The recent U.S. approval of intravascular lithotripsy (IVL) means a simpler new treatment option for certain types of calcified lesions – one of the most complex lesions in interventional cardiology – according to key opinion leaders speaking with CRTonline.org.
However, compared to more complicated atherectomy techniques, the cost could be prohibitive and make IVL difficult to adopt widely, some experts suggested, while others stressed that long-term safety data are yet to be established.
The Shockwave IVL System with Shockwave C2 Coronary IVL Catheter was approved by the U.S. Food and Drug Administration (FDA) in mid-February. It is a novel application of lithotripsy – a sonic pressure-wave therapy that has been used for decades to break up kidney stones. The waves are emitted via low-pressure balloon.
The device is intended for balloon-crossable lesions, although experts at the ongoing CRT 2021 Virtual conference have also suggested that IVL could be complementary to atherectomy. The key opinion leaders speaking with CRTonline.org, however – each of whom has experience with IVL via involvement in the Disrupt CAD III U.S. study – were divided on the matter.
Calcium build-up occurs in anywhere from 15% to 35% of cases, and the numbers are rising, Richard Shlofmitz, MD, chairman of cardiology at St. Francis Hospital, The Heart Center, Roslyn, New York said.
“The market is tremendous,” he said.
Severely calcified lesions – stubborn and bone-like – are particularly a growing problem as the population ages, Gregg W. Stone, MD, director of academic affairs for the Mount Sinai Heart Health System, New York, and a co-study chair on Disrupt CAD III, told CRTonline.org.
Balloon angioplasty, even cutting and scoring balloons, is often “insufficient” for severely calcified lesions, Stone said. Although atherectomy – wire-led procedures for drilling and lasering calcified lesions – has been available for decades and is an “excellent choice” in these cases, Stone and other experts agreed that these procedures require high expertise.
“The vast majority of physicians would shy away from it,” Shlofmitz said of atherectomy.
At the least, atherectomy tends to be the domain of larger, high-volume centers, according to Stone, who noted that it “entails a learning curve, a procedural experience that low-volume centers and operators may not be able to generate.”
It means that, despite sweeping advancements in drug-eluting stents in the last decade, the treatment of severely calcified lesions remains “challenging, with suboptimal acute and long-term outcomes, unless adequate lesion preparation is achieved,” said Stone.
Still, interventionalists are commonly asked to treat these patients, who also are often high-risk with multiple comorbidities, including diabetes and heart failure, he said.
The newest procedure, IVL, is simpler, the experts agreed. It means broader treatment options for these patients.
Any practitioner who can administer a balloon angioplasty will be able to administer IVL, Shlofmitz said.
Beside simplicity, there is a need for a technology to modify deep calcified coronary lesions, Hayder Hashim, MD, an interventional cardiologist at MedStar Washington Hospital Center, Washington, D.C., added. He noted that it is believed the ultrasound waves can delve into deeper places than mechanical atherectomy technologies.
Both Shlofmitz and Dean Kereiakes, MD, medical director of The Christ Hospital Heart and Vascular Center, Cincinnati – another Disrupt CAD III study co-chair – added that IVL has advantages over atheroblative technologies because it lacks wire bias.
“Rotational and orbital atherectomy, as well as excimer laser, all track the guide wire and exhibit wire bias with eccentric trough or rut formation,” said Kereiakes.
“Conversely, with IVL, low-pressure balloon inflation ‘centers’ the shaft of the balloon which contains the acoustic pressure wave emitters. Further, these acoustic pressure waves are emitted in a circumferential and transmural fashion so that they can impact and modify deep as well as superficial calcium. No other technology has this capacity.”
Complementary to atherectomy?
Nevertheless, several experts commented on the fact that IVL is only suited for balloon-crossable lesions.
Interventionalists at CRT 2021 Virtual suggested that for lesions that are not crossable, atherectomy prior to IVL could be needed to create a channel – commentary with which Stone and Kereiakes agreed.
“Atherectomy and lithotripsy may be complementary in that there may be certain lesions that are best suited for one versus the other – [for example] eccentric vs. concentric plaque, left main and ostial lesions, bifurcations, chronic occlusions,” said Stone. “Which device is best for a specific lesion type would likely be identified from comparative randomized trials.”
Kereiakes added that there are multiple cases reported in literature demonstrating that rotational atherectomy facilitated IVL.
The device’s manufacturer, Shockwave Medical, agreed that IVL could potentially complement atherectomy.
In an emailed response to CRTonline.org, a spokesperson said the company so far has 3 years of international experience – including in Europe, where IVL has been approved since 2018. From this, it has seen “physicians very quickly realize that the two technologies, both in their mechanism of action and the types of lesions that they treat, are very different.”
The spokesperson said concomitant usage in which physicians use rotational atherectomy to cross the lesion and create a channel to deliver an IVL catheter is known as the “RotaShock” strategy.
