Very long-term serial luminal changes after sirolimus-eluting stent implantation and progression process of very late stent failure.

Background: Very long-term angiographic results after sirolimus-eluting stent (SES) implantation have not been clarified. This study investigated serial angiographic results of early (<1year), late (1-5years), and very late (>5years) follow-up after SES implantation and the progression process to very late SES failure.

Methods: We analyzed 631 lesions undergoing serial coronary angiography at early, late, and very late follow-up after SES implantation. The results of 205 lesions undergoing very late target lesion revascularization (VL-TLR; TLR beyond 5years) for acute coronary syndrome (ACS; 83) and non-ACS (122) were evaluated in comparison with 426 non-TLR lesions as a control group.

Results: Non-TLR lesions showed no attenuated decline of minimum lumen diameter from postprocedure (2.51±0.47mm), early (2.37±0.58mm), late (2.22±0.60mm), up to very late (2.01±0.63mm) follow-up. In VL-TLR lesions, compared to non-TLR lesions, late lumen loss (LLL) from postprocedure to early follow-up was similar, but delayed LLL from early to late follow-up was significantly larger (0.25±0.48mm vs. 0.15±0.46mm, p=0.01). Although the delayed LLL was significantly larger in non-ACS lesions (0.29±0.44mm) than in non-TLR lesions (p<0.01), it was similar in ACS (0.19±0.52mm) and non-TLR lesions (p=0.54). Very delayed LLL from late to very late follow-up was 1.65±0.82mm in ACS lesions and 1.10±0.76mm in non-ACS lesions.

Conclusions: Progression of in-stent luminal narrowing did not attenuate beyond 5years after SES implantation. In very late SES failure, stent-related ACS lesions showed gradual luminal narrowing and subsequent rapid progression beyond 5years, whereas non-ACS lesions had progressive luminal narrowing within 5years.