Published online Jul 27, 2022. doi: 10.4254/wjh.v14.i7.1398
Peer-review started: April 5, 2022
First decision: April 28, 2022
Revised: May 10, 2022
Accepted: June 22, 2022
Article in press: June 22, 2022
Published online: July 27, 2022
Nonalcoholic fatty liver disease (NAFLD) describes the hepatic manifestations of metabolic syndrome, which is estimated to affect 25% of adults, and currently represents the second most common indication for liver transplant in the United States. Studies have shown that patients with NAFLD are at an increased risk for heart failure, arrhythmia, and coronary artery disease (CAD), which may impact outcomes of liver transplantation. However, it remains unclear whether the presence of cardiac disease affects survival prior to liver transplant. If so, this would represent an important opportunity to optimize cardiac status and improve outcomes before liver transplant.
To identify cardiac factors that impact survival to liver transplantation in patients with NAFLD and on the transplant waitlist.
The aim of this study was to identify cardiac risk factors that limit survival to transplant in patients with NAFLD. We performed a retrospective analysis of patients with NAFLD listed for liver transplant at a tertiary academic medical center in the United States from January 2015 to January 2021, identified through United Network of Organ Sharing registry. Exclusion criteria included a concurrent etiology of liver disease and removal from the transplant list due to chemical dependency, lack of social support, improvement in liver disease, or being lost to follow-up. We manually reviewed patient charts including electrocardiogram, echocardiogram, and cardiac catheterization reports as well as physician notes to identify cardiac disease states (i.e., heart failure, arrhythmia, valvular disease and CAD) and other related diagnoses. We performed a survival analysis by Cox proportional hazards regression model to analyze the association between cardiac factors at the time listed for transplant and death or clinical deterioration prior to transplant.
Between January 2015 and January 2021, 265 patients with nonalcoholic fatty liver disease were listed for liver transplant at our institution. Our patient sample had a median age of 63 and an even distribution between sexes. The median Model for End-Stage Liver Disease (MELD) score was 17 and the median body mass index was 31.6. Of these 265 patients, 197 (74.3%) survived to transplant and 68 (25.7%) died or clinically deteriorated prior to transplant. The presence of mild or moderate CAD represented a hazard ratio of 2.013 (95%CI 1.078-3.759, P = 0.029) for death or clinical deterioration when compared to patients without CAD, after adjustment for age, sex, and MELD. MELD represented an adjusted hazard ratio of 1.188.
Mild or moderate CAD represents a hazard for waitlist mortality prior to liver transplant in patients with NAFLD. Aggressive management of CAD may be needed to improve patient outcomes.
Core Tip: Nonalcoholic fatty liver disease (NAFLD) continues to rise in prevalence as a leading indication for liver transplantation. Due to its metabolic features, NAFLD is a risk factor for cardiovascular disease such as coronary artery disease (CAD), atrial fibrillation and heart failure. In our study, we examined the impact of cardiac factors on survival to liver transplant, once listed, in patients with NAFLD. We observed that even mild or moderate CAD represents an independent hazard for waitlist mortality before liver transplant after adjustment for confounding variables. This compels improved treatment of less severe forms of CAD in patients undergoing liver transplant.