To evaluate survival after acute myocardial infarction (AMI) in nonagenarians, we conducted a retrospective chart review of 177 consecutive patients > or =90 years of age admitted from 2000 to 2006 with a primary diagnosis of AMI confirmed by peak troponin I > or =1.5 microg/L. Mean follow-up was 3.7 years (range 4 months to 6.7 years). Mean age was 93 years, 34% were men, and 60% were Caucasian. Common co-morbidities included hypertension (67%), dyslipidemia (28%), atrial fibrillation (28%), renal insufficiency (27%), dementia (23%), and previous cerebrovascular events (22%). Mean peak troponin was 20 mug/L (range 1.5 to 183 microg/L). Cardiac catheterization was performed within 48 hours in 42 patients (24%) and after 48 hours in 14 patients (8%); 40 patients (23%) received an intervention. Hospital mortality was 15% (n = 27). Survival at 30 days, 90 days, and 1 year were 78%, 69%, and 47%. Independent predictors of shorter survival time by Cox analysis included body mass index <25 kg/m2 (p <0.001), creatinine > or =2.0 mg/dl (p = 0.001), hemoglobin <11.0 g/dl (p = 0.016), and dementia (p = 0.027). Patients receiving aspirin, clopidogrel, beta blockers, and renin-angiotensin system inhibitors appeared to have a lower mortality. In conclusion, AMI in nonagenarians is associated with high mortality, with over 50% of patients dying within one year of presentation; elevated creatinine and lower hemoglobin are strong predictors of adverse prognosis, and lower body mass index and the presence of dementia add independent prognostic significance.