Using SYNTAX scoring to indicate the outcomes from CABG and PCI procedures in multivessel coronary disease

Stockholm, Sweden, 29 August:  There have been several studies into the impact of completeness of revascularisation in recent years, yet few clear recommendations are available on the likely clinical outcomes.  This topic is not formally addressed in either the European Society of Cardiology guidelines or those jointly issued by the American Heart Association and American College of Cardiology.

Revascularisation is the result of two types of procedure – coronary artery bypass grafting surgery (CABG) and percutaneous coronary interventions (PCI) - both are carried out on patients with coronary artery disease, and the term ‘completeness’ is a measure of its extent.  Complete revascularisation has been defined as when all lesions >50% diameter stenosis in a vessel with a reference diameter >1.5mm have been successfully treated.  Those patients for whom no attempt was made to treat one or more lesions having these characteristics, or where treatment resulted in a final diameter stenosis >50%, were considered to be incompletely revascularised.

A research team led by Doctor Giovanna Sarno of the Erasmus Medical Center, Rotterdam, The Netherlands used data generated by the Arterial Revascularisation Therapies Studies-II (ARTS-II) to investigate the differences in clinical outcome of patients having complete and incomplete revascularisation.  “Our aim was to compare differences in clinical outcomes at the 5-year follow-up point within a group of multivessel-diseased patients.  All had undergone either complete or incomplete revascularisation using CABG or PCI with drug-eluting stents,” said Doctor Sarno. 

One finding of this research study is that incomplete reva scularisation in PCI patients with a high SYNTAX score leads to an increased rate of adverse events compared to those treated with CABG.  For patients with lower SYNTAX scores, however, the outcomes were broadly similar for both PCI and CABG procedures.  A patient’s SYNTAX score is an indication of the complexity of their coronary artery disease; the higher the score, the more anatomically complex is the coronary disease.

Incompletely revascularised patients that were treated with PCI were stratified according to their SYNTAX score tertiles.  For those in the upper tertile, the 5-year MACCE rate showed markedly reduced survival compared to those in the low tertile, however there was little difference between those in low and intermediate tertiles.  The use of SYNTAX scoring has enabled the identification of those patients with incomplete revascularisation having a low and intermediate SYNTAX score, who do not experience adverse events at long-tern follow-up compared to those patients that were completely revascularised.

Doctor Sarno concludes, “This study suggests that patients with complex coronary artery disease, in whom complete revascularisation cannot be achieved with PCI, should be offered CABG.  But in those patients with less complex disease, PCI remains a valid alternative even when complete revascularisation cannot be achieved.”

Contributors: Giovanna Sarno, Scot Garg, Yoshinobu Onuma, Juan-Luis Gutiérrez-Chico, Marcel J. B. M. van den Brand, Benno J. W. M. Rensing,  Marie-Angele Morel, Patrick W. Serruys. (all Erasmus Thorax Center, Rotterdam, Netherlands)

ENDS