STATISTICAL METHODS AND SAMPLE SIZE CALCULATION. A sample size of 100 to 110 patients was estimated to be necessary assuming 6-month restenosis rates of 50% in the PTA group3 and 25% in the nitinol stent group11. A two-sided p-value of 0.05 was considered statistically significant and a power of 80% was required with a 10% maximum drop-out rate. Data analysis for primary and secondary study end points was performed according to the intention-to-treat principle. A secondary as-treated (per-protocol) analysis compared the results of stent implantation (primary or secondary) vs. PTA alone with respect to the primary study end point.