Prognostic impact of residual SYNTAX score in patients with ST-elevation myocardial infarction and multivessel disease: Analysis of an 8-year all-comers registry.

BACKGROUND: The residual SYNTAX score (rSS) was designed and validated to quantify the burden of residual coronary artery disease after percutaneous coronary intervention (PCI). The aim of this study was to assess the prognostic impact of rSS in patients with ST-segment elevation myocardial infarction (STEMI) and multivessel disease undergoing primary-PCI.

METHODS: This retrospective cohort study included 1499 consecutive patients with STEMI who underwent primary-PCI between January 2008 and December 2015. After exclusion criteria, the multivessel disease cohort (n=535) was divided into three groups, according to rSS: complete revascularization (rSS=0; n=198), reasonable incomplete revascularization (0<rSS<8; n=238) and incomplete revascularization (rSS≥8; n=99).

RESULTS: In-hospital mortality was significantly lower in patients with complete and reasonable incomplete revascularization, when compared to those with incomplete revascularization (1.5% vs. 1.7% vs. 9.0%, p<0.001). During follow-up (median 2.4years), rSS was positively correlated with MACE (25.3% for rSS=0 vs. 31.1% for 0<rSS<8 vs. 47.0% for rSS≥8, p=0.001) and all-cause mortality (5.1% vs. 10.5% vs. 19.2%, p=0.001). The rSS was also an independent predictor of MACE (when compared with complete revascularization, odds ratio [OR] was 1.5 for reasonable incomplete and 1.8 for incomplete revascularization) and all-cause mortality during follow-up (OR 2.9 for reasonable incomplete and 3.9 for incomplete revascularization), adding prognostic value over control variables and GRACE.

CONCLUSIONS: In a real-world cohort of patients with STEMI and multivessel disease who underwent PCI, the rSS added important prognostic information over control variables and GRACE, being an independent predictor of MACE and all-cause mortality during follow-up.