New arteriovenous (AV) access results were presented at the 2020 Leipzig Interventional Course (LINC; 28–31 January, Leipzig, Germany), including data on percutaneous AV fistula creation and also the use of drug-coated balloons (DCBs) in AV access interventions. While Robert Jones (University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK) opened the session by revealing a high functional patency for endoAVF at six months, Andrew Holden (Auckland University School of Medicine, Auckland, New Zealand) revealed a sustained patency advantage for a DCB compared to percutaneous transluminal angioplasty (PTA).
EndoAVF shows high functional patency at six months
Jones opened the session by presenting initial multicentre experience results of the WavelinQ catheter. Concluding that “AV is now endovascular,” results of and EU and Canada post-market study showed 95% functional patency at six months as well as a limited need for secondary procedures.
“This is the first time that this additional data on the multicentre WavelinQ study has been seen,” Jones began. Endovascular AV fistula (endoAVF) devices—created with the intention of improving fistula outcomes—have performed well in clinical studies. “There are high rates of technical success in terms of creation, higher rates of maturation and patency and low rates of complications. But we have got to bear in mind that these closely monitored clinical trials are not the real world,” Jones commented.
At the University Hospitals Birmingham NHS Foundation Trust Jones and colleagues carried out a matched comparison of WavelinQ fistulas with surgical fistulas. They had 30 in the WavelinQ arm and 40 in the surgical arm. Patency results showed that WavelinQ fistulas outperformed those created surgically.
In terms of the post-market study, this was intended to collect data on WavelinQ cathether performance and outcomes in a prospective, multicentre, international study, which recruited 100 patients across 13 sites in the EU and Canada. Jones remarked: “The post-market study forms part of a wider programme of clinical trials looking at the WavelinQ device, most of which have already either completed or been published”.
Looking to the future, Jones informed the LINC audience that there are two other studies that are being lined up—a prospective, multicentre study in the USA, which aims to recruit 250 patients and a global study looking at another 100 patients. “Hopefully both of these will be rolled out in 2020,” Jones added.
Jones concluded: “In summary, this is the first time that this post-market data is being seen. We have got 95% functional patency at six months with a limited need for secondary reinterventions.”
DCB shows sustained patency advantage over PTA
Subsequently, Holden presented 12-month outcomes of the IN.PACT AV access study, showing a 63.8% target lesion primary patency in the DCB arm compared to 43.6% in the PTA arm, with no difference in mortality.
The AV access investigational device exemption (IDE) trial was designed to evaluate safety and effectiveness of the IN.PACT AV DCB compared to PTA for de novo or restenotic obstructive lesions of native AV fistulae in the upper limbs. This was performed in the USA, in Japan and in New Zealand.
A total of 330 patients were randomised 1:1. The primary safety endpoint was serious adverse event rate within 30 days and primary effectiveness endpoint was target lesion primary patency through six months, which is defined as freedom from clinically-driven target lesion revascularisation (CD-TLR) or access circuit thrombosis measured to six months post-procedure.
It was revealed last year that IN.PACT AV access was the first DCB versus angioplasty trial to meet its primary effectiveness endpoint—a “highly impressive” primary patency of 82.2% at six months compared to 59.5% with PTA with high statistical significance and also a significant advantage in terms of freedom from CD-TLR.
“I am delighted to share for the first time the 12-month primary effectiveness endpoint. Again, a highly significant difference in target lesion primary patency—63.8% in the DCB arm compared to 43.6% for the PTA arm,” Holden revealed, adding that “there was also a highly significant difference in CD-TLR, at 35% for the DCB arm and 54.3% in the PTA arm”.
Holden added that there was less than half the rate of access circuit thrombosis in the DCB arm. “This is such a severe and catastrophic complication that, even though it did not reach clinical significance, I think is worth mentioning”.
In terms of safety at 12 months, the serious adverse event rate for the DCB arm was 46.9% compared to 69.2% for the PTA group. In the DCB arm, 40.1% had lesion revascularisations compared to 62.4% in PTA arm. Holden added that there is “absolutely no mortality signal between the two groups at 12 months,” detailing that freedom from all-cause mortality in DCB arm was 90.6% and in PTA arm was 90.4%.
Holden summarised: “For the first time we have seen sustained patency advantage for a DCB over PTA using a combination of vessel preparation with a high-pressure balloon and DCB angioplasty with a target lesion primary patency of 63.8% for the DCB compared to 43.6% for PTA arm. Fewer interventions were required to maintain target lesion primary patency in the DCB arm compared to the PTA arm, and we also saw the incidence of access circuit thrombosis more than half—something I think is very important given the severity of that complication—and no difference in mortality out to 12 months.”