The PACIFIER Trial evaluated prevention of restenosis with paclitaxel-coated PTA balloon catheters in stenosis or occlusion of femoropopliteal arteries versus a control group treated with uncoated balloons. We specifically looked at the In.Pact Pacific drug-eluting balloon (Medtronic).
What criteria did patients meet to be entered into the study?
As the treatment technique with a coated balloon does not significantly differ from the treatment with an uncoated balloon, the study was planned to allow randomization of nearly any patient with a femoropopliteal lesion up to 30 cm in length. The patients had clinical symptoms in Rutherford class 2-5. We excluded patients with acute thrombosis, and those with unsuccessful treatment of a flow restricting inflow lesion. One patent outflow vessel was also mandatory. We accepted a total of 91 patients in this study.
What were the results of the study? Does this new treatment have a high success rate?
The study showed a highly significant difference concerning the primary end point late lumen loss in favor of the study group. What we had was actually a late lumen loss of 0 coming out of the 6-month period in our study group, which is the best you can achieve. Another surprise in the study was that our control group performed very well, even better than we had expected. The patients treated with a normal balloon had good results, but even with a strong control group like this, our study group was significantly better concerning the primary end point.
At follow-up visits, are patients still doing well after treatment with little or no side effects involved?
Patients did well at 6-month follow-up with no coating-related side effects detected. Follow-up will be continued for up to 3 years and we expect the 2 groups to be even more significantly different as we continue. With such significant differences between the groups after only 6 months, it shows the strong impact of the study device.
What makes this trial different from others testing drug-eluting balloons?
This is one of the few existing randomized multicenter trials testing drug-eluting balloons, and this is the first peripheral trial reporting a late lumen loss of 0. Angiographic readings at the core lab in this trial were blinded, which increase the scientific value and while there are 2 other similarly designed trials right now, those are testing a different balloon-coating technique.
What is the next step for the trial? Will there be another phase to further test your theories?
The follow-up period needs to be completed as we only have the first 6-month results. Follow-up will continue up to 3 years. We must also complete the subgroup analysis of in-stent restenosis because we not only treated de novo stenosis but we also treated patients who already failed after stent placement or PTA. It should be really interesting to see the difference in these indications.
Is there anything further you would like to add?
The late lumen loss with an actual number of 0 is really surprising and significant for our trial. One wouldn’t have expected a peripheral study to come out this well and that is truly exciting.
Dr. Michael Werk, MD, is the Assistant Medical Director for the Department of Radiology at the Martin Luther Hospital in Berlin. He is the principal investigator in the PACIFIER trial. Dr. Werk specializes in interventional radiology, oncological diagnostics, therapy monitoring, interventional procedures, magnetic resonance imaging, and computed tomography.