Mechanical Circulatory Support Use in Chronic Total Occlusion Percutaneous Coronary Intervention: A Systematic Review.

Background: Mechanical circulatory support (MCS) during percutaneous coronary intervention (PCI) remains controversial, particularly in high-risk procedures such as chronic total occlusion PCI (CTO-PCI), and real-world data on its frequency, patient selection, and outcomes are limited. Aims: To assess the frequency of MCS use during CTO-PCI, to describe the clinical and procedural characteristics of supported patients, and to synthesize the available outcome data. Methods: A systematic review was conducted according to PRISMA guidelines and registered in PROSPERO (CRD420251044868). PubMed, Scopus, and the Cochrane Library were systematically searched. Results: Nine studies were included in the qualitative synthesis. Reported rates of MCS use during CTO-PCI ranged from 0.7% to 6.4%. MCS was used more frequently in elderly patients and those with diabetes mellitus, chronic kidney disease, impaired left ventricular systolic function, greater anatomical complexity, and in procedures employing a retrograde approach. Across studies, procedural and clinical outcomes were consistently more favorable when MCS was implanted prophylactically rather than used as urgent rescue therapy. Conclusions: Overall, MCS use during CTO-PCI is infrequent and largely reserved for selected high-risk cases. In patients with a meaningful anticipated risk of hemodynamic instability, prophylactic implantation should be considered. Prospective multicenter studies are needed to refine indications and assess cost-effectiveness.