Objectifying the level of incomplete revascularization by the residual SYNTAX score and evaluating its impact on the one-year outcome of percutaneous coronary intervention in patients with multi-vessel disease

Background: Previous studies reported conflicting results regarding the impact of incomplete revascularization on the outcome of percutaneous coronary intervention (PCI). We evaluated the association between residual SYNTAX score (RSS) as a quantitative measure of incomplete revascularization and one-year outcome of patients with native multi-vessel disease undergoing PCI. Methods: A total of 760 patients (mean age= 59.14 +/- 10.36 years, 70.4% males) who underwent successful PCI with the incomplete revascularization strategy between September 2008 and March 2010 were included. The RSS was used to quantify the extent and complexity of residual coronary stenosis following PCI. Multivariable analysis was used to evaluate the impact of RSS on one-year major adverse cardiac events (MACE) including death, myocardial infarction, and revascularization. Results: Overall incidence of one-year MACE was 4.74%. Using ROC curve analysis a cut-off of >5 for baseline RSS had a significant association with occurrence of 12-month MACE (area under the curve= 0.769; P value < 0.001, sensitivity= 75% and specificity= 72%). Unadjusted effect of RSS >5 on 12 months MACE showed a hazard ratio of 7.34 (p value < 0.001). By multivariable analysis, effect of the RSS > 5 on 12 months MACE was adjusted for potential confounders. After adjustment to clinical SYNTAX score as the sole confounder, RSS > 5 remained a strong associate with 12 months MACE and its effect outweighed that of before adjustment (hazard ratio = 8.03, p value < 0.001). Conclusions: The RSS is a quantifiedmeasure of the complexity of residual coronary stenoses, and RSS >5 could be able to discriminate patients with an increased risk of one-year MACE. (C) 2016 Elsevier Inc. All rights reserved.