Risk Factors of Coronary In-Stent Restenosis in Drug-Eluting Stent: A Systematic Review and Meta-Analysis.

Background: In-stent restenosis (ISR) is an event of coronary atherosclerosis re-budling following the stent implantation in percutaneous coronary intervention. The events of ISR have been significantly reduced since the introduction of drug-eluting stents. However, ISR could still occur, and factors affecting the incident have not yet been discovered. This study aims to evaluate the risk factors of coronary in-stent restenosis in drug-eluting stents.

Methods: Studies on the factors and risks of ISR in patients with drug-eluting stents were systematically searched in databases (PubMed, ScienceDirect, Springer, Google Scholar, and ProQuest) on September 20th, 2023. The odds ratio (OR) and mean difference (MD) were analyzed using Review Manager 5.4.

Results: Diabetes mellitus (OR 1.73 [95%CI 1.56, 1.91] p < 0.00001) and smoking (OR 1.24 [95%CI 1.13, 1.36] p<0.0001) are the patients' clinical characteristics that are associated with ISR in DES. It is closely related to the contribution of diabetes mellitus in promoting platelet adhesion and smoking in enhancing intimal hyperplasia. As in the angiography characteristics, stent lesion at LAD (OR 1.20 [95%CI 1.07, 1.35] p = 0.002) and stent length (MD 3.61 [95%CI 1.81, 5.42] p < 0.0001) are correlated with the events of ISR. Every millimeter excess of stent length significantly increases the risk of ISR. Therefore, reducing the excess stent length may contribute to the reduced risk of ISR in DES.

Conclusion: The identification of risk factors contributing to ISR in DES may help cardiologists modify the attributable factors and prevent the occurrence of ISR.