BACKGROUND AND PURPOSE: 

• Nonalcoholic steatohepatitis (NASH) is the hepatic manifestation of metabolic syndrome 
• Aminian et al. (JAMA, 2021) investigated the long-term relationship between bariatric surgery and major adverse liver outcomes and major adverse cardiovascular events (MACE) in patients with obesity and NASH 

METHODS: 

• Retrospective cohort study | SPLENDOR (Surgical Procedures and Long-term Effectiveness in NASH Disease and Obesity Risk) study 
  • Patients undergoing liver biopsy at the Cleveland Clinic health system between 2004 and 2016 
  • Follow up through March 2021 
• Participants 
  • Adult patients with obesity 
  • Confirmed histological diagnosis of NASH 
  • Presence of liver fibrosis (histological stages 1-3) 
• Exposures 
  • Bariatric surgery with simultaneous liver biopsy 
    • Roux-en-Y gastric bypass | Sleeve gastrectomy 
  • Nonsurgical control group 
• Study design 
  • Exposure and control groups were balanced for: Baseline clinical characteristics | Histological disease activity | Fibrosis stage  
  • Regression analysis framework used for primary outcomes calculations  
• Primary outcomes 
  • Major adverse liver outcomes 
    • Progression to clinical or histological cirrhosis | Development of hepatocellular carcinoma | Liver transplantation | Liver-related mortality 
  • MACE 
    • Composite: Coronary artery events | Cerebrovascular events | Heart failure | Cardiovascular death 

RESULTS: 

• Bariatric surgery: 650 patients | Nonsurgical controls: 508 patients 
  • 63.9% women 
  • Median (IQR) age: 49.8 (40.9 to 57.9) years 
  • Mean (IQR) BMI: 44.1 (39.4 to 51.4) 
  • Median (IQR) follow-up: 7 (4 to 10) years 
• Unweighted incidence of outcomes at end of study period 
  • Major adverse liver outcomes 
    • Bariatric surgery: 5 patients 
    • Nonsurgical controls: 40 patients 
  • MACE 
    • Bariatric surgery: 39 patients 
    • Nonsurgical controls: 60 patients 
• There were fewer major adverse liver events in the bariatric surgery group, with lower risk  
  • Cumulative incidence at 10 years 
    • Bariatric surgery: 2.3% (95% CI, 0 to 4.6) 
    • Nonsurgical controls: 9.6% (95% CI, 6.1 to 12.9) 
  • Adjusted absolute risk difference 12.4% (95% CI, 5.7 to 19.7) 
  • Adjusted hazard ratio 0.12 (95% CI to 0.02 to 0.63); P=0.01 
• MACE incidence was lower in the bariatric surgery group, and risk was lower 
  • Cumulative incidence at 10 years 
    • Bariatric surgery: 8.5% (95% CI, 5.5 to 11.4) 
    • Nonsurgical controls: 15.7% (95 CI, 11.3 to 19.8) 
  • Adjusted absolute risk difference 13.9% (95% CI, 5.9 to 21.9) 
  • Adjusted hazard ratio 0.30 (95% CI, 0.12 to 0.72); P=0.007 
• Surgery related adverse events leading to death within first year after surgery: 4 (0.6%) 
  • Gastrointestinal leak: 2 patients 
  • Respiratory failure: 2 patients 

CONCLUSION: 

• For obese patients with NASH, those that underwent bariatric surgery had a significantly lower risk of major adverse liver events and MACE, compared to nonsurgical controls 
• The authors state 

NASH and cardiovascular diseases share numerous risk factors because both represent end-organ damage caused by metabolic derangements 

In addition, NASH independently increases the risk of atherosclerosis, cardiomyopathy, and cardiac arrhythmia 

Bariatric surgery leads to a substantial and sustained weight loss, and effectively improves cardiometabolic risk factors6-9 and quality of life 

Learn More – Primary Sources: 

Association of Bariatric Surgery With Major Adverse Liver and Cardiovascular Outcomes in Patients With Biopsy-Proven Nonalcoholic Steatohepatitis 

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