For Bifurcations, 2 Stents Better Than 1 at Reducing Revascularizations

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For the first time in a randomized trial, a 2-stent approach to coronary bifurcation lesions—specifically the double kissing crush technique—has reduced restenosis compared with provisional stenting. The findings were published in the February 22, 2011, issue of the Journal of the American College of Cardiology.

The results were originally presented in September 2010 at the annual Transcatheter Cardiovascular Therapeutics symposium in Washington, DC.

For the DKCRUSH (Double Kissing Crush versus Provisional Stenting Technique for Treatment of Coronary Bifurcation Lesions) II trial, investigators led by Shao-Liang Chen, MD, of Nanjing Medical University (Nanjing, China), randomized 370 unselected patients with bifurcation lesions at 7 Asian centers to double kissing crush stenting (n = 185) or stenting of the main vessel with provisional stenting of the side branch (n = 185). All patients received sirolimus-eluting stents with a biodegradable polymer (Excel; JW Medical System, Weihai, China).

Procedural and total fluoroscopy times as well as contrast volume were similar for the double kissing crush and provisional stenting groups. In the provisional arm, 28.6% of side branches required additional stents, 65.4% received balloon angioplasty only, and 5.9% received no therapy. Angiographic success in the side branch was lower with the provisional strategy compared with the double kissing approach (95.7% vs. 100%; P = 0.007). In addition, unsatisfactory kissing was more common in the provisional group than the double kissing group (25.4% vs. 8.1%; P < 0.001).

Advantage Seen at Follow-up Angiography

Angiography was performed at 8 months in 91.6% of patients. Restenosis rates were lower in the double kissing group compared with the provisional group for both the main vessel (3.8% vs. 9.7%; P = 0.036) and the side branch (4.9% vs. 22.2%; P < 0.001). The presence of unsatisfactory kissing predicted in-stent restenosis in both the main vessel (HR 4.01; 95% CI 1.64-10.11; P = 0.025) and the side branch (HR 0.49; 95% CI 0.24-0.99; P = 0.037).

At 12 months there were no differences between the 2 groups in the primary endpoint of MACE (composite of cardiac death, MI, or TVR), the individual endpoints of cardiac death and MI, or in Academic Research Consortium-defined definite stent thrombosis. However, rates of TLR and TVR were higher in the provisional stenting group (table 1).

Table 1. One-Year Outcomes

 

Double Kissing Crush

Provisional Stenting

P Value

MACE

10.3%

17.3%

0.070

Cardiac Death

1.1%

1.1%

1.000

MI

3.2%

2.2%

0.751

TVR

6.5%

14.6%

0.017

TLR

4.3%

13.0%

0.005

Definite Stent Thrombosis

2.2%

0.5%

0.372


The authors observe that “[s]everal studies have concluded that stenting the main vessel with provisional stenting of side branches is preferable in the great majority of bifurcation lesions.” However, these studies used different 2-stent techniques, including a classical crush approach. The investigators suggest that the double kissing crush technique, which emphasizes the performance and quality of final kissing balloon inflation in both the main vessel and the side branch, helped reduce revascularization.

The investigators acknowledge several limitations, including follow-up to only 1 year, lack of functional assessment by fractional flow reserve, and inadequate sample size for evaluation of stent thrombosis risk.

“The clinical implication of the present study is that [double kissing] crush stenting would be superior to [provisional stenting] for complex/high-risk bifurcation lesions,” the authors conclude.

Key Is Side Branch Stenting Only When Needed

In a telephone interview with TCTMD, Samin K. Sharma, MD, of Mount Sinai Medical Center (New York, NY), agreed that most experts advocate a 1-stent strategy, although some trials have shown that a 2-stent approach also can provide good results.

This study confirms that when a provisional approach is followed, about 25% to 30% of the time the side branch will nonetheless need to be stented, typically because it suffers extensive dissection and will close without a stent, Dr. Sharma said. Thus, the real issue is whether 2 stents should be used routinely or only in complex cases, he added.

A strike against the former strategy is that in some studies implanting 2 stents at the outset has been associated with higher rates of stent thrombosis, restenosis, and minor-to-intermediate MI, Dr. Sharma noted. On the other hand, adding a second stent after an initial provisional approach often makes for a longer, more complex procedure, he said.

The key to resolving the dilemma is to be able to identify upfront the lesions that will require a second stent, he suggested. “I believe the most important predictors are a highly angulated side branch—more than 75 degrees—and a long lesion in the side branch, rather than a focal ostial lesion,” he added.

“This is the first time ever in the literature that a bifurcation technique using 2 stents has been shown to be superior in any parameter,” Dr. Sharma said, noting that revascularization was reduced particularly in the side branch.

Whether other centers are able to reproduce the results remains to be seen, he added. “I have tried the [double kissing] crush technique a handful of times,” Dr. Sharma reported. “It takes a lot longer because it requires multiple steps. And I only do it in small side branches because in larger side branches the simple kissing technique works well. But the results are fantastic compared with the crush or even minicrush techniques. It eliminates their Achilles’ heel, which is the inability to open the ostium completely.”

If these data are replicated, DK crush may become the preferred technique in cases where a 2-stent approach is dictated, Dr. Sharma predicted. “In that sense, DKCRUSH is a victory for the 2-stent believers,” he concluded.

Not a Serious Challenge to Provisional Stenting?

In an e-mail communication with TCTMD, David J. Hildick-Smith, MD, of the Sussex Cardiac Centre (Brighton, United Kingdom), called the study a welcome addition to the literature. The trial shows that a systematic 2-stent strategy, when performed by expert operators using the more involved double-crush procedure, can produce high levels of success and very good clinical outcomes, he wrote.

“It does not seem to me, however, that this will challenge the general consensus [favoring] provisional stenting, which is straightforward and results in good symptomatic relief and low rates of complications,” he commented.

“It is important to note that in the DKCRUSH-II trial, periprocedural MI was not included in the primary endpoint, and the greater rate of TLR noted in the provisional stent arm came after repeat angiography and therefore may have been partly driven by the ‘oculostenotic reflex,’” he added.

Study Details

Baseline and clinical characteristics were well matched between the 2 treatment groups.

The double kissing crush technique consisted of stenting the side branch followed by balloon crush and the first kissing balloon inflation, then stenting the main vessel and final kissing balloon inflation. Another key step is the alternative inflation with a noncompliant balloon at high pressure (≥ 16 atm) for the side branch before each kissing.

In the provisional strategy, the criteria for treatment of the side branch were diameter stenosis greater than 50%, dissection greater than type B, or decreased TIMI flow. If balloon dilation was not successful, the T stent technique was performed, followed by final kissing balloon inflation.

  


Source:
Chen S-L, Santoso T, Zhang J-J, et al. A randomized clinical study comparing double kissing crush with provisional stenting for treatment of coronary bifurcation lesions: Results from the DKCRUSH-II (Double Kissing Crush versus Provisional Stenting Technique for Treatment of Coronary Bifurcation Lesions) trial. J Am Coll Cardiol. 2011;57:914-920.

 

 

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For Bifurcations, 2 Stents Better Than 1 at Reducing Revascularizations

For the first time in a randomized trial, a 2 stent approach to coronary bifurcation lesions—specifically the double kissing crush technique—has reduced restenosis compared with provisional stenting. The findings were published in the February 22, 2011, issue of the Journal
Disclosures
  • Drs. Chen, Sharma, and Hildick-Smith report no relevant conflicts of interest.

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