Procedural and Prognostic Implications of Guide Extension Catheter Use During Percutaneous Coronary Intervention: A Retrospective Cohort Study

BACKGROUND: Guide extension catheters (GECs) have become an essential adjunctive tool in complex percutaneous coronary interventions (PCIs). GECs provide additional catheter support and stability, enhancing device deliverability. AIMS: Our study aims to evaluate the technical and prognostic significance of the use of GECs in complex PCI. METHODS: Our study included 23,299 PCI cases performed in a large tertiary center between 2010 and 2023. We assessed rates of procedural success with GEC. The primary clinical endpoint was all cause-mortality. Other clinical endpoints included major adverse cardiac events (MACE) during follow-up. Cox regression, multivariate analysis, and propensity score matching were used to compare GEC and non-GEC PCI cases. RESULTS: Of the 23,299 PCI cases in our study, 532 patients (2%) were treated utilizing GECs. The median age was 66 [IQR 58-75], and 88% were males. Successful PCI was performed in 96.2% of the total cohort, with similar rates in the GEC and non-GEC group (94.9% vs. 96.2%, p = 0.144). GEC was used more often in calcified, bifurcation, and unprotected left main lesions. Patients requiring the use of GEC had higher long-term mortality rates (HR 1.86, 95% CI 1.54-2.23, p < 0.001) and MACE events (HR 1.26, 95% CI 1.07-1.47, p = 0.004). Multivariate adjustments, sensitivity analysis of complex-PCI cases, and a propensity score-matched model showed similar results. A landmark analysis showed no significant difference in 30-day mortality but divergence of the survival curves after 30 days with increased mortality among the GEC cohort. CONCLUSIONS: Our study showed that patients who required GEC during PCI were successfully treated in the vast majority of cases, with similar short-term results. However, the use of GEC is associated with a worse long-term prognosis, reflecting a surrogate for sicker patients and procedural complexity, thus requiring careful follow-up.