Guidezilla Guide Extension Catheter Use During Retrograde Chronic Total Occlusion Percutaneous Coronary Intervention: Procedural Success and Long-Term Outcomes

Background: The role of the Guidezilla guide extension catheter during retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI) remains uncertain. We examined its associations with procedural success, reported complications, and subsequent clinical events. Methods: This retrospective single-centre study included 819 patients undergoing elective retrograde CTO PCI between January 2011 and April 2023. Procedural associations were evaluated using logistic regression and propensity score matching. Long-term outcomes were evaluated using Kaplan–Meier analysis and Cox regression. Results: The Guidezilla guide extension catheter was used in 281 patients (34.3%). Retrograde technical success was 95.0% versus 87.0%, and final recanalisation success was 96.1% versus 88.3% (both p < 0.001). Corresponding adjusted odds ratios (ORs) were 3.80 (95% confidence interval [CI] 2.11–7.32) and 4.30 (95% CI 2.26–8.94; both p < 0.001). Associations persisted in 259 matched pairs (ORs 2.54, 95% CI 1.34–4.82, and 2.90, 95% CI 1.41–5.95; both p = 0.004). Reported in-hospital complications did not differ significantly, but rare events limited comparative safety assessment. In the fully adjusted Cox model, hazard ratios (HRs) were 0.99 (95% CI 0.48–2.04; p = 0.976) for cardiovascular events and 1.28 (95% CI 0.81–2.03; p = 0.295) for major adverse cardiovascular events. Conclusions: Guidezilla guide extension catheter use was associated with higher procedural success. These observational findings remain susceptible to selection bias and residual confounding, while limited event numbers preclude firm conclusions regarding comparative safety and long-term outcomes. Prospective confirmation is warranted.