SAN FRANCISCO – Although there are compelling reasons to treat complex calcified coronary lesions with rotablation instead of standard balloon dilatation before implanting drug-eluting stents, this strategy does not improve vascular or clinical outcomes in the long run, according to the results of the randomized ROTAXUS trial.
The results showed that rotablation was more effective at improving lumen dimensions early on, but this was offset by a subsequent proliferative response. Late lumen loss at 9 months was 0.44 mm with rotablation (also known as rotational atherectomy) and stenting vs. 0.31 mm with balloon dilatation and stenting, a significant difference. Rates of target lesion revascularization and other cardiovascular events did not differ significantly between groups.
"Superior acute gain ... after rotablation was counterbalanced by increased late loss, resulting in a neutral effect on restenosis," lead investigator Dr. Gert Richardt said at Transcatheter Cardiovascular Therapeutics 2011, sponsored by the Cardiovascular Research Foundation.
"So balloon dilatation with provisional rotablation – that is my suggestion – prior to stenting remains the default strategy for complex calcified lesions even in the drug-eluting stent era," he said.
Dr. Roxana Mehran, professor of medicine at Mount Sinai Medical Center in New York, noted that rotablation remains helpful, at least from a logistic point of view, in bad lesions. "It’s important to note that rotational atherectomy still does have a place in our armamentarium, but it would be in the severely calcified lesions and in complex morphologies where I think it would make our procedure easier," she explained. "But if it is to reduce late loss," this study, "in a randomized fashion, did not show that."
Discussant Dr. Ron Waksman, director of experimental angioplasty and emerging technologies at the Washington Hospital Center in Hyattsville, Md., agreed, and also expressed concern that the trial’s findings might be interpreted as cause to abandon rotablation.
"You don’t do rotablation to [address] the late loss issue, the restenosis. It’s to facilitate stent deployment," he asserted. "In my view, we are underusing rotablation today, and we should use more of this. I’m just afraid that people will interpret this [trial as indicating] that you can do without a rotablator, and that’s not the message. ... We should actually reconsider more usage of rotablation to facilitate stent deployment and [reduce] thromboembolic complications of the procedure."
"Rotablation does not increase the efficacy of drug-eluting stents in calcified lesions."
"We nowadays treat more and more elderly patients with complex and severely calcified lesions," noted Dr. Richardt, who is a professor at the Heart Center, Segeberger Kliniken, in Bad Segeberg, Germany. And there is good rationale for using rotablation before implantation of drug-eluting stents for these lesions, he said.
Calcified lesions not only damage the stent, stripping off its drug-containing polymer coat, but may also impair outward diffusion of the drug. Ablating these lesions facilitates stent deployment and expansion, and possibly also effectiveness.
To be eligible for the trial, patients had to have angina (stable or unstable) and coronary artery disease, plus both of two angiographic criteria (a de novo lesion in a native coronary artery and moderate to severe calcification) and at least one of several others (an ostial location, a bifurcation lesion, or a long lesion).
The 240 patients enrolled in the study were assigned in equal numbers to either rotablation or balloon dilatation, followed by implantation of paclitaxel-eluting stents (Taxus, manufactured by Boston Scientific).
Trial results showed that from the procedural perspective, the rotablation group was more likely to be treated with a 7-French guiding catheter (84% vs. 28%) and had a lower maximal predilatation balloon pressure (13.6 vs. 15.8 atm), Dr. Richardt reported.
In the rotablation group, the maximum burr size was 1.5 mm. "It was mainly the plaque modification concept that we followed, with small burrs, and we usually used just one burr on the study," he commented. The groups were similar with respect to numbers of stents used and the lengths of stented vessels, as well as the use of balloon dilatation after stenting.
Fluoroscopy time was somewhat longer with rotablation, but patients in the two groups received the same amount of contrast dye, according to Dr. Richardt.
The rotablation and balloon dilatation groups had similarly high rates of angiographic success (97% each) and low rates of stent loss (0% and 3%), but the former had a lower rate of crossover (4% vs. 12%).
Despite a greater early gain in lumen dimensions, the rate of in-stent late lumen loss at 9 months – the trial’s primary end point – was higher with rotablation than with balloon dilatation (0.44 vs. 0.31 mm).