Combined Liver Transplant and Cardiac Surgery: Long-term Outcomes and Predictors of Success

Abstract

Objective: We aim to report our institutional outcomes of single-staged combined liver transplantation (LT) and cardiac surgery (CS).

Background: Concurrent LT and CS is a potential treatment for combined cardiac dysfunction and end-stage liver disease, yet only 54 cases have been previously reported in the literature. Thus, the outcomes of this approach are relatively unknown, and this approach has been previously regarded as extremely risky.

Methods: Thirty-one patients at our institution underwent combined CS and liver transplant. Patients with at least 1-year follow-up were included. The Leave-One-Out Cross-Validation machine-learning approach was used to generate a model for mortality.

Results: Median follow-up was 8.2 years (IQR: 4.6-13.6 years). One- and 5-year survival was 74.2% (N=23) and 55% (N=17), respectively. Negative predictive factors of survival included recipient age >60 years ( P =0.036), nonalcoholic steatohepatitis-cirrhosis ( P =0.031), coronary artery bypass-graft (CABG)-based CS ( P =0.046), and preoperative renal dysfunction ( P =0.024). The final model demonstrated that renal dysfunction had a relative weighted impact of 3.2 versus CABG (1.7), age ≥60 years (1.7), or nonalcoholic steatohepatitis (1.3). Elevated LT+CS risk score was associated with an increased 5-year mortality after surgery (area under the curve=0.731, P =<0.001). Conversely, the widely accepted The Society of Thoracic Surgeons Predicted Risk of Mortality calculator was unable to successfully stratify patients according to 1-year ( P >0.99) or 5-year ( P =0.695) survival rates.

Conclusions: This is the largest series describing combined LT+CS, with joint surgical management appearing feasible in highly selected patients. CABG and preoperative renal dysfunction are important negative predictors of mortality. The 4-variable LT+CS score may help predict patients at high risk for postoperative mortality.

Keywords: cardiac surgery; coronary artery disease; end-stage liver disease; liver transplantation; machine learning; open heart surgery; transplantation.