Two Stents Better Than One for Coronary Bifurcation Lesions

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Key Points:
  • Initial 2-stent strategy yields lower restenosis rates than provisional approach
  • Clinical outcomes for the 2 techniques comparable
  • Retrospective study at odds with results of randomized trials

By Kim Dalton
Monday, March 23, 2009

For most patients receiving drug-eluting stents for coronary bifurcation disease, the alternative strategies of mini-crush stenting with 2 stents or provisional T stenting provide comparable procedural success with low complication rates and a similar incidence of longer-term major adverse cardiac events (MACE). However, the initial 2-stent approach yields a lower rate of angiographic restenosis in both the main and side branches, according to a paper published in the March 2009 issue of JACC: Cardiovascular Interventions.

For the retrospective single-center study, Alfredo R. Galassi, MD, and colleagues of Ferrarotto Hospital (Catania, Italy), looked at 457 consecutive patients who were treated with either the 2-stent mini-crush technique (n = 199) or the T-provisional approach (258), in which a second stent is used only if deemed necessary by the operator. In the provisional group, 88 patients (34%) eventually received a second stent.

At 9-month angiographic follow-up, after propensity score adjustment for baseline differences, there was significantly lower restenosis in both the main and side branches in the mini-crush group compared with patients in the provisional group who received a single stent (HR 0.52, 95% CI, 0.27-0.99; P = 0.047, and HR 0.41, 95% CI, 0.20-0.85; P = 0.016, respectively). Compared to the entire provisional group (with or without a second stent), restenosis was significantly reduced in the 2-stent mini-crush group only for the side branch (HR 0.55, 95% CI, 0.37-0.82; P = 0.004).

Little Difference in Clinical Outcomes

Clinical follow-up at a mean of 25 months showed no significant differences among the groups in rates of MACE (cardiac death, AMI, and TVR) or TLR. However, target bifurcation revascularization (TBR) was lower in the mini-crush group compared with the 2-stent provisional group. (TBR was defined as repeat revascularization with a stenosis ≥50% within 5 mm proximal or distal to the carina of bifurcation, onto the main branch and/or side branch.) In addition, rates of late stent thrombosis were low and comparable for all groups (table 1).

Table 1. Long-Term Clinical Outcomes for Mini Crush vs. T-Provisional Stenting

 

Mini Crush
(n = 199)

T-Provisional,
1-Stent
(n = 170)

T-Provisional,
2-Stent
(n = 88)

P Value

MACE

20.6%

25.9%

26.1%

NSa

TLR

16.0%

20.3%

26.1%

NSa

TBR

8.5%

14.5%

17.4%

<0.05b

Late Stent Thrombosis

1%

2.3%

0%

NA

aFor comparison among all 3 groups.

bFor mini-crush group vs. T-provisional 2-stent group.

A Challenge to the Current Paradigm?

The authors write, “These results may confirm the advantage of using a prescheduled 2-stent technique to give complete coverage of the side branch’s ostium as compared with a provisional technique, whether or not a second bail-out stent is needed.”

In an accompanying editorial, Aaron V. Kaplan, MD, of Dartmouth Medical School (Lebanon, NH), observed that despite the higher-risk angiographic characteristics and greater lesion lengths of the patients who received the mini-crush technique, they garnered a 60% reduction in restenosis rates in the side branch and a 21% reduction in MACE compared to the T-provisional patients. Because of the increased complexity and cost of the mini-crush procedure, he added, “one would expect that this technique would be reserved for higher-risk patients.”

This study appears to challenge the paradigm of provisional stenting as the default approach to bifurcation lesions, Gregg W. Stone, MD, of Columbia University Medical Center (New York, NY), told TCTMD in a telephone interview. “But we need to be very careful about drawing that conclusion from this single-center nonrandomized study,” he said, noting factors that suggest imbalance in the study groups, such as lower use of kissing balloon dilatation after the provisional approach with 2 stents compared with the mini-crush technique.

“When you critically examine the prior studies,” Dr. Stone continued, “you see that for very simple side branch lesions, most show that the provisional approach is superior, with equal or better outcomes and less periprocedural myonecrosis . . . . When it comes to more complex side branch lesions, that’s really a question. Many of the randomized trials have not examined that yet.” One that came closest to doing so, Dr. Stone noted, is the CACTUS trial (Circulation. 2009;119:71-78) led by Antonio Colombo, MD, of San Raffaele Hospital (Milan, Italy).

An Old Debate Rendered Obsolete?

In an e-mail communication with TCTMD, Dr. Colombo wrote, “The old debate of 1 or 2 stents for every bifurcation is obsolete. The important message which comes out of the experience of Dr. Galassi and from CACTUS is that the implantation of 2 stents does not give poor angiographic and clinical results. This does not mean that we should implant 2 stents in every bifurcation—it means that when 2 stents are needed, the act of implanting 2 stents should not be considered a failure, or a complication, or a precursor of stent thrombosis.”

Dr. Colombo added, “The important challenges we need to face now are: How can we identify the bifurcations which will need 2 stents, and what are the technical caveats we should know when implanting 2 stents.

“In my view, the side branches which may require an additional stent as intention-to-treat are (1) those with disease extending beyond the ostium, (2) those that develop a dissection after predilatation, and (3) those with a baseline very severe narrowing, such as a stenosis of 90% or more . . . . Another general rule is that the side branch should be at least 2.5 mm in diameter,” although there are exceptions, he noted.

“The consideration I always try to teach is that it is not the technique that matters—including 1 or 2 stents—but the final result that you achieve,” Dr. Colombo concluded.


Sources:
1. Galassi AR, Tomasello SD, Capodanno D, et al. Mini-crush versus T-provisional techniques in bifurcation lesions: Clinical and angiographic long-term outcome after implantation of drug-eluting stents. J Am Coll Cardiol Intv. 2009;2:185-194.

2. Kaplan AV. Percutaneous coronary intervention treatment of bifurcation lesions—a work in progress: The importance of single-center studies. J Am Coll Cardiol Intv. 2009;2:195-196.

Disclosures:

  • The study contains no statement regarding conflicts of interest.
  • Dr. Kaplan reports being a founder and director of Tryton Medical, Inc, a medical device start-up company developing a dedicated side branch stent.
  • Dr. Stone reports receiving consulting fees from Abbott Vascular and Boston Scientific and having equity in Devax.
  • Dr. Colombo made no statement regarding conflicts of interest; for the CACTUS trial, he reports receiving a grant from Cordis.

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