Bariatric Surgery Could Cut Risk of Adverse Liver, Cardiovascular Outcomes in NASH

Steve Nissen, MD

Data from a new study provides evidence detailing the apparent reduction in risks of major adverse liver and cardiovascular outcomes associated with undergoing bariatric surgery among patients with biopsy-proven nonalcoholic steatohepatitis (NASH).

Performed by investigators from the Cleveland Clinic, results of the retrospective cohort study indicate undergoing bariatric surgery was associated with an 88% reduction in risk of progression of fatty liver to cirrhosis, liver cancer, or liver-related death and a 70% reduction in risk of major adverse cardiovascular events (MACE).

“The SPLENDOR study shows that in patients with obesity and NASH, substantial and sustained weight loss achieved with bariatric surgery can simultaneously protect the heart and decrease the risk of progression to end-stage liver disease,” said the study’s senior investigator, Steven Nissen, MD, chief academic officer of the Heart, Vascular and Thoracic Institute at Cleveland Clinic, in a statement. “This is the first study in the medical field reporting a treatment modality that is associated with decreased risk of major adverse events in patients with biopsy-proven NASH.”

With an interest in assessing the effects of bariatric surgery compared with nonsurgical management of obesity in patients with NASH, a team of Cleveland Clinic investigators designed the current study as an analysis of data from the Surgical Procedures and Long-term Effectiveness in NASH Disease and Obesity Risk (SPLENDOR) study. SPLENDOR, which was designed to assess the long-term associations between bariatric surgery and future risk of progression to cirrhosis and MACE, collected data from more than 25,828 patients who had a liver biopsy from 2004-2016 and were followed through March 2021.

From the 25,828 who had a liver biopsy, investigators identified a cohort of 1158 patients with NASH and obesity. This cohort was 63.9% women, had a median age of 49.8 (IQR, 40.9-57.9) years, a median BMI of 44.1 (IQR, 39.4-51.4) kg/m2, and a median follow-up of 7 (IQR, 4-10) years. The cohort included 650 patients who underwent bariatric surgery and 508 who underwent nonsurgical management.

The primary outcomes of interest for the analysis were the incidence of major adverse liver outcomes and MACE. Major adverse liver outcomes included progression to clinical or histological cirrhosis, development of hepatocellular carcinoma, liver transplantation, or liver-related mortality. MACE was defined as a composite of coronary artery events, cerebrovascular events, heart failure, or cardiovascular death. Associations with bariatric surgery were estimated using the Firth penalized method in a multivariable-adjusted Cox regression analysis framework.

At the end of the follow-up period, in the unsighted data set, major adverse liver outcomes occurred among 5 patients who underwent Bariatric Surgery and 40 in the nonsurgical group. In regard to MACE among the same at a set, a MACE outcome occurred among 39 patients in the bariatric surgery group and 60 in the nonsurgical group.

In analyses with overlap weighting methods, results indicated the cumulative incidence of major adverse liver outcomes at 10 years was 2.3% (95% CI, 0-4.6) in the bariatric surgery group and 9.6% (95% CI, 6.1-12.9) in the nonsurgical group (adjusted absolute risk difference, 12.4% [95% CI, 5.7-19.7]; aHR, 0.12 [95% CI, 0.02-0.63]; P=.01). When assessing incidence of MACE at 10 years, results indicated the cumulative incidence was 8.5% (95% CI, 5.5%-11.4%) in the bariatric surgery group and 15.7% (95% CI, 11.3-19.8) in the nonsurgical group (adjusted ARD, 13.9% [95% CI, 5.9-21.9]; aHR, 0.30 [95% CI, 0.12-0.72]; P=.007). Investigators noted 4 patients (0.6%) died from surgical complications, including 2 with gastrointestinal leak and 2 with respiratory failure, within the first year of bariatric surgery.

“No treatment other than bariatric surgery has been shown to have such a significant effect in reducing the risk of severe outcomes or death in patients with NASH,” said Shanu N. Kothari, MD, president of the American Society for Metabolic and Bariatric Surgery, in a statement. “Bariatric surgery should be considered a first-line treatment for these patients.”

This study, “Association of Bariatric Surgery With Major Adverse Liver and Cardiovascular Outcomes in Patients With Biopsy-Proven Nonalcoholic Steatohepatitis,” was published in JAMA.