Angiographic evidence of progressive lumen narrowing over 2 years following drug-eluting stent implantation

Background: Questions persist regarding the ability of drug-eluting stents (DES) to inhibit intimal growth in the long-term.

Methods: We prospectively enrolled 766 lesions treated with DES that underwent angiographic examination at 6 months and 2 years after stenting. Lesions with 6-month restenosis (>50% of visual stenosis) were excluded. The primary end point was quantitative change in minimal lumen diameter (MLD) according to serial angiography of the segment (in-segment), the stented region (in-stent) and both edges. Late loss, defined as MLD change, was categorized as early (between post-procedure and 6 months), delayed (between 6 months and 2 years), or overall (between post-procedure and 2-years).

Results: MLD progressively decreased in both the in-stent and edge regions at both 6 months and 2 years (p<0.001 in all paired analyses). In-segment MLD decreased from a median 2.27 mm (interquartile range; 1.98, 2.62) at post-procedure to 2.18 mm (1.86, 2.47; p < 0.001 with post-procedure) at 6 months, and to 2.02 mm (1.66, 2.37; p<0.001 with 6 months) at 2 years. Late loss was 0.0 6 mm (-0.05, 0.26) in the early phase, 0.09 mm (-0.01, 0.28) in the delayed phase, and 0.20mm (0.03, 0.50) overall. Two-year angiographic restenosis occurred in 54 (7.0%) lesions, and 65 (8.5%) underwent target lesion revascularization over a median follow-up of 52.5 months.

Conclusion: Serial angiographic analysis showed that DES lumen diameter progressively narrowed over 2 years post-procedure. However, the incidence of target lesion revascularization was relatively low due to the small amount of late loss in the delayed phase.