Utility of the SYNTAX II Score for Deciding Between PCI and CABG
Patients selected for percutaneous coronary intervention (PCI) using the Syntax Score II in the SYNTAX II trial showed favorable 1-year post-intervention clinical outcomes compared to patients selected for PCI in the SYNTAX I trial, according to findings from the SYNTAX II trial.1
The SYNTAX II trial, an open-label, single-arm, multicenter study, sought to determine the clinical outcomes of PCI in 3-vessel disease patients. In this study, investigators used the SYNTAX II strategy, which includes coronary-physiology-guided revascularization, guideline-directed medical therapy, the implantation of thin strut bioresorbable-polymer drug-eluting stents, stent implantation with intravascular ultrasound (IVUS), and chronic total occlusion revascularization techniques.
Additionally, the SYNTAX II strategy involves heart team decision-making using the SYNTAX Score II, a scoring system based on clinical and anatomical factors for aiding decisions between PCI and CABG based on mortality at 4 years.2,3
In an analysis by Escaned et al, the investigators compared the 1-year follow-up outcomes of the SYNTAX II trial to those observed in the SYNTAX I study.1 Specifically, researchers compared the rate of major adverse cardiac and cerebrovascular events (MACCE), which was a composite of all-cause death, any myocardial infarction (MI), cerebrovascular event, and any revascularization. The investigators made direct comparisons with the historical CABG patients of the SYNTAX I trial.
The investigators screened 708 patients, of which 454 were recommended for PCI. The SYNTAX II strategy was associated with lower MACCE compared with SYNTAX I PCI (10.6% vs 17.4%, respectively; hazard ratio [HR] 0.58, 95% confidence interval [CI] 0.39–0.85, P = 0.006) at 1-year follow-up.
Reductions in MI incidence (HR 0.27, 95% CI 0.11–0.70, P = 0.007) as well as revascularization (HR 0.57, 95% CI 0.37–0.9, P = 0.015) represented the main drivers behind MACCE differences. Additionally, definite stent thrombosis rates were found to be significantly lower among those receiving the SYNTAX II strategy (0.7% vs 2.6%; HR 0.26, 95% CI 0.07–0.97, P = 0.045). Conversely, the investigators found no differences between the rates of stroke (HR 0.69, 95% CI 0.10–4.89, P = 0.71) or all-cause death (HR 0.69, 95% CI 0.27–1.73, P = 0.43).
In this analysis, the investigators excluded patients with a history of PCI. Since a large majority of patients seen in clinical practice have had a prior PCI, the ability to generalize the findings of this study is challenging. Additionally, the researchers suggest that, despite attempting to provide balance between the groups with several statistical methods, adjusting for every confounder was impossible. Also, only 16 patients in this study had a high anatomic SYNTAX score, limiting the ability to apply these findings across the entire patient population.
“Although the SYNTAX II study enticingly suggests an increasing role for PCI in multivessel disease,” said Stone GW4 in an accompanying editorial, “confirmatory evidence from adequately powered randomized trials is required prior to expanding the zone of equipoise to include most patients with complex CAD.”
- Escaned J, Collet C, Ryan N, et al. Clinical outcomes of state-of-the-art percutaneous coronary revascularization in patients with de novo three vessel disease: 1-year results of the SYNTAX II study. Eur Heart J. 2017;38(42):3124-3134.
- Farooq V, van Klaveren D, Steyerberg EW, Meliga E, Vergouwe Y, Chieffo A, Kappetein AP, Colombo A, Holmes DR Jr, Mack M, Feldman T, Morice MC, Stahle E, Onuma Y, Morel MA, Garcia-Garcia HM, van Es GA, Dawkins KD, Mohr FW, Serruys PW. Anatomical and clinical characteristics to guide decision making between coronary artery bypass surgery and percutaneous coronary intervention for individual patients: development and validation of SYNTAX score II. Lancet. 2013 Feb 23;381(9867):639-650.
- Kurniawan E, Ding FH, Zhang Q, et al. Predictive value of SYNTAX score II for clinical outcomes in octogenarian undergoing percutaneous coronary intervention. J Geriatr Cardiol. 2016;13(9):733-739.
- Stone GW. Multivessel PCI on its 40th anniversary: finally a match for CABG? Eur Heart J. 2017;38(42):3135-3138.