Late stent thrombosis, endothelialisation and drug-eluting stents

Area of Science:

• Cardiology
• Biomedical Engineering
• Interventional Cardiology

Background:

• Drug-eluting stents (DES) are used to prevent restenosis after percutaneous coronary revascularisation.
• Concerns exist regarding an increased risk of late stent thrombosis (LST) with DES.
• Meta-analyses of clinical trials do not support a higher LST risk with DES.

Purpose of the Study:

• To review clinical and animal studies on re-endothelialization and LST in DES.
• To evaluate the hypothesis that LST is associated with DES due to delayed endothelialization.
• To compare endothelialization of DES versus bare-metal stents (BMS).

Main Methods:

• Review of clinical trial meta-analyses.
• Analysis of autopsy studies and intracoronary angioscopy findings.
• Examination of preclinical studies, including porcine coronary artery models.

Main Results:

• Clinical meta-analyses do not support an increased LST risk with DES.
• Autopsy studies report differences in endothelialization between DES and BMS.
• Most preclinical studies and the authors' porcine model studies show no significant difference in re-endothelialization between DES and BMS.
• DES do, however, delay vascular healing and induce endothelial dysfunction.

Conclusions:

• The hypothesis linking LST to DES via delayed endothelialization is not consistently supported by clinical data.
• While DES may affect vascular healing and endothelial function, their impact on LST risk compared to BMS requires careful consideration of all evidence.
• Further research may be needed to fully elucidate the complex relationship between stent type, endothelialization, and long-term thrombotic events.