Rotational atherectomy viable option to modified balloon angioplasty before PCI

SAN DIEGO — Upfront high-speed rotational atherectomy may be more beneficial than angioplasty with modified balloons before PCI with drug-eluting stents, a speaker said at TCT 2018.

Specifically, the PREPARE-CALC study, presented by Gert Richardt, MD, of the Heart Center Segeberger Kliniken in Germany, not only showed that rotational atherectomy before DES implantation was safe and feasible but also more often proved to be a successful strategy for lesion preparation in patients with severely calcified lesions.

There is a growing demand for revascularization in patients with severely calcified lesions — a population that tends to be older, have more comorbidities and experience more long-term adverse events but are generally excluded from randomized trials. Therefore, there is little evidence regarding the best practice for PCI, according to Richardt.

“Compared with standard balloons, rotational atherectomy increases acute success of the procedure and achieves more acute luminal gain, but it also stimulates neointima formation and causes more late lumen loss,” he said. “The availability of modified balloons, such as scoring or cutting balloons, and new-generation DES may impact PCI practice.”

More success, comparable late lumen loss

The PREPARE-CALC study, which was simultaneously published in Circulation: Cardiovascular Interventions, sought to compare rotational atherectomy with modified balloons regarding acute success and intermediate-term efficacy.

Two hundred patients with documented myocardial ischemia and severely calcified native coronary lesions undergoing PCI with next-generation sirolimus-eluting stent with a bioabsorbable polymer (Orsiro, Biotronik) were randomly assigned lesion preparation with modified balloon angioplasty or rotational atherectomy. The primary endpoints included strategy success, defined as successful stent delivery and expansion with less than 20% in-stent residual stenosis and TIMI 3 flow without crossover or stent failure, and in-stent late lumen loss at 9 months.

More patients assigned atherectomy vs. modified balloon angioplasty experienced strategy success (98% vs. 81%; P for superiority = .0001). Strategy failure in the modified balloon study arm was mainly driven by the need to cross over from balloon angioplasty to atherectomy (16% vs. 0%; P < .0001), mostly due to uncrossable or undilatable lesions.

A prespecified subgroup analysis, however, showed that there was no benefit to rotational atherectomy in women (P = .03), patients with left anterior descending artery as the target vessel (P = .002) and those with nontype C lesions (P = .001).

Late lumen loss at 9 months — the coprimary endpoint — was not significantly different between the rotational atherectomy arm and the modified balloon arm (0.22 mm vs. 0.16 mm; P = .21; P for noninferiority = .01). This finding, Richardt said, is in contrast with previous studies linking rotational atherectomy to increased late lumen loss.

Additionally, at 9 months, the researchers found little difference between the rotational atherectomy and modified balloon arms in terms of clinical outcomes, including death, MI, stent thrombosis, target vessel revascularization and target vessel failure. Notably, Richardt said, rates of TVF — 6% and 8%, respectively — were considerably lower than expected, given those reported in other studies.

Conclusions, potential limitations

Study patients were enrolled at two German centers from 2014 to 2017. There was more left main disease and higher maximum stent implantation pressure in the modified balloon arm and more 7F guiding catheter use, more balloon predilatation and longer fluoroscopy time in the rotational atherectomy arm. Otherwise, baseline, procedural and angiographic characteristics were similar between study arms.

Study devices used included the Rotablator (Boston Scientific) for rotational atherectomy and the AngioSculpt Scoring Balloon (AngioScore), the Scoreflex Scoring Balloon (OrbusNeich Medical) and the Flextome Cutting Balloon (Boston Scientific) for modified balloon angioplasty. Rotational speed ranged from 140,000 to 180,000 rotations per minute.

PREPARE-CALC was not without limitations, according to Richardt. For instance, although crossover was restricted by protocol and was committee-adjudicated, crossover was a definitely a potential source of bias, he said. Furthermore, the study was underpowered for clinical endpoints, operators primarily used the transfemoral approach, acute and clinically unstable patients were excluded from the study and procedures were angiographically guided. Also, other techniques such as orbital atherectomy and laser lithoplasty were not tested.

Nevertheless, these findings showing that rotational atherectomy may be advantageous are compelling, according to Richardt.

“In patients with severely calcified coronary lesions, upfront elective rotational atherectomy is feasible in nearly all patients and the acute success rate is superior to modified balloons, but both elective rotational atherectomy and modified balloons with potential bailout rotational atherectomy are equally safe and effective. And use of rotational atherectomy is no longer associated with late lumen loss in the era of modern sirolimus-eluting stents,” he said. – by Melissa Foster

References:

Richardt G. Late-Breaking Clinical Science 2, Co-Sponsored by The European Heart Journal. Presented at: TCT Scientific Symposium; Sept. 21-25, 2018; San Diego.

Abdel-Wahab M, et al. Circ Cardiovasc Interv. 2018;doi:10.1161/CIRCINTERVENTIONS.118.007415.

Disclosure: Richardt reports he has received speakers’ honoraria from Boston Scientific and Biotronik.