Socioeconomic Status and Differences in the Management and Outcomes of 6.6 Million US Patients With Acute Myocardial Infarction

Abstract

Little is known about the impact of socioeconomic status (SES) on management strategies and in-hospital clinical outcomes in patients with acute myocardial infarction (AMI) and its subtypes, and whether these trends have changed over time. All AMI hospitalizations from the National Inpatient Sample (2004 to 2014) were analyzed and stratified by zip code-based median household income (MHI) into 4 quartiles (poorest to wealthiest): 0th to 25th, 26th to 50th, 51st to 75^th, and 76th to 100th. Logistic regression was performed to examine the association between MHI and AMI management strategy and in-hospital clinical outcomes. A total of 6,603,709 AMI hospitalizations were analyzed. Patients in the lowest MHI group had more co-morbidities, a worse cardiovascular risk factor profile and were more likely to be female. Differences in receipt of invasive management were observed between the lowest and highest MHI quartiles, with the lowest MHI group less likely to undergo coronary angiography (63.4% vs 64.3%, p <0.001) and percutaneous coronary intervention (40.4% vs 44.3%, p <0.001) compared with the highest MHI group, especially in the STEMI subgroup. In multivariable analysis, the highest MHI group experienced better outcomes including lower risk (adjusted odds ratio; 95% confidence intervals) of mortality (0.88; 0.88 to 0.89), MACCE (0.91; 0.91 to 0.92) and acute ischemic stroke (0.90; 0.88 to 0.91), but higher all-cause bleeding (1.08; 1.06 to 1.09) in comparison to the lowest MHI group. In conclusion, the provision of invasive management for AMI in patients with lower SES is less than patients with higher SES and is associated with worse in-hospital clinical outcomes. This work highlights the importance of ensuring equity of access and care across all strata SES.