2035Mid- and long-term outcome of the EXPLORE trial: investigating the impact of CTO PCI versus no-CTO PCI in STEMI patients with a concurrent CTO

Abstract

Background: At 4 month follow-up (FU) the EXPLORE trial showed no difference on the primary endpoint left ventricular (LV) function comparing early percutaneous coronary intervention of the chronic total occlusion (CTO PCI) to standard medical treatment (no-CTO PCI) in ST-elevation myocardial infarction (STEMI) patients. However, the long-term effects of CTO PCI versus no-CTO PCI are currently unknown. Purpose(s): To investigate the effect of CTO PCI versus no-CTO PCI in STEMI patients on mid- and long-term LV function and clinical outcome. Method(s): At 1, 2, 3, 4, and 5 years, clinical follow up was obtained on: angina status, dyspnoea status, all events and major adverse cardiac events (MACE); composite of cardiac death, myocardial infarction and coronary artery bypass graft surgery. Moreover, patients underwent cardiac magnetic resonance imaging (CMR) at 1 year. An independent corelab analysed all CMR data. All events underwent independent monitoring and were adjudicated by an independent critical events committee. For the incidence of MACE, Kaplan-Meier curves were constructed and compared using the log-rank test. Result(s): In the EXPLORE Trial there were 148 patients randomized to CTO PCI within 7 days and 154 patients to no-CTO PCI. There were no differences in baseline characteristics between both arms. One year LV function was comparable between CTO PCI patients (n=45) and no-CTO PCI patients (n=49) (LVEF 45.5+/-9.1% versus 44.6+/-10.7%, p=0.66, LVEDV 198.0+/-44.8ml versus 208.1+/-50.9ml, p=0.31). One year clinical follow-up was complete for all patients. MACE rates were comparable between CTO PCI and no-CTO PCI (6.8% versus 5.3%, p=0.56). In the no-CTO PCI group 27 patients (17.6%) underwent an additional CTO PCI after obtaining the primary endpoints. The median longterm follow-up of all patients is 3.9 (IQR 2.9) years. Conclusion(s): The EXPLORE trial is the first randomized clinical trial investigating the impact of revascularization of a CTO. The primary outcome (LVEF and LVEDV) of the EXPLORE Trial was not met at four months. Furthermore no benefit of CTO PCI on 1 year LV function was seen. There was no significant difference in MACE between the 2 treatment groups. Long-term follow-up is currently being analyzed and we will be able to present the long-term clinical outcome at ESC 2017. (Figure Presented).