Intravascular lithotripsy for coronary chronic total occlusion: a meta-analysis of procedural and clinical outcomes

Background: A significant gap exists within current guidelines for the treatment of chronic total occlusion (CTO), which has yielded poor prognostic outcomes. Intravascular lithotripsy (IVL) has emerged as a novel strategy implemented during percutaneous coronary intervention (PCI), but evidence to support its use is limited. Aims: We aimed to review the outcomes of IVL for CTO PCI. Methods: Databases including PubMed, Cochrane, Scopus, EBSCOhost, and ProQuest were searched for studies implementing IVL for CTO PCI. The quality of studies was assessed using the Cochrane Risk Of Bias In Non-randomized Studies of Interventions and JBI tools. An inverse variance, random-effects meta-analysis was conducted in RStudio version 2023.03.0+386 yielding pooled proportions and means along with their 95% confidence intervals (CIs). Where applicable, sensitivity and subgroup analyses were performed. Results: Five studies with 611 patients were included. Technical success was achieved in 97% (95% CI: 94-100%; I²=18%) of cases. Procedural success was achieved in 94% (95% CI: 90-97%; I²=27%), and the subgroup with a Japanese CTO score >2.8 yielded a significantly higher success rate (95% [95% CI: 93-97%] vs 91% [95% CI: 85-96%]; p=0.04). Major adverse cardiovascular events (MACE) occurred in 3% (95% CI: 2-5%; I²=0%) of cases within the in-hospital follow-up subgroup and in 6% (95% CI: 1-12%; I²=0%) of cases within the discharge follow-up subgroup. Mortality occurred in 1% (95% CI: 0-4%; I²=55%) of cases within the in-hospital subgroup and 0% (95% CI: 0-52%) of cases within the discharge subgroup. Perforation as a complication occurred in 5% (95% CI: 1-9%; I²=54%) of cases. The pooled mean procedural time was 122.94 minutes (95% CI: 102.24-143.64 minutes; I²=90%), and the mean contrast volume used was 154 mL (95% CI: 140.84-167.16 mL; I²=69%). Conclusions: IVL yielded high technical and procedural success, and comparable procedural times and contrast volume in CTO PCI. MACE, mortality, and perforation occurred in small proportions of patients. Further studies are needed to strengthen evidence and explore which subtype of CTO would benefit most from IVL.