Hospital-Level Disparities in the Outcomes of Acute Myocardial Infarction With Cardiogenic Shock

Abstract

There are limited data on hospital-level disparities in cardiogenic shock complicating acute myocardial infarction (AMI-CS). A retrospective cohort of adult admissions from the National Inpatient Sample database during 2000 to 2014, with primary diagnosis of AMI and concomitant CS were identified. Interhospital transfers were excluded. Hospitals were classified into rural, urban nonteaching and urban teaching (location and teaching status) and small, medium and large (bedsize). The primary endpoint was in-hospital mortality and secondary endpoints included use of early coronary angiography, percutaneous coronary intervention (PCI) and mechanical circulatory support (MCS). Multivariable regression was used to adjust for potential confounding. During 2000 to 2014, 362,065 AMI-CS admissions met the inclusion criteria, of which 92% and 69% respectively were admitted to urban and large hospitals. Admissions to urban and large hospitals were more frequently male, younger, with lower co-morbidity, and higher illness severity. There was a steady increase in early coronary angiography, PCI and MCS across the various hospital categories. Admission to an urban nonteaching hospital (adjusted odds ratio [aOR] 0.81; 95% confidence interval [CI] 0.78 to 0.84], p <0.001) and urban teaching hospital (aOR 0.87 [95% CI 0.84 to 0.91, p <0.001) were associated with lower mortality compared with rural hospitals. In comparison to a small hospital, admission to a large hospital (aOR 0.94 [95% CI 0.91 to 0.98); p = 0.002) was associated with lower in-hospital mortality. Large and urban hospitals had greater use of early coronary angiography, PCI, MCS. In conclusion, there are hospital-level disparities in the management and outcomes of AMI-CS which are not fully accounted for differences in patient characteristics.