Coronary atherosclerotic burden assessed by SYNTAX scores and outcomes in surgical, percutaneous, or medical strategies: A retrospective cohort study

Introduction   Coronary atherosclerotic burden and SYNTAX score
(SS) are predictors of cardiovascular events.   
Objectives   To investigate the value of SYNTAX scores (SS, SSII
and residual SS [rSS]) for predicting cardiovascular events in patients
with coronary artery disease (CAD).    Design  
Retrospective cohort study.    Setting   Single
tertiary centre.    Participants   Medicine,
Angioplasty or Surgery Study (MASS) database patients with stable
multivessel CAD and preserved ejection fraction.   
Interventions CAD patients undergoing coronary artery bypass graft (CABG),
percutaneous coronary intervention (PCI), or medical treatment (MT) alone
from January 2002 to December 2015.    Primary and
secondary outcomes Primary: 5-year all-cause mortality. Secondary:
composite of all-cause death, myocardial infarction, stroke, and
subsequent coronary revascularization at 5 years.   
Results   A total of 1,719 patients underwent PCI (n = 573), CABG
(n = 572), or MT (n = 574) alone. The SS was not considered an independent
predictor of 5-year mortality in the PCI (low, intermediate and high SS
6.5%, 6.8% and 4.3%, respectively, p=0.745), CABG (low, intermediate and
high SS 5.7%, 8.0% and 12.1%, respectively, p=0.194) and MT (low,
intermediate and high SS 6.8%, 6.9% and 6.5%, respectively, p=0.993)
cohorts. The SSII (low, intermediate and high SSII, 3.6% vs. 7.9% vs.
10.5%, respectively, p <0.001) was associated with a higher
mortality risk in the overall population. Within each treatment strategy,
SSII was associated with a significant 5-year mortality rate, especially
in CABG patients with higher SSII (low, intermediate and high SSII, 1.8%,
9.7% and 10.0%, respectively, p = 0.004) and in MT patients with high SSII
(low, intermediate and high SSII, 5.0%, 4.7% and 10.8%, respectively, p =
0.031). SSII demonstrated a better predictive accuracy for mortality
compared with SS and rSS (c-index = 0.62).    
Conclusions   Coronary atherosclerotic burden alone was not
associated with significantly increased risk of all-cause mortality. The
SSII better discriminates the risk of death.