Intravascular Lithotripsy: An Option for Severe Coronary Artery Calcification

Intravascular lithotripsy (IVL) was performed safely with a high rate of success and few complications in patients with severe coronary artery calcification (CAC) requiring coronary revascularization, according to a study published in Circulation: Cardiovascular Interventions. In most lesions, IVL led to substantial calcific plaque fracture.

Disrupt Coronary Artery Disease (Disrupt CAD) II was a prospective, multicenter, single-arm, post-approval study conducted at 15 hospitals in 9 countries (ClinicalTrials.gov identifier: NCT03328949). The Disrupt CAD I study demonstrated the feasibility of IVL for modifying severe CAC, and the Disrupt CAD II study was designed to confirm the safety and efficacy of IVL for these lesions. The primary end point was major adverse in-hospital cardiac events (myocardial infarction, cardiac death, or target vessel revascularization). An optical coherence tomography (OCT) substudy was performed to assess IVL’s mechanism of action and to quantify CAC characteristics and calcium plaque fracture. Angiography and OCT were adjudicated by independent core laboratories, and major adverse cardiac events were adjudicated by an independent clinical events committee.

Between May 2018 to March 2019, 120 participants were enrolled in the study. The most common target vessel was the left anterior descending coronary artery (62.5%). Severe calcification determined by angiographic core laboratory analysis was present in 94.2% of lesions. Clinical success was seen in 94.2% of participants, all of whom had <50% residual stenosis after stenting.

Post-IVL, angiographic acute luminal gain was 0.83 ±0.47 mm, and residual stenosis was 32.7±10.4%, which further decreased to 7.8±7.1% after drug eluting stent (DES) implantation.

The 30-day rate of major adverse cardiac events was 7.6%, and the in-hospital primary end point occurred in 5.8% of participants (7 non–Q-wave myocardial infarctions).

Calcium fracture was identified in 78.7% of lesions in 47 patients with post-percutaneous coronary intervention OCT. Mean fracture length was 5.5±5.0 mm and there were 3.4±2.6 mean fractures per lesion and 1.6±0.8 fractures per frame.

Preparing vessels with IVL increased minimal luminal area from 2.33±1.35 to 6.10±2.17 mm² (P <.001) after DES, with none of the lesions colocalizing the minimal luminal area with the site of maximal calcification.

This study had several limitations, including the nonrandomized design, small sample size, the lack of a concurrent control group, an overly conservative secondary end point of clinical success, severe calcification diagnosed by angiography alone, and incomplete follow-up. Despite these limitations, the study investigators concluded, “in patients with severe CAC who require revascularization, IVL before stent implantation was performed safely with a low rate of complications and with high procedural success.”

Disclosure: This study was funded by Shockwave Medical, Inc (Santa Clara, CA). Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.

Reference

Ali ZA, Holger N, Escaned J, et al. Safety and effectiveness of coronary intravascular lithotripsy for treatment of severely calcified coronary stenoses: the Disrupt CAD II study. Circ Cardiovasc Interv. 2019;12(10):e008434.