Introduction

Technical failure during chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is usually reported as a binary outcome, although failed procedures may follow different procedural courses.

Aim

To describe procedural patterns of technical failure during CTO PCI and assess their association with conventional CTO complexity scores.

Material and methods

We analyzed 2,375 CTO PCI procedures from a multicenter registry. Technical failure was classified as Pattern A (crossing- or device-delivery failure) or Pattern B (dissection- or flow-related failure). Multivariable logistic regression was used to examine correlates of overall and pattern-specific failure.

Results

Technical failure occurred in 192 (8.1%) procedures: 148 (77.1%) were Pattern A and 44 (22.9%) were Pattern B. J-CTO and CASTLE/EuroCTO scores were higher in Pattern A than in Pattern B. Overall technical failure was associated with blunt/absent proximal cap, CTO length ≥ 30 mm, moderate/severe calcification, previous coronary artery bypass grafting, and proximal tortuosity. In the exploratory Pattern B model, CTO length ≥ 30 mm, moderate/severe calcification, and left anterior descending versus right coronary artery target vessel were associated with Pattern B versus technical success. However, target vessel did not differentiate Pattern B from Pattern A after adjustment for J-CTO or CASTLE/EuroCTO score. Pattern B consisted mainly of persistent dissection and no/slow flow.

Conclusions

Technical failure during CTO PCI is heterogeneous. Conventional CTO complexity scores appeared to align more closely with crossing- or device-delivery failure, while dissection- or flow-related failure remained a smaller exploratory subgroup requiring external validation.