ObjectiveTo study the in-hospital outcomes and 30-day readmission data in homeless patients admitted with acute myocardial infarction (AMI). MethodsAdult patients (>18 years of age) who were admitted with AMI between January 1, 2015, and December 31, 2016, were identified in the National Readmission Database. Patients were classified into homeless or non-homeless. Baseline characteristics, rates of invasive assessment and revascularization, mortality, 30-day readmission rates, and reasons for readmission were compared between the 2 cohorts. ResultsA total of 3938 of 1,100,241 (0.4%) index hospitalizations for AMI involved homeless patients. Compared with non-homeless patients, homeless patients were younger (mean age, 57±10 years vs 68±14 years; P<.001) and had a lower prevalence of atherosclerotic risk factors (hypertension, hyperlipidemia, and diabetes) but a higher prevalence of anxiety, depression, and substance abuse. Homeless patients were less likely to undergo coronary angiography (38.1% vs 54%; P<.001), percutaneous coronary intervention (24.1% vs 38.7%; P<.001), or coronary artery bypass grafting (4.9% vs 6.7%; P<.001). Among patients who underwent percutaneous coronary intervention, bare-metal stent use was higher in homeless patients (34.6% vs 12.1%; P<.001). After propensity score matching, homeless patients had similar mortality but higher rates of acute kidney injury, discharge to an intermediate care facility or against medical advice, and longer hospitalizations. Thirty-day readmission rates were significantly higher in homeless patients (22.5% vs 10%; P<.001). Homeless patients had more readmissions for psychiatric causes (18.0% vs 2.0%; P<.001). ConclusionConsiderable differences in cardiovascular risk profile, in-hospital care, and rehospitalization rates were observed in the homeless compared with non-homeless cohort with AMI. Measures to remove the health care barriers and disparities are needed.