Prevalence, Causes, and Predictors of 30‐Day Readmissions Following Hospitalization With Acute Myocardial Infarction Complicated By Cardiogenic Shock: Findings From the 2013–2014 National Readmissions Database

BACKGROUND: Prior studies have shown that survivors of acute myocardial infarction (AMI) complicated by cardiogenic shock are likely to have increased risk of readmissions in the early post‐discharge period. However, the contemporary prevalence, reasons, and predictors of 30‐day readmissions are not well known. METHODS AND RESULTS: Hospitalizations for a primary diagnosis of AMI complicated by cardiogenic shock, and discharged alive, were identified in the 2013 and 2014 Nationwide Readmissions Databases. Prevalence and reasons for 30‐day unplanned readmissions were investigated. A hierarchical logistic regression model was used to identify independent predictors of 30‐day readmissions. Among 1 116 933 patient hospitalizations with AMI, 39 807 (3.6%) had cardiogenic shock and were discharged alive. Their 30‐day readmission rate was 18.6%, with a median time for readmission 10 days post discharge. Predictors of readmission included: non–ST‐segment elevation myocardial infarction, female sex, low‐income status, nonprivate insurance, chronic renal failure, long‐term ventricular assist device or intra‐aortic balloon placement, and tachyarrhythmia. The majority of readmissions were attributable to cardiac‐related causes (52%); heart failure being the most frequent cardiac cause (39% of all cardiac causes). Noncardiac‐related readmissions included infections (14.9%), bleeding (5.3%), and respiratory causes (4.9%). The median cost per readmission was $9473 US dollars ($5037–20 199). CONCLUSIONS: Among survivors of AMI complicated by cardiogenic shock who were discharged from hospital, almost 1 in 5 are readmitted at 30 days, mainly because of cardiac reasons such as heart failure and new AMI. The risk of readmission was associated with certain baseline patient/hospital characteristics.