麻豆传媒

PHOENIX -- The novel, next-generation Xience drug-eluting stent (DES) with a 48-mm length met the performance bar with a particularly low restenosis rate, the SPIRIT 48 trial showed.

The Xience Skypoint 48 stent had a target lesion failure (TLF) rate of 5.7% at 1 year, with a 95% CI upper bound of 9.5% that fell within the performance goal of 20%, reported researchers led by Ki Park, MD, of the University of Florida in Gainesville.

"SPIRIT 48 presents high quality data with high levels of device success consistent with prior iterations of the Xience family of stents," Park said at the featured clinical research session at the Society for Cardiovascular Angiography and Interventions (SCAI) meeting here.

Notably, definite or probable device thrombosis at 1 year occurred in only one of the 107 patients (1.0%) in the findings simultaneously published in .

"It sort of stands on its head the idea ... that the longer the lesion, the higher the restenosis rate," commented SCAI press conference moderator David Cox, MD, past president of SCAI. He called the restenosis rate "quite, quite low. And I think IVUS [intravascular ultrasound] would just add to that and improve it even more."

Session moderator Cindy L. Grines, MD, of Northside Hospital Cardiovascular Institute in Johns Creek, Georgia, also expressed surprise at how good the outcomes were for such long stents.

Park cautioned that without a comparator group in the single-arms study, it's hard to really say how the results stack up.

"Nowadays, the rates of overall TLF with contemporary drug-eluting stents are quite low," she said. "So this is an extension of what we know from our prior iteration of drug-eluting stents, and the data is just extrapolated to a longer platform. But I do feel that it does reduce the need for multiple overlapping stents, which is known to be associated with increased risk of stent failure in the long term."

The prospective, open-label SPIRIT 48 trial evaluated the safety and efficacy of the Xience Skypoint 48-mm length everolimus-eluting coronary stent system in 107 patients treated for coronary artery disease with 32.0-44.0 mm de novo native coronary lesions at 25 sites in three countries. The patients will be followed out to 2 years.

The device was implanted in 105 of those patients, for a device success rate of 97.2%. Other secondary outcomes included:

• Target vessel myocardial infarction (MI) in 4.8%
• Cardiac death in one patient (1.o%)
• Clinically-indicated target lesion revascularization in one patient (1.0%)
• A composite rate of all deaths, MIs, and revascularizations of 5.8% to 6.7%, depending on definition

A key limitation of the study, aside from the single-arm design, was lack of a mandate for imaging, which led to no routine collection of data on what imaging was used.

Imaging is "especially important within the LAD [left anterior descending artery], which is where this was most prominently implanted," Park noted. While the LAD anatomically tapers, how operators handled stent dilation was not mandated or routinely captured in the data. "The preference being most of the time that the reference vessel diameter distally is selected as the sort of mean baseline and then postdilation is performed proximally as needed based on the tapering."

If imaging had been required, enrollment would have been higher, she speculated. "Angiographically, we say it's 24 [mm], but then you do imaging and you really get to 38, which is not entirely uncommon, then you would be now in the territory or the range of this particular stent."

Nor was the use of a postdilation or a guide extension mandated, Park acknowledged. "The only mandate for the study was that it was a minimum of 6 French guide. We did modify the protocol to suggest use or consideration for 7 French as well as consideration for a guide extension use. Again, it wasn't mandated, so we don't have that data. But again, something that should be considered because it is a significantly longer stent."

"Currently, there is only one other drug eluting stent available on the market to treat complex coronary artery disease patients," Park said in a statement. "The results of this study are encouraging and offer a safe and efficient alternative option for patients with diffuse CAD [coronary artery disease] in need of stenting."

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