Intravascular Lithotripsy Safely Treats Severely Calcified Coronary-Artery Disease

Intravascular lithotripsy (IVL) is a safe and effective adjunct to stent implantation in severely calcified coronary-artery lesions, according to a single-arm multicenter study.

"IVL will be the treatment of 'first choice' for moderate-severe coronary calcification to facilitate and optimize stent placement and will apply to about 25% of patients undergoing percutaneous coronary intervention (PCI)," Dr. Dean J. Kereiakes of The Christ Hospital and Lindner Research Center, in Cincinnati, Ohio, told Reuters Health by email.

Coronary calcification can impede stent delivery and deployment and can be associated with early complications and/or late adverse events following PCI.

Dr. Kereiakes and colleagues in the Disrupt CAD III trial assessed the safety and effectiveness of IVL to optimize stent deployment in patients with severely calcified de novo coronary stenosis.

All target lesions in the 384 patients included in the analyses were severely calcified, and 29.9% had side-branch involvement.

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IVL delivery occurred in 98.2% of procedures, with a mean of 68.8 pulses delivered.

Freedom from 30-day major adverse cardiovascular events (MACE), the primary safety endpoint, was achieved in 92.2% of patients. Stent delivery with a residual stenosis <50% without in-hospital MACE, the primary effectiveness endpoint, was achieved in 92.4% of patients, the researchers report in the Journal of the American College of Cardiology.

MACE and target-lesion failure through 30 days (which occurred in 7.8% and 7.6% of patients, respectively) were driven primarily by target-vessel myocardial infarction. There were two deaths (0.5%) within 30 days following PCI/IVL.

Postprocedural in-stent residual stenosis <50% was achieved in all cases, and 99.5% of lesions had <30% residual stenosis.

IVL-induced heart-rhythm capture occurred in 41.1% of cases but did not result in sustained ventricular arrhythmias and was not associated with adverse events.

Among 100 patients enrolled in the optical coherence tomography (OCT) substudy, calcium fractures were identified after IVL in 67.4% of the lesions, with multiple fractures observed in 67.7%.

"Calcium fracture is the likely mechanism through which IVL enhances vessel compliance to facilitate optimal stent expansion, as evidenced by increased fracture width following stent expansion," the authors note.

"Longer-term clinical follow-up (ongoing in this study through 2 years) is required to determine the durability of clinical benefit associated with IVL-optimized stent implantation," they add.

"The remarkable degree of stent expansion (average 102%) despite the severity of calcification should predict excellent long-term clinical outcomes," Dr. Kereiakes said. "IVL is novel technology in a 'not novel' delivery system (balloon), which is what makes it so easy."

Shockwave Medical, Inc. funded the study and had financial ties to several authors, including Dr. Kereiakes.

—Will Boggs MD

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