients underwent CPET and 223 LT; 45% of patients had VO2 -peak <50% predicted and 31% AT<9ml/kg/min. VO2 -peak and AT correlated with MELD but more closely with serum sodium and albumin. Hand grip strength correlated strongly with VO2 -peak. Patients with impaired AC had prolonged post-LT hospitalisation and 1-year post-transplantation non-survivors had lower AT than survivors (p<0.05), significant on multivariate analysis. 176 patients did not undergo LT; 1-year mortality was 34.6%. AT (p<0.05) and VO2 -peak (p<0.001) were lower in non-survivors. On multivariate analysis, AT was independently associated with non-survival.
Aerobic capacity is markedly impaired in many patients with CLD. In those not transplanted, impaired AT was predictive of mortality and in those undergoing LT related to post-operative hospitalisation and survival. AC should be evaluated as a modifiable factor to improve patient survival, whether or not LT is anticipated.
2014. Vol. 20, no 1, 54-62 p.