Transfer to Hub Hospitals and Outcomes in Cardiogenic Shock

There are limited large-scale data on the outcomes of patients with cardiogenic shock (CS) transferred to hub centers. This study aimed to compare the characteristics and outcomes of transferred patients with CS versus those who were not transferred. Adults (aged ≥18 years) with a primary or secondary diagnosis of CS were identified from the Nationwide Readmissions Database (2016-2020) and stratified by transfer status. Overlap propensity score weighting was performed to assess the association between transfer status and in-hospital mortality. Secondary outcomes, including length of hospital stay, hospitalization costs, and readmissions for cardiac and noncardiac etiologies, were assessed using multivariable regression. Of 314 098 patients with CS (27% with acute myocardial infarction-related CS and 73% with nonacute myocardial infarction-related CS), 30 630 (9.8%) were transferred. In the unweighted population, compared with nontransferred patients, transferred patients were on average younger (65 versus 68 years), had higher comorbidities, and were more likely to be cared for at large teaching hospitals. During the hospitalization, they had higher rates of renal failure, pulmonary artery catheter use, and mechanical circulatory support use. In-hospital mortality was lower in transferred patients-39.1% versus 47.1%; unadjusted odds ratio (OR), 0.71 (95% CI, 0.70-0.73); adjusted OR, 0.73 ([95% CI, 0.71-0.76]; P<0.001). This was consistent across subgroups of CS cause, age, sex, hospital location, mechanical circulatory support use, and presence of cardiac arrest. The transferred cohort had lower costs and length of stay, but more frequent all-cause (adjusted OR, 1.21 [95% CI, 1.16-1.27]), cardiac (adjusted OR, 1.16 [95% CI, 1.11-1.22]), heart failure (adjusted OR, 1.14 [95% CI, 1.08-1.21]), and noncardiac readmissions (adjusted OR, 1.68 [95% CI, 1.21-2.33]) at 30 days postdischarge compared with the nontransferred cohort. Despite higher comorbidity, organ failure, and use of cardiac/noncardiac procedures, patients with CS who were transferred to hub centers had lower in-hospital mortality, hospitalization costs, and length of stay.