Syntax Score website: A tool for the best strategy


A new website dedicated to the understanding and use of the Syntax Score, a novel angiographic tool used to measure the complexity of coronary artery disease, was launched during the EuroPCR meeting in May, in Barcelona, Spain. The is an important tool to help physicians determine revascularisation strategies.

The Syntax Score was developed in connection with the SYNTAX trial, the first randomised, controlled clinical trial to compare percutaneous coronary intervention (PCI) using the Taxus Express2 stent to coronary artery bypass graft (CABG) surgery in patients with left main disease and/or significant narrowing of all three coronary arteries (three-vessel disease). These complex patients are traditionally treated with CABG and have been excluded from most prior drug-eluting stent clinical trials.

The Syntax Score was used in the trial to characterise coronary anatomy based on nine anatomic criteria, including lesion frequency, complexity and location, and a score was assigned to each patient. Higher Syntax scores indicate patients with more complex disease and increased treatment challenges.

The new website allows physicians to calculate a patient’s score and create a description of anatomical complexity of the coronary vasculature that can be used in combination with a clinical judgment to aid in determining the best revascularisation option. The team examines the patient anatomy and then uses the Syntax score software to answer a series of questions and sub-questions that guide the team towards a decision on the best treatment strategy. The site also includes a detailed tutorial on the use of the Syntax Score calculator, including definitions and example cases, together with SYNTAX data presentations and publications. A high Syntax score indicates that CABG is preferred whereas low to middle scores indicate that PCI is preferred.

“The Syntax Score website will be an important tool to assist with revascularisation strategies in these complex patient populations,” said Patrick W Serruys, chief of Interventional Cardiology, Thoraxcenter-Erasmus University, Rotterdam, The Netherlands, and chairman of the SYNTAX trial steering committee. “Having a consistent grading system for lesion complexity and severity of coronary artery disease allows me to better evaluate treatment options. The website’s interactive calculator makes it easier to determine a patient’s score and to reference current clinical data from the SYNTAX trial associated with that score.”

The SYNTAX trial will continue to provide important data throughout the life of the trial (one-, three- and five-year outcomes). As more data become available, understanding of the SYNTAX trial will increase as will the utility of the Syntax Score.

The Syntax Score and Syntax Score website were developed under the direction of the SYNTAX trial steering committee, chaired by Serruys and FW Mohr, and were made possible by support from Boston Scientific and Cardialysis BV.

PCI more cost effective
Ben van Hout, University of Utrecht, The Netherlands, presented results from an analysis of economic and quality of life outcomes, based on one-year data from the SYNTAX trial at EuroPCR. The results found that PCI was associated with fewer patient hospital days during the first year after treatment compared to bypass surgery. Total medical costs were also lower with PCI.
“This analysis demonstrates that although hospitalisation patterns vary by country, PCI patients consistently benefit from shorter hospital stays during the first year following treatment, as compared to CABG patients,” said Van Hout. “This analysis will be especially helpful to physicians and hospital administrators as they consider the most cost-effective course of treatment for these complex patients.”

The SYNTAX economic analysis compared quality of life outcomes using standardised health outcome measures and resource utilisation in patients in 11 European countries and the US who qualified for one or the other revascularisation option. The results indicated a short-term benefit for PCI versus CABG surgery, with no significant difference at one year, but with a gain in quality adjusted life years of 0.02 in favour of PCI.

The analysis also included a detailed calculation of total medical costs at one year for all patients treated in the UK, the country with the largest cohort of patients. Total costs included the initial procedure, all hospitalisations, repeat procedures and medication. Although initial procedure costs were similar (£4,201 for PCI vs. £4,246 for CABG), total medical costs for PCI were 25% lower than CABG at one year (£8,295 PCI vs. £11,101 CABG, p<0.001). The lower medical costs coupled with the net improvement in quality of life resulted in PCI as the dominant treatment strategy at one year.

Results further showed that although the average length of hospital stay varied by country, CABG patients were hospitalised on average an additional 7.8 days compared to PCI patients (13.7 vs. 5.9 days, including pre- and post-procedure).

Left main coronary disease
A substudy of patients with left main coronary disease who were treated with the Taxus Express2 has shown positive outcomes. SYNTAX-LE MANS is a substudy of the SYNTAX trial, and was presented by A Pieter Kappetein, at EuroPCR.

SYNTAX-LE MANS compares late angiographic and clinical outcomes in 263 patients with left main disease (149 treated with the Taxus stent and 114 treated with CABG). It is designed to assess 15-month patency and the safety of stents and grafts in this high-risk population; it includes separate primary endpoints for each treatment arm. For PCI patients, the primary endpoint is the rate of long-term patency (defined here as <50% stenosis) of the treated lesion sites. For CABG patients, the primary endpoint is the ratio of obstructed/occluded grafts (defined here as >50% stenosis) to total placed grafts. Results were presented separately for each group, and no formal statistical inferences between the two groups were made due to the different primary endpoints. Results were also broken out by left main lesion location, including distal and non-distal.

For patients receiving Taxus, the patency rate for the treated lesion was 92%. Restenosis was more common with distal lesions (90% patency) compared with non-distal lesions (98% patency). Reported in-stent late loss was 0.2mm for non-distal lesions. The reported 15-month major adverse cardiac and cerebrovascular events rate (all-cause death, stroke, infarction and revascularisation) for Taxus patients was 13%, driven primarily by a 9% repeat revascularisation rate.

For CABG patients, the overall obstruction/occlusion ratio at 15 months was 16%, with 6% of grafts obstructed in the range of greater than or equal to 50% to <100%, and 10% of grafts occluded 100%. On a per patient basis, the obstruction/occlusion ratio was 27%, with 9% of patients having a graft obstructed in the greater than or equal to 50% to <100% range and 18% of patients having a graft occluded 100%. The reported major adverse cardiac events rate for CABG patients at 15 months was 9%.