Bariatric Surgery Linked to Lower CVD Risk in Patients With NAFLD, Severe Obesity

Compared with nonsurgical care, adults with severe obesity and NAFLD who underwent bariatric surgery had a reduced risk for CVD.

Adult patients with severe obesity and nonalcoholic fatty liver disease (NAFLD) who had bariatric surgery have a lower risk for cardiovascular disease (CVD) compared with those who received nonsurgical care, according to a study in JAMA Network Open.

The population-based retrospective cohort study evaluated the association between bariatric surgery and CVD risk in individuals with severe obesity and NAFLD, using data from the MarketScan Commercial Claims and Encounters database.

Eligible participants were insured adults aged 18 to 64 years with 1 or more inpatient or outpatient NAFLD diagnoses and severe obesity (body mass index [BMI] ≥40 kg/m2). Only bariatric surgeries after the index date of the first NAFLD diagnosis were evaluated to avoid misclassifications and included Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy, and other bariatric procedures. The follow-up was measured from the index date to the event date for CVD outcomes.

The incidence of cardiovascular events (CVEs) was the main outcome and was defined as the first occurrence of either primary or secondary composite CVD outcomes. The primary composite outcome included myocardial infarction (MI), heart failure, or ischemic stroke. The secondary composite cardiovascular outcome included secondary ischemic heart events, transient ischemic attacks, secondary cerebrovascular events, arterial embolism and thrombosis, or atherosclerosis.

Although bariatric surgery is a more aggressive approach than lifestyle modifications, it may be associated with other benefits, such as improved quality of life and decreased long-term health care burden.

The analysis included 86,964 adults (mean [SD] age, 44.3 [10.9] years; women, 68.7%). Of the cohort, 34.8% of patients had bariatric surgery (surgical group) and 65.2% had nonsurgical care (nonsurgical group). The surgeries included 11,371 RYGBs, 10,404 sleeve gastrectomies, and 8525 other bariatric surgeries. The overall mean (SD) follow-up was 21.1 (20.7) months — 29.2 (24.6) months for participants in the surgical group and 16.8 (16.8) months for those in the nonsurgical group.

Bariatric surgery was associated with a significantly reduced risk for incident CVEs. At 96 months, the surgical group had 1568 incident CVEs during 57,061.4 person-years, and the nonsurgical group had 7215 CVD cases during 96,150.1 person-years (incidence rate difference, 4.8 [95% CI, 4.5-5.0] per 100 person-years).

A total of 2950 primary CVD events occurred, of which 784 followed a secondary CVD event. The risk of the primary incident event was significantly lower among the surgical group vs the nonsurgical group. At 96 months, bariatric surgery was associated with a 47% reduced cumulative incidence of primary events (9.7% in the surgical group vs 18.3% in the nonsurgical group; adjusted hazard ratio [aHR], 0.53 [95% CI, 0.48-0.59]).

Individuals who had surgery had lower adjusted hazards of MI (aHR, 0.80; 95% CI, 0.63-1.00), heart failure (aHR, 0.39; 95% CI, 0.34-0.45), and ischemic stroke (aHR, 0.79; 95% CI, 0.66-0.94).

A secondary CVD outcome was observed in 1191 participants in the surgical group during 57,061.4 person-years and in 5424 individuals in the nonsurgical group during 96,150.1 person-years (incidence rate difference, 35.5 [95% CI, 33.6-37.5] per 1000 person-years). The 96-month cumulative incidence of a secondary outcome was 17.3% in the surgical group and 28.2% in the nonsurgical group. Surgery status was associated with a 50% lower adjusted hazard of secondary outcomes compared with nonsurgical status (aHR, 0.50; 95% CI, 0.46-0.53).

Study limitations include using claims data; the observational study design, which could have resulted in unmeasured confounding; and the inability to adjust for race and ethnicity or determine the association between surgery and CVD by disease phenotype.

“The findings provide evidence in support of bariatric surgery as an effective therapeutic tool to lower elevated CVD risk for select individuals with obesity and NAFLD,” the study authors wrote. “Although bariatric surgery is a more aggressive approach than lifestyle modifications, it may be associated with other benefits, such as improved quality of life and decreased long-term health care burden.”