Effect of intravascular ultrasound-guided adjuvant high-pressure non-compliant balloon post-dilation after drug-eluting stent implantation

Abstract

Drug-eluting stent (DES) expansion characteristics after aggressive high-pressure post-dilation using a non-compliant (NC) balloon have not been fully investigated. We evaluated 58 patients with native coronary lesions treated with DESs [24 paclitaxel eluting stents (PES) and 34 sirolimus-eluting stents (SES)]. After post-dilation (12-14atm) using a stent-mounted semi-compliant balloon to reduce stent edge injury, adjuvant high-pressure post-dilation using NC balloon was performed within the stents. Stent size, stent length, and NC balloon size were selected based on preinterventional intravascular ultrasound (IVUS) assessment. Stent underexpansion was defined according to criteria of the Multicenter Ultrasound Stenting in Coronaries (MUSIC) study as a minimal stent cross-sectional area <90% of the average reference lumen area. Resultant endpoint was to obtain optimal stent expansion. Serial changes of stent expansion and stent symmetry were calculated in each group. After stent-mounted semi-compliant balloon post-dilation, both stents could not achieve adequate percent stent expansion (PES 73±18% vs. SES 67±9%, p=0.38). After high-pressure post-dilation using an NC balloon, percent stent expansion was 97±14% in PES and 91±13% in SES, respectively (p=0.25). Axial stent symmetry indices also significantly improved in both groups. Although radial stent symmetry indices improved significantly in PES group, those in the SES group had no significant changes. Finally, frequency of stent underexpansion significantly reduced, 87-20% in PES and 92-15% in SES, respectively (p=0.01) without any significant stent edge injury. DES expansion improved safely after adjuvant high-pressure post-dilation using an NC balloon under IVUS guidance.