SYNTAX TRIAL ; PCI WITH DES Vs CABG

One of the most important presentation in the just ended European Congress of Cardiology meeting in Munich must be the presentation of the much awaited SYNTAX trial. This is a 1,800 patient ( 900 to PCI with DES and 900 to CABG ) conducted in over 60 sites in Europe and 23 sites in USA. It has a 1 year followup ( which must favor CABG ). The investigators were studying to see if PCI with DES is not inferior to CABG ( non-inferiority is the way to go nowadays ). Well, in the primary endpoints which included the usual MACCE and repeat PCI, PCI with DES, was shown to be inferior to CABG at 1 year. If one excludes the endpoint of repeat PCI, and use only MACCE, then PCI with DES was not inferior to CABG.
I made a note earlier that a 1 year followup will certainly favour CABG, for the simple reason that in CABG, you are implanting a large 3.0mm ( or larger ) veingraft to by-pass a stenosis. Baring acute graft occlusion from poor technique, it will take 3-5 years for atherosclerosis to re-occur. I dare say that if one were to examine the numbers after 5 years of followup, then PCI with DES will not be inferior to CABG. But that is pure conjecture, at the moment.
What does this all mean to clinical practice? Well, in those patients with PCI favourable anatomy, the patients will have to decide, if they wish to undergo PCI with DES with the higher chance of re-PCI, but lesser morbidity or CABG, with a lesser chance of re-CABG at 1 year, but higher morbidity. It is important to note that in SYNTAX, about one third of the patients had complex anatomy which made PCI impossible.
The other lession that I got from the SYNTAX trial was the validation of the SYNTAX score, which allow cardiologist to better risk assess PCI candidates. I believe that this SYNTAX score is now widely applied, so that we can have a better idea of the risk to the patient because of his anatomy. This SYNTAX score takes into account the patients anatomical factors, which are important for PCI succes. CABG risk can be assessed using the Parsonnet score. Now we have reliable ways of procedural risk assessment for PCI and CABG.
All-in-all, the SYNTAX trial is certainly a landmark study in the care of the CAD patient. I can only hope that Dr Serruys and co-investigators, will continue to follow the patients up and be able to give us their 5 year follow-up results. That should also be important.