Geographic Variation in Treatment and Outcomes Among Patients With AMI: Investigating Urban-Rural Differences Among Hospitalized Patients

Background: The value of early invasive revascularization for patients suffering acute myocardial infarction (AMI) is well known. However, access to revascularization services varies geographically and demographically. Previous studies have not examined the influence of rural residence on revascularization rates and outcomes among patients hospitalized with AMI. Methods: Our retrospective cohort study included patients hospitalized in Washington State with a primary diagnosis of AMI from 2009 to 2012. Urban or rural residence was determined using rural-urban commuting area (RUCA) codes. Multivariable models were used to evaluate geographic variation in rates of invasive versus medical management, in-hospital mortality, rehospitalization, and subsequent revascularization procedures. Results: Our study included 25,156 urban dwellers and 2,770 rural residents. Adjusted models found rural patients to be at increased odds of undergoing invasive revascularization during the initial episode of AMI care (OR = 1.11; 95% CI: 1.01-1.21; P =.02) compared to urban dwelling patients. Rural patients were more likely to be transferred for care (OR = 4.28; 95% CI: 3.93-4.66; P < .001) and more likely to undergo coronary artery bypass grafting (CABG) (OR = 1.55; 95% CI: 1.35-1.78; P < .001) compared to the urban cohort. We found no significant geographic cohort differences in in-hospital mortality or subsequent revascularization rates. Conclusion: Our findings suggest that despite limited access to cardiac care facilities, rural patients are accessing revascularization services. However, rural residents are more likely to undergo CABG during their index admission. High transfer rates suggest that rural regions rely on effective transfer networks to access invasive cardiac services.