Two small studies offer mixed results using vastly different approaches to modify severely calcified lesions before percutaneous coronary intervention (PCI).
In the open-label COPS trial, use of a cutting balloon inflated at high pressure resulted in greater minimal stent area (MSA) and more symmetric stent expansion at the calcium site than standard noncompliant balloon angioplasty.
Although a number of calcium modification strategies are commonly used to improve suboptimal stent expansion and PCI outcomes in calcific disease, data comparing cutting balloons inflated at high pressure are lacking, according to co–principal investigator Antonio Mangieri, MD, Humanitas Research Hospital, Milan, Italy.
COPS enrolled 100 patients (mean age, 71 years) deemed suitable for PCI who had severely calcified lesions with a calcium arch of at least 100° and reference vessel diameter between 2.5 and 4.0 mm on baseline intravascular ultrasound. They were randomized in a 1:1 ratio to the high-pressure Wolverine cutting balloon (Boston Scientific) or to noncompliant balloon angioplasty.
Among the 87 evaluable patients, there was no significant difference in MSA (7.1 vs 6.5 mm2) with the cutting balloon and the noncompliant balloon, but MSA at the calcium site was greater with the cutting balloon (8.1 vs 7.3 mm2; P = .035).
The eccentricity index at the calcium site also favored the cutting balloon group (0.84 vs 0.8; P = .013), meaning that the stent was more symmetrically expanded, said Mangieri, when presenting the results at Transcatheter Cardiovascular Therapeutics (TCT) 2022.
Subgroup analysis showed the benefit in MSA at the calcium site in patients with severe calcifications (calcium arch > 270°; P = .047) but not in those with an arch of 270° or less (P = .192).
Device failure rates were similar with the cutting balloon and noncompliant balloon (3 vs 0; P = .517), but two perforations were observed in the cutting balloon group, one of which had to be managed with implantation of a covered stent, he noted.
"I like this. I think this is true because I see many times where the rotablator and cutting balloon looks better in terms of the calcium structure compared with just a noncompliant balloon," said discussant Akiko Maehara, MD, CRF Clinical Trials Center, New York.
She questioned what level of calcium is most likely to benefit from the cutting balloon, pointing out that despite enrolling patients with severely calcified lesions, the average calcium arch was just 266°.
Mangieri replied that they enrolled a wide population of patients with calcified lesions, making it difficult to do a subgroup analysis. "But I think the observed benefit was more when we have a more pronounced arch of calcium instead of a small spot of calcium, and especially when the calcium tends to be very superficial. Sometimes when you have deep calcification, it's hard for the cutting balloon, even if it's inflated to a high pressure, to create some cracks."
Commenting to theheart.org | Medscape Cardiology, Margaret McEntegart, MD, PhD, who oversees the complex PCI service at Columbia University Irving Medical Center/NewYork-Presbyterian Hospital, said "what bore out in that study is what we see intuitively in practice. The kind of lesions that he presented are the kind of lesions we see where the cutting balloon works in the clinical space."
"I think the COPS data is solid and very believable, but you have to think, though, about what patients weren't included," she added. "The patients that weren't included were those where you couldn't cross over the lesion with a cutting balloon, so you had to use atherectomy or something else. Inevitably, you end up with a subset of selected patients."
In the second trial, EXIT-CALC, intravascular lithotripsy, which uses pulsed acoustic pressure waves to fracture calcium, did not significantly increase stent expansion compared with balloon angioplasty in 40 randomized patients.
Atherectomy and specialty balloons have shown "no apparent clinical benefit" in randomized controlled trials and involve a certain risk for complications like dissection, perforation, and no reflow, said study investigator Maarten Vink, MD, PhD, OLVG Heart Center, Amsterdam, the Netherlands. Intravascular lithotripsy, however, has emerged as an alternative and has demonstrated safety and efficacy in large single-arm studies.
EXIT-CALC enrolled patients with a target vessel diameter between 2.5 and 4.0 mm and an optical coherence tomography–based calcium score of 4, calculated as a calcium angle > 180°, calcium thickness > 0.5 mm, and minimal calcified lesion length > 5 mm.
Among the 21 patients randomized to predilatation with balloon angiography, compliant balloons were used in 33.3%, noncompliant balloons in 66.7%, and scoring balloons in 38.1%. Postdilatation was performed in both groups. There was no difference in the number of stents, stent length, or diameter.
The procedure was successful in 100% of patients, with no periprocedural complications or major adverse cardiovascular events at 30 days.
Stent expansion occurred in 83.9% of the lithotripsy group and 82.2% of the balloon angioplasty group (P = .63).
"Stent expansion was higher than anticipated, because we anticipated around 70%, and that may have been the result of aggressive predilatation and also the scoring balloons used in our study," Vink explained.
"For future directions, I think adequately sized RCTs are required to determine a possible advantage of intravascular lithotripsy with regard to clinical endpoints or maybe we need to check a combination of devices," he said.
Vink noted that other vessel preparation devices are under investigation, including orbital atherectomy vs balloon angioplasty in the ECLIPSE trial in approximately 2000 patients, with a primary clinical endpoint of target vessel failure at 1 year.
McEntegart pointed out that earlier that day, Shockwave Medical announced it was launching EMPOWER CAD, the first female-only study of intravascular lithotripsy in 400 women with symptomatic ischemic heart disease in the United States and Europe. Women made up just 18.3% of the population in COPS and 35% in the EXIT-CALC cohort, yet data suggest that calcific disease and nodular calcium are more common in women, partly because they tend to be older.
"That's more of a problem acutely and more of a problem during follow-up; they come back with more MACE events," said McEntegart, coprincipal investigator of the new study. "The good thing is that the attention has now been put on that as a problem that they're under study. We don't know how best to treat them and, hopefully, as we move forward next year with the study and some other data collection, we'll get a better insight into how to manage female patients better."
COPS was supported by an institutional grant from Boston Scientific, which had no responsibility for study management, data collection, and monitoring. Mangieri reports a research grant from Boston Scientific and consulting fees/honoraria from Abbott Vascular, Boston Scientific, and Concept Medical. Vink reports having no relevant financial relationships. Maehara reports grant support/research contract with Abbott Vascular, consulting fees/honoraria/speaker's bureau with Boston Scientific and Spectrawave, Philips, Shockwave Medical. McEntegart reports consulting fees/honoraria/speaker's bureau with Abbott Vascular, Medtronic, Shockwave Medical, Teleflex, Biosensors, and grant support/research contract with Boston Scientific.
Transcatheter Cardiovascular Therapeutics 2022. Presented September 19, 2022.
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Cite this: One Win, One Near Miss for Calcium Modification Before PCI - Medscape - Sep 28, 2022.