1. JCTO score
JCTO score is a score where one point is given for each of
1. Blunt entry stump,
2. Calcification,
3. Bend > 45 degrees,
4. Occlusion length > 20 mm,
5. previous failed attempt.

The JCTO has been well correlated to successful wire crossing within 30 minutes (success rates of 88%, 67%, 42% and 10% with increasing JCTO scores). [Morino et al JACC Cardiovasc Interv. 2011 Feb;4(2):213-21] . The impact of proctor is useful in patients with JCTO scores ≥ 2 (success without proctor 49.5%, success with proctor 70.7%) [Sharma et al. Open Heart. 2015 Mar 28;2(1):e000228]. Therefore, for patients with JCTO scores ≥ 2, proctor assistance should be used for the CTO PCI. All retrograde cases and Cross Boss Stingray cases should be done with proctor until the proctor signs off the operator as being competent in these techniques.