# A Multicenter Retrospective Analysis of the Utility of Intravascular Lithotripsy in Underexpanded Stents

## TL;DR

This study shows that intravascular lithotripsy is safe and effective for treating underexpanded stents, with outcomes similar to new coronary lesions.

## Contribution

The study provides real-world evidence supporting the off-label use of IVL for in-stent lesions.

## Key findings

- 12-month MACE rates were 8.8%, comparable to de novo lesions.
- Procedural success was achieved in 87% of cases.
- Angiographic results showed significant improvement in lumen diameter post-IVL and post-stenting.

## Abstract

Stent underexpansion is a key determinant to both short- and long-term outcomes after percutaneous coronary intervention (PCI). Current strategies available have inherent limitations in the setting of stent underexpansion, and intravascular lithotripsy (IVL) remains off-label for in-stent use. Our study aimed to demonstrate the safety and efficacy of IVL use in underexpanded stents.

We undertook a retrospective analysis of PCIs involving IVL at 3 centers in New Zealand between September 2018 and November 2023. We identified cases in which IVL was utilized for both old and new in-stent lesions. The primary outcome was a 12-month major adverse cardiac events (cardiac death, nonfatal myocardial infarction [MI], or ischemia-driven target vessel revascularization [ID-TVR]). Secondary outcomes were procedural success (<30% residual stenosis), 30-day cardiac and noncardiac death, nonfatal MI, ID-TVR, and stent thrombosis. Angiographic and intravascular imaging outcomes were also analyzed.

Between September 2018 and November 2023, 68 of 743 IVL cases involved in-stent lesions. Of the cases, 69% were acute coronary syndrome presentations. Twelve-month major adverse cardiac events were 8.8%. Procedural success was 87%. At 30 days, there was 1 noncardiac death but no cardiac death, nonfatal MI, ID-TVR, or stent thrombosis events. Serious complications included 2 cases of slow flow. Angiographic mean minimal lumen diameter pre-PCI was 0.89 ± 0.54 mm, post-IVL was 2.40 ± 0.60 mm, and post-stenting was 3.01 ± 0.69 mm. Intravascular imaging use was 41%; mean minimal lumen area was 3.60 ±1.78 mm2 pre-PCI and 8.71 ± 3.28 mm2 post-PCI.

Our multicenter retrospective analysis demonstrates that IVL is a safe and effective tool in the treatment of underexpanded stents with 12-month MACE rates comparable to those of de novo coronary lesions and a high rate of procedural success. Larger, randomized studies are required to elucidate the optimal approach for treating underexpanded stents.