Clinical utility of low-pressure implantation of drug-eluting stent into very small vessels

Abstract

Background: Although drug-eluting stents (DES) reduce restenosis, the best strategy for DES implantation in small vessels has not been established.

Purpose: We investigated the clinical usefulness of low-pressure implantation of a 2.5-mm DES for small vessels less than 2.5mm in diameter.

Methods: In 118 patients, a 2.5-mm DES was implanted for small vessels less than 2.5mm in diameter between 2007 and 2009 in our hospital. The patients were divided into two groups by initial deployment pressure: low-pressure (LP; n=46) and nominal-pressure (NP; n=72).

Results: Patients with impaired glucose tolerance were more frequent (p=0.02) and the target vessel diameter was significantly smaller (p=0.01) in the LP group than in the NP group. A smaller minimum lumen diameter (MLD) was obtained (LP: 2.22±0.27mm vs. NP: 2.34±0.26mm, p=0.02) after DES implantation with a smaller balloon-to-artery ratio (p=0.03) in the LP group. However, at mid-term follow-up (7.7±3.9 months), MLD (p=0.55) and the binary restenosis rate (LP: 2.6% vs. NP: 11.1%, p=0.12) were not significantly different between the LP and NP groups. Furthermore, by Kaplan-Meier analysis, the incidence of major adverse cardiac events was not different between the groups during the long-term follow-up (32.4±8.6 months).

Conclusion: The present study indicates that low-pressure implantation of 2.5-mm DES for very small vessels may be feasible with regard to short- and long-term clinical outcomes.

Keywords: Clinical outcome; Coronary artery disease; Drug-eluting stent; Small vessel disease.