Abstract
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.