Bariatric surgery yields favorable long-term cardiac outcomes in obese patients: JACC
USA: Weight loss after bariatric surgery is associated with reduced ventricular interaction, epicardial fat reduction, improved longitudinal biventricular mechanics, and reverse remodeling, according to an observational study published in the Journal of the American College of Cardiology. LA myopathy and hemodynamic congestion, however, still progressed.
The study further found that reduction in visceral fat was linked with favorable cardiac effects, indicating this might be a key target of weight loss (WL) interventions.
Studies with short-term follow-ups have shown the beneficial effects of weight loss on the heart, but not much information is available on the long-term effects of visceral fat reduction. Considering this, Hidemi Sorimachi, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota, USA, and colleagues sought to investigate the effects of long-term weight loss following bariatric surgery on cardiac function, structure, ventricular interaction, and body composition, including abdominal visceral adipose tissue (VAT) and epicardial adipose thickness.
Before and >180 days following bariatric surgery, 213 obese patients underwent echocardiography. In 52 patients, the abdominal VAT area was measured by computed tomography.
The study demonstrated the following findings:
- After 5.3 years, body mass index (BMI) decreased by 22%, with favorable reductions in fasting glucose, blood pressure, and left ventricular (LV) remodeling in the total sample.
- The VAT area decreased by 30% in the subgroup of patients with abdominal computed tomography.
- In all subjects, the epicardial adipose thickness was reduced by 14% in tandem with reductions in ventricular interdependence.
- Following WL, LV and right ventricular longitudinal strain improved but left atrial (LA) strain worsened, while LA volume and estimated LA pressures increased.
- In subgroup analysis, LV wall thickness and strain were associated more strongly with VAT than BMI at baseline, and a decrease in LV mass after surgery was associated with reductions in VAT but not BMI.
"The divergent effects of weight loss on LV strain and LVEF was an interesting finding. The LVEF reduced slightly but significantly (66%-64%); however, LV global longitudinal strain increased (14.3%-15.1%)," Paul Heidenreich, VA Palo Alto Health Care, California, USA, wrote in an accompanying editorial comment. These results showed the limitations of LVEF as a contractility measure, mainly when the LV wall thickness is not constant.
The authors note that despite worsening contractility, the increase in LV wall thickness with obesity may have allowed EF maintenance. The decreased wall thickness with weight loss may lead to unchanged or worse LVEF despite improved strain. As measured by strain, right ventricular contractility also increased with no significant change in fractional area change.
"Reduction in visceral fat was linked with favorable cardiac effects, indicating this might be a key target of WL interventions," the researchers wrote in their conclusion.
Reference:
Sorimachi H, Obokata M, Omote K, Reddy YNV, Takahashi N, Koepp KE, Ng ACT, Rider OJ, Borlaug BA. Long-Term Changes in Cardiac Structure and Function Following Bariatric Surgery. J Am Coll Cardiol. 2022 Oct 18;80(16):1501-1512. doi: 10.1016/j.jacc.2022.08.738. PMID: 36229085.
