Aerobic capacity during cardiopulmonary exercise testing and survival with and without liver transplantation for patients with chronic liver disease

Abstract

Chronic liver disease (CLD) is associated with muscle wasting, reduced exercise tolerance and aerobic capacity (AC). Measures of AC determined with cardiopulmonary exercise testing (CPET) may predict survival after liver transplantation (LT), but the relationship with nontransplant outcomes is uncertain. In patients assessed for LT, we examined the relationship of CPET AC parameters with the severity of liver disease, nutritional state, and survival with and without LT. Patients assessed for elective first LT who underwent CPET and an anthropometric assessment at a single center were studied. CPET-derived measures of AC that were evaluated included the peak oxygen consumption (VO 2 peak) and the anaerobic threshold (AT). Three hundred ninety-nine patients underwent CPET, and 223 underwent LT; 45% of the patients had a VO 2 peak < 50% of the predicted value, and 31% had an AT < 9 mL/kg/minute. The VO 2 peak and AT values correlated with the Model for End-Stage Liver Disease score, but they more closely correlated with serum sodium and albumin levels. The handgrip strength correlated strongly with the VO 2 peak. Patients with impaired AC had prolonged hospitalization after LT, and nonsurvivors had lower AT values than survivors 1 year after transplantation (P < 0.05); this was significant in a multivariate analysis. One hundred seventy-six patients did not undergo LT; the 1-year mortality rate was 34.6%. The AT (P < 0.05) and VO 2 peak values (P < 0.001) were lower for nonsurvivors. In a multivariate analysis, AT was independently associated with nonsurvival. In conclusion, AC was markedly impaired in many patients with CLD. In patients who did not undergo transplantation, impaired AT was predictive of mortality, and in patients undergoing LT, it was related to postoperative hospitalization and survival. AC should be evaluated as a modifiable factor for improving patient survival whether or not LT is anticipated. Liver Transpl 20:54-62, 2014. V C 2013 AASLD.Received June 4, 2013; accepted September 30, 2013.Many patients with chronic liver disease (CLD) develop progressive impairment of their fitness and exercise capacity.1 The clinical significance of these changes is reflected by the close association of altered musculature and exercise capacity with the risk for major disease-related complications and mortality.2-8

Exercise Capacity Impairment Can Predict Postoperative Pulmonary Complications after Liver Transplantation

“…However, as ESLD patients usually suffer from fatigue, muscle wasting, malnutrition, and weakness, it is difficult to obtain an objective assessment of overall fitness. In a study on 47 LT candidates, Mancuzo et al [6] found an independent association between aerobic capacity (peak VO 2 ) and time of hospitalization, matching the findings of Bernal et al [7] .…”

“…Recent studies showed that they develop impairment of exercise capacity and fitness [37,38] . Also reduced peak V O 2 can help identify patients at risk for mor- bidity and mortality after LT [7,39,40] . In our study, a poor exercise testing (6MWT) results were indeed predictive of PRCs after LT. A possible explanation for the association of poor exercise capacity and PRCs is the ability of this test to determine patients' physiological capacity to cope with the demands placed on the cardiorespiratory system following major surgery [15] .…”

Sarcopenia and survival after liver transplantation

“…Methods such as cardiopulmonary exercise testing are being used in some centers to determine a patient's preoperative and postoperative survival. [3][4][5] An assessment of sarcopenia by computer tomography techniques or a functional assessment by hand-grip strength may complement dynamic assessments such as cardiopulmonary exercise testing as well as existing hepatological models to better identify those patients who are likely to benefit as well as those who are likely to be disadvantaged by LT. The work of Montano-Loza et al is, therefore, a useful contribution to this goal.…”

Is the aerobic capacity at the time of cardiopulmonary exercise testing useful in predicting survival following liver transplantation?

“…We read with interest the recent article from Bernal et al 1 about the use of cardiopulmonary exercise testing (CPET) during the liver transplant assessment to determine the aerobic capacity and hence survival of patients with chronic liver disease. The aim of the study group was to confirm the relationship between the aerobic capacity determined at the time of CPET and survival after liver transplantation.…”