BACKGROUND

Stent underexpansion significantly heightens the risk of major adverse cardiac events (MACE), and available treatment options for this condition remain limited. Intravascular Lithotripsy (IVL) technology disrupts superficial and deep calcium by using localized pulsative sonic pressure waves, emerges as a promising tool for underexpanded stents.

AIMS

This study examines the overall efficacy and safety of IVL, an until-now off-label modality, in the management of underexpanded stents.

METHODS

Following PRISMA guidelines, we systematically explored PubMed, SCOPUS, and Cochrane databases up to April 30, 2024, for studies evaluating IVL's safety and efficacy in treating underexpanded stents. We gathered angiographic (QCA) and intracoronary imaging (OCT or IVUS) data, examining the stent's diameter stenosis (SDS), minimal lumen diameter (MLD), minimal stent area (MSA), and minimal lumen area (MLA) pre- and post-IVL application. Procedural success constituted the efficacy endpoint, while peri-procedural complications, in-hospital-30-days and long-term mortality, and MACE were safety endpoints.

RESULTS

This meta-analysis comprised 23 studies including 819 patients and 837 treated lesions in underexpanded stent. The mean age was 71.7 ± 8.8 years, with an overall IVL procedural success rate of 92% [(95% confidence interval (CI): 88%-95%, I = 35%), while the in-hospital-30-days and long-term mortality incidence were 1% (95% CI: 1%-3%, I = 0%) and 4% (95% CI: 2%-6%, I = 0), respectively. The 30-day rates acute myocardial infarction and stroke were 1% [(95% CI: 0%-1%, I² = 0%), (95% CI: 0%-2%, I = 0%)] each. No need for short term target lesion revascularization (TLR) was observed while the long-term rates were 6% (95% CI: 3%-10%, I = 48%). There was a significant decrease in the SDS [Standardized Mean Difference (SMD): -3.57 (95% CI: -4.64 to -2.44%, I = 94%)] and increase in MSA (SMD: +1.98, 95% CI: 0.86-3.09, I = 93%) after IVL application. It was observed a significant increase in MLD (SMD: +2.68, 95% CI: 1.94-3.41, I = 90%) and in the MLA (SMD: +1.92, 95% CI: 1.46-2.38, I = 69%). Major procedural and device related complications were 2% (95% CI: 1%-5%, I = 0%) and 1% (95% CI: 0%-2%, I = 80%) respectively. Notably low rates were observed for stent thrombosis (1%, 95% CI: 0%-2%, I = 0%), dissections (1%, 95% CI: 1%-4%, I = 0%), perforations (1%, 95% CI: 1%-3%, I = 0%) and no-reflow (0%, 95% CI: 0%-46%, I = 0%).

CONCLUSIONS

IVL demonstrates promise as a safe and effective strategy for underexpanded stent treatment, characterized by low rates of periprocedural complications. Future prospective studies are now warranted to compare IVL to other lesion preparation strategies.