The Euro CTO Score – Comparison with existing scores David Hildick-Smith, United Kingdom The Experts “Live” Workshop 2017 Friday, September 15th, 2017

1. The EuroCTO Score
David Hildick-Smith
Professor of Interventional Cardiology
Sussex Cardiac Centre, Brighton, UK

2. Why?
• Rapid changes in
• Operator skills
• Technical options
• Equipment sophistication
• Existing scoring systems ?incomplete
• Massive Euro-CTO Registry

3. Existing scoring systems

4. J-CTO

5. J-CTO

6. J-CTO
• Derived in 2006!
• (think how your practice has changed!)
• 500 cases
• Antegrade only
• Wiring within 30 minutes
• 48% success

7. PROGRESS
• 800 cases
• Proximal cap ambiguity
• Tortuosity
• Circumflex
• Absence of interventional collaterals

8. EuroCTO Score
• London School of Hygiene And Tropical
Medicine (Z. Szijgyarto; T. Clayton)
• Data from the Prospective EuroCTO Registry
• 2008-14: 12,500 cases
• 2015-16: 5,000 cases

9. EuroCTO Score
• Advantages:
• Massive dasaset
• Prospective data entry
• >100 dedicated CTO operators
• Living database
• Disadvantages:
• Massive dataset
• Unmonitored

10. Euro-CTO Score
The Brier score measures the total difference between the event (failure of PCI) and the forecast
probability of that event (failure of PCI) as an average squared difference.
Brier score: 𝐵𝑟𝑖𝑒𝑟 𝑠𝑐𝑜𝑟𝑒 = 𝑗
𝑑 𝑗−𝑝 𝑗
2
𝑁
𝑤ℎ𝑒𝑟𝑒 𝑑𝑗 𝑖𝑠 𝑡ℎ𝑒 𝑜𝑏𝑠𝑒𝑟𝑣𝑒𝑑 𝑜𝑢𝑡𝑐𝑜𝑚𝑒 𝑓𝑜𝑟 𝑗 𝑤𝑖𝑡ℎ 𝑣𝑎𝑙𝑢𝑒𝑠 0 𝑎𝑛𝑑 1; 𝑝𝑗 𝑖𝑠 𝑡ℎ𝑒 𝑝𝑟𝑒𝑑𝑖𝑐𝑡𝑒𝑑 𝑜𝑢𝑡𝑐𝑜𝑚𝑒
(𝑐𝑜𝑚𝑝𝑢𝑡𝑒𝑑 𝑏𝑦 𝑡ℎ𝑒 𝑎𝑙𝑔𝑜𝑟𝑡ℎ𝑖𝑚 𝑜𝑓 𝐶𝐴𝑆𝑇𝐿𝐸 𝑟𝑖𝑠𝑘 𝑡𝑜𝑜𝑙)
(Rules: for perfect prediction (forecast) Brier score = 0; for a non-informative model with a 50 %
chance of outcome would be an expected Brier score of 0.25).

11. Score
• CABG (previous)
• Age (>70)
• Stump (Blunt or none)
• Tortuosity (severe or unseen)
• Length (>20mm)
• Extent of Calcification

12. CASTLE Score
• CABG (previous)
• Age (>70)
• Stump (Blunt or none)
• Tortuosity (severe or unseen)
• Length (>20mm)
• Extent of Calcification

15. Grouping
• Scores:
• 0-1 92% success
• 2 85% success
• 3 80% success
• 4+ 70% success 0.0
0.1
0.2
0.3
0.4
ProbabilityoffailureofPCI
1 2 3 4
Risk groups
observed
predicted

16. Strengths
• Simple
• Memorable
• Includes two objective variables

17. Weaknesses
• Simple
• Includes four subjective variables

18. Complex version
• Same six variables with weighted scoring (0-7)
for greater accuracy

19. Comparison
J-CTO PROGRESS Euro-CTO CASTLE
CABG √
Age √
Stump √ √
Tortuosity √ √ √
Length √ √ √
Calcification √ √
Circumflex √
Collaterals √
Re-try √

20. Discussion
• Your club
• Your score