Overestimation of stent delivery balloon diameters by manufacturers' compliance tables: a quantitative coronary analysis of Duet and NIR stent implantation

Abstract

Although manufacturers' compliance tables of stent delivery balloons indicate the diameter of the balloon at a given inflation pressure, it is unclear whether these data correlate with in vivo true intracoronary balloon diameters (TBDs). The TBDs of two new-generation balloon-expandable stent delivery systems (Duet and NIR) were measured by quantitative coronary analysis (QCA) in 100 consecutive patients. The manufacturers' stated balloon diameter (BD) of the stent delivery systems overestimated the TBD in 94% +/- 4% of patients receiving both Duet or NIR stent implantations. In only 6% of the patients, the TBD matched the manufacturers' stated balloon diameter. There was no underestimation of TBDs by both manufacturers' compliance tables. The Duet tables overestimated TBDs by 14% +/- 8% (range, 1%-36%), the NIR tables by 18% +/- 8% (range, 1%-41%), P < 0.05, Duet vs. NIR, respectively. When the manufacturers' data were corrected for the differences in reporting data from in vitro tests, i.e., balloon compliance data with or without the stent, the degree of overestimation of diameters was similar for Duet and NIR stent delivery balloons (14% +/- 8% vs. 13% +/- 7%, Duet vs. NIR; P = NS). Manufacturers' compliance tables of both the Duet and NIR stent delivery balloon systems significantly overestimate the true intracoronary balloon diameter. The manufacturers' of stent delivery balloons should clearly state on the box, if balloon compliance data were derived from in vitro bench testing, which phantoms were used for compliance analysis, and that the tables may overestimate the true intracoronary balloon diameter. The findings of the present study have important clinical implications with respect to performing coronary stent implantation with precision.