High steatosis liver grafts linked to mortality in patients with obesity

SAN FRANCISCO — Liver grafts with high macrosteatosis correlated with a higher posttransplant mortality in patients with obesity compared with patients with normal BMI, according to data presented at The Liver Meeting 2018.

“The obesity epidemic in the U.S. has changed both liver recipient and liver donor characteristics,” Patrick G. Northup, MD, from the University of Virginia, said in his presentation. “Many transplants in the high MELD era of these modern days now involve very sick recipients and more risky donors by nature of the system we have. It was the aim of this study to assess the influence of recipient obesity combined with and without these high graft macrosteatosis organs.”

According to Northup, up to 30% of liver donors in 2010 had a BMI higher than 30 kg/m² and 5% had a BMI higher than 40 kg/m². In 2017, 53% of all liver transplantation involved either a donor or recipient with obesity.

The researchers analyzed 23,504 liver donors and recipients who underwent graft biopsy prior to successful transplantation. During the study, 2,675 patients with a BMI higher than 35 kg/m² underwent a successful transplantation and 2,002 liver transplants were performed with high macrosteatosis grafts (HSGs).

Multivariate analysis showed that BMI higher than 35 kg/m² was an independent predictor of posttransplant mortality at 30 days (HR = 1.78; 95% CI, 1.47-2.16) and persisted at 1 year (HR = 1.18; 95% CI, 1.04-1.34).

In this model, donor HSG was the most significant independent predictor of 30-day mortality (HR = 2.05; 95% CI, 1.66-2.53), which remained significant at 1 year (HR = 1.27; 95% CI, 1.1-1.46).

Posttransplant mortality was highest among patients with BMI higher than 35 kg/m² who received an HSG at all time points: 6.9% at 30 days, 9.58% at 90 days, and 13.03% at 1 year. In contrast, mortality was the lowest among those with a lower BMI who received a normal graft.

Patients with a higher BMI who received a normal graft and those with a normal BMI who received an HSG showed intermediate mortality rates at all time points.

According to Northup, mortality among patients with obesity who received an HSG occurred most frequently within 5 days to 7 days posttransplant and there was an additional spike in mortality at 2 weeks.

“The increase in mortality associated with an HSG into a non-obese recipient is similar in magnitude to a graft with lower macrosteatosis transplanted into an obese recipient,” Northup said. “Make no mistake, we are not calling for cessation of transplantation in the obese patient, or discard of high steatosis grafts. Waitlist death is a real significant risk and less than optimal grafts will be used and can be beneficial. We call for the smart use of the high steatosis grafts into the proper recipients.” – Talitha Bennett

Reference:

Northup PG, et al. Abstract 0004. Presented at: The Liver Meeting 2018; Nov. 9-13, 2018; San Francisco.

Disclosure: Northup reports no relevant financial disclosures.