DENVER, CO — For patients with unprotected true distal bifurcation lesions of the left main artery, a technically challenging two-stent double-kissing (DK) crush technique was associated with a halving of target lesion failure (TLF) rates at 1 year compared with provisional stenting, results of the DKCRUSH-V trial show.
Among 484 patients randomly assigned to DK crush stenting or provisional stenting, the respective rates of TLF (a composite of cardiac death, target vessel MI, and/or target lesion revascularization) at 1 year were 5.0% and 10.7%, translating into a hazard ratio for DK crush of 0.42 (P=0.02).
DK crush was also associated with significantly lower rates of target vessel MI (0.4% vs 2.9%, P=0.03) and definite or probable stent thrombosis (0.4% vs 3.3%, P=0.02), according to Dr Shao-Liang Chen (Nanjing Medical University, China).
"These results indicate that double-kissing crush may be a better option for these patients," he said. Chen presented the data October 30, 2017 at TCT 2017, and the study was published online at the same time in the Journal of the American College of Cardiology.
Don't Try This at Home
But the DK crush technique is not for the novice or the faint of heart: primary operators in the study were required to have more than 300 PCIs per year for the previous 5 years under their belts, including at least 20 left main PCIs per year, and each was observed by the steering committee while they performed from three to five DK crush procedures to ensure that they had the procedure down pat.
In their published report, Chen and colleagues acknowledged that the technique "requires training, experience, and attention to procedural detail," including careful rewiring of the side branch, sequential postdilation with noncompliant balloons at high pressure before each kissing inflation, and final proximal optimization technique after kissing-balloon inflation.
Nonetheless, the procedure, when it can be accomplished, is highly successful, commented Dr Cindy Grines (Hofstra/Northwell Medical Center, Hempstead, New York), in an interview with theheart.org | Medscape Cardiology.
"I personally find it difficult to get a wire to cross three layers of stent—you have to cross the original stent plus two layers of crushed stent, so sometimes I have not been successful at doing that," she said. "But if you are successful and you can do the kissing balloon, then the stent coverage in the carina is superior to other methods of managing a bifurcation lesion."
Grines was an invited discussant at a briefing where Chen presented that data prior to a late-breaking clinical-trials session.
Beats the Pants Off Culotte Stenting
Chen and colleagues had previously shown in the DKCRUSH-III randomized trial that the two-stent technique was associated with lower rates of target lesion revascularization compared with provisional stenting in non–left main coronary bifurcation lesions.
They also reported in 3-year follow-up results from that study that the technique resulted in lower rates of target vessel revascularization, stent thrombosis, and a composite end point of major adverse cardiac events compared with culotte stenting for distal left main bifurcation lesions.
In DKCRUSH-V, the investigators tested DK crush and provisional stenting head-to-head in a randomized trial, the first of its kind. They enrolled 482 patients from 26 centers in China, Indonesia, Thailand, Italy, and the US with true distal left main bifurcation lesions (Medina classification 1,1,1 or 0,1,1). The patients were randomized to receive PCI with either DK crush (240 patients) or provisional stenting (242).
As noted, TLF at 12 months was significantly lower among patients who underwent DK crush. The benefit was driven by reductions in target vessel MI (0.4% vs 2.9%, P=0.003) and clinically driven target lesion revascularization (3.8 vs 7.9%, P=0.006) rather than cardiac death (1.2 % vs 2.1%, P=0.48).
The reduction in target vessel MI itself was driven by significant reductions with DK crush in definite or probable stent thrombosis (0.4% vs 3.3%, P=0.02).
The reduction in TLF at 1 year with DK crush was observed both in patients with simple and complex lesions, but the difference was statistically significant only among those patients with complex lesions (7.0% vs 18.2%; HR 0.68, 95% CI 0.5–0.54).
Chen acknowledged that the study was limited by the use of intravascular ultrasound guidance in less than half of all patients and less use of proximal optimal technique and final kissing inflation in the provisional-stenting group.
In addition, he emphasized that the findings of this study don't apply to left main lesions with less than 50% diameter stenosis of the side branch. For patients with these lesions, provisional stenting should remain the standard of care, Chen said.
Following Chen's presentation, Dr Antonio Colombo (San Raffeale Hospital, Milan, Italy), an invited discussant, expressed skepticism about the true benefits (or lack thereof) of the DK crush technique vs more conventional stenting.
"I'm not totally convinced about the findings, despite the fact that they seem to be supported by the data. To me, the message is that I will not feel guilty if I plant two stents in the bifurcation, provided I've done a good job. Nevertheless, I think most 1,1,1 Medina should require provisional stenting unless the side branch is large," he said.
Discussant Dr David Hildick-Smith (Brighton and Sussex University Hospitals, UK) noted that although angiography was planned at 13 months of follow-up, some patients had angiography performed between 11 and 12 months of follow-up, "so there must have been some angiographically driven revascularization, which is a shame."
The DKCRUSH-V trial was funded by a grant from the National Science Foundation of China and jointly supported by Nanjing Municipal Medical Development Project, Microport, Abbott Vascular, and Medtronic. Chen, Colombo, and Hildick-Smith reported no relevant financial relationships. Grines discloses within the past 12 months she has had a financial interest/arrangement or affiliation with Abbott Vascular and Volcano Corp.
Medscape Medical News © 2017
Cite this: DKCRUSH-V: Double-Kiss Crush Stenting Better for Complex LM Bifurcations - Medscape - Oct 31, 2017.