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.