Coronary intravascular lithotripsy beneficial in severely calcified lesions
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Among patients with severely calcified coronary lesions, use of intravascular lithotripsy was associated with low rates of 30-day MACE and high rates of procedural success, according to the single-arm DISRUPT CAD III study.
Intravascular lithotripsy, which has been used to treat kidney stones for about 30 years, modifies calcium by delivering acoustic pressure waves and could be an adjunct to stent implantation, Dean J. Kereiakes, MD, FACC, FSCAI, medical director of The Christ Hospital Heart and Vascular Center and the Christ Hospital Research Institute and professor of clinical medicine at The Ohio State University, said during a presentation at the virtual TCT Connect.
The findings were simultaneously published in the Journal of the American College of Cardiology.
The researchers evaluated intravascular lithotripsy (IVL; Shockwave Coronary IVL system with the Shockwave C2 Coronary IVL catheter, Shockwave Medical) in 431 patients (mean age, 71 years; 77% men) with severely calcified coronary lesions.
“It’s easy to use because it’s a novel technology packaged in a not-novel delivery system,” Kereiakes told Healio. “It’s a balloon, the most basic technology for any interventionalist.”
The primary safety endpoint of freedom from 30-day MACE, defined as cardiac death, MI or target vessel revascularization, occurred in 92.2% of patients, Kereiakes said, noting the lower bound of the 95% CI was 89.5%, exceeding the performance goal of 84.4% (P < .0001), which was based on 1.5 times the observed 30-day MACE rate in the ORBIT II trial of an orbital atherectomy system (Diamondback 360, Cardiovascular Systems Inc.).
The primary effectiveness endpoint, successful stent delivery with less than 50% residual stenosis and no in-hospital MACE, occurred in 92.4% of patients, and the lower bound of the 95% CI was 90.2%, exceeding the performance goal of 83.4% (P < .0001), which was based on 1.5 times the observed procedural failure rate in ORBIT II, Kereiakes said.
Percent diameter stenosis declined from 65.1% before the procedure to 37.2% after IVL to 11.9% after stent implantation, with almost all patients achieving a final in-stent diameter stenosis of less than 30%, according to the researchers.
The rate of serious angiographic complications was 2.6% after IVL and 0.5% after stent implantation, Kereiakes said.
“Following IVL, our incidence of perforation or abrupt closure was zero,” he told Healio. “That’s hard to find in other trials.”
In an analysis comparing the 47 patients who were the first case for each study site (roll-in) with the remaining 384 patients (pivotal), there were no differences in freedom from 30-day MACE (roll-in, 89.4%; pivotal, 92.2%; P = .57), procedural success (roll-in, 87.2%; pivotal, 92.4%; P = .25) and device crossing success (roll-in, 93.6%; pivotal, 95.8%; P = .45), according to the researchers.
“This technology is easy, predictable, reliable, safe and, most of all, effective,” Kereiakes told Healio. “The average stent expansion in that population was 102%. I don’t know if there has been anything like that that we’ve had access to that can successfully modify calcium and optimize the results of stent deployment as safely as this technology.”
The device is not yet indicated for treatment of coronary lesions in the United States, but an FDA application is pending, Kereiakes told Healio. A larger version of the device (Shockwave M5) has been approved by the FDA to treat calcified lesions in peripheral arteries.
In a related editorial published in JACC, Philippe Généreux, MD, co-director of the structural heart program at Morristown Medical Center in New Jersey, wrote: “It is expected that IVL would be rapidly adopted and considered by many as the preferred first-line of therapy to manage severely calcified lesions prior to drug-eluting stent implantation. It is also easy to conceive that its use could be expanded as a bailout option after implantation of DES, where underexpansion remains. Similarly, the potential off-label use of this device in re-stenotic lesions, where long-term stent underexpansion due to a calcified lesion is frequent, is also intuitively appealing. That being said, further studies are needed to better understand the role of this novel technology among these lesion subsets.”
References:
- Généreux P. J Am Coll Cardiol. 2020;doi:10.1016/j.jacc.2020.10.014.
- Hill JM, et al. J Am Coll Cardiol. 2020;doi:10.1016/j.jacc.2020.09.603.
Perspective
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Daniel Schimmel, MD, MS, FACC, FSCAI
DISRUPT III is a multicenter, prospective single-arm study describing the efficacy and safety using intravascular lithotripsy to treat severely calcified lesions in 431 patients. Heavily calcified lesions can prevent stent delivery or proper stent and lesion expansion. Historically, high pressure inflation of balloons, cutting balloons, rotational atherectomy and orbital atherectomy have been the tools used to modify heavy calcified arteries prior to stent implantation. These tools can be successful in modifying calcified lesions but also have their limitations in certain situations.
Intravascular lithotripsy for plaque modification may avoid certain complications, or allow treatment of areas otherwise inaccessible to other forms of atherectomy.
Two other smaller single-arm studies, DISRUPT I and DISRUPT II, showed proof of concept, efficacy and safety. DISRUPT III is statistically powered to show efficacy and safety in hopes of obtaining U.S. regulatory approval.
DISRUPT III was successful in demonstrating high rates of success in treating de novo heavily calcified lesions while also meeting its primary safety endpoints. The protocol for treatment was regimented and if the device gains regulatory approval, operators should be aware of the lesion treatment protocol to obtain real-world results of clinical success and safety as was done in the trial.
An interesting substudy of the group applied OCT to 100 of the patients pre-IVL therapy and post-IVL therapy but before stent deployment and then following stent deployment to assess success of therapy and investigate the mechanism of plaque modification.
The main take-home message is that IVL provides a safe and highly successful alternative to athero-ablative techniques such as orbital or rotational atherectomy. While the mechanism of calcium fracture is thought to play a dominant role in the success of the technology to allow stent expansion, OCT only observed fracture of calcium in 67.4% of lesions.
The IVL platform will provide options for atherectomy, particularly where other platform use is complex. One potential opportunity for IVL to be the first choice for atherectomy may be at bifurcations or ostial lesions where preserving a branch may be difficult with rotational or orbital atherectomy devices. Treatment of lesions at bifurcations in this study occurred in 29.9% of lesions.
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Kereiakes DJ, et al. Late-breaking clinical science II: Complex PCI strategies. Presented at: TCT Connect; Oct. 14-18, 2020 (virtual meeting).
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