International Circulation: Some people may argue that the Syntax score is not ideal for identifying the best candidates for CABG or PCI because it is mainly based on the angiographic findings of the lesion and the general condition of the patient， including comorbidity， is given less consideration. Do you agree with this viewpoint?
Prof. Serruys: During the Syntax trial we were collecting the Syntax score which is purely angiographic and we were also collecting the Euroscore， which is more about comorbidity. Initially， the collection of these data were essentially to define， characterize， and analyze the patient prior to the procedure. It turns out that the Syntax score has a certain prognostic value mainly for the PCI patient but much less so for the surgical patient and classically the Euroscore has a predictive and prognostic value mainly for surgical case. Many of us were puzzled by that and attempted to combine both scores. Among these attempts， you have the ACEF where you take the age， creatinine， and ejection fraction and you can predict quite nicely what is going to happen with surgery. We also did a clinical Syntax， which means you multiply the Euroscore by the Syntax score， and we found the prognostic value somewhat better. Also， an Italian team from Catania used a combination of the Euroscore and the Syntax score， but in a categorical way. This kind of score helps the practitioner and patient to make a decision. These prognostic factors always have an element of discrimination separating the patients and an element of calibration. When you look at all these factors you must be sure that you have a good tradeoff between discrimination and calibration and people are still struggling with these two parameters.