Drug-eluting balloons were a much-discussed topic at this year’s TCT conference, in October 2008, Washington DC. Two sets of results showed that the area is making headway, and the usefulness of this type of device.
Thunder trial: safe angioplasty with drug-eluting balloons
Dr Gunnar Tepe, University of Tuebingen, Germany, presented the two-year results of the Thunder trial, which investigated the safety of paclitaxel-eluting balloons and whether rates of reduction of restenosis previously established by Tepe et al would be maintained. The results showed that the use of these balloons in angioplasty is safe and reduces restenosis and repeat target lesion revascularisation (TLR).
The blinded, multi-centre trial studied 154 patients with stenosis or occlusion of a femoropopliteal artery. Each was randomised to receive one of three treatments: angioplasty with a conventional balloon catheter coated with paclitaxel; paclitaxel admixed to the contrast agent intra-arterially during conventional balloon angioplasty; or balloon angioplasty without paclitaxel (the control group). The primary endpoint was late lumen loss at six months as observed using quantitative angiography and analysed by an independent core lab. Further angiography was taken at 12 and 24 months. An important secondary endpoint was TLR.
The six-month results showed that the paclitaxel in contrast agent group had a late lumen loss of 0.4±1.2mm and 0.4±1.2mm in the group that received the paclitaxel-coated balloon, compared to 1.7±1.8mm in the control group. TLR at six months was 3/48 (6%) in the coated balloon and 12/52 (23%) in the paclitaxel in contrast agent group vs. 15/54 (30%) in the control group. At 24 months follow-up, TLR increased to 7/48 (15%) in the coated balloon group, 21/52 (40%) in the paclitaxel in the contrast agent group and 32/54 (59%) in the control group.
Tepe concluded that the use of the paclitaxel-eluting balloon is safe and reduces restenosis and the need for TLR out to two years in femoropopliteal arteries, showing improved results over control and paclitaxel administered in the contrast agent.
The study cohort comprised 24% smokers and 49% diabetics, with a mean age of 68. Twenty-seven percent had occlusions and 36% restenotic lesions. Mean lesion length was 7.4cm ± 6.5cm and there were no significant differences in baseline characteristics between the groups.
Guided re-shaping technology safe in humans
The guided re-shaping technology (GRST) peripheral catheter system, manufactured by Minnow Medical, has been tested in its first-in-human trial. Investigators found that it was safe and gave “excellent” acute results, offering an alternative to stenting in superficial femoral arterial (SFA) or popliteal lesions. Results from the trial were presented at TCT by Dr Dierk Scheinert, Universität Leipzig Herssentrum, Germany.
The prospective, open-label, non-randomised trial enrolled 30 patients with up to two de novo lesions at sites in Germany, Argentina and Chile. The GRST, which adds “gentle energy” to the conventional balloon angioplasty process, was used to place a balloon in the target lesion. Energy was delivered to the lesion for two to four seconds per treatment. Lesions were evaluated with intravascular ultrasound and virtual histology before and after treatment and follow-up was planned with duplex ultrasound and ABI assessments at one, three, six and 12 months post-procedure (mean follow-up was 4.1 months).
A total of 35 lesions (26 SFA, length 3.2 ± 2.2cm) were treated with maximum balloon pressures of 4.5 ± 1.8 atmospheres. The average number of treatments per patient was 4.5 ± 3.1, with acute angiographic success observed in all cases, resulting in a reduction in diameter stenosis from 84.7% to 11.6%. No stents or other adjunctive therapies were used. Out to one month, no revascularisation procedures were needed and ABI assessments improved from 0.76 ± 0.31 at baseline to 1.01 ± 0.32 (p <0.01). Duplex peak velocity ratios decreased from 4.4 ± 2.0 baseline to 1.1 ± 0.44 (p<0.01).
Investigators concluded that the GRST system was both safe and efficacious in treating patients with SFA or popliteal lesions.