APPOSITION IV: Self-Expanding SES Covers Struts Better, Faster than Balloon-Expandable DES

PARIS, France—A self-apposing sirolimus-eluting stent (SES) shows ‘excellent’ apposition over time—better than an existing balloon-expandable drug-eluting stent—in patients with ST-segment elevation myocardial infarction (STEMI), according to a late-breaking trial presented on May 20 at EuroPCR 2014. Additionally, the newer device is associated with faster strut coverage.

For the APPOSITION IV (RAndomized comParison between a self-APposing SIrolimus-Eluting Coronary STent and a balloon-expandable stent in Acute MyocardIal InfarctiON) study, Robert-Jan van Geuns, MD, PhD, of Erasmus Medical Center (Rotterdam, the Netherlands), and colleagues randomized 152 STEMI patients to treatment with the Stentys self-apposing SES (Stentys, Paris, France; n = 90) or the balloon-expandable Resolute zotarolimus-eluting stent (ZES; Medtronic, Santa Rosa, CA; n = 62) at 12 European centers. Each treatment arm was then randomized to either 4- or 9-month follow-up.

On QCA, no differences were observed between the treatment arms just after the procedure for in-stent minimal and mean lumen diameter. However, in-stent mean lumen diameter was larger at both 4- and 9-month follow-up for Stentys compared with Resolute (table 1).

Table 1. In-Stent QCA Outcomes

 

Stentys SES

Resolute ZES

P Value

4-Month Follow-Up Cohort
Mean Lumen Diameter, mm
Minimal Lumen Diameter, mm
Late Lumen Loss, mm

 
3.39 ± 0.46
2.47 ± 0.90
0.08 ± 0.48

 
3.13 ± 0.35
2.65 ± 0.50
0.18 ± 0.88

 
.03
.40
.65

9-Month Follow-Up Cohort
Mean Lumen Diameter, mm
Minimal Lumen Diameter, mm
Late Lumen Loss, mm

 
3.27 ± 0.55
2.49 ± 0.63
0.04 ± 0.43

 
2.93 ± 0.43
2.41 ± 0.51
0.17 ± 0.43

 
.01
.62
.23


Furthermore, OCT demonstrated that Stentys SES was associated with fewer malapposed struts and more covered struts than Resolute ZES at 4 months (table 2).

Table 2. OCT Outcomes at 4 Months

 

Stentys SES
(n = 21)

Resolute ZES
(n = 26)

P Value

Malapposed Struts

0.07 ± 0.26%

1.16 ± 1.59%

.002

Covered Struts > 20 μm

94.32 ± 5.69%

89.09 ± 5.65%

.003

Stents with All Struts Covered

33.3%

3.8%

.02


No differences in malapposition (P = .55) or coverage (P = .81) were seen between the treatment arms in the 9-month cohort.

Clinical outcomes were low and well balanced between stent groups in terms of MACE (P = .46), TVF (P = .46), and target vessel MI (P = .39).

Matches ‘Best-in-Class’ DES

The results are in line with those of the APPOSITION II study, which showed good apposition with the Stentys SES at 3 days, Dr. van Geuns said, adding that the late lumen loss seen with the device “matches that of best-in-class DES at this moment.” Because of this, the findings support future randomized studies investigating the safety of early termination of dual antiplatelet therapy when using the Stentys SES for STEMI, he continued.

However, panel member Helge Möllmann, MD, of Kerckhoff Heart Centre (Bad Nauheim, Germany), cautioned against stopping dual therapy early “because you don’t treat the stent itself but [the] whole coronary artery disease.”

Dr. van Geuns countered that in patients with single vessel disease and no serious complications or comorbidities, “there is an option for shorter DAPT.”

Predilatation Needed at Least Until Design Evolves

Answering a question related to predilatation and the low yet relevant rates of device failure, Dr. van Geuns pointed out that the current delivery system is made up of an outer sleeve, “which results in a significantly larger profile compared with a balloon-expandable stent.

“To make the procedures easier and faster [with minimal failure], we recommend predilatation,” he continued, adding that a new delivery mechanism is currently being designed as a “peel-off sleeve which can be discarded exactly at the spot [the stent is needed].”

Utilizing self-expanding stent technology will also help curb the need for aggressive oversizing sometimes seen with balloon expandable stent implantation, Dr. van Geuns said.

Study Details

Mean patient age was 58 years, and more than three-quarters of patients were men. Baseline and procedural characteristics were well balanced between the treatment arms, but those treated with Stentys were more likely to undergo post-dilatation (90.0% vs 30.6%; P < .001).

 


Source:
van Geuns RJ. Randomised comparison between a self-apposing sirolimus-eluting coronary stent and a balloon-expandable stent in acute myocardial infarction. Presented at: EuroPCR; May 20, 2014; Paris, France.

 

 

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Disclosures
  • Dr. van Geuns reports receiving honorarium from Abbott Vascular, Boston Scientific, Stentys, and Tryton Medical and institutional grant/research support from Abbott Vascular, Boston Scientific, and Tryton Medical.

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