Cardiovascular outcomes in obesity: bariatric surgery versus medical therapy. A network meta-analysis
A Roumeliotis, N Vythoulkas-Biotis, A Giannakodimos, E Oikonomou, O Katsarou, L Pliouta, V Lambadiari, E Gialafos, P Stampouloglou, N Tripyla, A Lysandrou, S Sarantos, P Theofilis, G SiasosAbstract
Background
Obesity is strongly associated with cardiovascular morbidity and mortality. While bariatric surgery and modern medical therapies improve cardiometabolic risk factors, direct head-to-head comparisons assessing their impact on cardiovascular outcomes remain limited.
Purpose
We performed a systematic review and network meta-analysis (NMA) to compare bariatric surgery and medical treatment on major clinical outcomes in adults with obesity.
Methods
A systematic literature search using PubMed and Scopus databases was conducted. Randomized and observational studies comparing bariatric surgery, medical treatment, or controls (patients that did not receive either medical treatment or undergone any bariatric surgery) were included in the analysis. The primary outcomes were all-cause mortality and MACE (as defined by each individual study), while cardiovascular mortality, heart failure hospitalization, myocardial infarction and stroke served as secondary outcomes. A frequentist random-effects NMA was conducted across three nodes with control patients as the reference comparator. Treatment effects were expressed as hazard ratios (HR) with 95% confidence intervals (CI) and treatments were ranked using p-scores.
Results
A total of 36 studies, comprising more than 1.8 million patients, were included in the meta-analysis. Compared with control, bariatric surgery significantly reduced all evaluated outcomes, including all-cause mortality (HR: 0.56, 95%CI: 0.49–0.64), MACE (HR: 0.54, 95%CI: 0.46–0.64), cardiovascular mortality (HR: 0.49, 95%CI: 0.36–0.67), heart failure hospitalization (HR: 0.48, 95%CI: 0.40–0.57), myocardial infarction (HR: 0.55, 95%CI: 0.47–0.64), and stroke (HR: 0.73, 95%CI: 0.63–0.83). Medical treatment was also associated with lower all-cause mortality (HR: 0.64, 95%CI 0.52–0.77), lower MACE (HR: 0.81, 95%CI: 0.66-0.99) and reduced heart failure hospitalization (HR: 0.79, 95%CI: 0.64–0.98), but showed no significant benefit for cardiovascular mortality, myocardial infarction, or stroke. In head-to-head network comparisons, bariatric surgery was significantly more effective than medical treatment in reducing MACE, cardiovascular mortality, heart failure hospitalization, and myocardial infarction. Notably, all-cause mortality—representing the most direct and clinically relevant endpoint—did not differ significantly between the two strategies, while no significant difference was observed for stroke. Bariatric surgery consistently ranked as the most effective intervention across all outcomes based on p-scores.
Conclusion
Bariatric surgery is associated with substantial reductions in major cardiovascular outcomes in adults with obesity and outperforms medical treatment for most endpoints in head-to-head comparisons. These findings support its central role in cardiovascular risk reduction, while highlighting the need for randomized trials directly comparing contemporary medical therapies with surgical approaches.Primary OutcomesSecondary Outcomes