Stent length is a contributing factor of suboptimal stent expansion in drug-eluting stents

Background: Failure to achieve optimal stent expansion poses a risk of treatment failure in percutaneous coronary intervention (PCI). Although intravascular ultrasound provides useful information for suboptimal stent expansion, a substantial portion of PCIs are currently being performed under angiographic guidance only. Aim: In order to evaluate the adequacy of stent expansion of four widely used drug-eluting stents in angiography-guided PCI, we performed a retrospective analysis of lesions undergoing PCI using quantitative coronary angiography. Methods: A total of 112 de novo lesions were analysed. Minimal lumen diameter (MLD) was measured at peak pressure during stent deployment (MLD1), after stent deployment (MLD2), and after postdilatation (MLD3). Stent underexpansion, stent elastic recoil, and stent deficit were calculated. Optimal stent deployment was defined as final MLD >= 90% of predicted diameter. Results: For deploying a stent balloon, higher than nominal pressure was used in 83% of cases (93/112). However, optimal deployment was observed in only 32% (36/112). Adjuvant post-dilatation was performed in 59% (45/76) of lesions with suboptimal expansion, which increased the optimal deployment rate by 60% (27/45). Final optimal stent deployment rate was achieved in 56% (63/112). We found that the MLD1 (p = 0.04), MLD3 (p = 0.02), final MLD (p = 0.04), and optimal stent deployment rate (p = 0.036) were significantly reduced in longer stent deployment lesions (= 20 mm) compared to shorter lesions (< 20 mm). Conclusions: Stent length may be a contributing factor of suboptimal stent expansion in angiography-guided PCI.