The Association of Socioeconomic Status with Three-Year Clinical Outcomes in Patients with Acute Myocardial Infarction Who Underwent Percutaneous Coronary Intervention

The aim of this study was to evaluate whether the clinical outcomes were associated with socioeconomic status (SES) in patients with acute myocardial infarction (AMI) who underwent percutaneous coronary intervention (PCI). The author analyzed 2,358 patients (64.9 ± 12.3 yr old, 71.5% male) hospitalized with AMI between November 2005 and June 2010. SES was measured by the self-reported education (years of schooling), the residential address (social deprivation index), and the national health insurance status (medical aid beneficiaries). Sequential multivariable modeling assessed the relationship of SES factors with 3-yr major adverse cardiovascular events (MACEs) and mortality after the adjustment for demographic and clinical factors. During the 3-yr follow-up, 630 (26.7%) MACEs and 322 (13.7%) all-cause deaths occurred in 2,358 patients. In multivariate Cox proportional hazards regression modeling, the only lower education of SES variables was associated with MACEs (hazard ratio [HR], 1.41; 95% confidence interval [CI], 1.04-1.91) and mortality (HR, 1.93; 95% CI, 1.16-3.20) in the patients with AMI who underwent PCI. The study results indicate that the lower education is a significant associated factor to increased poor clinical outcomes in patients with AMI who underwent PCI. Graphical Abstract Keywords: Social Class, Acute Myocardial Infarction, Mortality INTRODUCTION Coronary heart disease (CHD) is one of the leading causes of death in both high- and low-income countries (1). The increased prevalence and mortality associated with the large burden of CHD is a reflection of the epidemiological transition that has accompanied economic and social development (2). Numerous studies show that the socioeconomic status (SES) is associated with a risk of CHD (3, 4, 5, 6). There was the definite relationship between the low SES and the predicted risk of ischemic heart disease (IHD) (7). Also, both individual SES and the SES of the neighborhood of residence are independently associated with the incidence of acute myocardial infarction (AMI) (8, 9). The association between SES and outcomes of AMI is generally well documented in western countries (10, 11, 12). Therefore, the measures of SES have been identified as the risk factors after AMI (13, 14). However, because the SES is a multidimensional concept comprising various indicators acting at different levels, the mechanisms by which it affects post-AMI prognosis are incompletely understood (15, 16). The objective of this study was to investigate whether the SES variables independently contribute to 3-yr clinical outcomes in Korean patients with AMI who underwent percutaneous coronary intervention (PCI).