Impaired functional capacity in potential liver transplant candidates predicts short-term mortality before transplantation

Abstract

Liver transplantation (LT) is a lifesaving treatment. Because of the shortage of donor organs, some patients will not survive long enough to receive a transplant. The identification of LT candidates at increased risk of short-term mortality without transplantation may affect listing decisions. Functional capacity, determined with cardiopulmonary exercise testing (CPET), is a measure of cardiorespiratory reserve and predicts perioperative outcomes. This study examined the association between functional capacity and short-term survival before LT and the potential for CPET to predict 90-day mortality without transplantation. A total of 176 patients who were assessed for nonacute LT underwent CPET. Ninety days after the assessment, 10 of the 164 patients who had not undergone transplantation were deceased (mortality rate 5 6.1%). According to a comparison of survivors and nonsurvivors, the Model for End-Stage Liver Disease score, UK Model for End-Stage Liver Disease (UKELD) score, age, anaerobic threshold, and peak oxygen uptake (VO 2 ) were significant univariate predictors of 90-day mortality without transplantation, but only the UKELD score and peak VO 2 retained significance in a multivariate analysis. The mean peak VO 2 was significantly lower for nonsurvivors versus survivors (15.2 6 3.3 versus 21.2 6 5.3 mL/minute/kg, P < 0.001). According to a receiver operating characteristic (ROC) curve analysis, peak VO 2 performed well as a diagnostic test (area under the ROC curve 5 0.84, 95% confidence interval 5 0.76-0.92, sensitivity 5 0.90, specificity 5 0.74, P < 0.001). The optimal cutoff value for predicting mortality was 17.6 mL/minute/kg. The positive predictive value of a peak VO 2 17.6 mL/minute/kg for 90-day mortality was greatest for patients with high UKELD scores: 38% of the patients with a UKELD score 57 and a peak VO 2 17.6 mL/minute/kg died, whereas only 6% of the patients with a UKELD score 57 and a peak VO 2 > 17.6 mL/minute/kg died (P 5 0.03). In conclusion, patients assessed for LT with an impaired functional capacity have poorer short-term survival; this is particularly true for individuals with worse liver disease severity.

Multidisciplinary approach to cardiac and pulmonary vascular disease risk assessment in liver transplantation: An evaluation of the evidence and consensus recommendations

“…31 A reduction in aerobic capacity has been shown to predict outcomes in LT candidates waiting for LT 32 and at 90 33 and 100 days post-LT. 34 The 6-minute walk test (6MWT) is easily performed measuring the distance a patient can walk in that time frame. It has been shown to be predictive of outcomes in multiple conditions including cardiac and pulmonary.…”

“…62,84 Patients with HF resulting from either systolic or diastolic dysfunction have impaired aerobic capacity and thus CPET may be useful to identify candidates who are at increased risk for poor outcomes. [31][32][33][34] The presence of preoperative left ventricular dysfunction is not an absolute contraindication to LT per se, but is a risk factor for perioperative cardiovascular complications. 2,3 There is no welldocumented EF cut-off for which LT alone is considered prohibitive.…”

The gap between clinically assessed physical performance and objective physical activity in liver transplant candidates

“…Patients with advanced cirrhosis are at high risk for frailty, a state of compromised physiologic reserve and vulnerability to stress that increases the risks of liver‐related death, transplant wait‐list attrition, and major transplant complications in patients with cirrhosis awaiting and undergoing liver transplantation . Frailty as a risk factor for such adverse outcomes may be measured anatomically as sarcopenia, or functionally as an impaired capacity for physical performance …”

Sarcopenia in Patients with Chronic Liver Disease: Can It Be Altered by Diet and Exercise?

“…The critical pathways for how fragility evolves in this population are not clear. Both sarcopenia and frailty are associated with waitlist death, waitlist removals, and transplantrelated morbidity and mortality [51][52][53][54][55][56][57][58][59][60]. A program of exercise and physical conditioning may preserve muscle mass and reverse sarcopenia.…”