Cardiac Risk Assessment in Liver Transplant Candidates: Current Controversies and Future Directions

Abstract

In the changing landscape of liver transplantation (LT), we are now evaluating older and sicker patients with more cardiovascular comorbidities, and the spectrum of cardiovascular disease is uniquely physiologically impacted by end-stage liver disease. Cardiac complications are now the leading cause of morbidity and mortality in LT recipients, and the pretransplant risk is exacerbated immediately during the transplant operation and continues long term under the umbrella of immunosuppression. Accurate risk estimation of cardiac complications before LT is paramount to guide allocation of limited health care resources and to improve both short-term and long-term clinical outcomes for patients. Current screening and diagnostic testing are limited in their capacity to accurately identify early coronary disease and myocardial dysfunction in persons with end-stage liver disease physiology. Furthermore, a number of testing modalities have not been evaluated in patients with end-stage liver disease. As a result, there is wide variation in cardiac risk assessment practices across transplant centers. In this review, we propose a definition for defining cardiac events in LT, evaluate the current evidence for surgery-related, short-term and long-term cardiac risk assessment in LT candidates, propose an evidence-based testing algorithm, and highlight specific gaps in knowledge and current controversies, identifying areas for future research.

Figure 1.

Proposed definitions of cardiac, vascular and pulmonary events and diseases

Figure 2.

Interaction between cirrhosis, medical comorbidities and vascular risk factors increasing inflammation and endothelial dysfunction contributing to the development of cardiac disease

Figure 3.

Timeline of major cardiac events and related risk factors

Figure 4.

Cardiovascular risk factor burden in relation to liver transplant

Figure 5.

Algorithm for assessment of coronary artery disease risk in liver transplantation candidates Abbreviations: CAD, coronary artery disease; TTE, transthoracic echocardiogram; ECG, electrocardiogram; METS, metabolic equivalent of task; NASH, nonalcoholic steatohepatitis; CCTA, coronary computed tomography angiography; LBBB, left bundle branch block; RV, right ventricle