Introduction

Chronic total occlusion (CTO) complexity scores were developed to predict procedural difficulty during CTO percutaneous coronary intervention (CTO-PCI). Their value for predicting long-term clinical outcomes remains uncertain.

Aim

We investigated the association between commonly used CTO complexity scores and adverse outcomes after CTO-PCI and compared their prognostic performance.

Material and methods

This retrospective single-center cohort study included 149 consecutive patients undergoing CTO-PCI. Five CTO complexity scores (J-CTO, RECHARGE, PROGRESS-CTO, CL, and CASTLE) were calculated. The primary endpoint was a composite of all-cause mortality or urgent coronary revascularization. Multivariable Cox regression, receiver operating characteristic (ROC) analysis, and Kaplan-Meier survival analysis were performed.

Results

During a mean follow-up of 17.1 ±10.6 months, the composite endpoint occurred in 30 (20.1%) patients. After adjustment for age, left ventricular ejection fraction, serum creatinine, and albumin, all five CTO scores remained independently associated with the composite outcome. The J-CTO score showed the strongest association (adjusted HR = 2.18, 95% CI: 1.38–3.45; p = 0.001). The CASTLE score had the highest observed ROC-AUC (0.726, p < 0.001), although its discriminatory performance did not differ significantly from that of the J-CTO score. Harrell’s C-index also demonstrated comparable discrimination between the CASTLE and J-CTO scores (both C-index 0.697), indicating modest-to-moderate discriminatory ability. Patients with J-CTO ≥ 2 or CASTLE ≥ 2 had significantly worse event-free survival (log-rank p = 0.013 and p = 0.004, respectively).

Conclusions

CTO complexity scores were independently associated with long-term adverse outcomes after CTO-PCI and may have prognostic relevance in addition to their established role in procedural planning. These findings should be confirmed in larger prospective studies.