Bariatric surgery was associated with a substantially lower risk of incidents of major adverse cardiovascular (CV) events and all-cause mortality in patients nonalcoholic fatty liver disease (NAFLD) and obesity, according to research led by West Virginia University School of Medicine, Morgantown.
Although surgery is associated with significantly reduced incidence of cardiovascular diseases and mortality in patients with obesity, the investigators stated, whether surgery can decrease major adverse CV events in patients with NAFLD “remains poorly understood”. Therefore, they designed a study to investigate the association of surgery with the incidence of adverse CV events and all-cause mortality in patients with NAFLD and obesity.
The study included 4,687 patients with a BMI>35 and NAFLD (without cirrhosis) who had bariatric surgery (Roux-en-Y gastric bypass (RYGB, 35%) or sleeve gastrectomy (SG, 65%) and they were matched with 4,687 individuals who did not have surgery, according to age, demographics, comorbidities and medication (1:1 propensity score matching, PSM). The primary outcomes were defined as new-onset heart failure (HF), composite cardiovascular events (unstable angina, myocardial infarction, or revascularisation, including percutaneous coronary intervention or coronary artery bypass graft), composite cerebrovascular disease (ischemic or haemorrhagic stroke, cerebral infarction, transient ischemic attack, carotid intervention, or surgery), and a composite of coronary artery procedures or surgeries (coronary stenting, percutaneous coronary intervention, or coronary artery bypass).
The outcomes revealed that surgical patients had significantly lower risk of new-onset of HF (HR, 0.60; 95% CI, 0.51-0.70), CV events (HR, 0.53; 95% CI, 0.44-0.65), cerebrovascular events (HR, 0.59; 95% CI, 0.51-0.69) and coronary artery interventions (HR, 0.47; 95% CI, 0.35-0.63) vs the non-surgical group. Furthermore, all-cause mortality was substantially lower in the surgical group (HR, 0.56; 95% CI, 0.42-0.74). These outcomes were consistent at follow-up duration of one-, three-, five- and seven- years.
Kaplan-Meier survival analysis showed that the cumulative probability of being event-free up to seven years from the index event remained significantly lower in the non-surgical group vs. the surgical group for all studied outcomes (p<0.001). The authors noted that the results of their sensitivity analysis were consistent with the results from the primary study analysis, and all statistically significant associations remained unchanged.
In the secondary analysis, which compared CVD outcomes between patients with obesity without NAFLD who underwent surgery and patients with obesity without NAFLD who did not undergo surgery, surgery was associated with a reduction in CVD outcomes, including risk of new-onset of HF (HR, 0.40; 95% CI, 0.37-0.45), composite cardiovascular events (HR, 0.52; 95% CI, 0.46-0.60), composite cerebrovascular events (HR, 0.54; 95% CI, 0.49-0.60), and composite coronary artery interventions or surgical treatments (HR, 0.44; 95% CI, 0.36-0.53). Similar findings were observed in secondary outcome mortality (HR, 0.41; 95% CI, 0.35-0.47).
Within 30 days after bariatric surgery, 271 patients (5.8%) experienced postoperative complications. Complications included postprocedural haemorrhage (51 patients [1.1%]), gastrointestinal leak (61 patients [1.3%]), postoperative sepsis (58 patients [1.2%]), venous thromboembolism (19 patients [0.4%]), small bowel obstruction (36 patients [0.8%]), acute postprocedural respiratory failure (12 patients [0.2%]), and acute kidney injury (53 patients [1.1%]).
“Although our study provides novel information, randomised clinical trials and additional observational studies are needed to corroborate our findings,” the researchers concluded.
The findings were reported in the paper, 'Cardiovascular Outcomes and Mortality After Bariatric Surgery in Patients With Nonalcoholic Fatty Liver Disease and Obesity', published in JAMA Network Open. To access this paper, please click here