Résumé : OBJECTIVES: To assess feasibility and short-term clinical outcomes associated with resorbable magnesium scaffold (RMS) implantation in the setting of primary percutaneous coronary intervention for ST-segment elevation myocardial infarction (STEMI). BACKGROUND: RMS implantation has demonstrated favorable clinical outcomes in stable coronary artery disease patients. However, to date, data are lacking in the setting of STEMI. METHODS: This is a single-center prospective non-randomized pilot study. Patients admitted for STEMI were enrolled according to prespecified inclusion and exclusion criteria. The primary endpoint was device-oriented composite endpoint (DOCE), including cardiac death, target-vessel myocardial infarction, and target-lesion revascularization (TLR) within 30 days of the index procedure. Secondary endpoints were procedural success, any probable/definite scaffold thrombosis, and DOCE at subsequent follow-up. RESULTS: From December 1, 2016 to October 30, 2017, a total of 18 patients were included. Follow-up data were available for 17 patients (94%). There was no primary endpoint event. Procedural success was 100%. Patients were followed for a median of 153 days (range, 59-326 days). Over that extended follow-up period, 1 case of TLR occurred 102 days after the index procedure. There was no case of definite or probable scaffold thrombosis. CONCLUSIONS: This pilot study is the first to assess feasibility and clinical outcomes associated with RMS implantation in selected STEMI patients. The results seem reassuring, with favorable short-term clinical outcomes and absence of definite/probable scaffold thrombosis, and should prompt further research including randomized controlled trials evaluating RMS implantation in the setting of STEMI.