Drug Coated Balloons for Prevention of Restenosis

Overview

The study will be performed as a randomized, double blind trial (in respect of the primary end point) with treatment of the stenotic lesion using uncoated PTA-catheters as control group. 114 patients will be included in the trial at about 5 study centers. Follow-up includes control angiography after 6 and 18 months and clinical follow-up examinations up to 18 months. Primary objective: Efficacy of paclitaxel coated PTA balloons in inhibiting restenosis of below the knee arteries (late lumen loss) Secondary objective: Various angiographic and clinical efficacy measures, safety and tolerance of pacli-taxel coated PTA balloons in inhibiting restenosis of below the knee arteries Descriptive statistics, comparison by t-test, chi-square test for binary events 10.1 Descriptive statistics As far as applicable descriptive statistics will be applied to data and will be referring to individual changes versus baseline (predilatation or immediately postdilatation). The groups will be compared to each other testing the statistical significance of differences (p ≤ 0.05). Con-tinuous data will be expressed as mean ± standard deviation. Categorical variables will be compared using the chi-squared test, and continuous variables will be compared using Student's t test or ANOVA analysis. In addition to the assessment of the primary endpoint and the secondary endpoints a multi-variate analysis to investigate the influence of risk factors on the interventional outcome (interventional success, early restenosis/occlusion, LLL, stent integrity) and clinical outcomes will be performed. For this analysis the following factors will be considered: age, diabetes, neurological status (only Rutherford 5), lesion length, grade of dissection and calcification, reststenosis, number of run-off vessels, stent administration in the index lesion(s). 10.2 Estimated number of patients The primary endpoint of the study is late lumen loss (LLL) at 6 months evaluated by quantitative angiography. Because no data according this endpoint are available for both the control group and the group which will be treated with the paclitaxel coated balloon an assumption according the LLL at 6 months was made according the expectations of the principle investigator. An estimate for LLL as % of MLD in the control group is 50% and in the drug coated balloon group 30 %. The standard deviation is calculated to be 30% of LLL. A sample size of 37 patients in each group will allow the detection of a statistically significant difference (p\<0.05) with 80% power. Based on the "Below study" which enrolled patients with comparable arterial lesions in Tuebingen and the data of the Basil study, it is estimated that 35% of the patients who will be enrolled in the study will not be available for follow-up investigations in order to calculate the MLD. In order to meet a statistical endpoint a total of 114 patients will be enrolled.