Comparison of paclitaxel-eluting stent and sirolimus-eluting stent expansion at incremental delivery pressures

Abstract 

Objectives

We sought to compare the adequacy of paclitaxel-eluting stent (PES) and sirolimus-eluting stent (SES) expansion based on intravascular ultrasound (IVUS) imaging criteria at conventional delivery pressures.

Methods

Forty-six patients underwent SES implantation and 42 patients underwent PES implantation for de novo native coronary lesions <33 mm in length with reference lumen diameters of 2.5–3.5 mm. Stents were serially expanded with gradual balloon inflations at 14 and 20 atm. IVUS imaging was performed prior to intervention and after each balloon inflation. Stent expansion (minimal stent cross-sectional area/reference lumen cross-sectional area) was measured. Inadequate stent expansion was defined using the MUSIC criteria (all struts apposed, no tissue protrusion, and final lumen cross-sectional area >80% of the reference or >90% if minimal lumen cross-sectional area was <9 mm²).

Results

The baseline characteristics of the two groups were similar except for shorter lesion length, larger mean lumen cross-sectional area, larger lumen diameter, and lower plaque burden in the PES group. Stent expansion was inadequate in 80% of patients with SES versus 63% of patients with PES at 14 atm, although this was not statistically significant. After 20 atm, 48% of patients with SES remained underexpanded as compared with 35% of patients with PES.

Conclusion

Drug-eluting stents showed significant underexpansion by MUSIC criteria at conventionally used inflation pressures. Higher balloon inflations are required especially during deployment of a SES. IVUS guidance is recommended to ensure optimal results and outcomes with both stents.

Keywords: Paclitaxel-eluting stent, Sirolimus-eluting stent, Intravascular ultrasound