Intravascular lithotripsy (IVL) is being used more often to treat severely calcified coronary lesions, and that can only be expected to continue to increase now that the Shockwave IVL device has been commercially approved in the U.S.
Jonathan M. Hill, MD, of Royal Brompton and Harefield Hospitals, London, described the new treatment modality and its advantages during a session held Saturday at CRT 2021 Virtual. The device’s manufacturer, Shockwave Medical Inc., sponsored the session.
“IVL appears to have a very useful place in our toolbox,” Hill said.
Hill also reported that, through 2021, there were more than 30,000 cases of IVL procedures and more than 2,400 operators worldwide in more than 50 countries.
Dean J. Kereiakes, MD, of The Christ Hospital Health Network, Cincinnati, performed a rigorous analysis of the results from the DISRUPT CAD III Trial, a prospective, multicenter, single-arm global investigational device exemption study with an enrollment of 431 patients.
“There is absolutely no question that vascular calcium is becoming a bigger and bigger problem,” Kereiakes said. He pointed to a meta-analysis of seven contemporary percutaneous coronary intervention trials, which showed that patients with severely calcified lesions had a higher cumulative incidence of death, myocardial infarction, and revascularization compared to patients without severe calcification.
While there are various methods to treat severely calcified lesions, these methods are not without their problems. Kereiakes used optical coherence tomography (OCT) to show examples of wire bias and insufficient penetration of calcium at deeper depths.
Shockwave IVL, according to Kereiakes, can solve these problems. The device uses acoustic pressure waves (1 pulse/sec) with a pressure of around 50 atmospheres to fracture superficial as well as deep calcium.
The DISRUPT CAD III trial exemplified the kind of results Shockwave IVL can achieve.
A vast majority, 92.2%, of patients had a 30-day freedom from major adverse cardiac events (MACE). A severe dissection following stent-deployment occurred in only one patient (0.3%). Rates of perforation, slow flow and no-reflow were 0% immediately following IVL treatment. While transient IVL-induced ventricular capture was common among 171 patients, the outcomes were benign.
Despite the study being the initial coronary IVL experience for U.S. operators, high procedural success and low complication rates were achieved. The first 47 cases at each of the 47 sites had a freedom from MACE at 30 days was 89.4% , a procedural success rate of 87.2%, and a successful rate of crossing of 93.6%.
The average lesion length in the study was 26.0 mm, with an average length of calcification of 47.9 mm. Findings from the DISRUPT CAD III OCT sub-study showed that the average post-stent expansion was 102%.
“The reluctance of people to tackle calcium properly has been a problem,” Richard Shlofmitz, MD, of St. Francis Hospital, The Heart Center, Roslyn, New York, said. “What is amazing about this device [is] it is so user-friendly, and the complication rate is so low, it’s going to make people comfortable treating calcium. So I think this is a major advance in treating a very difficult problem in coronary artery disease.”
Yet, issues of price remain. IVL catheters have a national standardized price of $4,700 and some physicians worry that the cost might discourage usage of the device. Competing atherectomy catheters can cost under $2,000.
“The cost is going to be prohibitive for long-term use at this point,” Robert F. Riley, MD, of The Christ Hospital Network and Linder Center for Research and Education, Cincinnati, said during a panel discussion. “Now, the hope is obviously that this isn’t the end-all, be-all price, that there’s a rhyme and a reason … But, certainly, there will have to be modifications in use-patterns and reimbursement, etcetera, in order to justify practice-use now.”
“My take on the price [is] that eventually prices will come down,” CRT 2021 Virtual Course Chairman Ron Waksman, MD, of MedStar Washington Hospital Center, Washington, D.C., said. He gave the price trajectory of Cordis Corporation’s Cypher stents as possible model that Shockwave IVL’s pricing could follow.