Supplementary Material for: Body mass index and all-cause mortality in elderly patients with percutaneous coronary intervention: A meta-analysis

Background: The ‘obesity paradox’ in elderly patients suffering from percutaneous coronary intervention (PCI) remains a source of controversy. The present meta-analysis focused on exploring the real existence of ‘obesity paradox’ in these patients. Methods: As of November 2022, PubMed, Cochrane and Embase databases were comprehensively searched to identify articles reporting all-cause mortality according to diverse body mass index (BMI) categories after PCI among the old cases developing coronary artery disease (CAD). Summary estimates of risk ratios (RRs) were assigned four BMI groups, including underweight, normal weight, overweight, and obesity groups. Results: There were altogether nine articles involving 25,798 cases selected for further analysis. Relative to normal weight group, overweight and obesity groups had decreased all-cause mortality (RR 0.86, 95%CI 0.77-0.95 for overweight group; RR 0.57,95%CI 0.40-0.80 for obesity group), while underweight group had elevated all-cause mortality (RR 1.52, 95%CI 1.01-2.29). Conclusions: Our study revealed an ‘obesity paradox’ relation of BMI with all-cause mortality in elderly cases receiving PCI. In comparison with normal weight group, overweight and obesity groups had decreased all-cause mortality, while underweight group had increased all-cause mortality.