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To treat drug-eluting stent (DES) restenosis, a sirolimus-eluting stent (SES) is more effective than a cutting balloon if the lesion is focal and just as effective as a second-generation everolimus-eluting stent (EES) if the lesion is diffuse, according to a small study published in the March 20, 2012, issue of the Journal of the American College of Cardiology.

Investigators led by Seung-Jung Park, MD, of Asan Medical Center (Seoul, South Korea), stratified 162 patients by their pattern of DES restenosis:

• Focal (≤ 10 mm; n = 96)
• Diffuse (> 10 mm; n = 66)

The focal group was then randomized to treatment with a cutting balloon (n = 48; Boston Scientific, Natick, MA) or SES (n = 48; Cypher Select, Cordis/Johnson and Johnson, Miami Lakes, FL). The diffuse group was randomized to implantation of SES (n = 32) or EES (n = 34; Xience V, Abbott Vascular, Santa Clara, CA).

Most clinical, lesion, and procedural characteristics were well matched between the 2 groups in both the focal and diffuse cohorts.

SES Better for Focal, Equivalent for Diffuse Lesions

In the focal cohort, device success was achieved in 95.8% of the cutting balloon arm and 100% of the SES arm (P = 0.16). In-segment acute gain was similar between the treatment groups. However, at 9-month angiographic follow-up, in-segment late luminal loss was lower and minimal luminal diameter (MLD) was higher in the SES group compared with the cutting balloon group. In addition, there was a trend toward a lower rate of angiographic in-segment restenosis in the SES group (table 1).

Table 1. QCA Outcomes at 9 Months: Focal Cohort

 
In addition, at 12 months, clinical events including MACE (composite of death, MI, and TVR; 6.3% vs. 6.3%; P = 1.00), the component endpoints, and Academic Research Consortium-defined definite/probable stent thrombosis did not differ between the cutting balloon and SES groups. No deaths were observed over the study period in either group.

In the diffuse cohort, device success rates were 97.9% for SES and 95.7% for EES (P = 0.16). Nine-month angiographic endpoints were similar between the groups (table 2).

Table 2. QCA Outcomes at 9 Months: Diffuse Cohort

 
At 12 months there were no differences in rates of MACE (9.6% vs. 8.8%; P = 1.00) or other clinical endpoints between the SES and EES groups. One death was observed in the SES group.

DES Treatment Strategy Now ‘More Established’

The authors note that cutting balloons have been shown to be beneficial in treating focal BMS restenosis. The lack of benefit for focal DES restenosis in the current study, they speculate, may be due to the fact that neoatherosclerosis is more common and occurs earlier in DES than BMS restenosis, which may make cutting less effective.

With regard to diffuse DES restenosis, the authors say that the comparable results for SES and EES, despite the latter’s reduced strut thickness and thinner polymer coating, may be due to extensive use of IVUS.

According to David E. Kandzari, MD, of the Piedmont Heart Institute (Atlanta, GA), when DES in-stent restenosis first became evident, many operators tried to use a balloon for very focal disease, given the uncertainty about the safety of implanting another DES. “But now that the safety of DES treatment of DES in-stent restenosis is more established, many [clinicians] have a much lower threshold to just use a DES,” he told TCTMD in a telephone interview.

Moreover, he pointed out, the primary mechanism for failure of cutting balloons in this situation is not achieving as strong an acute gain as DES. “Given the morphology of restenosis—very rubbery neointimal hyperplasia—and the high water content, the opportunity for recoil is very high, and that’s where the benefit of the stent comes in,” he explained.

Why Not a Trial Balloon?

But Jeffrey W. Moses, MD, of Columbia University Medical Center/Weill Cornell Medical Center (New York, NY), told TCTMD in a telephone interview that the issue is whether implanting another stent is worth the accompanying increased risk of thrombosis. “You still have an almost 80% success rate with the cutting balloon,” he said, “so why not give that a shot before going to a [stent]?”

With focal restenosis, a scoring balloon, similar to a cutting balloon, is often used, he continued. “It’s not surprising that late loss is lower with an SES, but I don’t think that makes a compelling case for jumping right to another stent.”

Dr. Moses said he also looks for mechanical causes of restenosis. “If the problem is underexpansion, we may be even more prone to use a balloon,” he said.

Meanwhile, Adnan Kastrati, MD, of Deutsches Herzzentrum (Munich, Germany), told TCTMD in an e-mail communication that the role of cutting balloons in Europe, where drug-eluting balloons are approved, revolves around increasing overall effectiveness. “The cutting balloon alone is not a solution for treating DES restenosis, but it still may enhance drug-eluting balloon efficacy by improving tissue diffusion of the drug if used in combination with the latter.”

On the other hand, for diffuse restenosis, if the original stent is well expanded and the lesion is predominantly hyperplastic, Dr. Moses said he leans toward using another stent. Although data do not support the strategy, he tends to switch to a different type of DES from the original—especially to a paclitaxel-eluting stent for limus-eluting stent failures—in case drug resistance was responsible for the restenosis.

Equivalence of SES, EES No Surprise

Drs. Moses, Kandzari, and Kastrati all said they were unsurprised by the angiographic similarity between SES and EES for diffuse lesions. “Even thousands of patients from several randomized trials have barely been able to generate a difference between these 2 types of DES for de novo lesions,” Dr. Kastrati wrote.

“The difference is more in the safety profile,” Dr. Moses added, noting that Xience is less thrombogenic than Cypher.

Overall, management of DES restenosis varies considerably, Dr. Moses indicated. For instance, several dozen centers still use radiation, he said, but in general, European practitioners favor drug-eluting balloons, while most clinicians in the United States choose to re-stent, he said.

Related Stories:

• Efficacy of SES for In-stent Restenosis Dependent on Original Stent Type
• RIBS III: Alternative DES Best Bet for DES In-Stent Restenosis
• Therapies Take on In-Stent Restenosis with Mixed Results

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