DOI: 10.5061/dryad.4f4qrfjfv
title: Coronary atherosclerotic burden assessed by SYNTAX scores and outcomes in surgical, percutaneous, or medical strategies: A retrospective cohort study

description: 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 &lt;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. 
description: <strong>Study
 Design</strong> This is a single-center retrospective
 study that enrolled patients from the Medicine, Angioplasty or Surgery
 Study (MASS) unit database at the Heart Institute of the University of Sao
 Paulo, Brazil. Patients with multivessel CAD (defined as stenosis ≥ 70% in
 at least 2 of the 3 main coronary arteries) and preserved LVEF who
 underwent coronary artery bypass grafting (CABG), percutaneous coronary
 intervention (PCI), or medical treatment (MT) between January 2002 and
 December 2015 were included in this study.
 <strong>Data Collection and Criteria
 </strong> SS and SSII were calculated by scoring
 all coronary lesions with a diameter stenosis ≥ 50%, in vessels with a
 diameter ≥ 1.5 mm, using the SS algorithm, which is described in full
 elsewhere. Two experienced clinical cardiologists and two interventional
 cardiologists blinded to clinical outcomes calculated the SS
 retrospectively for each patient. Clinical data were obtained from the
 medical records for the calculation of SSII. Intraobserver and
 interobserver variability for the SS were performed for 100 coronary
 angiograms according to the kappa [k] coefficient. Coefficients ranging
 from 0.21 to 0.40 are considered fair, from 0.41 to 0.60 moderate, from
 0.61 to 0.80 substantial, and over 0.81 excellent. For ordinal variables,
 the weighted kappa coefficient was used to express the degree of agreement
 inter-observer and intra-observer.  For
 the SS and SSII calculation of the MT group, we used the CABG group as a
 reference. This option assumed that surgery is the strategy that provides
 the most complete revascularization in patients with multivessel CAD. The
 residual SYNTAX Score (rSS) was calculated for each coronary lesion that
 was evaluated with the SS but was not treated. The coronary angiogram
 performed immediately after the percutaneous intervention or the surgical
 report of the CABG patients was used to calculate the rSS. For the MT
 group, the rSS is similar to the SS. A higher value of rSS suggests that
 more CAD lesions were untreated. Finally, patients were categorized within
 each score as low, intermediate, and high. 
 <strong>Treatment</strong> Patients were categorized according to three coronary revascularization strategies: MT, PCI and CABG. Patients in the three groups received intensive secondary prevention with lifestyle and pharmacologic interventions, using “treat-to-target” algorithms. All patients were treated according to the current guidelines at the time of study enrollment.  Among patients undergoing PCI, target-lesion revascularization was always attempted, and complete revascularization was performed as clinically appropriate. Subjects in the PCI group received plain bare metal stents (BMS), or drug eluting stents (DES), as available. A successful PCI was defined as a normal coronary artery flow or less than 20% stenosis in the luminal diameter after coronary stent implantation, as assessed by visual estimation of the angiograms before and after the procedure. Clinical success was defined as angiographic success plus the absence of in-hospital myocardial infarction (MI), emergency CABG, or death.   CABG was performed in accordance with the best current practices. The use of cardiac extracorporeal circulation was defined at the discretion of the surgical team, but the surgical team had experience in both on-pump and off-pump surgery.   <strong>Study Endpoints</strong> The primary endpoint was death from any cause at 5 years. Secondary endpoint was major adverse cardiac and cerebrovascular events (MACCE), defined as the composite of all-cause death, MI, stroke, and subsequent coronary revascularization measured.
description: Continuous variables were summarized as
 mean ± SD and compared using the Student unpaired t test or the Mann-Whitney test, as
 appropriate. The normality assumption for continuous variables was
 evaluated using the Kolmogorov-Smirnov test. Categorical variables were
 summarized as counts and percentages and compared with the chi-square test
 when appropriate. Otherwise, the Fisher exact test was used. Cox
 regression analysis was used to find independent predictors of mortality
 in the PCI, CABG, and MT groups. The variables with a probability value of
 &lt;0.20 in the univariate analyses were included in the backward
 stepwise multivariable model. Only variables with statistical significance
 (p &lt;0.05) remained in the Cox multivariable model.
 No correction was made for multiple
 tests. Receiver-operating characteristic (ROC)
 curves were created to evaluate the capacity of each score to discriminate
 MACCE in the PCI, CABG, and MT groups. Survival curves were constructed
 using Kaplan-Meier estimates and compared by using the log-rank test at 5
 years of follow-up. A 2-sided p-value &lt;0.05 was considered
 statistically significant. All analyses were conducted using the
 statistical package SPSS 25.0 (IBM®) software for
 Windows.