Large Scale Evaluation of CPET as Predictor of Survival Outcome is Needed
Researchers from the U.K. determined that preoperative cardiopulmonary
exercise testing (CPET) is a specific predictor of 90-day survival
following liver transplantation. Study results available in the February
issue of Liver
Transplantation, a journal published by Wiley-Blackwell on
behalf of the American Association for the Study of Liver Diseases,
shows that the CPET measurement—the anaerobic threshold or fitness
level—significantly predicts mortality in patients post-transplantation.
CPET is a non-invasive measure of cardiorespiratory fitness and has been
previously used as a predictor of morbidity and mortality following
other types of major surgeries. “Liver transplantation carries a
significant mortality risk in the early days following surgery,”
explains Dr. James Prentis from Freeman Hospital in Newcastle upon Tyne
in the U.K. “An accurate preoperative assessment like CPET could help
minimize patient mortality and optimize limited donor organs.”
For the current study, researchers included CPET as part of the
preoperative assessment in 182 patients undergoing liver transplantation
at Freeman Hospital over a 3-year period. Of those in the study, 91%
(165) successfully completed the CPET which the team defined as the
ability to determine the anaerobic threshold. Following transplantation
patients received follow-up to determine 90-day mortality, critical care
and length of hospital stay.
Findings report that 60 patients (33%) received a liver transplant and
of those 6 (10%) died following transplantation. The mean anaerobic
threshold was significantly higher in survivors compared to
non-survivors, with multivariate analysis showing cardiopulmonary
reserve to be a significant predictor of mortality. Dr. Prentis
concludes, “CPET is a non-invasive, sensitive and specific predictor of
survival following liver transplantation. However, further evaluation of
its predictive value in larger cohorts is necessary.”
In a related editorial also published in Liver Transplantation,
Dr. James Findlay from the Mayo Clinic in Rochester, Minnesota writes,
“While CPET is widely available there are similar preoperative
assessments such as the six-minute walking test that could also be used.
Liver transplantation specialists have a duty to provide candidates with
an accurate risk-benefit assessment and ensure that scarce donor organs
are used effectively. The findings of Prentis and colleagues are
striking enough to merit further evaluation.” Dr. Findlay suggests
large, multi-center investigations of CPET that include additional
mortality indicators are necessary to develop an outcome model that
could be widely used in evaluating candidates for liver transplantation.
