To assess the impact of in-hospital late ventricular fibrillation (VF) (>48 hours) on the 1-year mortality risk among patients presenting with acute myocardial infarction (AMI) who survived the index hospitalisation.

Retrospective cohort study estimating the incidence rates of late VF following AMI and the associated 1-year risk of all-cause mortality.

Cardiac intensive care units (CICUs) in Israel between the years 2000 and 2018.

Patients presenting with AMI (ST-segment elevation MI (STEMI) and non-ST-segment elevation MI (NSTEMI)) who were admitted to CICUs.

A total of 14 280 consecutive AMI patients of whom 118 developed late VF and 68 of these survived the index hospitalisation. Patients with late VF had higher mortality rates within 1 year following AMI overall (54.8% vs 10.2%, p

Late VF was found to be associated with increased 1-year mortality risk among patients presenting with AMI. However, this association was only significant among STEMI patients, but not NSTEMI patients.