Regional Variation in the Management and Outcomes of Acute Myocardial Infarction With Cardiogenic Shock in the United States

Abstract

Background: There are few studies evaluating regional disparities in the care of acute myocardial infarction-cardiogenic shock (AMI-CS).

Methods and results: Using the National Inpatient Sample from 2000 to 2016, we identified adults with a primary diagnosis of AMI and concomitant CS admitted to the United States census regions of Northeast, Midwest, South, and West. Interhospital transfers were excluded. End points of interest included in-hospital mortality, use of coronary angiography, percutaneous coronary intervention, mechanical circulatory support, hospitalization costs, length of stay, and discharge disposition. Multivariable regression was used to adjust for potential confounding. Of the 402 825 AMI-CS admissions, 16.8%, 22.5%, 39.3%, and 21.4% were admitted to the Northeast, Midwest, South, and West, respectively. Higher rates of ST-elevation AMI-CS were noted in the Midwest and West. Admissions to the Northeast were on average characterized by a higher frequency of whites, Medicare beneficiaries, and lower rates of cardiac arrest. Admissions to the Northeast were less likely to receive coronary angiography, percutaneous coronary intervention, and mechanical circulatory support, despite the highest rates of extracorporeal membrane oxygenation use. Compared with the Northeast, in-hospital mortality was lower in the Midwest (adjusted odds ratio [aOR], 0.96 [95% CI, 0.93-0.98]; P<0.001) and West (aOR, 0.96 [95% CI, 0.94-0.98]; P=0.001) but higher in the South (aOR, 1.04 [95% CI, 1.01-1.06]; P=0.002). The Midwest (aOR, 1.68 [95% CI, 1.62-1.74]; P<0.001), South (aOR, 1.86 [95% CI, 1.80-1.92]; P<0.001), and West (aOR, 1.93 [95% CI, 1.86-2.00]; P<0.001) had higher discharges to home.

Conclusions: There remain significant regional disparities in the management and outcomes of AMI-CS.

Keywords: coronary angiography; hospitalization; length of stay; myocardial infarction; percutaneous coronary intervention.

Figure 1.

United States geographic regions demonstrating states included in census regions as defined by the Healthcare Cost and Utilization Project-National Inpatient Sample

Figure 2.. Unadjusted and adjusted 17-year temporal trends for proportion of acute myocardial infarction admissions with cardiogenic shock by geographic regions

2A: Unadjusted temporal trends of proportion of acute myocardial infarction admissions with cardiogenic shock; all p<0.001 for trend; 2B: Adjusted multivariate logistic regression for temporal trends of proportion of acute myocardial infarction admissions with cardiogenic shock with 2000 as referent year; adjusted for age, sex, race, primary payer, socio-economic status, hospital location/teaching status, hospital bedsize, and comorbidity; all p<0.001 for trend

Figure 3.. 17-year temporal trends in cardiac procedures in acute myocardial infarction-cardiogenic shock by geographic regions

Seventeen-year trends of coronary angiography (3A), PCI (3B), total MCS (3C), IABP (3D), pLVAD* (3E) and ECMO (3F) in acute myocardial infarction-cardiogenic shock stratified by geographic regions; all p<0.001 for trend *The administrative codes for pLVAD were introduced in 2004, and therefore temporal trends are presented from 2005 onwards Abbreviations: ECMO: extra-corporeal membrane oxygenation; IABP: intra-aortic balloon pump; MCS: mechanical circulatory support; PCI: percutaneous coronary intervention; pLVAD: percutaneous left ventricular assist device

Figure 4.. Unadjusted and adjusted 17-year temporal trends for in-hospital mortality in acute myocardial infarction-cardiogenic shock by geographic regions

4A: Unadjusted temporal trends of in-hospital mortality in acute myocardial infarction-cardiogenic shock; all p<0.001 for trend; 4B: Adjusted multivariate logistic regression for in-hospital mortality temporal trends in acute myocardial infarction-cardiogenic shock with 2000 as referent year; adjusted for age, sex, race, primary payer, socio-economic status, hospital location/teaching status, hospital bedsize, comorbidity, acute organ failure, cardiac arrest, coronary angiography, percutaneous coronary intervention, invasive hemodynamic monitoring, mechanical circulatory support, invasive mechanical ventilation, hemodialysis; all p<0.001 for trend