Cardiopulmonary Exercise Testing and Dobutamine Stress Echocardiography in Pre-Operative Assessment of Liver Transplant Patients

Abstract

Orthotopic Liver Transplantation (OLT) is the established treatment for end-stage liver disease. Surgical procedures per se, with excessive bleeding, fluid shift, re-perfusion syndrome and electrolyte disturbances impose stress on the cardiovascular system. Patients with cardiac comorbidity undergoing OLT have higher perioperative morbidity and mortality. Cardiac assessment and optimisation are integral parts of the preoperative evaluation.

Different liver transplant (LT) centres have different pre-assessment policies, but in general, all centres are moving towards more structured and objective pre-assessment. Dobutamine Stress Echocardiography (DSE) and Cardiopulmonary Exercise Testing (CPEX) are useful tools in preoperative risk assessment and patient optimization. With time, we will also learn more about their limitations.

In this paper, we reviewed the literature on the value of DSE and CPEX for preoperative risk assessment and preoperative optimization of liver LT patients. We also added our high-volume LT centre experience.

Current literature and our experience suggest that the DSE test, used widely as a non-invasive procedure to detect patients with coronary artery disease, is not as sensitive and specific as we would have expected. It is currently being used primarily for its negative predictive value. DSE has been gradually replaced with a completely different test that measures functional capacity and the ability to cope with increasing demands during the perioperative and postoperative periods. Because CPEX is comprised of several components and its interpretation is complex, anaerobic threshold (AT) was a good component to start with. Although there is evidence that lower AT is associated with higher morbidity, intra-hospital stay and mortality, further investigation is needed in order to clarify its value in LT patient pre-assessments.