Andrew Holden

Interventionists can confidently use lower profile drug delivery platforms, based on data that shows 0.018-inch guidewire devices are non-inferior to 0.035-inch guidewires. In a Podium 1st presentation at Charing Cross (CX) Symposium on Thursday, Andrew Holden (Auckland, New Zealand) said: “At 90 days, we can see that the 0.018-inch IN.PACT Pacific device is certainly non-inferior to the [0.035-inch] IN.PACT Admiral device—the device with so much five-year follow-up data. What this means is we can have confidence transposing all the published data from 0.035-inch technologies to these newer low-profile 0.018-inch devices.”

Randomised controlled trials and real-world registries have established a patency advantage in the femoropopliteal segment for drug coated balloons (DCBs) with an 0.035-inch guidewire compatible platform. But Holden pointed out: “There are a lot of clinicians who would like to use lower profile, 0.018-inch guidewire-compatible devices,” and he listed the clinical advantages. “The profile is smaller and that reduces access sheath size and bleeding risk,” he said. “And that is often very relevant, particularly in elderly female patients with small calibre vessels. Lower profile means we have better deliverability and crossing ability, and we can just use one guidewire to cross lesions above and below the knee.”

Researchers created arterial injuries in swine models using angioplasty and stenting, and treated 30 days later with a DCB or drug eluting stent. They then assessed restenosis rates using quantitative vessel analysis (QVA) and optical coherence tomography (OCT) imaging at 60, 90 or 120 days post-treatment, and also measured tissue levels of drug at the terminal timepoint.

Firstly, the performance of two 0.035-inch compatible guidewire devices, the IN.PACT Admiral (Medtronic) and the Stellarex (Phillips), were compared: “At various timepoints, both 60 and 90 days, there is a significant reduction in restenosis with the IN.PACT Admiral compared to the Stellarex, and this is not surprising given that the higher input dose with the IN.PACT Admiral. The tissue concentrations that were obtained at the terminal timepoint also showed that there was higher tissue dose of paclitaxel with the IN.PACT Admiral.”

The investigators also looked at two 0.018-inch guidewire compatible devices—the Pacific (Medtronic) and the Ranger (Boston Scientific); this comparison extended the timepoint to 120 days. “The Pacific was trending towards a lower restenosis rate with QVA and OCT compared to the Ranger at 60 and 120 days. It did not reach statistical significance, but there was a positive trend.”

Holden told CX Daily News that the lower stenosis rates found with Pacific compared to Ranger could also be explained by the higher input dose for the Pacific balloon. The dissolution rates with paclitaxel for all the devices are pretty much the same so if you have a higher input dose at the start you are likely to see a pronounced, more prolonged restenosis effect.” However, “both platforms performed extremely well in terms of preventing re-stenosis,” Holden said

A comparison between the IN.PACT Pacific and the IN.PACT Admiral—the 0.018-inch and the 0.035-inch devices from the same company—by QVA and OCT found comparable performance in terms of restenosis. Holden said: “This implies that the data we have from the 0.035-inch database can be translated to the 0.018-inch platform.”

He concluded: “We certainly could show that the 0.018” guidewire devices were non-inferior to the 0.035” devices. Although this is a pre-clinical study, it is one that really does have clinical relevance.”