Abstract Background Myocardial infarction (MI) in nonagenarians is associated with high morbidity and mortality. Nonetheless, this population has typically been underrepresented in cardiovascular clinical trials. Objective The aim of this study was to evaluate outcomes of nonagenarian patients presenting with MI who underwent either conservative or invasive management. Methods We retrospectively included all consecutive patients equal to or older than 90yo admitted with non-ST segment elevation (NSTEMI) or ST segment elevation MI (STEMI) in four tertiary care centers between 2005 and 2018. Patients with type 2 myocardial infarction were excluded. We collected patients' baseline characteristic and procedural data. In-hospital and at 1-year follow-up all-cause mortality and major adverse cardiovascular events were assessed. Results 523 patients (mean age 92.6±2 years; 60% females) were analyzed. Overall, 184 patients (35.2%) underwent percutaneous coronary intervention (PCI), increasing over the years, mostly in STEMI group (from 16% of patients in 2005 to 75% in 2018). PCI was preferred in those subjects with less prevalence of disability for activities of daily living (p<0.01). The use of a radial access (76.6%) and bare metal stents (52.7%) was predominant. No significant differences were found in the incidence of major bleeding events or MI-related mechanical complications between both strategies. During index hospitalization, 99 (18.9%) patients died. Whereas no differences were found in the NSTEMI group (p=0.61), a significant lower in-hospital mortality was observed in STEMI group treated with PCI (p<0.01). At one-year follow up, 203 (38.8%) patients died, most of them due to a cardiovascular cause (60.6%). PCI was related to a lower all-cause mortality in either NSTEMI (p<0.01) or STEMI groups (p<0.01) however, lower cardiovascular mortality was only found in STEMI group (p=0.03). Conclusion An invasive approach was performed in over a third of nonagenarian patients, carrying prognostic implications and with a few numbers of complications. PCI seems to be the preferred strategy for STEMI in this high-risk population in spite of age. Figure 1 Funding Acknowledgement Type of funding source: None