The Impact of Chronic Total Occlusion (CTO) Scoring Systems on Procedural Success and Patient Outcomes

Chronic total occlusion (CTO) lesions in coronary arteries present a significant challenge, often resulting in referrals for coronary artery bypass graft surgery. Successful percutaneous coronary intervention (PCI) for CTOs demands an accurate assessment of procedural potential.

This study aimed to compare the efficacy of different CTO scoring systems in predicting the PCI procedural success and the associated patient complications. It included patients with a CTO in at least one coronary artery who were scheduled for elective PCI based on objective evidence of ischemia. Experienced operators performed the PCI, recorded procedural variables, and assessed complications.

Our findings indicated that the Japan CTO (J-CTO) score had the highest positive predictive value at 88.89%, closely followed by the CL CTO score at 88.79%, the CASTLE CTO score at 86.84%, and lastly, the Prospective Global Registry for the Study of Chronic Total Occlusion Intervention (PROGRESS) CTO score at 86.51%. All scores fell within an acceptable specificity range of 59.2% to 76.3%, while accuracy varied from 62.61% to 72.52%. We also estimated these values using the best Youden index, which was 0.362 for J-CTO, 0.355 for Euro CTO (CASTLE), 0.330 for CL CTO, and 0.283 for PROGRESS CTO, thus maximizing sensitivity and specificity at a particular point. The relation between CTO scores and complications showed comparable differences with no statistical significance and no correlation regarding the cutoff value.

This study shows that J-CTO and CASTLE provide slightly greater accuracy in predicting complex CTO PCI success compared to PROGRESS CTO and CL. However, the ostial location score did not demonstrate statistical significance in our patients.