NEXT Published: Biodegradable Polymer BES Shows Noninferiority to EES

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Key Points:
  • Randomized Japanese study compares novel BES to current-generation EES
  • Noninferiority shown with regard to 1-year TLR, in-segment late loss
  • Definite stent thrombosis rates low, similar for both devices

By Yael L. Maxwell
Tuesday, May 07, 2013

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A novel biolimus A9-eluting stent (BES) with a biodegradable polymer appears clinically and angiographically noninferior to a current-generation everolimus-eluting stent (EES), according to results of the randomized NEXT trial scheduled to be published online May 7, 2013, ahead of print in the Journal of the American College of Cardiology.

The findings were first presented at the American College of Cardiology/i2 Scientific Sessions in San Francisco in March 2013.

Researchers led by Takeshi Kimura, MD, of Kyoto University Graduate School of Medicine (Kyoto, Japan), randomized 3,235 patients undergoing PCI with DES to receive either the Nobori BES (n = 1,617; Terumo, Tokyo, Japan) or the Xience V/Promus EES (n = 1,618; Boston Scientific, Abbott Vascular) in an all-comer study design. Subjects were treated at 98 Japanese centers from May to October 2011.

Nobori the NEXT Frontier?

At 1 year, the primary efficacy endpoint of TLR occurred in 4.2% of patients in each group, showing the noninferiority of BES compared with EES (P < 0.0001 for noninferiority; P = 0.93 for superiority). There were no differences in other clinical endpoints, as well, with very low rates of definite stent thrombosis in both arms (table 1).

Table 1. Clinical Outcomes at 1 Year

 

Nobori
(n = 1,617)

Xience/Promus
(n = 1,618)

P Value

Clinically Driven TLR

3.0%

3.0%

0.998

TVR

6.8%

6.5%

0.67

Death

2.6%

2.5%

0.9

MI

3.3%

3.1%

0.77

Definite Stent Thrombosis

0.25%

0.06%

0.18

 

TLR results were maintained across multiple subgroups, with a trend favoring Nobori in patients on hemodialysis (HR 0.6; 95% CI 0.28-1.28; P = 0.19), showing a P value for interaction of 0.16.

In an angiographic substudy of 528 patients performed at 8 to 12 months, in-segment late loss was similar between the Nobori and Xience/Promus groups (0.03 ± 0.39 mm vs. 0.06 ± 0.45 mm; P = 0.52), again demonstrating noninferiority (P < 0.0001). In-stent late loss, binary restenosis, and peri-stent contrast staining were also similar between the 2 groups. However, those implanted with BES saw a higher rate of stent fracture (table 2).

Table 2. Angiographic Substudy Outcomes at 8 Months

 

Nobori
(n = 263)

Xience/Promus
(n = 265)

P Value

In-Stent Late Loss, mm

0.17 ± 0.35

0.14 ± 0.36

0.35

Binary Restenosis

7.1%

7.5%

0.86

Peri-stent Contrast Staining

2.7%

1.4%

0.24

Stent Fracture

3.1%

0

0.004

 

The number of stents used per patient was similar in the BES and EES groups (1.59 ± 0.84 vs. 1.6 ± 0.83; P = 0.74), and procedural success was also similarly high for each cohort (96.8% vs. 96.7%; P = 0.9). Slightly more than one-quarter (27%) of procedures in each group were staged.

Don’t Neglect Early Restenosis

“Although biodegradable polymer DES have been developed mainly to overcome late adverse events, it is crucially important for biodegradable polymer DES to have efficacy in preventing early restenosis at least equivalent to that of current standard DES using biocompatible durable polymer,” Dr. Kimura and colleagues write, adding that the Nobori stent was developed with this goal in mind.

They reference results of the COMPARE-2 trial, which demonstrated noninferiority of BES relative to EES, although with high procedural failure for BES.

The authors observe that although the NEXT trial was “not powered for evaluating this low-frequency event,” the rates were low and equivalent between groups.

They add that “continued follow-up of the current and the COMPARE-2 trials would shed light on the long-term outcome of biodegradable polymer BES as compared with durable polymer EES, providing crucial implications [for] future development of improved metallic DES.”

 

Confirmatory Findings

In an e-mail communication with TCTMD, Giulio G. Stefanini, MD, of Bern University Hospital (Bern, Switzerland), said the results of NEXT are not surprising given the similar findings in COMPARE-2.

“Beyond NEXT, several randomized controlled trials have provided evidence on the favorable safety and efficacy profile of biolimus-eluting stents with biodegradable polymer coating, which . . . are performing at least as good as everolimus-eluting stents with durable fluoropolymer coatings,” he said. “I therefore think that biolimus-eluting stents with biodegradable polymer coating indeed show potential for the future. Notably, these devices are already being widely used in routine clinical practice [outside] the [United States].”

Because DES with biodegradable polymer coatings have been associated with a lower risk of very late stent thrombosis compared with early-generation DES with durable polymer coatings, “it will be interesting to see whether there is any difference between these technologies during longer-term follow-up of NEXT and COMPARE-2,” Dr. Stefanini continued. In addition, because of the “extremely low event rates observed for stent thrombosis at 1 year with available newer-generation drug-eluting stents, it would be interesting to investigate whether dual antiplatelet therapy duration may be shortened below the currently recommended 12 months.”

Study Details

Overall, patients were primarily older and had histories of diabetes, multivessel coronary artery disease, and prior PCI, heart failure, hemodialysis, left main CAD, small vessel disease, chronic total occlusion, and bifurcation lesions. There were few patients with acute MI or high Syntax scores.

The research protocol recommended aspirin (≥ 81 mg daily) indefinitely and thienopyridine (75 mg clopidogrel daily or 200 mg ticlopidine) for at least 3 months, but the duration of dual antiplatelet therapy was left to the discretion of each attending physician.

 

Source:

Natsuaki M, Kozuma K, Morimoto T, et al. Biodegradable polymer biolimus-eluting stent versus durable polymer everolimus-eluting stent: A randomized, controlled, non-inferiority trial. J Am Coll Cardiol. 2013;Epub ahead of print.

Disclosures:

  • Dr. Kimura reports serving on the advisory board of Abbott Vascular and Terumo Japan.
  • Dr. Stefanini reports no relevant conflicts of interest.

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