Influence of Metabolic Syndrome on the Long-Term Prognosis of Patients with Myocardial Infarction: A Meta-Analysis

The influence of metabolic syndrome (MetS) on long-term prognosis of patients with myocardial infarction (MI), the most severe type of coronary artery disease, remains not fully determined. This systematic review and meta-analysis were conducted to investigate the association between MetS and long-term clinical outcomes of patients with MI. A systematic search of Medline, Web of Science, and Embase databases from inception to June 25, 2023, was conducted to obtain eligible studies. Only studies with follow-up duration for at least one year were considered. A random-effects model was utilized to pool the results, accounting for heterogeneity. Ten observational studies were included, which included 33 197 patients with MI. Among them, 17 244 (51.9%) were with MetS at baseline. During a follow-up duration of 12 to 48 months (mean: 22.5 months), patients with MetS were associated with higher incidence of major adverse cardiovascular events [risk ratio (RR): 1.35. 95% confidence interval (CI): 1.19 to 1.54, p<0.001; I2=64%] and all-cause deaths (RR: 1.34, 95% CI: 1.18 to 1.52, p<0.001; I2=23%), as compared to those without MetS at baseline. Subgroup analyses showed that the results were not significantly affected by study characteristics such as study country, design, type of MI, mean age of the patients, treatment with percutaneous coronary intervention, follow-up durations, or study quality scores (p for subgroup difference all>0.05). In patients with MI, MetS may be a risk factor of poor long-term prognosis.