SYNTAX Cost-effectiveness Analysis Supports Existing Guidelines

San Francisco, CA—Final five-year results of the economic analysis of the SYNTAX trial demonstrate clinical and economic superiority of CABG surgery in patients with three-vessel coronary artery disease, and similar outcomes with CABG and PCI in patients with less complex CAD, including left main disease. David J. Cohen, MD, MSc, of Saint Luke’s Mid-America Heart Institute at the University of Missouri-Kansas City, presented the results Monday evening at TCT 2013.

The investigators compared the cumulative five-year costs of multivessel revascularization with PCI (Taxus Express, Boston Scientific) vs. CABG, as well as the lifetime cost-effectiveness of both interventions, measured as cost per quality-adjusted life-year (QALY) gained. They also examined the cost effectiveness of each intervention in subsets of patients according to the clinical outcomes of the SYNTAX trial.

The economic study analysis plan was conducted in two stages – an in-trial analysis of survival, health state utility and costs, and a lifetime analysis based on projections of survival, quality-adjusted survival and costs following the trial period.

Among patients in the lowest Syntax score tertile (<23), CABG was more expensive and less effective than PCI, with lower QALYs gained. In the intermediate Syntax score tertile subset (23-32), the cost difference was positive for CABG, with slightly higher QALYs compared with PCI. Similar results were demonstrated in the high Syntax score tertile subset (>32); despite higher costs with CABG, substantial QALYs were gained, according to Cohen (see Figure 1). 

When costs were separated according to type of CAD, CABG was superior to PCI in patients with three-vessel disease; however, among patients with left main disease, PCI produced similar outcomes compared with CABG, but with a lower long-term cost (see Figure 2).

“This is a very interesting, surprising and unanticipated result that needs verification,” Cohen said. Furthermore, he said the findings provide additional support for existing societal guidelines and also underscore the importance of the ongoing EXCEL trial, which is attempting to find the optimal revascularization strategy for patients with left main disease.

Disclosures: 

Cohen reported no relevant financial conflicts of interest.

The SYNTAX trial and its associated economic analysis were supported by a research grant from Boston Scientific.