Garcia-Garcia C, et al. - In this prospective multicenter regional registry of primary percutaneous coronary intervention (PPCI)-treated ST segment elevation myocardial infarction (STEMI) patients, researchers compared 30-day and 1-year mortality for patients with and without primary ventricular fibrillation (PVF) (including out-of-hospital and in-hospital PVF). The registry included 10,965 patients. PVF occurred in 949 patients (8.65%), including 74.2% out-of-hospital and 25.8% in-hospital PVF. In this largest registry of PVF patients in the era of routine PPCI in STEMI. although a decline has been observed in the overall STEMI mortality, PVF was identified as a predictor of both 30-day and 1-year mortality.