Value of the SYNTAX Score in ST-Elevation Myocardial Infarction Patients With a Concomitant Chronic Total Coronary Occlusion(from the EXPLORE Trial)

`To analyze the impact of additional coronary artery disease, quantified by the SYNTAX (SYNergy between PCI with TAXus and cardiac surgery) score, on left ventricular ejection fraction (LVEF) and long-term outcomes in a cohort of ST-elevated myocardial infarction (STEMI) patients with a concomitant chronic total coronary occlusion (CTO). A total of 302 STEMI patients were randomized to percutaneous coronary intervention of a CTO (CTO PCI) (n = 148) or conservative CTO treatment (n = 154). SYNTAX scores were calculated by an independent corelab (Cardialysis BV, Rotterdam) at two time-points: (1) at baseline, and (2) after primary PCI in the conservative CTO arm and after CTO PCI in the invasive arm (named 'discharge SYNTAX score'). The population was divided in two groups (below or equal to the median SYNTAX score preprimary PCI, or above the median). At 4-month follow-up, the LVEF was significantly lower in patients in the group with a SYNTAX score above the group median (42.8% vs 48.5%, p = 0.001), and the SYNTAX score was an independent predictor for LVEF at 4 months (β-0.151 (SE 0.068), p = 0.028). In the group with a SYNTAX score above the group median the mortality rate was higher (10.1% vs 3.9%, p = 0.025), and there was a trend towards a higher MACE rate (15.4% vs 8.5%, p = 0.063). In conclusion, in this sub-analysis of the EXPLORE trial we observed a worse LVEF and a higher mortality rate for patients with a SYNTAX score above the median. We found that the SYNTAX score is an independent negative predictor for LVEF and an independent positive predictor for LVEDV at 4-month follow-up.