A Guide to Calculating SYNTAX Score

Interventional Cardiology, 2012;7(1):21–3

Abstract

Since its first publication, the SYNTAX score has been used and validated in several subsets of lesions and populations. Despite some concerns about its reproducibility between cardiologists and its power of discrimination, the SYNTAX score remains the most powerful angiographic tool to predict events after percutaneous coronary intervention. Knowledge and mastering of the SYNTAX score definitions is of paramount importance and is the first step to an adequate stratification. This short article presents the different steps of the scoring system of SYNTAX score and focuses on the variables with the highest interobserver variability.

Keywords
SYNTAX score, percutaneous coronary intervention, multiple vessel disease
Disclosure The authors have no conflicts of interest to declare.
Received: January 14, 2012 | Accepted February 04, 2012 | Citation Interventional Cardiology, 2012;7(1):21–3
Correspondence: Philippe Généreux, Columbia University Medical Centre, The Cardiovascular Research Foundation, 111 East 59th St, 11th Floor, New York, NY 10022, US. E: pg2295@columbia.edu

Accurate characterisation of coronary artery disease (CAD) anatomy based on the diagnostic angiogram is essential to select the optimal strategy of revascularisation. Recently, the SYNTAX score generated a great amount of interest because of its ability to risk-stratify and discriminate outcomes of patients with complex CAD undergoing percutaneous coronary intervention (PCI) as compared to coronary artery bypass graft surgery.1–3 Additionally, it has been validated in different clinical settings of patients undergoing PCI, as well as in various subsets of lesions.4–11 Thus, SYNTAX score is a pioneer anatomical-based risk score that aids in the decision-making process. However, assessment of the SYNTAX score relies on pure visual interpretation of lesion severity and other semi-quantitative and subjective variables, which for even simple measures may be inaccurate. Although some studies report acceptable reproducibility when determined by angiographic core laboratory technicians,2 concerns remain regarding its reproducibility, especially among ‘SYNTAX-score naive’ or inappropriately trained cardiologists.12 The recent introduction of a ‘functional SYNTAX score’ that incorporates ischaemia-producing lesions as determined by fractional flow reserve (FFR), has brought some hope by better risk-stratifying of patients.13 Moreover, a limitation of the SYNTAX score relies on the fact that the score algorithm does not entail any clinical variable. Co-morbidities are known to impact early outcomes of patients undergoing revascularisation. Accordingly, to address the relative lack of discrimination and predictability of the pure SYNTAX score, some attempts to combine clinical variables into the SYNTAX score were reported recently. The ‘clinical SYNTAX score’, a combination of ACEF and SYNTAX score strata, parsimoniously combines three strong clinical predictors of clinical outcome (i.e., age, creatinine and ejection fraction). An alternative approach combines the SYNTAX score and the EuroSCORE, the so-called ‘Global risk classification’.14–16 Overall, their findings underline the potential importance of the interplay between clinical and angiographic data in predicting clinical outcomes after PCI.
Although the precise training requirements to optimise the performance of cardiologists using the SYNTAX score are unknown, some recent published data suggest that training beyond the standard on-line tutorial (www.syntaxscore.com) is warranted if the full clinical potential of the SYNTAX score is to be realised.12 The aim of this short article is to overview the basics and essentials of the SYNTAX score assessment, to ensure appropriate reading and, therefore, improve its reproducibility between readers.

References:
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