Still, despite the fact that there could be crossover in certain patients, “at the most fundamental level, atherectomy is a great technology for balloon uncrossable lesions, while IVL holds the potential to transform the safety outcomes of treating balloon crossable calcified lesions,” the spokesperson said.
For Hashim and Shlofmitz, this sort of combination strategy is for exceptional cases only, however.
Orbital and rotational atherectomy have been successfully used for many years without the need for a complementary technology, said Hashim. On IVL as a complementary procedure, he said: “I think that underestimates or undervalues the technology, and undervalues the technology of atherectomy.”
Tandem use would also drive up healthcare costs and hinder uptake, Hashim stressed.
However, Stone argued that, despite cost considerations of multiple device use, avoiding complications and re-admissions by safely achieving “an excellent outcome” in these complex and high-risk patients may be cost-saving in the long run.
All experts agreed that the device appears to be very safe – with trial data exceeding safety performance goals in Disrupt CAD III and more than 25,000 patients successfully treated since its 2018 approval in Europe.
“IVL represents the most predictable, reliable, safe, and effective technology for calcium modification and facilitation of optimal stent deployment,” according to Kereiakes.
“Despite treatment of the most severely calcified coronary arteries ever enrolled into a clinical trial in Disrupt CAD III, perforation, abrupt coronary closure and no reflow were not observed following IVL alone. Complex coronary dissection occurred in only 2% of all patients following IVL and was reduced to a single patient (0.3%) following subsequent stent deployment,” he said.
However, Stone and Hashim stressed that, despite the strong safety profile, longer-term safety data are yet to be established.
The Disrupt CAD III trial used for approval was a single-arm, non-randomized trial. While a similar trial design was used for U.S. approval of orbital atherectomy, “comparative randomized trials are necessary before the relative safety and effectiveness of atherectomy and lithotripsy can be known with certainty,” Stone stressed.
Besides studies, real-world experience is also crucial as IVL’s use becomes generalized to even more complex lesions and lower-volume operators, he said.
These data should provide the necessary improved understanding over the effect of ultrasound waveforms on non-target areas that are not treated by stent, for instance, when there has been a “geographic miss,” said Hashim. “We need to understand what the long-term effect of that is.”
Concerns over uptake due to reimbursement issues were raised by several of the experts.
According to the Shockwave Medical spokesperson, Shockwave C2 will be sold at a “premium price” relative to other calcium modification devices that have been on the market for many years, as it has done in other markets.
“Currently, the market leading atherectomy device costs about $4,000 per procedure in most U.S. hospitals. The national standardized price for coronary IVL catheters are $4,700,” the spokesperson said, adding: “We believe it is a novel, differentiated product that safely improves PCI [percutaneous coronary intervention] outcomes, is easy to use, and expands the population of patients that cardiologists can safely treat.”
However, Shlofmitz said competing atherectomy catheters already on the market in the U.S. are priced under $2,000 in some cases.
He foretold “major reimbursement issues to come” because payers will look at the device as a balloon and not an atherectomy.
Hashim said IVL is already considered as a balloon angioplasty rather than atherectomy, but he argued it should be valued differently. Pricing should be on par with atherectomy devices, he said.
Nevertheless, a price tag higher than atherectomy – as the company has hinted toward – would see interventionalists who are “very comfortable” with the older procedure continuing to use it at a cheaper price “and probably the same outcome,” Hashim said.
“At the end of the day, more value on a device will add more to the healthcare bill, which is already high in the United States,” he said.
Although Kereiakes said he was unaware of any reimbursement hurdles now, he did stress: “I am concerned if the price tag is too high, hospitals may restrict access of this technology to physicians. Although the price may not be prohibitive, physicians will have to justify use of IVL on a case-by-case basis.”
Questioned over reimbursement concerns, the Shockwave Medical spokesperson replied: “We believe that we have set the price for coronary IVL at a level that will optimize the future reimbursement of IVL.”
Further, the company recognizes that the use of IVL may be “limited,” said the spokesperson, adding that it has been training field support teams in recent months on identifying the best candidates for the procedure based on lessons learned outside the States.
“In partnership with international interventional cardiologists operating in cost-constrained environments, we have learned how to identify patients and lesions where the benefit of IVL will be most significant, and where other tools would be the best first line of defense.”
The spokesperson added that, for near-term U.S. reimbursement, IVL’s FDA “Breakthrough” status aligns it with the Centers for Medicare & Medicaid Services’ (CMS’) New Tech Add on Payment (NTAP) and Transitional Pass Through (TPT) reimbursement programs for inpatient and outpatient procedures.
The company has already submitted for NTAP and will soon apply for the TPT. If awarded, they will provide incremental payment for IVL for inpatients (NTAP) and for hospital outpatients (TPT).
“We hope to have both the NTAP and TPT payments in place within the year,” the spokesperson added.