Postdilatation following coronary stent deployment: lesion and procedural characteristics associated with an increase in stent dimensions.

UNLABELLED: Adjunctive balloon postdilatation following stent deployment is often used to optimize stent expansion. However, the benefit of this strategy with modern stent delivery systems is not known. We investigated angiographic and procedural factors associated with a favorable response to postdilatation after coronary stent deployment. METHODS: We performed a prospective study recruiting 385 patients (490 lesions) who underwent stent deployment. Quantitative coronary angiography was used to measure the minimal lumen diameter (MLD) within the stent before and after postdilatation. Optimal stent deployment was defined as a stent MLD greater than or equal to 90% of the reference vessel diameter. RESULTS: Postdilatation was performed in 41.2% (202/490) of cases, with an increase in stent MLD from mean (SD) 2.50 (0.40) to 2.70 (0.38) mm, p < 0.0001. Optimal stent deployment increased from 35.6% (72/202) to 56.5% (115/202). The percentage increase in stent MLD with postdilatation was greatest in cases with a residual stenosis of > 20% after coronary stenting or a stent deployment pressure < or = 14 atm. Vessel size and predilatation had no impact on the response to postdilatation. In those cases where postdilatation was not performed, optimal stent deployment was achieved in 64.9% (187/288) of cases. CONCLUSION: A significant proportion of patients did not achieve optimal stent deployment with modern stent delivery systems. The increase in stent MLD with postdilatation was greater in cases with lower stent deployment pressures and more significant residual stenoses.